Torex XCL205 Series User manual

1/25
XCL205/XCL206/XCL207 Series
Inductor Built-in Step-Down “micro DC/DC” Converters
0
20
40
60
80
100
0.1 1 10 100 1000
Output Current:I
OUT
(mA)
Efficency:EFFI(%
)
VIN= 5.5V
5.0V
4.2V
VOUT=3.3V
(
PWM
)
XCL206/XCL207
(
PWM/PFM
)
XCL205/XCL207
■TYPICAL PERFORMANCE
CHARACTERISTICS
☆GreenOperation Compatible
■APPLICATIONS
●Mobile phones, Smart phones
●Bluetooth Headsets
●WiMAX PDAs, MIDs, UMPCs
●Portable game consoles
●Digital cameras, Camcorders
●Electronic dictionaries
■TYPICAL APPLICATION CIRCUIT
ETR2801-010
■GENERAL DESCRIPTION
The XCL205/XCL206/XCL207 series is a synchronous step-down micro DC/DC converter which integrates an inductor and a
control IC in one tiny package (2.5mm×2.0mm, H=1.0mm). A stable power supply with an output current of 600mA is
configured using only two capacitors connected externally.
Operating voltage range is from 2.0V to 6.0V(XCL20xG:1.8V～6.0V). Output voltage is internally set in a range from 0.8V to
4.0V in increments of 0.05V. The device is operated by 3.0MHz, and includes 0.42ΩP-channel driver transistor and 0.52Ω
N-channel switching transistor. As for operation mode, the XCL205 series is PWM control, the XCL206 series is automatic
PWM/PFM switching control and the XCL207 series can be manually switched between the PWM control mode and the
automatic PWM/PFM switching control mode, allowing fast response, low ripple and high efficiency over the full range of loads
(from light load to heavy load). During stand-by, the device is shutdown to reduce current consumption to as low as 1.0μA or
less. With the built-in UVLO (Under Voltage Lock Out) function, the internal driver transistor is forced OFF when input voltage
becomes 1.4V or lower. XCL205B(G)/XCL206B(G)/XCL207B(G) series provide short-time turn-on by the soft start function
internally set in 0.25 ms (TYP). XCL205B(C,G) /XCL206 B(C,G) / XCL207B(C,G) integrate CLauto discharge function which
enables the electric charge stored at the output capacitor CLto be discharged via the internal auto-discharge switch located
between the LXand VSS pins. When the devices enter stand-by mode, output voltage quickly returns to the VSS level as a result
of this function.
VIN
Vss
CE/MODE
LX
V
ss
VOUT
CL
10μF
4.7μF
CIN
L1
L2
600mA
(TOP VIEW)
* “L1 and LX”, and “L2 and VOUT” is connected by wiring.
■FEATURES
Ultra Small : 2.5mm×2.0mm, H=1.0mm
Input Voltage : 2.0V ~ 6.0V(A/B/C Type)
1.8V ~ 6.0V(G Type)
Output Voltage : 0.8V ~ 4.0V (+2.0%)
High Efficiency : 90% (VIN=4.2V, VOUT=3.3V)
Output Current : 600mA
Oscillation Frequency : 3.0MHz (+15%)
Maximum Duty Cycle
Capacitor
CE Function
Protection Circuits
: 100%
: Low ESR Ceramic
: Active High
Soft-Start Circuit Built-In
CLHigh Speed Auto Discharge
:Current Limiter Circuit Built-In
(Constant Current & Latching)
Control Methods : PWM (XCL205)
PWM/PFM Auto (XCL206)
PWM/PFM Manual (XCL207)
Operating Ambient Temperature
Environmentally Friendly
: -40℃～+85℃
: EU RoHS Compliant, Pb Free
XCL205A333xx/XCL206A333xx/XCL207A333xx
XCL205/206/207 Series

2/25
XCL205/XCL206/XCL207 Series
■PIN CONFIGURATION
■PIN ASSIGNMENT
■PRODUCT CLASSIFICATION
●Ordering Information
XCL205①②③④⑤⑥-⑦(*1) Fixed PWM control
XCL206①②③④⑤⑥-⑦(*1) PWM / PFM automatic switching control
XCL207①②③④⑤⑥-⑦(*1) Manual Mode Selection Pin (Semi-custom)
PIN NUMBER PIN NAME FUNCTION
1 LxSwitching Output
2,5 VSS Ground
3 VOUT Output Voltage
4 CE / MODE Chip Enable & Mode Switch
6 VIN Power Input
7 L1
8 L2 Inductor Electrodes
DESIGNATOR ITEM SYMBOL DESCRIPTION
A VIN≧2.0V, No CLauto discharge, Standard soft-start
B VIN≧2.0V, CLauto discharge, High speed soft-start
C VIN≧2.0V, CLauto discharge, Standard soft-start
①Functions selection
(All CE active high)
G VIN≧1.8V, CLauto discharge, High speed soft-start
10 1.0V
12 1.2V
14 1.4V
15 1.5V
1K 1.75V
18 1.8V
19 1.9V
25 2.5V
28 2.8V
2L 2.85V
30 3.0V
②③ Output Voltage(*2)
33 3.3V
④Oscillation Frequency
3 3.0MHz
⑤⑥-⑦(*1) Package
(Order Unit) AR-G CL-2025 (3,000/Reel)
(BOTTOMVIEW)
L1
L2
7
8
V
IN 6
V
ss 5
CE/MODE 4
1Lx
2V ss
3VOUT
* It should be connected the VSS pin (No. 2 and 5) to the GND pin.
* If the dissipation pad needs to be connected to other pins, it should be
connected to the GND pin.
* Please refer to pattern layout page for the connecting to PCB.
(*1) The “-G” suffix indicates that the products are Halogen and Antimony free as well as being fully RoHS compliant.
(*2) When other output voltages are needed, please contact your local Torex sales office for more information.
Output voltage range is 0.8~4.0V.

3/25
XCL205/XCL206/XCL207
Series
■BLOCK DIAGRAM
■ABSOLUTE MAXIMUM RATINGS
Ta = 25℃
PARAMETER SYMBOL RATINGS UNITS
VIN Pin Voltage VIN VSS- 0.3 ~VSS +6.5 V
LXPin Voltage VLXVSS- 0.3 ~ VIN + 0.3≦VSS+6.5 V
VOUT Pin Voltage VOUT VSS- 0.3 ~VSS +6.5 V
CE/MODE Pin Voltage VCE VSS- 0.3 ~VSS +6.5 V
LXPin Current ILX±1500 mA
Power Dissipation Pd 1000*1 mW
Operating Ambient Temperature Topr - 40 ~ + 85 ℃
Storage Temperature Tstg - 40 ~ + 105 ℃
●XCL205 / XCL206 / XCL207 series A T
yp
e
NOTE: The XCL205 offers a fixed PWM control, a signal from CE/MODE Control Logic to PWM/PFM Selector is fixed to "L" level inside.
The XCL206 control scheme is PWM/PFM automatic switching, a signal from CE/MODE Control Logic to PWM/PFM Selector is fixed to
"H" level inside. The diodes placed inside are ESD protection diodes and parasitic diodes.
CE/MODE
R2
R1
Error Amp.
Vref with
Soft Start,
CE
Phase
Compensation
PWM/PFM
Selector
Current Feedback
Current Limit
PWM
Comparator
Logic
Synch
Buffer
Drive
R3
R4
UVLO
UVLO Cmp Ramp Wave
Generator
OSC
Lx
VSS
VIN
VOUT
CE/MODE
Control
Logic
VSHORT
FB
CFB
Inductor
VSS
L2 L1
*1: The power dissipation figure shown is PCB mounted (40mm×40mm, t=1.6mm, Glass Epoxy FR-4).
Please refer to page 16 for details.
●XCL205 / XCL206 / XCL207 / XCL205 / XCL206 / XCL207 series B/C/G T
yp
e
CE/MODE
R2
R1
Error Amp.
Vref with
Soft Start,
CE
Phase
Compensation
PWM/PFM
Selector
Current Feedback
Current Limit
PWM
Comparator
Logic
Synch
Buffer
Drive
R3
R4
UVLO
UVLO Cmp Ramp Wave
Generator
OSC
Lx
VSS
VIN
VOUT
CE/MODE
Control
Logic
CE/
VSHORT
FB
CFB
VSS
Inductor
L2 L1
NOTE: The XCL205 offers a fixed PWM control, a signal from CE/MODE Control Logic to PWM/PFM Selector is fixed to "L" level inside.
The XCL206 control scheme is PWM/PFM automatic switching, a signal from CE/MODE Control Logic to PWM/PFM Selector is fixed to
"H" level inside. The diodes placed inside are ESD protection diodes and parasitic diodes.

