Linear Analog Devices LTC4040 Quick setup guide

1
DEMO MANUAL DC2118B
Rev. 0
DESCRIPTION
LTC4040
Battery Charger and Backup
Power Manager
Demonstration circuit 2118B is a combination step-down
battery charger and step-up battery backup regulator
using the LT C
®
4040 monolithic system power manager.
The DC2118B has an input voltage range from 4.8V to
5.5V with overvoltage protection (OVP) to 40V, as limited
by the external MOSFET. The input current is monitored to
prioritize the load up to the 2.5A threshold before charge
current is reduced.
Battery Charging
As initially configured, DC2118B is programmed for 2A
charge current limit when in charge mode. The charge
voltage is jumper-selectable in 8 discrete steps from
3.45V to 3.6V for LiFePO4chemistry or 3.95V to 4.1V for
Li-ion chemistry, according to the F2/F1/F0 programming
input settings.
The charge current limit is adjustable via the PROG pin
resistor. End-of-charge status is triggered by current
falling below C/8 and indicated by the CHRG LED. The
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PERFORMANCE SUMMARY
optional NTC input provides temperature fault detection
and status indicated by the FAULT LED. Charging can be
enabled/disabled with the ENCHG jumper.
Battery Backup
Following an input power failure, the circuit automatically
shifts to battery backup boost mode to regulate the VSYS
output rail. The backup mode system output voltage is ini -
tially programmed for 5V. The input power failure status
is indicated by the PFO LED.
If VSYS ever falls below the programmed reset threshold
voltage, the RST LED will change states to indicate the
need to reset the system and recharge the battery. Backup
regulation can be enabled/disabled with the ENBST jumper.
For convenience, all LEDs can be disabled with the LED
jumper to reduce the quiescent current of the system.
Design files for this circuit board are available.
Specifications are at TA= 25°C
PARAMETER CONDITIONS VALUE
Charge Mode
Input Voltage Range 4.8V to 5.5V
Overvoltage Protection Range Limited by Q1 BVDSS 5.5V to 40V
Input Current Limit R7 = 10mΩ 2.5A
Default Charging Voltage F2 = 1 (Li-Ion), F1 = 1, F0 = 1 4.10V
Charging Current RPROG = 1.00k 2.0A
Safety Timer Period F2 = 1 (Li-Ion) 4Hr
F2 = 0 (LiFePO4) 2Hr
Backup Mode
DCIN Input Power Fail Threshold R2 = 357k, R27 = 121k, DCIN Falling 4.8V
System Output Voltage R4 = 1.69M, R5 = 324k 5.0V
Backup Battery Voltage Range 2.7V to 5.0V
System Reset Threshold R4 = 1.69M, R5 = 324k, VSYS Falling 4.6V
Backup Boost Efficiency VBAT = 3.6V, ISYS = 2A, VOUT = 5V 89%

2
DEMO MANUAL DC2118B
Rev. 0
QUICK START PROCEDURE
Demonstration circuit 2118B is easy to set up to evalu-
ate the performance of LTC4040. Refer to Figure2 for
proper measurement equipment setup and follow the
procedurebelow.
1. The jumpers are set as below for a typical 4.1V charg-
ing application:
JP1 NTC INT
JP2 ENCHG ON
JP3 ENBST ON
JP4 F1 1
JP5 F0 1
JP6 LEDS ON
JP7 F2 1
2. With all power off, connect the input supply, system
load, and meters as shown in Figure3.
Charge Mode
3. Connect the battery as shown in Figure3 to charge at
4.1V, 2A. For alternate charge voltage settings, refer
to Table1.
4. Turn on the input power supply to evaluate charge
mode. Adjust the input voltage and current limit to
the desired value.
NOTE: While DC2118B is robust to overvoltage condi-
tions up to 40V on DCIN, DO NOT exceed this limit or
damage may occur to MOSFET Q1 and IC U1.
5. Turn on and adjust the system load as necessary.
Charging current will be limited when input current
exceeds 2.5A.
6. The CHRG LED will toggle off when the charge current
has dropped below 250mA. The timer will continue to
run and charging will continue until the timer period
ends. Multiple timer periods may be necessary to fully
charge a large capacity battery, such as the one used
to obtain Figure1.
7. If the battery voltage does not increase above the low
battery threshold during the precondition time or the
thermistor value exceeds the normal range, CHRG
will toggle off and FAULT will toggle on indicating a
badbattery.
