Analog Devices EVAL-LTM4702-AZ Quick setup guide

1
DEMO MANUAL
EVAL-LTM4702-AZ
Rev. 0
DESCRIPTION
LTM4702EY
16V, 8A Step-Down μModule
Regulator with Low Noise Reference
Evaluation board EVAL-LTM4702-AZ is a step-down
DC/DC switching converter featuring the LTM
®
4702
μModule
®
regulator. The evaluation board is designed to
deliver 8A maximum output current from a 4V to 16V
input. The LTM4702 employs Silent Switcher
®
architec-
ture with internal hot loop bypass capacitors to achieve
both low EMI and high efficiency. The LTM4702 contains
a current mode regulator IC, power inductor, and a modest
amount of input and output capacitance. A single resis-
tor(R3) sets the output voltage, providing unity gain oper-
ation over the output range, resulting in virtually constant
output noise independent of outputvoltage.
The EVAL-LTM4702-AZ evaluation board default switch-
ing frequency is 800kHz. An external resistor is placed
from RT pin to GND (R7) to set the switching frequency.
SYNC pin programs three different operating modes
(JP1 jumper):select PULSE for pulse-skipping mode
All registered trademarks and trademarks are the property of their respective owners.
BOARD PHOTO
with improved efficiency at light loads;select FCM for
forced continuous mode operation where fixed frequency
operation is more critical than low current efficiency and
where the lowest output ripple is desired;select SYNC to
synchronize to an external clock signal.
The RUN terminal can be used to set the LTM4702 in
shutdown mode. The power good output (PG) will be low
when the output voltage is outside of the ±7.5% regula-
tion window. When the power good feature is used, set
the PGSET resistor (R1) value according to the regulator
output voltage.
The LTM4702 data sheet gives a complete description of
the operation and application information. The data sheet
must be read in conjunction with this evaluation board.
Design files for this circuit board are available.
Part marking is either ink mark or laser mark

2
DEMO MANUAL
EVAL-LTM4702-AZ
Rev. 0
QUICK START PROCEDURE
Evaluation board EVAL-LTM4702-AZ is easy to set up to
evaluate the performance of the LTM4702. See Figure1
for the proper measurement equipment setup and follow
the procedure below.
1. With power off, connect the input power supply to V
IN
(4V to 16V) and GND (input return).
2. Connect the 1V output load between VOUT and GND
(Initial load: no load).
3. Connect the DVMs to the input and output. Set default
jumper position:
JP1: FCM ON
JP2: 120 PS ON
PERFORMANCE SUMMARY
Specifications are at TA= 25°C
PARAMETER CONDITIONS MIN TYP MAX VALUE
Input Voltage Range 4 16 V
Output Voltage VIN = 4V to 16V, IOUT = 0A to 8A 1 ±2% V
Maximum Output Current VIN = 4V to 16V 8 A
Typical Switching Frequency 800 kHz
Typical Efficiency VIN = 12V, IOUT = 8A 80.5 %
4. Turn on the input power supply and check for the
proper output voltage. VOUT should be 1V ±2%.
5. Once the proper output voltage is established, adjust
the load within the operating range and observe
the output voltage regulation, efficiency, and
otherparameters.
NOTE: When measuring the output or input voltage rip-
ple, do not use the long ground lead on the oscilloscope
probe. See Figure2 for the proper scope probe technique.
Short, stiff leads may be soldered to the (+) and (–) ter-
minals of an output capacitor. The probe’s ground ring
needs to touch the (–) lead, and the probe tip needs to
touch the (+) lead.