4/25
XCL205/XCL206/XCL207 Series
■ELECTRICAL CHARACTERISTICS
●XCL205Axx3AR/XCL206Axx3AR/XCL207Axx3AR, fOSC=3.0MHz, Ta=25℃
PARAMETER SYMBOL CONDITIONS MIN. TYP. MAX. UNITS CIRCUIT
Output Voltage VOUT When connected to external components,
VIN=VCE=5.0V, IOUT=30mA <E-1> <E-2> <E-3> V ①
Operating Voltage Range VIN 2.0 - 6.0 V ①
Maximum Output Current IOUTMAX VIN=VOUT(T)+2.0V, VCE=1.0V
When connected to external components (*9) 600 - - mA ①
UVLO Voltage VUVLO VCE=VIN,VOUT=0V,
Voltage which Lx pin holding “L” level (*1, *11)
1.00 1.40 1.78 V ③
Supply Current (XCL205) - 46 65
Supply Current (XCL206, XCL207)
IDD V
IN=VCE=5.0V, VOUT=VOUT(T)×1.1V - 21 35
μA ②
Stand-by Current ISTB V
IN=5.0V, VCE=0V, VOUT=VOUT(T)×1.1V - 0 1.0 μA ②
Oscillation Frequency fOSC When connected to external components,
VIN=VOUT(T)+2.0V,VCE=1.0V, IOUT=100mA 2550 3000 3450 kHz ①
PFM Switching Current (*12) I
PFM When connected to external components,
VIN=VOUT(T)+2.0V, VCE=VIN , IOUT=1mA <E-4> <E-5> <E-6> mA ⑩
PFM Duty Limit (*12) DTYLIMIT_PFM VCE= VIN= VOUT(T) +1.0V, IOUT=1mA - 200 300 % ①
Maximum Duty Cycle DMAX VIN=VCE=5.0V, VOUT=VOUT (T)×0.9V 100 - - % ③
Minimum Duty Cycle DMIN VIN=VCE=5.0V, VOUT=VOUT (T)×1.1V - - 0 % ③
Efficiency(*2) EFFI When connected to external components,
VCE=VIN＝VOUT (T)+1.2V, IOUT = 100mA - <E-7> - % ①
Lx SW "H" ON Resistance 1 RLｘHV
IN=VCE=5.0V, VOUT=0V, ILX=100mA (*3) - 0.35 0.55 Ω④
Lx SW "H" ON Resistance 2 RLｘHV
IN=VCE=3.6V, VOUT=0V, ILX=100mA (*3) - 0.42 0.67 Ω④
Lx SW "L" ON Resistance 1 RLｘLV
IN=VCE=5.0V (*4) - 0.45 0.66 Ω-
Lx SW "L" ON Resistance 2 RLｘLV
IN=VCE=3.6V, (*4) - 0.52 0.77 Ω-
Lx SW "H" Leakage Current (*5) I
LEAKH V IN=VOUT=5.0V, VCE=0V, LX=0V - 0.01 1.0 μA ⑤
Lx SW "L" Leakage Current (*5) I
LEAKL V IN=VOUT=5.0V, VCE=0V, LX= 5.0V - 0.01 1.0 μA ⑤
Current Limit (*10) I
LIM V IN=VCE=5.0V, VOUT=VOUT(T)×0.9V (*8) 900 1050 1350 mA ⑥
Output Voltage
Temperature Characteristics
△ V
OUT
/
(V
OUT
・△ Topr)
IOUT =30mA
-40℃≦Topr≦85℃- ±100 - ppm/ ℃ ①
CE "H" Voltage VCEH VOUT=0V, Applied voltage to VCE,
Voltage changes Lx to “H” level (*11) 0.65 - VIN V ③
CE "L" Voltage VCEL VOUT=0V, Applied voltage to VCE,
Voltage changes Lx to “L” level (*11) VSS - 0.25 V ③
PWM "H" Level Voltage (*13) V
PWMH
When connected to external components,
IOUT=1mA (*6), Voltage which oscillation
frequency becomes 2550kHz≦fOSC≦3450kHz (*13)
- - VIN - 1.0 V ①
PWM "L" Level Voltage (*13) V
PWML
When connected to external components,
IOUT=1mA (*6), Voltage which oscillation
frequency becomes fOSC＜2550kHz (*13)
VIN -
0.25 - - V ①
CE "H" Current ICEH V
IN=VCE=5.0V, VOUT=0V - 0.1 - 0.1 μA ⑤
CE "L" Current ICEL V
IN=5.0V, VCE=0V, VOUT=0V - 0.1 - 0.1 μA ⑤
Soft Start Time tSS When connected to external components,
VCE=0V→VIN , IOUT=1mA 0.5 0.9 2.5 ms ①
Latch Time tLAT VIN
= VCE =5.0V, VOUT =0.8 × VOUT
(T)
Short Lx at 1Ωresistance
(*7)
1.0 - 20 ms ⑦
Short Protection
Threshold Voltage VSHORT
Sweeping VOUT, VIN=VCE=5.0V, Short Lx at
1Ωresistance, VOUT voltage which Lx becomes “L”
level within 1ms
<E-8> <E-9> <E-10> V ⑦
Inductance Value L Test frequency=1MHz - 1.5 - μH
Allowed Inductor Current IDC ΔT=40℃- 1000 - mA
Test conditions: Unless otherwise stated, VIN=5.0V, VOUT(T)=Nominal Voltage
NOTE:
*1: Including hysteresis operating voltage range.
*2: EFFI = { ( output voltage×output current ) / ( input voltage×input current) }×100
*3: ON resistance (Ω)= (VIN - Lx pin measurement voltage) / 100mA
*4: Design value
*5: When temperature is high, a current of approximately 10μA (maximum) may leak.
*6:The CE/MODE pin of the XCL207 series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the
operation, control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than VIN minus
0.3V, and to the PWM mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0V and equal to or greater than VCEH.
*7:Time until it short-circuits VOUT with GND via 1Ωof resistor from an operational state and is set to Lx=0V from current limit pulse generating.
*8: When VIN is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance.
*9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes.
If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance.
*10: Current limit denotes the level of detection at peak of coil current.
*11: “H”=VIN~VIN-1.2V, “L”=+0.1V~-0.1V
*12: IPFM and DTYLIMIT_PFM are defined only for the XCL206 and XCL207 series which have PFM control function. (Not for the XCL 205 series)
*13: VPWMH and VPWML are defined only for the XCL207 series. (They are not used in the XCL205/and XCL206 series)

