Evaluation Board User Guide
DC3248A
LTM4659
Low VIN, High Efficiency 10A Step-Down DC-to-DC μModule Regulator
General Description
The DC3248A evaluation board circuit features the
LTM®4659, a high efficiency, 10A step-down power
µModule® regulator. The input voltage range is from 2.25V
to 5.5V. The output voltage range is 0.5V to VIN. Derating
may be necessary for certain VIN, VOUT, frequency and
thermal conditions. The DC3248A evaluation board offers
the SSTT pin, allowing the user to program output tracking,
soft start period and die temperature monitoring.
The LTM4659 uses external compensation. Users can
tune the compensation circuit to ensure the loop is stable
and that the desired transient performance can be
achieved.
The MODE/SYNC pin either synchronizes the switching
frequency to an external clock, is a clock output, or sets
the PWM mode. It can be externally synchronized to a
clock from 1MHz to 2.6MHz. The Pulse width modulation
(PWM) modes of operation are Forced continuous mode
(FCM) for low noise or pulse-skipping mode (PSM) for high
efficiency at light load. The LTM4659 defaults to FCM
during synchronization and operates in PSM when both
the FREQ and MODE/SYNC pins are connected to VIN.
The LTM4659 data sheet must be read in conjunction with
this evaluation board manual prior to working on or
modifying the DC3248A evaluation board.
Ordering Information appears at end of demo manual.
For output loads that demand more than 10A of current,
multiple LTM4659s can be paralleled to run out-of-phase
to provide more output current without increasing input and
output voltage ripples.
Features and Benefits
•
•
•
Tiny surface mount, 4mm × 4mm × 1.43mm LGA
Silent Switcher®2 architecture
Ultralow Electromagnetic Interference (EMI) noise
DC3248A Evaluation Board Files
FILE
DESCRIPTION
DC3248A
Evaluation board circuit design files.
Figure 1. DC3248A Evaluation Board Circuit (Part Marking Is Either Ink Mark or Laser Mark)
Rev. 0
DOCUMENT FEEDBACK
TECHNICAL SUPPORT
O n e A n a l o g Wa y , W i lm i ng t o n, M A 0 1 8 8 7 - 2 3 5 6 , U . S . A .
Tel: 781.329.4700
© 2 0 2 4 A n a l o g D e v i c e s , In c . A l l r i g h t s r e s e r v e d .
DC3248A
Evaluation Board User Guide
Table 1. Performance Summary
Specifications are at TA = 25°C
PARAMETER
CONDITIONS/NOTES
MIN
Input voltage range
2.25
Output voltage
0.985
Maximum continuous output current
Derating is necessary for certain operating
conditions. Refer to the data sheet for details.
Operating frequency
TYP
1.0
MAX
UNITS
5.5
V
1.015
V
10
ADC
2
MHz
Efficiency
VIN = 3.3V, VOUT = 1.0V, IOUT = 10A
82.16
(see Figure 3)
%
Load transient
VIN = 3.3V, VOUT = 1.0V, ISTEP = 0A to 2.5A
70
(see Figure 5)
mV
Quick Start
Required Equipment
•
•
•
One 0V to 30V DC, 20A power supply
Electronic load with 20A sink capacity
Four digital multimeters (DMM)
Procedure
The DC3248A evaluation board is an easy way to evaluate the performance of the LTM4659. See Figure 2 for proper
measurement equipment setup and follow the procedure below.
1. Place jumpers in the following positions for a typical application.
JP1
RUN
ON
JP2
MODE/CLK
CCM
2. With the power off, connect the input power supply, load and meters as shown in Figure 2. Preset the load to 0A and
VIN supply to 3.3V.
3. Turn on the power supply at the input. The output voltage should be 1.0V ±1.5% (0.985V to 1.015V).
4. Vary the input voltage from 2.25V to 5.5V and adjust the load current from 0A to 10A. Observe the output voltage
regulation, ripple voltage, efficiency, and other parameters.
5. (Optional) To set LTM4659 to PSM, set the MODE/CLK jumper JP8 to PS. See Table 2 for more details.
