Linear Analog Devices DC2721A-B Quick setup guide

1
Rev.A
DEMO MANUAL
DC2721A-B
DESCRIPTION
LTM4625
Tiny 3A DC/DC Inverting Buck-Boost
µModule Regulator
Demonstration circuit 2721A-B features the LTM
®
4625EY
µModule
®
regulator, a tiny high performance high effi-
ciency step-down regulator configured as an inverting
buck-boost regulator. DC2721A-B has an operating input
voltage range of 4V to 15V and is able to provide an out-
put current of up to 3A. The output voltage can be pro-
grammed from –0.6V and –5.5V. The LTM4625EY is a
complete DC/DC point of load regulator in a thermally
All registered trademarks and trademarks are the property of their respective owners.
BOARD PHOTO
enhanced 6.25mm ×6.25mm ×5.01mm BGA package
requiring only a few input and output capacitors. The
LTM4625 data sheet must be read in conjunction with
this demo manual for working on or modifying demo cir-
cuit 2721A-B.
Design files for this circuit board are available .
PERFORMANCE SUMMARY
Specifications are at TA= 25°C
PARAMETER CONDITIONS/NOTES VALUE
Input Voltage Range 4V to 15V
Output Voltage VOUT Jumper Selectable –0.9VDC, –5.2VDC
Maximum Continuous Output Current Derating is Necessary for Certain Operating Conditions.
See Data Sheet for Details
3ADC
Default Operating Frequency 1MHz
Efficiency VIN = 12V, VOUT = –2.5V, IOUT = 3A 84% See Figure 2

2
Rev.A
DEMO MANUAL
DC2721A-B
QUICK START PROCEDURE
Demonstration circuit 2721A-B is an easy way to evaluate
the performance of the LTM4625EY. Please refer to Figure
1 for test setup connections and follow the procedure
below.
1. With power off, place the jumpers in the following posi-
tions for a typical –0.9VOUT application:
JP7 JP5 JP1
RUN MODE VOUT Select
ON CCM –0.9V
2.Before connecting input supply, load and meters, pre-
set the input voltage supply to be between 4V to 15V.
Preset the load current to 0A.
3.With power off, connect the load, input voltage supply
and meters as shown in Figure 1.
4.Turn on input power supply. The output voltage meter
should display the selected output voltage ± 2%.
5.Once the proper output voltage is established, adjust
the load current within the 0A to 3A range and observe
the load regulation, efficiency, and other parameters.
Output voltage ripple should be measured across C12
with a BNC cable terminated into 50Ω and an oscil-
loscope.
6.To observe increased light load efficiency place the
mode pin jumper (JP5) in the DCM position.
7.Level shifting circuits are provided for PGOOD, CLKIN
and RUN signals. The CLKIN turret E6 can be connected
to a ground referenced clock with amplitude up to 3.3V
for optional external clock synchronization. The PGOOD
turret E8 provides a ground referenced 3.3V PGOOD
signal.
8.Note that CLKOUT and TRACK signals are not level
shifted and are referenced to –VOUT. If ground refer-
enced CLKOUT output and TRACK input signals are
desired, external level shifting circuits for these pins
are necessary.

3
Rev.A
DEMO MANUAL
DC2721A-B
QUICK START PROCEDURE
Figure 1. Test Setup
LOAD
0A TO 3A
VIN
DC2721ab F01
+
+
–
–
A
+–
V
+
–
V
+
–
A
+–

4
Rev.A
DEMO MANUAL
DC2721A-B
QUICK START PROCEDURE
Figure 2. Measured Supply Efficiency at 12VIN and 5VIN
OUTPUT CURRENT (A)
0
EFFICIENCY (%)
81
79
77
75
73
71
69
67
65
63
61
59
57
83
87
89
85 –0.9V, 1MHz
–1V, 1MHz
–1.5V, 1MHz
–2.5V, 1MHz
–3.3V, 1MHz
–5.2V, 1MHz
55 21.51
dc2721ab F02a
30.5 2.5
CCM = 12VIN
OUTPUT CURRENT (A)
0
EFFICIENCY (%)
74
76
78
82
80
84
86
88
–0.9V, 1MHz
–1V, 1MHz
–1.5V, 1MHz
–2.5V, 1MHz
–3.3V, 1MHz
–5.2V, 1MHz
72 21.51
dc2721ab F02b
30.5 2.5
CCM = 5VIN

5
Rev.A
DEMO MANUAL
DC2721A-B
QUICK START PROCEDURE
Figure 3. Measured Load Transient Response
(0A to 1.5A Load Step)
Figure 4. Measured VOUT Ripple
Figure 5. Measured Case Temperature
VOUT = 20mV/DIV
IOUTSTEP = 2A/DIV 1.5A DC
VOUT = 2mV/DIV
VIN (V) VOUT (V) COUT
12 –0.9 1 ×100µF/6.3V +
1 ×22µF/6.3V +
1 ×47µF/6.3V
VIN (V) VOUT (V) IOUT (A) COUT
12 –0.9 3 1 ×100µF/6.3V +
1 ×22µF/6.3V +
1 ×47µF/6.3V
VIN (V) VOUT (V) ILOAD (A) fSW (MHz) TAMBIENT (C) FORCED AIRFLOW (LFM)
12 –0.9 3 1 25 0