5/25
XCL205/XCL206/XCL207
Series
■ELECTRICAL CHARACTERISTICS (Continued)
●XCL205Bxx3AR/XCL206Bxx3AR/XCL207Bxx3AR, fOSC=3.0MHz, Ta=25℃
PARAMETER SYMBOL CONDITIONS MIN. TYP. MAX. UNITS CIRCUIT
Output Voltage VOUT When connected to external components,
VIN=VCE=5.0V, IOUT=30mA <E-1> <E-2> <E-3> V ①
Operating Voltage Range VIN 2.0 - 6.0 V ①
Maximum Output Current IOUTMAX VIN=VOUT(T)+2.0V, VCE=1.0V
When connected to external components (*9) 600 - - mA ①
UVLO Voltage VUVLO VCE=VIN,VOUT=0V,
Voltage which Lx pin holding “L” level (*1, *11)
1.00 1.40 1.78 V ③
Supply Current (XCL205) - 46 65
Supply Current (XCL206, XCL207) IDD VIN=VCE=5.0V, VOUT=VOUT(T)×1.1V - 21 35
μA ②
Stand-by Current ISTB VIN=5.0V, VCE=0V, VOUT=VOUT(T)×1.1V - 0 1.0 μA ②
Oscillation Frequency fOSC When connected to external components,
VIN =VOUT(T)+2.0V,VCE=1.0V, IOUT=100mA 2550 3000 3450 kHz ①
PFM Switching Current (*12) IPFM When connected to external components,
VIN =VOUT(T)+2.0V, VCE = VIN , IOUT=1mA <E-4> <E-5> <E-6> mA ⑩
PFM Duty Limit (*12) DTYLIMIT_PFM VCE=VIN= VOUT(T) +1.0V, IOUT=1mA - 200 300 % ①
Maximum Duty Cycle DMAX VIN=VCE=5.0V, VOUT=VOUT (T)×0.9V 100 - - % ③
Minimum Duty Cycle DMIN VIN=VCE=5.0V, VOUT=VOUT (T)×1.1V - - 0 % ③
Efficiency(*2) EFFI When connected to external components,
VCE=VIN＝VOUT (T)+1.2V, IOUT=100mA - <E-7> - % ①
Lx SW "H" ON Resistance 1 RLｘHVIN=VCE=5.0V, VOUT=0V, ILX=100mA (*3) - 0.35 0.55 Ω④
Lx SW "H" ON Resistance 2 RLｘHVIN=VCE=3.6V, VOUT=0V, ILX=100mA (*3) - 0.42 0.67 Ω④
Lx SW "L" ON Resistance 1 RLｘLVIN=VCE=5.0V (*4) - 0.45 0.66 Ω-
Lx SW "L" ON Resistance 2 RLｘLVIN=VCE = 3.6V (*4) - 0.52 0.77 Ω-
Lx SW "H" Leakage Current (*5) ILEAKH VIN=VOUT=5.0V, VCE =0V, LX=0V - 0.01 1.0 μA ⑨
Current Limit (*10) ILIM VIN=VCE=5.0V, VOUT=VOUT (T)×0.9V (*8) 900 1050 1350 mA ⑥
Output Voltage
Temperature Characteristics
△ V
OUT
/
(V
OUT
・△ To p r )
IOUT =30mA
-40℃≦Topr≦85℃- ±100 - ppm/ ℃ ①
CE "H" Voltage VCEH VOUT=0V, Applied voltage to VCE,
Voltage changes Lx to “H” level (*11) 0.65 - VIN V ③
CE "L" Voltage VCEL VOUT=0V, Applied voltage to VCE,
Voltage changes Lx to “L” level (*11) VSS - 0.25 V ③
PWM "H" Level Voltage (*13) VPWMH
When connected to external components,
IOUT=1mA (*6), Voltage which oscillation
frequency becomes 2550kHz≦fOSC≦3450kHz (*13) - - VIN - 1.0 V ①
PWM "L" Level Voltage (*13) VPWML
When connected to external components,
IOUT=1mA (*6), Voltage which oscillation
frequency becomes fOSC＜2550kHz (*13)
VIN -
0.25 - - V ①
CE "H" Current ICEH VIN=VCE=5.0V, VOUT=0V - 0.1 - 0.1 μA ⑤
CE "L" Current ICEL VIN=5.0V, VCE=0V, VOUT=0V - 0.1 - 0.1 μA ⑤
Soft Start Time tSS When connected to external components,
VCE=0V→VIN , IOUT=1mA -<E-11> <E-12> ms ①
Latch Time tLAT VIN=VCE=5.0V, VOUT=0.8×VOUT(T)
Short Lx at 1Ωresistance
(*7)
1.0 - 20 ms ⑦
Short Protection
Threshold Voltage VSHORT
Sweeping VOUT, VIN=VCE=5.0V, Short Lx at
1Ωresistance, VOUT voltage which Lx becomes “L”
level within 1ms
<E-8> <E-9> <E-10> V ⑦
CL Discharge RDCHG VIN=5.0V, LX=5.0V, VCE=0V, VOUT=Open 200 300 450 Ω⑧
Inductance Value L Test frequency =1MHz - 1.5 - μH
Allowed Inductor Current IDC ΔT=40℃- 1000 - mA
Test conditions: Unless otherwise stated, VIN=5.0V, VOUT (T) =Nominal Voltage
NOTE:
*1: Including hysteresis operating voltage range.
*2: EFFI = { ( output voltage×output current ) / ( input voltage×input current) }×100
*3: ON resistance (Ω)= (VIN - Lx pin measurement voltage) / 100mA
*4: Design value
*5: When temperature is high, a current of approximately 10μA (maximum) may leak.
*6:The CE/MODE pin of the XCL207 series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the
operation, control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than VIN minus
0.3V, and to the PWM mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0V and equal to or greater than VCEH.
*7:Time until it short-circuits VOUT with GND via 1Ωof resistor from an operational state and is set to Lx=0V from current limit pulse generating.
*8: When VIN is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance.
*9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes.
If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance.
*10: Current limit denotes the level of detection at peak of coil current.
*11: “H”=VIN~VIN-1.2V, “L”=+0.1V~-0.1V
*12: IPFM and DTYLIMIT_PFM are defined only for the XCL206 and XCL207 series which have PFM control function. (Not for the XCL 205 series)
*13: VPWMH and VPWML are defined only for the XCL207 series. (They are not used in the XCL205/and XCL206 series)