Backup Mode
8. Turn off the input power supply to evaluate back-
upmode.
9. The PFO LED will toggle on indicating input power
failure.
10. Adjust the system load as necessary.
Figure1. Typical Battery Charge Cycle Figure2. Typical Battery Discharge Cycle
PERFORMANCE SUMMARY
TIME (Hrs)
0
I
BAT
(A)
2.25
2.00
1.50
1.00
0.50
1.75
1.25
0.75
0.25
0
V
BAT
+ V
CHRG
(V)
4.2
4.0
3.6
3.2
2.8
3.8
3.4
3.0
2.6
2.4
5 93 7
dc2118b F01
104 82 61
9600mAh Li-Ion
VIN = 5V
RPROG = 1.00k
TIMER
RESTART
TIMER
START
CHRG
VBAT
IBAT
C/8
TERMINATION
TIME (Hrs)
0:00
V
BAT
(V)
5
4
2
3
1
0
I
BAT
(A)
5
4
2
3
1
0
1:30
dc2118b F02
2:302:001:000:30
9600mAh Li-Ion
VSYS = 5V
ISYS = 2A
POWER
FAIL
BACKUP
STARTED
VSYS
IBAT VBAT

3
DEMO MANUAL DC2118B
Rev. 0
QUICK START PROCEDURE
Figure3. Proper Measurement Equipment Setup
11. Total backup runtime is based on battery capacity,
circuit efficiency, and system load. Figure2 shows
an example discharge curve with constant current
systemload.
12. WhenVSYS fallsbelow7.5%of the programmed value,
or 4.6V, then RST will toggle on.
Optional
1. Usean externalthermistorconnected betweenEXTNTC
and GND as shown in Figure3, with the NTC jumper,
JP1, set to EXT.
2. Change the setting of the ENCHG, JP2, or ENBST,
JP3, jumpers to enable/disable charging and backup
boostrespectively.
3. Monitor the PROG pin voltage for a scaled representa-
tion of the instantaneous charge current according to
the relationship:
IBAT =
2000 • V
PROG
RPROG
Where RPROG = R6 = 1kΩ.
4. MonitortheCLPROGpinvoltageforascaledrepresenta-
tion of the instantaneous total input current according
to the relationship:
IVIN =
V
CLPROG
32 • R
S
Where RS= R7 = 10mΩ.
5. All status LEDs can be disconnected to reduce the
quiescent current by setting the LEDS jumper, JP6
toOFF.
6. External VDD can be used by connecting to EXTVDD
and installing 0Ω for R16.
Table1. Battery Charge Voltage Jumper Settings
JP7 JP5 JP4
F2 = 1 (Li-Ion) F2 = 0 (LiFePO4) F1 F0
3.95 3.45 0 0
4.00 3.50 0 1
4.05 3.55 1 0
4.10 3.60 1 1

4
DEMO MANUAL DC2118B
Rev. 0
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 1 CIN1 CAP., X7R, 0.1µF, 10%, 50V, 0805 AVX, 08055C104KAT4A
2 2 COUT1, COUT2 CAP., X5R, 100µF, 20%, 10V, 1210 MURATA, GRM32ER61A107ME20L
3 1 C2 CAP., X7R, 2.2µF, 10%, 6.3V, 0805 MURATA, GRM21BR70J225MA01L
4 1 C3 CAP., X5R, 10µF, 20%, 10V, 0603 AVX, 0603ZD106MAT2A
5 2 C7, C9 CAP., X7R, 0.1µF, 10%, 10V, 0603 AVX, 0603ZC104KA72
6 1 L1 INDUCTOR, 2.2µH COILCRAFT, XAL5030-222ME
7 1 Q2 XSTR, MOSFET N-CHANNEL, 20-V VISHAY, SiS424DN-T1-GE3
8 1 R2 RES., 357k, 1/16W, 1%, 0402 VISHAY, CRCW0402357KFKED
9 1 R4 RES., 1.69MΩ, 1/16W, 1%, 0402 VISHAY, CRCW04021M69FKED
10 1 R5 RES., 324k, 1/16W, 1%, 0402 VISHAY, CRCW0402324KFKED