Table 2. LTM4659 Single-Phase Configuration
FREQ PIN CONNECTION
MODE/SYNC PIN CONNECTION
MODE OF OPERATION
SWITCHING FREQUENCY
VIN
Clock input
FCM
External clock
VIN
AGND
FCM
2MHz default
VIN
VIN
PSM
2MHz default
Resistor to AGND
Clock output
FCM
RFREQ-programmed
6. (Optional) For the optional load transient test, apply an adjustable pulse signal between IOSTEP_CLK and GND test
points. The pulse amplitude sets the load step current amplitude. Keep the pulse width short (<1ms) and pulse duty
cycle low (<5%) to limit the thermal stress on the load transient circuit.
7. (Optional) LTM4659 can be synchronized to an external clock signal. Place the JP8 jumper on CLK and apply a clock
signal on the CLK test point.
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DC3248A
8. (Optional) The output of LTM4659 can track another voltage. This external voltage can be connected to the test point
TRACK on this board.
Figure 2. Measurement Setup of DC3248A
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DC3248A
Evaluation Board User Guide
Typical Performance Characteristics
95
90
80
VOUT
5mV/DIV
75
70
2.5VIN
3.3VIN
5.0VIN
5.5VIN
60
55
50
0
2
4
6
8
10
004
65
003
EFFICIENCY (%)
85
1µs/DIV
12
LOAD CURRENT (A)
Figure 4. Output Voltage Ripple at VIN = 3.3V,
VOUT = 1.0V, IOUT = 0A
Figure 3. Measured Efficiency at f SW = 2MHz
VOUT
50mV/DIV
VOUT
5mV/DIV
005
006
ILOAD
2A/DIV
1µs/DIV
Figure 5. Output Voltage Ripple at VIN = 3.3V,
VOUT = 1.0V, IOUT =10A
100µs/DIV
VIN = 3.3V, VOUT = 1.0V, IOUT = 0A
OUTPUT CAPACITOR = 100µF + 2 × 22µF
fSW = 2MHz
Figure 6. Load Transient at VIN = 3.3V, VOUT = 1.0V,
IOUT_STEP = 0A to 2.5A
Figure 7. Thermal Image of LTM4659 at VIN = 3.3V, VOUT = 1.0V, IOUT = 10A (TA = 25°C, No Forced Airflow)
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DC3248A
DC3248A Bill of Materials
ITEM
QTY REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Required Circuit Components
1
4
C1, C3, CIN1, CIN5
CAP., 10μF, X7R, 16V, 10%, 0805
TAIYO YUDEN, EMK212BB7106MG-T
2
2
C2, CIN6
CAP., 150μF, ALUM ELECT, 10V, 20%,
8mm × 6.9mm
PANASONIC, 10SVP150MX
3
1
C4
CAP., 0.1μF, X7R, 6.3V, 10%, 0603
AVX, 06036C104KAT2A
4
1
C13
CAP., 680pF, C0G, 25V, 5%, 0603
AVX, 06033A681JAT2A
5
1
CIN2
CAP., 22μF, X5R, 10V, 20%, 0603
AVX, 0603ZD226MAT2A
6
2
CIN3, CIN4
CAP., 22μF, X5R, 16V, 10%, 0805
TDK, C2012X5R1C226M125AC
7
1
COUT1
CAP., 22μF, X5R, 6.3V, 20%, 0603
MURATA, GRM188R60J226MEA0D
8
1
COUT2
CAP., 22μF, X5R, 6.3V, 20%, 0805
MURATA, C0805C226M9PACTU
9
1
COUT3
CAP., 100μF, X5R, 6.3V, 20%, 0805
MURATA, GRM21BR60J107ME15K
10
1
R3
RES., 100kΩ, 1%, 1/10W, 0603
STACKPOLE ELECTRONICS, INC.,
RMCF0603FG100K
11
2
R4, R6