3
DEMO MANUAL
EVAL-LTM4702-AZ
Rev. 0
TYPICAL PERFORMANCE CHARACTERISTICS
Figure1. Proper Measurement Equipment Setup
Figure2. Measuring Output Ripple Voltage
+ –
VOUT GND
COUT
eval-ltm4702-az F02
AARRTTFFIILLMM--QQSSGG
AARRTTFFIILLMM--QQSSGG

4
DEMO MANUAL
EVAL-LTM4702-AZ
Rev. 0
TEST RESULTS
1.0V
OUT
AT 800kHz
1.5V
OUT
AT 1.2MHz
2.5V
OUT
AT 1.4MHz
3.3V
OUT
AT 1.7MHz
5.0V
OUT
AT 1.9MHz
LOAD CURRENT (A)
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
60
65
70
75
80
85
90
95
100
EFFICIENCY (%)
eval-ltm4702-az F03
Figure3. Efficiency vs Load Current, VIN = 12V
eval-ltm4702-az F04
2μs/DIV
VOUT
AC-COUPLED
10mV/DIV
eval-ltm4702-az F05
40μs/DIV
4A LOAD STEP
2A/DIV
IOUT: 4A TO/FROM 8A/DIV
VOUT
AC-COUPLED
20mV/DIV
Figure4. Output Voltage Ripple (12VIN, 1V, 8A Output) Figure5. Load Step Transient Test (VIN = 12V, VOUT = 1V)
Figure6. Thermal Image, VIN = 12V, 1V, 8A Output (No Heat Sink, No Forced Airflow)

5
DEMO MANUAL
EVAL-LTM4702-AZ
Rev. 0
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 1 C1 CAP., ALUM POLY HYBRID, 100μF, 25V, 20%,
6.3mm × 7.7mm, AEC-Q200
PANASONIC, EEHZC1E101XP
2 1 C10 CAP. CER, 1μF, 25V, 10%, X7R, 0603, AEC-Q200 TDK, CGA3E1X7R1E105K080AC
3 2 C11, C12 CAP. CER, 22μF, 25V, 10%, X7R, 1210 MURATA, GRM32ER71E226KE15L
4 4 C13, C14, C15, C16 CAP. CER, 10μF, 6.3V, 20%, X7S, 0603 TDK, C1608X7S0J106M080AC
5 2 C6, C17 CAP. CER, 100μF, 10V, 20%, X5R, 1206, LOW ESR TDK, C3216X5R1A107M160AC
6 3 C18, C23, C24 CAP. CER, 0.1μF, 25V, 10%, X7R, 0603 SAMSUNG, CL10B104KA8NNNC
7 1 C19 CAP. CER, 2200pF, 16V, 10%, X7R, 0603 VISHAY, VJ0603Y222KXJCW1BC
8 1 C2 CAP. CER, 22μF, 25V, 20%, X5R, 0805, AEC-Q200 MURATA, GRT21BR61E226ME13L
9 2 C21, C22 CAP FEEDTHRU, 4.7μF, 10V, 20%, 0805, 3-TERMINAL MURATA, NFM21PC475B1A3D
10 3 C3, C4, C5 CAP. CER, 2.2μF, 25V, 10%, X5R, 0603 MURATAGRM188R61E225KA12D
11 1 C9 CAP. CER, 1μF, 10V, 10%, X7R, 0805 AVX, 0805ZC105KAT2A
12 1 FB1 IND., CHIP FERRITE BEAD, 0.015Ω, DCR, 5.1A WURTH ELEKTRONIK, 74279228600
13 1 L1 IND., POWER SHIELDED WIREWOUND, 0.0073Ω, DCR, 9.5A WURTH ELEKTRONIK, 744373240022
14 1 R1 RES., SMD, 49.9k, 1%, 1/10W, 0603, AEC-Q200 PANASONIC, ERJ-3EKF4992V
15 1 R10 RES., SMD, 0Ω, 1%, 1/4W, 1206 VISHAYWSL, 120600000ZEA9
16 1 R12 RES., 1.2k, 1%, 1/10W, 0603, AEC-Q200 VISHAY, CRCW06031K20FKEA
17 1 R13 RES., SMD, 0Ω, JUMPER, 1/10W, 0603, AEC-Q200,
PRECISION POWER
VISHAY, CRCW06030000Z0EA
18 2 R2, R5 RES., SMD, 100k, 1%, 1/10W, 0603, AEC-Q200 PANASONIC, ERJ-3EKF1003V
19 1 R3 RES., SMD, 10k 1%, 1/10W, 0603, AEC-Q200 PANASONIC, ERJ-3EKF1002V
20 1 R4 RES., SMD, 1Ω, 1%, 1/10W, 0603 YAGEO, RC0603FR-071RL
21 1 R7 RES., 137k, 1%, 1/10W, 0603, AEC-Q200 VISHAY, CRCW0603137KFKEA
22 1 U1 IC-ADI, 18VIN, 8A, Silent Switcher, μModule REGULATOR ANALOG DEVICES, LTM4702EY#PBF
Additional Demo Board Circuit Components
18 0 C7, C8, C20, C25 OPTIONAL CAPACITOR
19 0 R6, R8, R9, R11 OPTIONAL RESISTOR
20 0 L2 OPTIONAL INDUCTOR
Hardware: For Demo Board Only
24 2 J1, J2 CONN., PCB, SMA, FEMALE JACK, RCP, 50Ω MOLEX, 732511350
26 2 JP1, JP2 CONN., HDR, MALE, 2 × 3, 2mm, VERT, ST, THT WURTH ELEKTRONIK, 62000621121
27 4 STANDOFF, BRD, SPT, SNAP-FIT, 9.53mm LENGTH,
EVAL BOARD MTG
KEYSTONE, 8832
28 2 CONN., SHUNT, FEMALE, 2-POS, 2mm KEYSTONE, 8831
29 1 PCBs FAB PRINTED CIRCUIT BOARD WURTH ELEKTRONIK, 702931000

