Linear Technology DC1400A Quick setup guide

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DEMO MANUAL DC1400A
DESCRIPTION
LTM4608AEV:
8A Step-Down Power
µModule
®
Regulator
DemonstrationcircuitDC1400AfeaturestheLTM
®
4608AEV,
the high efficiency, high density switch mode step-down
power module. The input voltage range is 2.5V to 5.5V.
The output voltage is jumper selectable from 0.6V to 3.3V.
The rated load current is 8A although derating is necessary
for certain VIN, VOUT and thermal conditions. LTM4608A
offers a novel phase-shift clock output to support current
sharing with other regulators. The TRACK/SS pin allows
the user to program output voltage ramp-up and ramp-
down slew rate. The same pin also allows the output to L, LT, LTC, LTM, μModule, Linear Technology and the Linear logo are registered trademarks of
Linear Technology Corporation. All other trademarks are the property of their respective owners.
BOARD PHOTO
PERFORMANCE SUMMARY
(TA= 25°C)
coincidentally or ratiometrically track another voltage
rail. The margining function is provided for users who
wish to stress their systems by varying supply voltages
during testing. The LTM4608A data sheet must be read in
conjunction with this demo manual prior to working on
or modifying the DC1400A
Design files for this circuit board are available at
http://www.linear.com/demo
PARAMETER CONDITION VALUE
Input Voltage Range 2.5V to 5.5V
Output Voltage Range Jumper Selectable (Open for 0.6V) 1.2V, 1.5V, 1.8V, 2.5V, 3.3V; ±2%
Maximum Continuous Output Current Derating is Necessary for Certain VIN, VOUT and
Thermal Conditions
8A DC
Default Operating Frequency 1.5MHz
Efficiency VIN = 5V, VOUT = 2.5V, IOUT = 8A 84.5%, See Figure 3 for More Information

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DEMO MANUAL DC1400A
QUICK START PROCEDURE
Figure 1. Test Setup of DC1400A
Figure 2. Proper Scope Probe Technique for Measuring Input or Output Ripple
Demonstration circuit DC1400A is an easy way to evalu-
ate the LTM4608AEV. Please refer to Figure 1 for proper
measurement equipment setup and follow the procedure
below:
1. Place jumpers in the following positions for a typical
1.2VOUT application:
TRACK RUN VOUT SELECT MARGINING
DISABLE ON 1.2V NO
2. With power off, connect the input power supply, load
and meters as shown in Figure 1. Preset the load to
0A and input power supply between 2.5V to 5.5V.
3. Turn on the power at the input. The output voltage
should be 1.2V ±2%.
4. Once the proper output voltage is established, adjust
the load within the operating range and observe the
output voltage regulation, ripple voltage, efficiency and
other parameters.
5. To measure the input and output ripple, please refer to
Figure 2 for proper setup.
6. For an optional load transient test, apply an adjustable
pulse signal between IOSTEP CLK and GND pins. The
pulse amplitude sets the current step. The pulse signal
should have very small duty cycle (<5%) to limit the
thermal stress on the transient load circuit. The out-
put current is best monitored with a BNC cable at J5
(10mV/A). The output voltage is best monitored with
a BNC cable at J6.
Note: To disable margining in applications when VOUT is
close to VIN (dropout mode), the MGN pin should be tied
to a voltage rail equal to 50% of VIN created by a resistor
divider.
+–
INPUT OR OUTPUT CAPACITOR
+–
A
–
+
V
+–
A
–+
LOAD
0A TO
8A
VIN
V
+
–

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DEMO MANUAL DC1400A
QUICK START PROCEDURE
Efficiency vs Load Current with 5VIN, 1.2VOUT
Efficiency vs Load Current with 3.3VIN, 1.2VOUT
Figure 3. Measured Supply Efficiency with Different VIN and VOUT
Figure 4. Measured Load Transient Response (4A Step, 25% to 75%)
Efficiency vs Load Current with 5VIN, 1.5VOUT
Efficiency vs Load Current with 3.3VIN, 1.5VOUT
LOAD CURRENT (A)
0.1
45
EFFICIENCY (%)
55
65
110
DC1400 F03a
35
25
85
75
40
50
60
30
80
70
BURST
PULSE SKIPPING
CONTINUOUS
LOAD CURRENT (A)
0.1
50
EFFICIENCY (%)
60
70
110
DC1400 F03b
40
30
90
80
45
55
65
35
85
75
BURST
PULSE SKIPPING
CONTINUOUS
LOAD CURRENT (A)
0.1
50
EFFICIENCY (%)
60
70
110
DC1400 F03c
40
30
90
80
45
55
65
35
85
75
BURST
PULSE SKIPPING
CONTINUOUS
LOAD CURRENT (A)
0.1
50
EFFICIENCY (%)
60
70
110
DC1400 F03b
40
30
90
80
45
55
65
35
85
75
BURST
PULSE SKIPPING
CONTINUOUS
ISTEP
2A/DIV
VOUT(AC)
50mV/DIV
50μs/DIVVIN = 3.3V
VOUT = 1.2V
2A TO 6A LOAD STEP
COUT = 1 w22μF CERAMIC (1206, X5R, 6.3V),
2 w100μF CERAMIC (1812, X5R, 6.3V)
CFF = 47pF
DC1400A F04