6/25
XCL205/XCL206/XCL207 Series
■ELECTRICAL CHARACTERISTICS (Continued)
●XCL205Cxx3AR/XCL206Cxx3AR/XCL207Cxx3AR, fOSC=3.0MHz, Ta=25℃
PARAMETER SYMBOL CONDITIONS MIN. TYP. MAX. UNITS CIRCUIT
Output Voltage VOUT When connected to external components,
VIN = VCE =5.0V, IOUT =30mA <E-1> <E-2> <E-3> V ①
Operating Voltage Range VIN 2.0 - 6.0 V ①
Maximum Output Current IOUTMAX VIN=VOUT(T)+2.0V, VCE=1.0V
When connected to external components (*9) 600 - - mA ①
UVLO Voltage VUVLO VCE=VIN,VOUT=0V,
Voltage which Lx pin holding “L” level (*1, *11)
1.00 1.40 1.78 V ③
Supply Current (XCL205) - 46 65
Supply Current (XCL206, XCL207) IDD V
IN =VCE=5.0V, VOUT= VOUT(T)×1.1V 21 35
μA ②
Stand-by Current ISTB V
IN =5.0V, VCE=0V, VOUT= VOUT(T)×1.1V - 0 1.0 μA ②
Oscillation Frequency fOSC When connected to external components,
VIN =VOUT(T)+2.0V,VCE=1.0V, IOUT=100mA 2550 3000 3450 kHz ①
PFM Switching Current (*12) I
PFM When connected to external components,
VIN =VOUT(T)+2.0V, VCE = VIN , IOUT=1mA <E-4> <E-5> <E-6> mA ⑩
PFM Duty Limit (*12) DTYLIMIT_PFM V
CE= VIN = VOUT(T) +1.0V, IOUT=1mA - 200 300 % ①
Maximum Duty Cycle MAXDTY VIN = VCE =5.0V, VOUT = VOUT (T)×0.9V 100 - - % ③
Minimum Duty Cycle MINDTY VIN = VCE =5.0V, VOUT = VOUT (T)×1.1V - - 0 % ③
Efficiency(*2) EFFI
When connected to external components,
VCE = VIN ＝V
OUT (T)+1.2V, IOUT = 100mA - <E-7> - % ①
Lx SW "H" ON Resistance 1 RLｘHV
IN = VCE = 5.0V, VOUT = 0V,ILX = 100mA (*3) - 0.35 0.55 Ω④
Lx SW "H" ON Resistance 2 RLｘHV
IN = VCE = 3.6V, VOUT = 0V,ILX = 100mA (*3) - 0.42 0.67 Ω④
Lx SW "L" ON Resistance 1 RLｘLV
IN = VCE = 5.0V (*4) - 0.45 0.66 Ω-
Lx SW "L" ON Resistance 2 RLｘLV
IN = VCE = 3.6V (*4) - 0.52 0.77 Ω-
Lx SW "H" Leakage Current (*5) I
LEAKH V IN= VOUT =5.0V, VCE =0V, LX=0V - 0.01 1.0 μA ⑨
Current Limit (*10) I
LIM V IN = VCE= 5.0V, VOUT = VOUT (T)×0.9V (*8) 900 1050 1350 mA ⑥
Output Voltage
Temperature Characteristics
△ V
OUT
/
(V
OUT
・△ Topr)
IOUT =30mA
-40℃≦Topr≦85℃- ±100 - ppm/ ℃ ①
CE "H" Voltage VCEH VOUT=0V, Applied voltage to VCE,
Voltage changes Lx to “H” level (*11) 0.65 - 6.0 V ③
CE "L" Voltage VCEL VOUT=0V, Applied voltage to VCE,
Voltage changes Lx to “L” level (*11) VSS - 0.25 V ③
PWM "H" Level Voltage (*13) VPWMH
When connected to external components,
IOUT=1mA (*6), Voltage which oscillation
frequency becomes 2550kHz≦fOSC≦3450kHz (*13) - - VIN - 1.0 V ①
PWM "H" Level Voltage (*13) VPWML
When connected to external components,
IOUT=1mA (*6), Voltage which oscillation
frequency becomes fOSC＜2550kHz (*13)
VIN -
0.25 - - V ①
CE "H" Current ICEH V
IN = VCE =5.0V, VOUT = 0V - 0.1 - 0.1 μA ⑤
CE "L" Current ICEL V
IN =5.0V, VCE = 0V, VOUT = 0V - 0.1 - 0.1 μA ⑤
Soft Start Time tSS When connected to external components,
VCE=0V→VIN , IOUT=1mA 0.5 0.9 2.5 ms ①
Latch Time tLAT VIN=VCE=5.0V, VOUT=0.8×VOUT(T)
Short Lx at 1Ωresistance
(*7)
1.0 - 20 ms ⑦
Short Protection
Threshold Voltage VSHORT
Sweeping VOUT, VIN=VCE=5.0V, Short Lx at
1Ωresistance, VOUT voltage which Lx becomes “L”
level within 1ms
<E-8> <E-9> <E-10> V ⑦
CL Discharge RDCHG V
IN = 5.0V LX= 5.0V VCE = 0V VOUT = open 200 300 450 Ω⑧
Inductance Value L Test frequency=1MHz - 1.5 - μH-
Allowed Inductor Current IDC Δ T=40 ℃ - 1000 - mA -
Test conditions: Unless otherwise stated, VIN=5.0V, VOUT (T) = Nominal Voltage
NOTE:
*1: Including hysteresis operating voltage range.
*2: EFFI = { ( output voltage×output current ) / ( input voltage×input current) }×100
*3: ON resistance (Ω)= (VIN - Lx pin measurement voltage) / 100mA
*4: Design value
*5: When temperature is high, a current of approximately 10μA (maximum) may leak.
*6:The CE/MODE pin of the XCL207 series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the
operation, control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than VIN minus
0.3V, and to the PWM mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0V and equal to or greater than VCEH.
*7:Time until it short-circuits VOUT with GND via 1Ωof resistor from an operational state and is set to Lx=0V from current limit pulse generating.
*8: When VIN is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance.
*9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes.
If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance.
*10: Current limit denotes the level of detection at peak of coil current.
*11: “H”=VIN~VIN-1.2V, “L”=+0.1V~-0.1V
*12: IPFM and DTYLIMIT_PFM are defined only for the XCL206 and XCL207 series which have PFM control function. (Not for the XCL 205 series)
*13: VPWMH and VPWML are defined only for the XCL207 series. (They are not used in the XCL205/and XCL206 series)