11 1 R6 RES., 1.00k, 1/10W, 1%, 0603 VISHAY, CRCW06031K00FKED
12 1 R7 RES., 0.01Ω, 1/4W, 1%, 1206 VISHAY, WSL1206R0100FEB
13 1 R8 RES., 10k, 1/16W, 1%, 0402 VISHAY, CRCW040210K0FKED
14 1 R11 RES., 0Ω JUMPER, 0402 VISHAY, CRCW04020000Z0ED
15 1 R25 RES., 1Ω, 1/8W, 5%, 0805 VISHAY, CRCW0805100RJNEA
16 1 R27 RES., 121k, 1/16W, 1%, 0402 VISHAY, CRCW040260K4FKED
17 1 U1 I.C., LTC4040EUFD ANALOG DEVICES, LTC4040EUFD#PBF
Additional Demo Board Circuit Components
1 0 C4, C6 CAP., 0402 OPT
2 1 C5 CAP., X5R, 0.1µF, 10%, 10V, 0402 MURATA, GRM155R71A104KA01J
3 1 D1 DIODE, SCHOTTKY NXP, BAT46WJ
4 1 D3 DIODE, LED, SMT, RED, 0603 LITE-ON, LTST-C193KRKT-5A
5 2 D4, D5 DIODE, LED, SMT, ORANGE, 0603 LTIE-ON, LTST-C193KFKT-5A
6 1 D6 DIODE, LED, SMT, GREEN, 0603 LITE-ON, LTST-C193KGKT-5A
7 1 Q1 XSTR, MOSFET N-CHANNEL, 40-V VISHAY, SiS488DN-T1-GE3
8 1 RNTC RES., 10k, 1/16W, 1%, 0402 VISHAY, CRCW040210K0FKED
9 1 R1 RES., 6.2k, 1/8W, 5%, 0805 VISHAY, CRCW08056K20JNEA
10 0 R12, R13, R16 RES., 0402 OPT
11 4 R21-R24 RES., 390Ω, 1/16W, 5%, 0402 VISHAY, CRCW0402390RJNED
Hardware: For Demo Board Only
1 18 E1, E2, E4-E19 TEST POINT, TURRET, 0.094" MILL-MAX, 2501-2-00-80-00-00-07-0
2 7 JP1-JP7 3 PIN JUMPER, 2mm SAMTEC TMM-103-02-L-S
3 7 XJP1-XJP7 SHUNT, 2mm SAMTEC 2SN-BK-G
4 4 STAND-OFF STAND-OFF, NYLON KEYSTONE, 8834(SNAP ON)

5
DEMO MANUAL DC2118B
Rev. 0
Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog
Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications
subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
SCHEMATIC DIAGRAM
5
5
4
4
3
3
2
2
1
1
D D C C B B A A
VSYS GND
VBAT GND
GND DCIN
EXTNTC
4.8V - 5.5V
BSTOFF
CHGOFF
F2=1(LI-ION) F2=0(LIFEP04) F1 F0
3.95V 3.45V 0 0 4.00V 3.50V 0 1 4.05V 3.55V 1 0 4.10V 3.60V 1 1
3.
FAULT
PFO RST
CHRG
CLPROG
NOTES: UNLESS OTHERWISE SPECIFIED,
1. ALL RESISTORS ARE 0402, 1%.
EXTVDD
2. ALL CAPACITORS ARE 0603, X7R.
OV PROTECTION
GND
GND
5V IN BACKUP
2A CHARGE
4. LIMITED BY Q1 VDS RATING.
SEE NOTE 4
PROG
(DEFAULT)
REV
Z P
DESCRIPTION DATE
REVISION HISTORY
06/13/19
ECO
1PROD
APPROVED
VIN
VIN
VSYS
VDD
VDD VDD VDD VDD
VSYS
VDD
VDD
DATE:
IC NO.
SHEET OF
TITLE: DEMO CIRCUIT SCHEMATIC,
APPROVALS
PCB DES. APP ENG. Phone: [phone]
Milpitas, CA 95035
1630 McCarthy Blvd.
For ADI Customer Use Only
CUSTOMER NOTICE
ANALOG DEVICES INC. HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT ANALOG DEVICES INC. APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO ANALOG DEVICES INC. AND SUPPLIED FOR USE WITH ANALOG DEVICES INC. PARTS.
SCALE = NONE
SIZE:
SKU NO. SCHEMATIC NO. AND REVISION:
PCA BOM: PCA ASS'Y:
www.analog.com
11
Z P
LTC4040EUFD24
DC2118B
700-DC2118B_REV01
705-DC2118B_REV01
N/A
Thursday, June 13, 2019
710-DC2118B_REV01
BATTERY CHARGER BACKUP POWER MANAGER
M I
DATE:
IC NO.