6
DEMO MANUAL
EVAL-LTM4702-AZ
Rev. 0
SCHEMATIC DIAGRAM
VOUT
OPT 0603
0805
DGND_A CONNECTED TO GROUND
AT C3 ON PRIMARY SIDE
SYNC
SHUNTS FOR JP1,JP2
INSTALLED IN POSITION B
120 PS
GND
1206
VIN SENSE
PG
CLK OUT
GND
OPT 0603
1210
VEMI
LTM4702EY
RUN
GND
GND
1210
SENSE GND
OPT 0603
1V/8A
02-23-23PRODUCTION ZCB
4V-16V
VIN
4V-16V
VO SENSE
0805
TSENSE+
SENSE GND
SYNC
180 PS
PH MODE
SYNC
PULSE
90 PS
FCM
1206
OPT 0603
TSENSE-
OPT 0603
OPT 0603
OPT 0603
OPT
PANASONIC
DGND-AGND CONNECTED TOGETHER ON LAYER 3
C16 ON PRIMARY SIDE
DGND_B CONNECTED TO GROUND AT
OPT 0603
16V,8A uMODULE REGULATOR with LOW NOISE REFERENCE HW TYPE : Customer Evaluation
Product(s): LTM4702-AZ
<DESIGN_VIEW>
1 1
1:1
B
02_065996
-
49.9K
R1
R10
S2751-46R
R8
E12
DNI
R11
L2
0
10UF
744373240022
6.3V
S2751-46R
S2751-46R
C8
CLKOUT
D3
PG
C7
E7
S2751-46R
VOUT
S2751-46R
S2751-46R
1
74279228600
VEMI
C12
1UF
E17
25V
C10
C22
NFM21PC475B1A3D
100UF
6.3V
732511350
P
62000621121
C11
22UF
25V
FB1
3
DNI
4.7UF
E3
R6
25V
22UF
C2
25V
0.1UF
2.2UF
C5
DNI
C1
E4 2200PF
137K
INTVCC
S2751-46R S2751-46R
PHMODE COMPB SET TSENSE+ TSENSE-
62000621121
5019
25V 10V
100UF25V
2.2UF
10UF 6.3V
VOUT
100K
NFM21PC475B1A3D
DUTVOUT
25V
10UF
VOUT 5019
6.3V
10UF
4.7UF
25V
22UF
0.22UH
0.1UF
EEHZC1E101XP
100UF
SYNC
VIN
RUN SVN
SW
VIN
INTVCC
0
100K
5019
1
COMPA
10K
RT
2.2UF
25V
S2751-46R
732511350
0.1UF
VOSNS PGSET
25V
5019
S2751-46R
1UF
S2751-46R
S2751-46R
S2751-46R
10V
DNI
1.2K
DNI
25V
C4
N
C20
C18
E1
1
E5
1
E10
1
E6
1
E9
1
1
E13
1
E14
1
E15
1
J2
1
2345
J1
1
2345
R2
R3
R4R5
C3
C23
1
R9
U1
D2
F7
C2 C3
B4
C4
C5
C6
C7
D4
D5
D6
D7
E4
E5
E6
E7
F4
F5
G4
G5
G7
F2 E2
E3
D1 C1
E1 A4
F6
G6
B1 B2 A5 A6 A7 B5 B6 B7
F1 A1 A2 A3 B3 F3 G1 G2 G3
E11
1
1 2
L1
C6
E16
C17
1
C24
1
G1 G2
1
C21
G1 G2
1 3
E8
1
1
E2
1
R13
C9
C19
C25
R12
R7
C14C13
C15 C16
JP2
1 2 3 4 5 6
JP1
1 2 3 4 5 6
D
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IT IS NOT TO BE REPRODUCED OR COPIED, IN WHOLE OR
DRAWING NO.
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SCALE
D
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SIZE
D
REV
SHEET
1
1
A
2
3
4
3
5
8
D
7
67
8
A
B
CC
D
5
4
APPROVED
B
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DESCRIPTION
REVISIONS
OF
OL G
E
OWNED OR CONTROLLED BY OWNED ANALOG DEVICES.
E
AN
V
OF ANALOG DEVICES.
SCHEMATIC
S
PTD ENGINEER DESIGN VIEW
REV DATE
PHMODE
GND
SYNC
GND
GND
VOUT VOUT VOUT
CLKOUT
SW
GND
GND
VOUT
PG
VOSNS
GND
GND
GND
GND
PGSET
SET
GND
GND
GND
GND
INTVCC
AGND
RT
GND
GND
GND
GND
COMPB COMPA RUN VIN VIN VIN
GND
VOUT
TSENSE- TSENSE+ VIN VIN VIN SVIN
VOUT VOUT VOUT
DGND_A
DGND_A
DGND_B
DGND_B
OUTIN OUTIN

