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DEMO MANUAL DC1889A
Description
LTM4624EY
4A Step-Down µModule
Regulator
Demonstration circuit 1889A features the LT M
®
4624EY
µModule
®
regulator, a tiny high performance high
efficiency step-down regulator. The LTM4624EY has an
operating input voltage range of 4V to 14V and is able to
provide an output current of up to 4A. The output voltage
is programmable from 0.6V to 5.5V. The LTM4624EY is
a complete DC/DC point-of-load regulator in a thermally
enhanced 6.25mm × 6.25mm × 5.01mm BGA package
requiring only a couple capacitors and a resistor. Output L, LT, LTC, LTM, Linear Technology, the Linear logo and µModule are registered trademarks of
Linear Technology Corporation. All other trademarks are the property of their respective owners.
performance summary
BoarD photo
voltage tracking is available through the TRACK/SS pin for
supply rail sequencing. The LTM4624 data sheet must be
read in conjunction with this demo manual prior to working
on or modifying demo circuit 1889A.
Design files for this circuit board are available at
http://www.linear.com/demo
Specifications are at TA = 25°C
PARAMETER CONDITIONS/NOTES VALUE
Input Voltage Range 4V – 14V
Output Voltage, VOUT Jumper Selectable 1.0VDC, 1.2VDC, 1.5VDC, 1.8VDC, 2.5VDC, 3.3VDC,
5VDC
Maximum Continuous Output Current Derating is Necessary for Certain operating
Conditions. See Data Sheet for Details
4A DC
Default Operating Frequency 1MHz
Efficiency VIN = 12V, VOUT = 1.8V, IOUT = 4A 83.6% See Figure 2
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DEMO MANUAL DC1889A
Quick start proceDure
Demonstration circuit 1889A is an easy way to evaluate the
performance of the LTM4624EY. Please refer to Figure 1
for test setup connections and follow the procedure below.
1. With power off, place the jumpers in the follow-ing
positions for a typical 1.8Vout application:
JP7 JP6 JP4
RUN MODE VOUT Select
ON CCM 1.8V
2. Before connecting input supply, load and meters, pre-
set the input voltage supply to be between 4V to 14V.
Pre-set 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 4A range and observe
the load regulation, efficiency, and other parameters.
Output voltage ripple should be measured at J6 with a
BNC cable terminated into 50Ω and an oscilloscope.
6. To observe increased light load efficiency place the
MODE pin jumper (JP6) in the DCM position while input
power is removed.
7. For optional load transient testing apply an adjustable
positive pulse signal between IOSTEP CLK and GND
pins. The pulse amplitude sets the load step current
amplitude. The pulse width should be short (<1ms)
and pulse duty cycle should be low (<15%) to limit the
thermal stress on the load transient circuit. The load
step current can be monitored with a BNC connected
to J5 (50mV/A).
+–
A
– +
A
–
+
LOAD
0A TO 4A
+
–
V
+
–
V
+
–
VIN
Figure 1. Test Setup
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DEMO MANUAL DC1889A
Quick start proceDure
LOAD CURRENT (A)
0
EFFICIENCY (%)
85
90
4
80
75 123
95
5VOUT
3.3VOUT
2.5VOUT
1.8VOUT
1.5VOUT
1.2VOUT
1VOUT
LOAD CURRENT (A)
0
EFFICIENCY (%)
85
90
4
80
75 123
95
3.3VOUT
2.5VOUT
1.8VOUT
1.5VOUT
1.2VOUT
1VOUT