RES., 60.4kΩ, 1%, 1/10W, 0603, AEC-Q200
VISHAY, CRCW060360K4FKEA
12
1
R15
RES., 6.8 kΩ, 5%, 1/16W, 0603
KOA SPEER, RK73B1JTTD682J
13
1
U1
IC, 5.5VIN, 10A μModule, 4mm × 4mm PCKG, BGA ADI, LTM4659EV#PBF
Additional Evaluation Board Circuit Components
1
0
C5–C7, C12
CAP., OPTION, 0603
2
0
C11
CAP., OPTION, 0805
3
1
R11
RES., 0Ω, 1/10W, 0603
4
0
R12
RES., OPTION, 0603
5
3
C8–C10
CAP., 1μF, X7R, 16V, 10%, 0603
6
1
L1
7
1
Q1
8
1
R13
RES., 10kΩ, 1%, 1/10W, 0603, AEC-Q200
VISHAY, CRCW060310K0FKEA
9
1
R14
RES., 10Ω, 1%, 1/10W, 0603
VISHAY, CRCW060310R0FKEA
RS1
RES., 0.020Ω, 1%, 1W, 1206, PWR, METAL,
SENSE, AEC-Q200
VISHAY, WSLP1206R0200FEA
10
1
IND., 100 AT 100MHz, FERRITE BEAD, 25%, 8A,
6m, 1812
XSTR., MOSFET, N-CHAN, 30V, 5.5A, 3-PIN
SOT-23
BOURNS, CR0603-J/-000ELF
KEMET, C0603C105K4RAC7867
WURTH ELEKTRONIK, 74279226101
VISHAY, Si2338DS-T1-GE3
Hardware: For Evaluation Board Circuit Only
TEST POINT, TURRET, 0.094˝ MTG. HOLE, PCB
0.062˝ THK
CONN., BANANA JACK, FEMALE, THT, NONINSULATED, SWAGE, 0.218˝
CONN., RF, BNC, RCPT, JACK, 5-PIN, ST,
THT, 50
CONN., HDR, MALE, 1 × 3, 2mm, VERT, ST, THT,
NO SUBS. ALLOWED
1
8
E1-E8
2
5
J1–J5
3
2
J6, J7
4
1
JP1
5
1
JP8
CONN., HDR., MALE, 2 × 3, 2mm, VERT, ST, THT
WURTH ELEKTRONIK, 62000621121
6
4
MP1–MP4
STANDOFF, NYLON, SNAP-ON, 0.50˝
KEYSTONE, 8833
7
2
XJP1, XJP8
CONN., SHUNT, FEMALE, 2-POS, 2mm
WURTH ELEKTRONIK, 60800213421
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MILL-MAX, 2501-2-00-80-00-00-07-0
KEYSTONE, 575-4
AMPHENOL RF, 112404
WURTH ELEKTRONIK, 62000311121
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DC3248A
DC3248A Schematic
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DC3248A
Ordering Information
PART
DC3248A
TYPE
Evaluation board circuit.
#Denotes RoHS-compliant.
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DC3248A
Revision History
REVISION
NUMBER
0
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REVISION
DESCRIPTION
DATE
04/24
PAGES
CHANGED
Initial release
—
Rev. 0
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Evaluation Board User Guide
DC3248A
Notes
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 ARE SUBJECT TO CHANGE WITHOUT NOTICE. NO LICENCE, EITHER EXPRESSED OR
IMPLIED, IS GRANTED UNDER ANY ADI PATENT RIGHT, COPYRIGHT, MASK WORK RIGHT, OR ANY OTHER ADI INTELLECTUAL PROPERTY
RIGHT RELATING TO ANY COMBINATION, MACHINE, OR PROCESS WHICH ADI PRODUCTS ALL INFORMATION CONTAINED HEREIN IS
PROVIDED “AS IS” WITHOUT REPRESENTATION OR WARRANTY. NO RESPONSIBILITY IS OR SERVICES ARE USED. TRADEMARKS AND
REGISTERED TRADEMARKS ARE THE PROPERTY OF THEIR RESPECTIVE OWNERS.
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