7
DEMO MANUAL
EVAL-LTM4702-AZ
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.
REV DATE DESCRIPTION PAGE NUMBER
0 04/23 Initial Release —
REVISION HISTORY

8
DEMO MANUAL
EVAL-LTM4702-AZ
Rev. 0
 ANALOG DEVICES, INC. 2023
04/23
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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By using the evaluation board discussed herein (together with any tools, components documentation or support materials, the “Evaluation Board”), you are agreeing to be bound by the terms and
conditions set forth below (“Agreement”) unless you have purchased the Evaluation Board, in which case the Analog Devices Standard Terms and Conditions of Sale shall govern. Do not use the Evaluation
Board until you have read and agreed to the Agreement. Your use of the Evaluation Board shall signify your acceptance of the Agreement. This Agreement is made by and between you (“Customer”)
and Analog Devices, Inc. (“ADI”), with its principal place of business at One Technology Way, Norwood, MA 02062, USA. Subject to the terms and conditions of the Agreement, ADI hereby grants to
Customer a free, limited, personal, temporary, non-exclusive, non-sublicensable, non-transferable license to use the Evaluation Board FOR EVALUATION PURPOSES ONLY. Customer understands and
agrees that the Evaluation Board is provided for the sole and exclusive purpose referenced above, and agrees not to use the Evaluation Board for any other purpose. Furthermore, the license granted
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