7/25
XCL205/XCL206/XCL207
Series
■ELECTRICAL CHARACTERISTICS (Continued)
●XCL205Gxx3AR/XCL206Gxx3AR/XCL207Gxx3AR, fOSC=3.0MHz, Ta=25℃
PARAMETER SYMBOL CONDITIONS MIN. TYP. MAX. UNITS CIRCUIT
Output Voltage VOUT When connected to external components,
VIN = VCE =5.0V, IOUT =30mA <E-1> <E-2> <E-3> V ①
Operating Voltage Range VIN 1.8 - 6.0 V ①
Maximum Output Current IOUTMAX VIN=VOUT(T)+2.0V, VCE=1.0V
When connected to external components (*9) 600 - - mA ①
UVLO Voltage VUVLO VCE=VIN,VOUT(T)×0.5V(*14),
Voltage which Lx pin holding “L” level (*1, *11)
1.00 1.40 1.78 V ③
Supply Current (XCL205) - 46 65
Supply Current (XCL206, XCL207) IDD V
IN =VCE=5.0V, VOUT= VOUT(T)×1.1V - 21 35
μA ②
Stand-by Current ISTB V
IN =5.0V, VCE=0V, VOUT= VOUT(T)×1.1V - 0 1.0 μA ②
Oscillation Frequency fOSC When connected to external components,
VIN =VOUT(T)+2.0V,VCE=1.0V, IOUT=100mA 2550 3000 3450 kHz ①
PFM Switching Current (*12) I
PFM When connected to external components,
VIN =VOUT(T)+2.0V, VCE = VIN , IOUT=1mA <E-4> <E-5> <E-6> mA ⑩
PFM Duty Limit (*12) DTYLIMIT_PFM V
CE= VIN = VOUT(T) +1.0V, IOUT=1mA - 200 300 % ①
Maximum Duty Cycle MAXDTY VIN = VCE =5.0V, VOUT = VOUT (T)×0.9V 100 - - % ③
Minimum Duty Cycle MINDTY VIN = VCE =5.0V, VOUT = VOUT (T)×1.1V - - 0 % ③
Efficiency(*2) EFFI
When connected to external components,
VCE = VIN ＝V
OUT (T)+1.2V, IOUT = 100mA - <E-7> - % ①
Lx SW "H" ON Resistance 1 RLｘHV
IN = VCE = 5.0V, VOUT = 0V,ILX = 100mA (*3) - 0.35 0.55 Ω④
Lx SW "H" ON Resistance 2 RLｘHV
IN = VCE = 3.6V, VOUT = 0V,ILX = 100mA (*3) - 0.42 0.67 Ω④
Lx SW "L" ON Resistance 1 RLｘLV
IN = VCE = 5.0V (*4) - 0.45 0.66 Ω-
Lx SW "L" ON Resistance 2 RLｘLV
IN = VCE = 3.6V (*4) - 0.52 0.77 Ω-
Lx SW "H" Leakage Current (*5) I
LEAKH V IN= VOUT =5.0V, VCE =0V, LX=0V - 0.01 1.0 μA ⑨
Current Limit (*10) I
LIM V IN = VCE= 5.0V, VOUT = VOUT (T)×0.9V (*8) 900 1050 1350 mA ⑥
Output Voltage
Temperature Characteristics
△ V
OUT
/
(V
OUT
・△ Topr)
IOUT =30mA
-40℃≦Topr≦85℃- ±100 - ppm/ ℃ ①
CE "H" Voltage VCEH VOUT=0V, Applied voltage to VCE,
Voltage changes Lx to “H” level (*11) 0.65 - 6.0 V ③
CE "L" Voltage VCEL VOUT=0V, Applied voltage to VCE,
Voltage changes Lx to “L” level (*11) VSS - 0.25 V ③
PWM "H" Level Voltage (*13) VPWMH
When connected to external components,
IOUT=1mA (*6), Voltage which oscillation
frequency becomes 2550kHz≦fOSC≦3450kHz (*13) - - VIN - 1.0 V ①
PWM "H" Level Voltage (*13) VPWML
When connected to external components,
IOUT=1mA (*6), Voltage which oscillation
frequency becomes fOSC＜2550kHz (*13)
VIN -
0.25 - - V ①
CE "H" Current ICEH V
IN = VCE =5.0V, VOUT = 0V - 0.1 - 0.1 μA ⑤
CE "L" Current ICEL V
IN =5.0V, VCE = 0V, VOUT = 0V - 0.1 - 0.1 μA ⑤
Soft Start Time tSS When connected to external components,
VCE=0V→VIN , IOUT=1mA - <E-11> <E-12> ms ①
Latch Time tLAT VIN=VCE=5.0V, VOUT=0.8×VOUT(T)
Short Lx at 1Ωresistance
(*7)
1.0 - 20 ms ⑦
Short Protection
Threshold Voltage VSHORT
Sweeping VOUT, VIN=VCE=5.0V, Short Lx at
1Ωresistance, VOUT voltage which Lx becomes “L”
level within 1ms
<E-8> <E-9> <E-10> V ⑦
CL Discharge RDCHG V
IN = 5.0V LX= 5.0V VCE = 0V VOUT = open 200 300 450 Ω⑧
Inductance Value L Test frequency=1MHz - 1.5 - μH-
Allowed Inductor Current IDC Δ T=40 ℃ - 1000 - mA -
Test conditions: Unless otherwise stated, VIN=5.0V, VOUT (T) = Nominal Voltage
NOTE:
*1: Including hysteresis operating voltage range.
*2: EFFI = { ( output voltage×output current ) / ( input voltage×input current) }×100
*3: ON resistance (Ω)= (VIN - Lx pin measurement voltage) / 100mA
*4: Design value
*5: When temperature is high, a current of approximately 10μA (maximum) may leak.
*6:The CE/MODE pin of the XCL207 series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the
operation, control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than VIN minus
0.3V, and to the PWM mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0V and equal to or greater than VCEH.
*7:Time until it short-circuits VOUT with GND via 1Ωof resistor from an operational state and is set to Lx=0V from current limit pulse generating.
*8: When VIN is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance.
*9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes.
If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance.
*10: Current limit denotes the level of detection at peak of coil current.
*11: “H”=VIN~VIN-1.2V, “L”=+0.1V~-0.1V
*12: IPFM and DTYLIMIT_PFM are defined only for the XCL206 and XCL207 series which have PFM control function. (Not for the XCL 205 series)
*13: VPWMH and VPWML are defined only for the XCL207 series. (They are not used in the XCL205/and XCL206 series)
*14: VIN is applied when VOUT (T) x 0.5V becomes more than VIN.

8/25
XCL205/XCL206/XCL207 Series
■ELECTRICAL CHARACTERISTICS (Continued)
●Output Voltage
VOUT(V)
NOMINAL
OUTPUT
VOLTAGE <E-1> <E-2> <E-3>
VOUT(T) MIN TYP MAX
1.00 0.980 1.000 1.020
1.20 1.176 1.200 1.224
1.40 1.372 1.400 1.428
1.50 1.470 1.500 1.530
1.75 1.715 1.750 1.785
1.80 1.764 1.800 1.836
1.90 1.862 1.900 1.938
2.50 2.450 2.500 2.550
2.80 2.744 2.800 2.856
2.85 2.793 2.850 2.907
3.00 2.940 3.000 3.060
3.30 3.234 3.300 3.366
●Efficiency ●Short Protection Threshold Voltage
Efficiency(%)
XCL205/206/207
NOMINAL
OUTPUT
VOLTAGE <E-7>
VOUT(T) 3.0MHz
1.00 79
1.20 82
1.40 83
1.50 84
1.75
1.80
1.90
85
2.50
2.80
2.85
3.00
3.30
86
VSHORT(V)
XCL205/206/207A,B,C XCL205/206/207G
NOMINAL
OUTPUT
VOLTAGE <E-8> <E-9> <E-10> <E-8> <E-9> <E-10>
VOUT(T) MIN TYP MAX MIN TYP MAX
1.00 0.375 0.500 0.625 0.188 0.250 0.313
1.20 0.450 0.600 0.750 0.225 0.300 0.375
1.40 0.525 0.700 0.875 0.263 0.350 0.438
1.50 0.563 0.750 0.938 0.282 0.375 0.469
1.75 0.656 0.875 1.094 0.328 0.438 0.547
1.80 0.675 0.900 1.125 0.338 0.450 0.563
1.90 0.713 0.950 1.188 0.357 0.475 0.594
2.50 0.938 1.250 1.563 0.469 0.625 0.782
2.80 1.050 1.400 1.750 0.525 0.700 0.875
2.85 1.069 1.425 1.781 0.535 0.713 0.891
3.00 1.125 1.500 1.875 0.563 0.750 0.938
3.30 1.238 1.650 2.063 0.619 0.825 1.032
●PFM Switching Current
IPFM(mA)
<E-4> <E-5> <E-6>
NOMINAL OUTPUT
VOLTAGE
MIN TYP MAX
VOUT(T)≦1.2Ｖ190 260 350
1.2V＜VOUT(T)≦1.75Ｖ180 240 300
1.8V≦VOUT(T) 170 220 270
●Soft Start Time (XCL20xB, XCL20xG)
tSS(ms)
<E-11> <E-12>
NOMINAL OUTPUT
VOLTAGE TYP MAX
0.8V≦VOUT(T)≦1.75Ｖ0.25 0.4
1.8V≦VOUT(T)≦4.0Ｖ0.32 0.5

9/25
XCL205/XCL206/XCL207
Series
■TYPICAL APPLICATION CIRCUIT
●XCL205/XCL206/XCL207 Series
●External Components
CIN : 10V/4.7μF (Ceramic)
CL : 6.3V/10μF (Ceramic)
NOTE
The Inductor can be used only for this DC/DC converter.
Please do not use this inductor for the other reasons.
Please use B, X5R, and X7R grades in temperature characteristics for CIN and CL capacitors.
These grade ceramic capacitors minimize capacitance-loss as a function of voltage stress.
V
Vss
V
ss
Lx
V
OUT
IN
CE/MODE
L1
L2
C
C
IN
L