12VIN CCM Efficiency vs Load Current 5VIN CCM Efficiency vs Load Current
Figure 2. Measured Supply Efficiency at 12VIN and 5VIN
VOUT
50mV/DIV
IOUT(STEP)
2A/DIV
VIN (V)
12
VOUT (V)
1.8
COUT
1 × 100µF/6.3V+
1 × 22µF/6.3V+
1 × 47µF/6.3V
VOUT
10mV/DIV
VIN (V)
12
VOUT (V)
1.8
iOUT (A)
4
COUT
1 × 100µF/6.3V+
1 × 22µF/6.3V+
1 × 47µF/6.3V
Figure 3. Measured Load Transient Response (2A to 4A Load Step) Figure 4. Measured VOUT Ripple (20MHz)
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DEMO MANUAL DC1889A
parts List
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
1 1 C1 CAP., X5R, 2.2µF, 10V, 10%, 0603 TAIYO YUDEN, LMK107BJ225KA-T
2 2 C3, C13 CAP., X5R, 22µF, 16V, 20%, 1206 TAIYO YUDEN, EMK316BJ226ML-T
3 1 C20 CAP., X5R, 47µF, 6.3V, 20%,1206 TAIYO YUDEN, JMK316BJ476ML
4 1 C12 CAP., X5R, 100µF, 6.3V, 20%,1210 TAIYO YUDEN, JMK325ABJ107MM-T
5 2 C9, C15 CAP., X5R, 0.1µF, 25V, 10%, 0603 AVX, 06033D104KAT
6 1 R4 RES., CHIP, 90.9k, 1/16W, 1%, 0603 VISHAY, CRCW060390K9FKEA
7 1 R11 RES., CHIP, 10Ω, 1/16W, 1%, 0603 VISHAY, CRCW060310R0FKEA
8 1 U1 I.C., LTM4624EY, BGA LINEAR TECH., LTM4624EY#PBF
Additional Demo Board Circuit Components
1 1 C10 CAP., X5R, 22µF, 25V, 10%, 7343 SANYO, 25TQC22MV
2 0 C11, C14 CAP., 1210, OPTION OPTION
3 0 C5 CAP., 1206, OPTION OPTION
4 3 C4, C6, C18 CAP., X5R, 1µF, 10V, 10%, 0603, OPTION TAIYO YUDEN, LMK107BJ105KA-T
5 0 C7, C19 CAP., 0603, OPTION OPTION
6 0 C17 CAP., 7343, OPTION OPTION
7 1 C2 CAP., X5R, 10µF, 16V, 20%, 0805 TAIYO YUDEN, EMK212ABJ106KG-T
8 1 C16 CAP., X5R, 22µF, 6.3V, 20%, 0805 TAIYO YUDEN, JMK212ABJ226MD-T
9 1 C8 CAP., X7R, 100pF, 50V, 10%, 0603 AVX, 06033C101KAT2A
10 1 Q1 N-Channel 30-V MOSFET,TO-252 VISHAY, SUD50N03-09P-E3
11 1 RS2 RES., CHIP, 0.05Ω, 1W, 1%, 2512 VISHAY, WSL2512R0500FEB
12 1 R3 RES., CHIP, 10k, 1/16W, 1%, 0603 VISHAY, CRCW060310K0FKEA
13 7 R5, R6, R7, R14, R15, R16, R10 RES., CHIP, OPTION, 1/16W, 1%, 0603 OPTION
14 0 R1, R12, R2 RES., CHIP, OPTION, 1/16W, 1%, 0603 OPTION
15 1 R8 RES., CHIP, 100k, 1/16W, 1%, 0603 VISHAY, CRCW0603100KFKEA
16 1 R9 RES., CHIP, 150k, 1/16W, 1%, 0603 VISHAY, CRCW0603150KFKEA
17 1 R13 RES., CHIP, 0Ω, 1/16W, 1%, 0603 VISHAY, CRCW06030000Z0EA
Hardware
1 11 E2, E4-E13 TESTPOINT, TURRET, 0.095" MILL-MAX, 2501-2-00-80-00-00-07-0
2 7 JP1-JP4, JP8-JP10 2MM SINGLE ROW HEADER, 2-PIN SAMTEC, TMM102-02-L-S
3 1 JP6 2MM DOUBLE ROW HEADER, 2X2 PIN SAMTEC, TMM-102-02-L-D
4 1 JP7 2MM SINGLE ROW HEADER, 3-PIN SAMTEC, TMM-103-02-L-S
5 2 J5, J6 CONN, BNC, 5 PINS CONNEX, 112404
6 3 JP1, JP6, JP7 SHUNT SAMTEC, 2SN-BK-G
7 4 STAND OFF STAND OFF, SNAP ON KEYSTONE_8832
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DEMO MANUAL DC1889A
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 representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
schematic Diagram
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DEMO MANUAL DC1889A
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com
LINEAR TECHNOLOGY CORPORATION 2013
LT 0713 • 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 LT C 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
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If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date
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