6
Rev.A
DEMO MANUAL
DC2721A-B
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 1 C1 CAP., 2.2uF, X5R, 10V, 10%, 0603 MURATA, GRM188R61A225KE34D
2 1 C2 CAP., 10uF, X5R, 25V, 10%, 0805 AVX, 08053D106KAT2A
3 1 C12 CAP., 100uF, X5R, 6.3V, 20%,1210 MURATA, GRM32ER60J107ME20L
4 1 C16 CAP., 22uF, X5R, 6.3V, 20%, 0805 TDK, C2012X5R0J226M125AC
5 1 C20 CAP., 47uF, X5R, 6.3V, 20%,1206 TDK, C3216X5R0J476M160AC
6 1 R4 RES., 121k, 1/10W, 1%, 0603 VISHAY, CRCW0603121KFKEA
7 1 U1 I.C., STEP-DOWN µMODULE REGULATOR, BGA-25 ANALOG DEVICES, LTM4625EY#PBF
Additional Demo Board Circuit Components
1 0 C3,C5 (OPT) CAP., OPTION, 1206 OPT
2 0 C7,C19 (OPT) CAP., OPTION, 0603 OPT
3 1 C8 CAP., 100pF, X7R, 50V, 10%, 0603 AVX, 06035C101KAT2A
4 2 C9,C15 CAP., 0.1uF, X5R, 25V, 10%, 0603 AVX, 06033D104KAT2A
5 1 C10 CAP., 22uF, TANT. POLY., 25V, 20%, 7343 PANSONIC, 25TQC22MV
6 0 C11,C14 (OPT) CAP., OPTION, 1210 OPT
7 1 C13 CAP., 22uF, X5R, 16V, 10%, 1206 MURATA, GRM31CR61C226ME15L
7 1 C23 CAP., 2.2uF, X5R, 10V, 10%,1206 AVX, 1206ZD225KAT2A
7 1 C24 CAP., 1uF, X7R, 25V, 10%,1206 AVX, 12063C105KAT2A
8 0 C17 (OPT) CAP., OPTION, 7343 OPT
9 2 C21,C22 CAP., 0.01uF, X7R, 16V, 10%, 0603 AVX, 0603YC103KAT2A
10 1 D1 DIODE, ZENER, SOD323 CENTRAL SEMI., CMDZ5230B-L
11 1 D2 DIODE, SCHOTTKY, SOD323 CENTRAL SEMI., CMDSH2-3
12 1 D3 DIODE, SCHOTTKY, SOD323 CENTRAL SEMI., CMDSH2-4L
13 1 Q1 XSTR., MOSFET, N-CHAN., 20V, TSOP-6 VISHAY, Si3900DV-T1-GE3
14 1 Q2 XSTR., PNP 40V 0.2A SOT-23 ON SEMI., MMBT3906LT1G
15 0 R1,R2,R12 (OPT) CAP., OPTION, 0603 OPT
16 1 R5 RES., 7.87k, 1/10W, 1%, 0603 VISHAY, CRCW06037K87FKEA
17 5 R8,R18,R19,R20,R21 RES., 100k, 1/10W, 1%, 0603 VISHAY, CRCW0603100KFKEA
18 1 R9 RES., 15k, 1/10W, 1%, 0603 VISHAY, CRCW060315KF0KEA
19 1 R10 RES., 10k, 1/10W, 1%, 0603 VISHAY, CRCW060310K0FKEA
20 1 R11 RES., 10 OHMS, 1/10W, 1%, 0603 VISHAY, CRCW060310R0FKEA
21 2 R13,R23 RES., 0 OHM, 1/10W, 0603 VISHAY, CRCW06030000Z0EA
22 2 R17,R22 RES., 1k, 1/10W, 1%, 0603 VISHAY, CRCW06031K0FKEA
23 1 U2 IC, REG LDO 3.3V 0.1A DFN8 ANALOG DEVICES, LT3060EDC-3.3#TRPBF
Hardware: For Demo Board Only
1 8 E1,E2,E3,E4,E5,E6,E7,E8 TEST POINT, TURRET, 0.094", MTG. HOLE MILL MAX 2501-2-00-80-00-00-07-0
2 2 JP1,JP2 CONN., HEADER, 1X2, 2mm WURTH ELEKTRONIK, 62000211121
3 1 JP5 CONN., HEADER, 2X2, 2mm WURTH ELEKTRONIK, 62000421121
4 1 JP7 CONN., HEADER, 1X3, 2mm WURTH ELEKTRONIK, 62000311121
5 4 XJP1,XJP5,XJP6,XJP7 CONN., SHUNT, FEMALE, 2 POS, 2mm WURTH ELEKTRONIK, 60800213421
6 4 J1,J2,J3,J4 CONN., BANANA JACK, FEMALE, THT, NON-
INSULATED, SWAGE, 0.218"
KEYSTONE, 575-4
7 4 MH1,MH2,MH3,MH4 STANDOFF, NYLON, SNAP-ON , 0.375" KEYSTONE, 8832