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DEMO MANUAL DC1400A
PARTS LIST
ITEM QTY REFERENCE DESCRIPTION MANUFACTURER’S PART NUMBER
Required Circuit Components
1 1 CFF CAP, 0603 47pF 10% 25V NPO AVX 06033A470KAT
2 1 CIN1 CAP, 150μF 20% 10V ELEC SANYO 10SVPA150MAA
3 2 CIN5, CIN4 CAP, 0805 10μF 10% 6.3V X5R AVX 08056D106KAT2A
4 1 C03 CAP, 1206 22μF 20% 6.3V X5R AVX 12066D266MAT2A
5 2 C05, C04 CAP, 1812 100μF 20% 6.3V X5R TDK C4532X5R0J107MZ
6 1 R14 RES, 0603 9.76k 1% 1/10W VISHAY CRCW06039K76FKEA
7 1 U1 IC, LOW VOLTAGE POWER MODULE LINEAR TECH. LTM4608AEV
Additional Demo Board Circuit Components
1 0 C02, CIN3 CAP, 1812 100μF 20% 6.3V X5R OPTION TDK C4532X5R0J107MZ OPTION
2 0 CO1 CAP, 1812 OPTION TAIYO YUDEN JMK432BJ107MU-T OPTION
3 0 C14, C21, CTHP, CP CAP, 0603 OPTION OPTION
4 1 C15 CAP, 0603 1μF 20% 10V X5R TAIYO YUDEN LMK107BJ105MA-T
5 0 C17 CAP, 0603 1μF 20% 16V X5R OPTION TDK C1608X7R1C105M OPTION
6 1 Q14 XSTR, MOSFET VISHAY SUD50N03-09CP-E3
7 1 R1 RES, 0603 4.99k 1% 1/10W VISHAY CRCW06034K99FKEA
8 1 R2 RES, 0603 6.65k 1% 1/10W VISHAY CRCW06036K65FKEA
9 1 R3 RES, 0603 3.16k 1% 1/10W VISHAY CRCW06033K16FKEA
10 1 R4 RES, 0603 2.21k 1% 1/10W VISHAY CRCW06032K21FKEA
11 0 R8, R5 RES, 0603 OPTION OPTION
12 3 R6, R9, R16 RES, 0603 0Ω JUMPER VISHAY CRCW06030000Z0EA
13 2 R10, R15 RES, 0603 10k 5% 1/10W VISHAY CRCW060310K0JNEA
14 1 R11 RES,2512 0.01Ω 1% 1W PANASONIC ERJ-M1WSF10MU
15 2 R18, R17 RES, 0603 51Ω 5% 1/10W VISHAY CRCW060351R0JNEA
Hardware
1 5 JP1, JP2, JP3, JP4, JP5 HEADER, 2-PIN, 2mm SAMTEC TMM 102-02-L-S
2 3 JP7, JP8, JP13 HEADER, 3-PIN, 2mm SAMTEC TMM-103-02-L-S
3 4 JP9, JP10, JP11, JP12 HEADER, 3 ×2 2mm SAMTEC TMM-103-02-L-D
4 4 J1, J2, J3, J4 JACK, BANANA KEYSTONE 575-4
5 2 J5, J6 CONN, BNC, 5 PINS CONNEX 112404
6 10 TP1-TP9, TP11 TURRET MILL MAX 2501-2-00-80-00-00-07-0
7 8 JP1, JP7-JP13 SHUNT, 2mm SAMTEC 2SN-BK-G
8 4 STANDOFF, SNAP ON KEYSTONE_8834

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DEMO MANUAL DC1400A
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However,no responsibility is assumed for its use. Linear Technology Corporation makes no representation
that the interconnection of its circuits as described herein will not infringe on existing patent rights.
SCHEMATIC DIAGRAM

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DEMO MANUAL DC1400A
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ●FAX: [phone] ●www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2010
LT 1110 • PRINTED IN USA
DEMONSTRATION BOARD IMPORTANT NOTICE
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This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT
OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete
in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety
measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union direc-
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