SHEET OF
TITLE: DEMO CIRCUIT SCHEMATIC,
APPROVALS
PCB DES. APP ENG. Phone: [phone]
Milpitas, CA 95035
1630 McCarthy Blvd.
For ADI Customer Use Only
CUSTOMER NOTICE
ANALOG DEVICES INC. HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT ANALOG DEVICES INC. APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO ANALOG DEVICES INC. AND SUPPLIED FOR USE WITH ANALOG DEVICES INC. PARTS.
SCALE = NONE
SIZE:
SKU NO. SCHEMATIC NO. AND REVISION:
PCA BOM: PCA ASS'Y:
www.analog.com
11
Z P
LTC4040EUFD24
DC2118B
700-DC2118B_REV01
705-DC2118B_REV01
N/A
Thursday, June 13, 2019
710-DC2118B_REV01
BATTERY CHARGER BACKUP POWER MANAGER
M I
DATE:
IC NO.
SHEET OF
TITLE: DEMO CIRCUIT SCHEMATIC,
APPROVALS
PCB DES. APP ENG. Phone: [phone]
Milpitas, CA 95035
1630 McCarthy Blvd.
For ADI Customer Use Only
CUSTOMER NOTICE
ANALOG DEVICES INC. HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT ANALOG DEVICES INC. APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO ANALOG DEVICES INC. AND SUPPLIED FOR USE WITH ANALOG DEVICES INC. PARTS.
SCALE = NONE
SIZE:
SKU NO. SCHEMATIC NO. AND REVISION:
PCA BOM: PCA ASS'Y:
www.analog.com
11
Z P
LTC4040EUFD24
DC2118B
700-DC2118B_REV01
705-DC2118B_REV01
N/A
Thursday, June 13, 2019
710-DC2118B_REV01
BATTERY CHARGER BACKUP POWER MANAGER
M I
E14
C7 0.1uF
0603
JP4
1 0
F0
1 3 2
Q2
SiS424DN
3 1 2
4
5 6 7 8
E4
JP2
OFF
ON
ENCHG
1 3 2
R21 390 5%
D3 RED D5
ORG
R25 1 5% 0805
D4 ORG
R1 6.2k 0805
R5 324k
R22 390 5%
JP3
OFF
ON
ENBST
1 3 2
COUT1
100uF
10V 1210
E12
RNTC
10k
E8
JP6
ON OFF
LEDS
1 3 2
R23 390 5% R12
OPT
E7
R6
1.00k 0603
1%
Q1 SiS488DN
3 1 2
4
5 6 7 8
E10
R2
357k 1%
U1
LTC4040EUFD
FAULT
9
VIN 6
F1
13
F0
14
F2
12
PFI
19
BSTFB 18
SW 22 SW 21
2PROG
CLPROG
3
VSYS 1
VSYS 24
BAT 23
CHGOFF
4
BSTOFF
5
RST
11
CLN 7
RSTFB 10
OVSNS 16
NTC 17
CHRG
8
IGATE 15
PFO
20
25
GND
E2
R24 390 5%
C5
0.1uF
R16
OPT
D6 GRN
E9
R8
10k
C9
0.1uF
10V
R27
121k 1%
E5
CIN1 0.1uF 50V 0805
C4
OPT
L1
2.2uH
COILCRAFT
XAL5030-222ME
R7
0.01 1%
1206
D1 BAT46WJ
E13
JP1
INT EXT
NTC
1
3
2
E15
R13 OPT
R4 1.69M
E16
C3
10uF, 10V
0603
E1
JP5
1
0
F1
1 3 2
C2
2.2uF 6.3V
0805
JP7
1 0
F2
1 3 2
E11
E18
R11
0
E19
E6
SEE NOTE 3
COUT2
100uF
10V 1210
E17
C6
OPT

6
DEMO MANUAL DC2118B
Rev. 0
 ANALOG DEVICES, INC. 2019
10/19
www.analog.com
ESD Caution
ESD (electrostatic discharge) sensitive device. Charged devices and circuit boards can discharge without detection. Although this product features patented or proprietary protection
circuitry, damage may occur on devices subjected to high energy ESD. Therefore, proper ESD precautions should be taken to avoid performance degradation or loss of functionality.
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