10/25
XCL205/XCL206/XCL207 Series
■OPERATIONAL DESCRIPTION
The XCL205/XCL/206/XCL207 series consists of a reference voltage source, ramp wave circuit, error amplifier, PWM
comparator, phase compensation circuit, output voltage adjustment resistors, P-channel MOSFET driver transistor, N-channel
MOSFET switching transistor for the synchronous switch, current limiter circuit, UVLO circuit with control IC, and an inductor.
(See the block diagram above.) Using the error amplifier, the voltage of the internal voltage reference source is compared with
the feedback voltage from the VOUT pin through split resistors, R1 and R2. Phase compensation is performed on the resulting
error amplifier output, to input a signal to the PWM comparator to determine the turn-on time during PWM operation. The PWM
comparator compares, in terms of voltage level, the signal from the error amplifier with the ramp wave from the ramp wave circuit,
and delivers the resulting output to the buffer driver circuit to cause the Lx pin to output a switching duty cycle. This process is
continuously performed to ensure stable output voltage. The current feedback circuit monitors the P-channel MOS driver
transistor current for each switching operation, and modulates the error amplifier output signal to provide multiple feedback
signals. This enables a stable feedback loop even when a low ESR capacitor such as a ceramic capacitor is used ensuring
stable output voltage.
<Reference Voltage Source>
The reference voltage source provides the reference voltage to ensure stable output voltage of the DC/DC converter.
<Ramp Wave Circuit>
The ramp wave circuit determines switching frequency. The frequency is fixed internally 3.0MHz. Clock pulses generated in
this circuit are used to produce ramp waveforms needed for PWM operation, and to synchronize all the internal circuits.
<Error Amplifier>
The error amplifier is designed to monitor output voltage. The amplifier compares the reference voltage with the feedback
voltage divided by the internal split resistors, R1 and R2. When a feed back voltage is lower than the reference voltage, the
output voltage of the error amplifier is increased. The gain and frequency characteristics of the error amplifier output are fixed
internally to deliver an optimized signal to the mixer.
<Current Limit>
The current limiter circuit of the XCL205/XCL206/XCL207 series monitors the current flowing through the P-channel MOS driver
transistor connected to the Lx pin, and features a combination of the current limit mode and the operation suspension mode.
① When the driver current is greater than a specific level, the current limit function operates to turn off the pulses from the Lx pin
at any given timing.
② When the driver transistor is turned off, the limiter circuit is then released from the current limit detection state.
③ At the next pulse, the driver transistor is turned on. However, the transistor is immediately turned off in the case of an over
current state.
④ When the over current state is eliminated, the IC resumes its normal operation.
The IC waits for the over current state to end by repeating the steps ① through ③. If an over current state continues for a few
milliseconds and the above three steps are repeatedly performed, the IC performs the function of latching the OFF state of the
driver transistor, and goes into operation suspension state. Once the IC is in suspension state, operations can be resumed by
either turning the IC off via the CE/MODE pin, or by restoring power to the VIN pin. The suspension state does not mean a
complete shutdown, but a state in which pulse output is suspended; therefore, the internal circuitry remains in operation. The
current limit of the XCL205/XCL206/XCL207 series can be set at 1050mA at typical. Depending on the state of the PC Board,
latch time may become longer and latch operation may not work. In order to avoid the effect of noise, an input capacitor is
placed as close to the IC as possible.
Limit > # ms
Current Limit LEVEL
0mA
I
OUT
V
Lx
IN
V
CE
V
Lx
Vss
R
esta
r
t
Limit < # ms

11/25
XCL205/XCL206/XCL207
Series
■OPERATIONAL DESCRIPTION (Continued)
<Short-Circuit Protection>
The short-circuit protection circuit monitors the internal R1 and R2 divider voltage from the VOUT pin (refer to FB point in the
block diagram shown in the previous page). In case where output is accidentally shorted to the Ground and when the FB
point voltage decreases less than half of the reference voltage (Vref) and a current more than the ILIM flows to the driver
transistor, the short-circuit protection quickly operates to turn off and to latch the driver transistor. In the latch state, the
operation can be resumed by either turning the IC off and on via the CE/MODE pin, or by restoring power supply to the VIN
pin.
When sharp load transient happens, a voltage drop at the VOUT is propagated to the FB point through CFB, as a result, short
circuit protection may operate in the voltage higher than 1/2 VOUT voltage.
<UVLO Circuit>
When the VIN pin voltage becomes 1.4V or lower, the P-channel output driver transistor is forced OFF to prevent false pulse
output caused by unstable operation of the internal circuitry. When the VIN pin voltage becomes 1.8V or higher, switching
operation takes place. By releasing the UVLO function, the IC performs the soft start function to initiate output startup operation.
The soft start function operates even when the VIN pin voltage falls momentarily below the UVLO operating voltage. The UVLO
circuit does not cause a complete shutdown of the IC, but causes pulse output to be suspended; therefore, the internal circuitry
remains in operation.
<PFM Switch Current>
In PFM control operation, until coil current reaches to a specified level (IPFM), the IC keeps the P-ch MOSFET on. In this case,
on-time (tON) that the P-ch MOSFET is kept on can be given by the following formula.
tON = L
× IPFM / (VIN － VOUT)→IPFM①
<PFM Duty Limit>
In the PFM control operation, the PFM Duty Limit (DTYLIMIT_PFM) is set to 200% (TYP.). Therefore, under the condition that the
duty increases (e.g. the condition that the step-down ratio is small), it’s possible for P-ch MOSFET to be turned off even when coil
current doesn’t reach to IPFM. →IPFM②
tON
Lx
IPFM
0mA
IPFM①IPFM②
0mA
Lx fOSC
Maximum IPFM Limit
ILx ILx
IPFM

12/25
XCL205/XCL206/XCL207 Series
■OPERATIONAL DESCRIPTION (Continued)
＜CLHigh Speed Discharge＞
The XCL205B(C,G)/ XCL206B(C,G)/ XCL207B(C,G) series can quickly discharge the electric charge at the output capacitor (CL)
when a low signal to the CE pin which enables a whole IC circuit put into OFF state, is inputted via the N-channel transistor
located between the LXpin and the VSS pin. When the IC is disabled, electric charge at the output capacitor (CL) is quickly
discharged so that it may avoid application malfunction. Discharge time of the output capacitor (CL) is set by the CL
auto-discharge resistance (R) and the output capacitor (CL). By setting time constant of a CLauto-discharge resistance value [R]
and an output capacitor value (CL) as τ(τ=C x R), discharge time of the output voltage after discharge via the N channel
transistor is calculated by the following formula.
V = VOUT(T) x e –t/τor t=τln (VOUT(T) / V)
V : Output voltage after discharge
VOUT(T) : Output voltage
t: Discharge time,
τ: C x R
C= Capacitance of Output capacitor (CL)
R= CLauto-discharge resistance
0
20
40
60
80
100
0 20406080100
Discharge Time ｔ(ms)
Output Voltage (Relative Value)
100 = Setting Voltage Value
CL=10uF
CL=20uF
CL=50uF
Output Voltage Discharge Characteristics
RDCHG=300Ω(TYP.)