7
Rev.A
DEMO MANUAL
DC2721A-B
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
4V - 15V
GND
ON
OFF
PGOOD
GND
*
C10 IS AN OPTIONAL CAPACITOR. IT IS INSERTED TO DAMPEN THE (POSSIBLE) RINGING VOLTAGE DUE TO LONG INPUT LEADS. ON A NORMAL, TYPICAL PCB, WITH SHORT TRACES, THE CAPACITOR IS NOT NEEDED.
-VOUT
TRACK
-0.9V -5.2V
VIN
BUCK-BOOST DC/DC µMODULE REGULATOR
NOTE: UNLESS OTHERWISE SPECIFIED
1. ALL CAPACITORS AND RESISTORS ARE 0603
CLKOUT CLKIN
VERSION U1
- A
- B
LTM4623EV LTM4625EY
**
25V
Iout 2A 3A
GND
2. VIN + |VOUT| SHOULD NOT EXCEED 20V
TINY, HIGH EFFICIENCY, 2A INVERTING
FOR |-VOUT| > 3.3V, 2MHz SWITCHING FREQUENCY IS RECOMMENDED
**
CLKOUT, TRACK SIGNALS ARE NOT LEVEL SHIFTED (REFERENCED TO -VOUT)
INTVCC
VIN
INTVCC
VIN V_3.3
PG
PG
V_3.3
-VOUT
-VOUT
-VOUT-VOUT
-VOUT
-VOUT
-VOUT
-VOUT
-VOUT
-VOUT
-VOUT
-VOUT
-VOUT
INTVCC
INTVCC
SIZE DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: [phone]
Milpitas, CA 95035 Phone: [phone] McCarthy Blvd. LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY 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 LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
SCALE = NONE
www.linear.com
2
LTM4623EV / LTM4625EY
Wednesday, August 15, 2018 1 1
LT
SAM Y.
N/A
DEMO CIRCUIT 2721A(A,B)
SIZE DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: [phone]
Milpitas, CA 95035 Phone: [phone] McCarthy Blvd. LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY 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 LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
SCALE = NONE
www.linear.com
2
LTM4623EV / LTM4625EY
Wednesday, August 15, 2018 1 1
LT
SAM Y.
N/A
DEMO CIRCUIT 2721A(A,B)
SIZE DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: [phone]
Milpitas, CA 95035 Phone: [phone] McCarthy Blvd. LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY 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 LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
SCALE = NONE
www.linear.com
2
LTM4623EV / LTM4625EY
Wednesday, August 15, 2018 1 1
LT
SAM Y.
N/A
DEMO CIRCUIT 2721A(A,B)
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
SAM Y.
PRODUCTION2 08-15-2018
_
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
SAM Y.
PRODUCTION2 08-15-2018
_
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
SAM Y.
PRODUCTION2 08-15-2018
_
E3
E5
C11 OPT 1210
R23
0
D1
CMDZ5230B-L
C13
1206
22uF
J2 GND
E6
JP5
MODE
DCM CCM
1 2 3 4
E1
JP1
R17 1K 1%
R18 100K 1%
D2 CMDSH2-3
C1
2.2uF
10V
J1
VIN
E2
R5
7.87K
R13
0
+
C17
OPT
C3
OPT 1206
C8 100pF
E4
JP7 RUN
13
2
R21 100K
C20
47uF 1206
C16 22uF 6.3V 0805
R2
OPT
E8
R8 100K
R9 15K
R19 100K
Q2
MMBT3906
2
1
3
R20 100K
R1
OPT
U2
LT3060EDC-3.3
GND
8
ADJ 2
1
REF/BYP
SHDN
7
OUT 3
VIN
5
GND
9
OUT 4
VIN
6
C7
OPT
Q1B
Si3900DV
3
2 4
C21
0.01uF
C5
OPT
6.3V
1206
C19 OPT
C24 1206 1uF
J4 -VOUT
**
U1
FREQ
A4
PHMODE
B2
MODE
C4
FB
B1
TRACK/SS
A2
COMP
A1
RUN
A3
PGOOD C2
VOUT C1
PGND
B3
VIN D5
SVIN C5
INTVCC E4
SGND
B4
CLKOUT B5
CLKIN A5
VIN E5
VOUT D1 VOUT D2 VOUT E1 VOUT E2
PGND
C3
PGND
D3
PGND
D4
PGND
E3
C15 0.1uF 25V
J3 GND
C14 OPT 1210
Q1A Si3900DV
1
5 6
R12 OPT
C12 100uF
6.3V
1210
C2
10uF
25V
0805
E7
R4
121K
R22
1K
C23 1206 2.2uF
C9 0.1uF 25V
+
C10
22uF
25V
*
R10 10K 1%
C22
0.01uF
D3
CMDSH2-4L
JP2
R11
10
VIN

8
Rev.A
DEMO MANUAL
DC2721A-B
 ANALOG DEVICES, INC. 2017–2018
10/18
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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