13/25
XCL205/XCL206/XCL207
Series
■OPERATIONAL DESCRIPTION (Continued)
<CE/MODE Pin Function>
The operation of the XCL205/XCL206/ XCL207 series will enter into the shut down mode when a low level signal is input to the
CE/MODE pin. During the shutdown mode, the current consumption of the IC becomes 0μA (TYP.), with a state of high
impedance at the Lx pin and VOUT pin. The IC starts its operation by inputting a high level signal to the CE/MODE pin. The
input to the CE/MODE pin is a CMOS input and the sink current is 0μA (TYP.).
（A） （B）
（A） （B）
Intermediate voltage can be generated by RM1 and RM2. Please set the value
of each R1, R2, RM1, RM2 from
few hundreds kΩto few hundreds MΩ. For switches, CPU open-drain I/O
port and transistor can be used.
(A)
SW_CE SELECTED
STATUS
ON Stand-by
OFF Operation
(B)
SW_CE SELECTED
STATUS
ON Operation
OFF Stand-by
(A)
SW_CE SW_PWM/PFM SELECTED
STATUS
ON *
PWM/PFM
Automatic
Switching Control
OFF ON PWM Control
OFF OFF Stand-by
(B)
SW_CE SW_PWM/PFM SELECTED
STATUS
ON * Stand-by
OFF ON PWM Control
OFF OFF
PWM/PFM
Automatic
Switching Control
CE/MODE CE/MODE
V
V V V
IN IN
DD DD
SW_CE
SW_CE
R1
R2
< IC inside > < IC inside >
< IC inside >
< IC inside >
CE/MODE
CE/MODE
RM1
RM2
RM1
RM2
SW_CE
SW_CE
SW_PWM/PFM
SW_PWM/PFM
V
DD V DD V IN
V
IN
●XCL205/XCL206 series - Exam
p
les of how to use CE/MODE
p
in
●XCL207 series - Exam
p
les of how to use CE/MODE
p
in

14/25
XCL205/XCL206/XCL207 Series
■OPERATIONAL DESCRIPTION (Continued)
<Soft Start>
The XCL205/XCL206/XCL207 series (A, C type) provide 0.9ms (TYP). The XCL205/XCL206/XCL207 series (B, G type)
provide 0.32ms (TYP) however, when VOUT is less than 1.8V, provide 0.25ms (TYP.). Soft start time is defined as the time to
reach 90% of the output nominal voltage when the CE pin is turned on.
■FUNCTION CHART
OPERATIONAL STATES CE/MODE
VOLTAGE
LEVEL XCL205 XCL206 XCL207
H Level (*1)
Synchronous
PWM Fixed
Control
Synchronous
PWM/PFM
Automatic Switching
Synchronous
PWM/PFM
Automatic Switching
M Level (*2) ━ ━ Synchronous
PWM Fixed Control
L Level (*2) Stand-by Stand-by Stand-by
tSS
VCEH
0V
0V
VOUT 90% of setting voltage
Note on CE/MODE pin voltage level range
(*1) H level: 0.65V < H level < 6V (for XCL205/XCL206)
H level: VIN – 0.25V < H level < VIN (for XCL207)
(*2) M level: 0.65V < M level < VIN - 1.0V (for XCL207)
(*3) L level: 0V < L level < 0.25V

15/25
XCL205/XCL206/XCL207
Series
■NOTE ON USE
④
Limit > # ms
⑤
③
②
①
Duty
Lx
ILIM
ILx
1. The XCL205/XCL206/XCL207 series is designed for use with ceramic output capacitors. If, however, the potential
difference is too large between the input voltage and the output voltage, a ceramic capacitor may fail to absorb the resulting
high switching energy and oscillation could occur on the output. If the input-output potential difference is large, connect an
electrolytic capacitor in parallel to compensate for insufficient capacitance.
2. Spike noise and ripple voltage arise in a switching regulator as with a DC/DC converter. These are greatly influenced by
external component selection, such as the coil inductance, capacitance values, and board layout of external components.
Once the design has been completed, verification with actual components should be done.
3. Depending on the input-output voltage differential, or load current, some pulses may be skipped, and the ripple voltage may
increase.
4. When the difference between VIN and VOUT is large in PWM control, very narrow pulses will be outputted, and there is the
possibility that some cycles may be skipped completely.
5. When the difference between VIN and VOUT is small, and the load current is heavy, very wide pulses will be outputted and
there is the possibility that some cycles may be skipped completely.
6. With the IC, the peak current of the coil is controlled by the current limit circuit. Since the peak current increases when
dropout voltage or load current is high, current limit starts operation, and this can lead to instability. When peak current
becomes high, please adjust the coil inductance value and fully check the circuit operation. In addition, please calculate
the peak current according to the following formula:
Ipk = (VIN - VOUT) x OnDuty / (2 x L x fOSC) + IOUT
L: Coil Inductance Value
fOSC: Oscillation Frequency
7. When the peak current which exceeds limit current flows within the specified time, the built-in P-ch driver transistor turns off.
During the time until it detects limit current and before the built-in transistor can be turned off, the current for limit current
flows; therefore, care must be taken when selecting the rating for the external components such as a coil.
8. When VIN is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance.
9. Depending on the state of the PC Board, latch time may become longer and latch operation may not work. In order to avoid
the effect of noise, the board should be laid out so that input capacitors are placed as close to the IC as possible.
10. Use of the IC at voltages below the recommended voltage range may lead to instability.
11. This IC should be used within the stated absolute maximum ratings in order to prevent damage to the device.
12. When the IC is used in high temperature, output voltage may increase up to input voltage level at no load because of the
leak current of the driver transistor.
13. The current limit is set to 1350mA (MAX.) at typical. However, the current of 1350mA or more may flow. In case that the
current limit functions while the VOUT pin is shorted to the GND pin, when P-ch MOSFET is ON, the potential difference for
input voltage will occur at both ends of a coil. For this, the time rate of coil current becomes large. By contrast, when
N-ch MOSFET is ON, there is almost no potential difference at both ends of the coil since the VOUT pin is shorted to the
GND pin. Consequently, the time rate of coil current becomes quite small. According to the repetition of this operation,
and the delay time of the circuit, coil current will be converged on a certain current value, exceeding the amount of current,
which is supposed to be limited originally. Even in this case, however, after the over current state continues for several
ms, the circuit will be latched. A coil should be used within the stated absolute maximum rating in order to prevent
damage to the device.
①Current flows into P-ch MOSFET to reach the current limit (ILIM).
②The current of ILIM or more flows since the delay time of the circuit occurs during from the detection of the current limit to
OFF of P-ch MOSFET.
③Because of no potential difference at both ends of the coil, the time rate of coil current becomes quite small.
④Lx oscillates very narrow pulses by the current limit for several ms.
⑤The circuit is latched, stopping its operation.

16/25
XCL205/XCL206/XCL207 Series
■NOTE ON USE (Continued)
the power loss of micro DC/DC according to the following formula:
power loss = VOUT×IOUT×((100/EFFI) – 1) (W)
VOUT：Output Voltage (V)
IOUT ：Output Current (A)
EFFI：Conversion Efficiency (%)
Measurement Condition (Reference data)
Condition: Mount on a board
Ambient: Natural convection
Soldering: Lead (Pb) free
Board: Dimensions 40 x 40 mm (1600 mm2in one side)
Copper (Cu) traces occupy 50% of the board area
In top and back faces
Package heat-sink is tied to the copper traces
Material: Glass Epoxy (FR-4)
Thickness: 1.6mm
Through-hole: 4 x 0.8 Diameter
14. In order to stabilize VIN voltage level and oscillation frequency, we recommend that a by-pass capacitor (CIN) be
connected as close as possible to the VIN & VSS pins.
15. High step-down ratio and very light load may lead an intermittent oscillation when PWM mode.
16. Please use within the power dissipation range below. Please also note that the power dissipation may changed by test
conditions, the power dissipation figure shown is PCB mounted.
0.0
0.2
0.4
0.6
0.8
1.0
1.2
0 25 50 75 100
Operating Temperature Ta (℃)
Maximum Power Disspation Pd (W)
Evaluation Board (Unit: mm)
.
28.9
.
40.0
40.0
28.9
2.54 1.4
2.5

17/25
XCL205/XCL206/XCL207
Series
■NOTE ON USE (Continued)
●Instructions of pattern layouts
1. In order to stabilize VIN voltage level, we recommend that a by-pass capacitor (CIN) be connected as close as possible to the
VIN (No.6) & VSS (No.5) pins.
2. Please mount each external component as close to the IC as possible.
3. Wire external components as close to the IC as possible and use thick, short connecting traces to reduce the circuit
impedance.
4. Make sure that the PCB GND traces are as thick as possible, as variations in ground potential caused by high ground currents
at the time of switching may result in instability of the IC.
5. This series’ internal driver transistors bring on heat because of the output current and ON resistance of driver transistors.
6. Please connect Lx (No.1) pin and L1 (No.7) pin by wiring on the PCB.
7. Please connect VOUT (No.3) pin and L2 (No.8) pin by wiring on the PCB.
CIN
CL
IC
LX
VINGND
GNDVOUT
CE
CIN
CL
IC
LX
VINGND
GNDVOUT
CE
CE LX
VIN
GND
GND
VOUT
BACK (Flip Horizontal)
FRONT (PCB mounted)
FRONT

18/25
XCL205/XCL206/XCL207 Series
■TEST CIRCUITS
< Circuit No.1 > < Circuit No.2 >
VIN Lx
VSS
CE/
MODE VOUT
A
V
CL
CIN
Wave Form Measure Point
VIN Lx
VSS
CE/
MODE VOUT
A
1μF
※ External Components
CIN : 4.7μF(ceramic)
CL : 10μF(ceramic)
L1
L2 L2
L1
< Circuit No.3 > < Circuit No.4 >
VIN Lx
VSS
CE/
MODE VOUT
VIN Lx
Wave Form Measure Point
L1 L1
V100mA
CE/
MODE VOUT Rpulldown
200Ω 1μF
ON resistance = (VIN-VLx)/100mA
VSS
< Circuit No.5 >
VIN Lx
VSS
CE/
MODE VOUT
A
ILeakH
ILeakL
A
ICEH
ICEL
<CircuitNo.6>
< Circuit No.7 >
VIN Lx
VSS
CE/
MODE VOUT
Rpulldown
1Ω
Ilat
Wave Form Measure Point
VIN Lx
VSS
CE/
MODE VOUT VILIM
Wave Form Measure Point
1μF
1μF
1μF
1μF
<CircuitNo.8> ILx
VIN Lx
VSS
CE/
MODE VOUT
1uF
A
< Circuit No.9 >
VIN Lx
VSS
CE/
MODE VOUT
A
CIN
L2 L2
L2
L2 L2
L2
L2
L1 L1
L1L1
L1
< Circuit No.10 >
VIN Lx
VSS
CE/
MODE VOUT
A
V
CL
L
CIN
Wave Form Measure Point
L1
L2
※ External Components
L : 1.5uH(選別品)
CIN : 4.7μF(ceramic)
CL : 10μF(ceramic)
*External Components
L : 1.5μH
CIN : 4.7μF(ceramic)
CL : 10μF(ceramic)

19/25
XCL205/XCL206/XCL207
Series
■TYPICAL PERFORMANCE CHARACTERISTICS
(1) Efficiency vs. Output Current (2) Output Voltage vs. Output Current
0
20
40
60
80
100
0.1 1 10 100 1000
Output Current:I
OUT
(mA)
Efficency:EFFI(%
)
(
PWM
)
2.4V
3.6V
VIN= 4.2V
XCL206/XCL207(PWM/PFM)
XCL205/XCL207
1.5
1.6
1.7
1.8
1.9
2.0
2.1
0.1 1 10 100 1000
Output Current:I
OUT
(mA)
Output Voltage:V
OUT
(V)
VI
N
＝4.2V,3.6V,2.4V
XCL205/XCL207
(
PWM/ PFM
)
(
PWM
)
XCL/206/XCL207
(3) Ripple Voltage vs. Output Current (4) Oscillation Frequency vs. Ambient Temperature
0
20
40
60
80
100
0.1 1 10 100 1000
Output Current:I
OUT
(mA)
Ripple Voltage:Vr(mV)
3.6V
VI
N
＝4.2V,3.6V,2.4V
XCL205/XCL207
XCL206/XCL207
(PWM)
(PWM/PFM)
VI
N
＝4.2V
2.4V
2.5
2.6
2.7
2.8
2.9
3.0
3.1
3.2
3.3
3.4
3.5
-50 -25 0 25 50 75 100
Ambient Temperature: Ta (℃)
VIN=3.6V
Oscillation Frequency : fosc(MHz)
(5) Supply Current vs. Ambient Temperature (6) Output Voltage vs. Ambient Temperature
0
5
10
15
20
25
30
35
40
-50 -25 0 25 50 75 100
Ambient Temperature: Ta (℃)
Supply Current : I
DD
(μA)
VIN=6.0V
4.0V
2.0V
1.5
1.6
1.7
1.8
1.9
2.0
2.1
-50 -25 0 25 50 75 100
Ambient Temperature: Ta (℃)
Output Voltage : V
OUT
(V)
VIN=3.6V
XCL206A183AR/XCL207A183AR XCL205A183AR/XCL206A183AR/XCL207A183AR
XCL205A183AR/XCL206A183AR/XCL207A183ARXCL205A183AR/XCL206A183AR/XCL207A183AR
XCL205A183AR/XCL206A183AR/XCL207A183AR XCL205A183AR/XCL206A183AR/XCL207A183AR

20/25
XCL205/XCL206/XCL207 Series
■TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
(7) UVLO Voltage vs. Ambient Temperature (8) CE "H" Voltage vs. Ambient Temperature
0.0
0.3
0.6
0.9
1.2
1.5
1.8
-50 -25 0 25 50 75 100
Ambient Temperature: Ta (℃)
UVLO Voltage : UVLO (V)
CE=V IN
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
-50 -25 0 25 50 75 100
Ambient Temperature: Ta (℃)
CE "H" Voltage : VCEH (V
)
VIN=5.0V
3.6V
2.4V
(9) CE "L" Voltage vs. Ambient Temperature (10) Soft Start Time vs. Ambient Temperature
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
-50 -25 0 25 50 75 100
Ambient Temperature: Ta (℃)
CE "L" Voltage : V
CEL
(V)
VIN=5.0V
3.6V
2.4V
0.0
1.0
2.0
3.0
4.0
5.0
-50 -25 0 25 50 75 100
Ambient Temperature: Ta (℃)
Soft Start Time : tss (ms)
VIN=3.6V
(11) "Pch / Nch" Driver on Resistance vs. Input Voltage (12) Rise Wave Form
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
0123456
Input Voltage : VIN (V)
Pch on Resistance
Nch on Resistance
Lx SW ON Resistance:RLxH,RLxL (Ω)
CE:0.0V⇒1.0V
XCL206B333
VIN=5.0V
IOUT=1.0mA
Time:100μs/div
VOUT
1ch
2ch
1ch:1V/div 2ch:1V/div
XCL205B333AR/XCL206B333AR/XCL207B333AR
XCL205A183AR/XCL206A183AR/XCL207A183AR
XCL205A183AR/XCL206A183AR/XCL207A183AR XCL205A183AR/XCL206A183AR/XCL207A183AR
XCL205A183AR/XCL206A183AR/XCL207A183AR XCL205A183AR/XCL206A183AR/XCL207A183AR
Time: 100μs /div