Linear Technology DC1669A Quick setup guide

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DEMO MANUAL DC1669A
DESCRIPTION
LTM4627EV:
15A Step-Down µModule
Regulator
Demonstration circuit 1669A features the LTM
®
4627EV
μModule
®
regulator, a high performance high efficiency
step-down regulator. The LTM4627EV has an operating
input voltage range of 4.5V to 20V and is able to provide
an output current of up to 15A. The output voltage is pro-
grammable from 0.6V to 5V and can be remotely sensed
with the internal optional differential remote sensing
amplifier. The LTM4627EV is a complete DC/DC point-of-
load regulator in a thermally enhanced 15mm ×15mm ×
4.32mmLGApackagerequiringonlyafewinputandoutput
capacitors. This regulator is internally compensated and
employs constant frequency current mode architecture,
enabling a fast transient response and stable control
L, LT, LTC, LTM, μModule, Burst Mode, 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
loop over a wide range of output capacitance. It supports
frequency synchronization and Burst Mode
®
operation for
increased light-load efficiency. Output voltage tracking
is also available through the TRACK/SS pin for supply
rail sequencing. The LTM4627 data sheet must be read
in conjunction with this demo manual for working on or
modifying demo circuit 1669.
Design files for this circuit board are available at
http://www.linear.com/demo
PARAMETER CONDITIONS / NOTES VALUE
Input Voltage Range 4.5V to 20V
Output Voltage, VOUT Jumper Selectable 1.0VDC, 1.2VDC, 1.5VDC, 2.5VDC, 1.8VDC, 3.3VDC
Maximum Continuous Output Current Derating is Necessary for Certain Operating
Conditions. See Data Sheet for Details
15A DC
Default Operating Frequency 500kHz
External Clock Synchronous Frequency Range 250kHz to 770kHz
Efficiency VIN = 12V, VOUT = 1.8V, IOUT = 15A 86.6%, See Figure 2

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DEMO MANUAL DC1669A
QUICK START PROCEDURE
Figure 1. Test Setup of DC1669A
Demonstration circuit 1669 is easy to set up to evaluate the
performance of the LTM4627EV. Please refer to Figure 1
for test setup connections and follow the procedure below.
1. With power off, place the jumpers in the following
positions for a typical 1.8Vout application:
JP1 JP2 JP3 JP4
TRACK/SS RUN MODE VOUT Select
SOFTSTART ON CCM 1.8V
2. Before connecting input supply, load and meters, preset
the input voltage supply to be less than 20V. 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 15A range and observe
the load regulation, efficiency and other parameters.
Output voltage ripple should be measured at J4 with a
BNC cable and oscilloscope.
6. To observe increased light load efficiency place the
Mode pin jumper (JP3) in the Burst Mode position. To
observe increased light load efficiency with a reduced
output ripple ascomparedto Burst Modeoperation place
the MODE pin jumper in the pulse-skipping position.
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 (<1μs)
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 J3 (15mV/A).
Note:
To set the output voltage to 5V turn off the input supply
power, apply the following changes listed below.
R7 R6 R12 JP4
Remove 0Ω 8.25k (1%) 1V
A
+–
A
–+
+
–
VIN
V
+
–
V
+
–
–
+
LOAD
0A TO
15A

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DEMO MANUAL DC1669A
QUICK START PROCEDURE
Figure 2. Measured Supply Efficiency at 12VIN and 18VIN
VOUT
100mV/DIV
IOUT(STEP)
3.33A/DIV
50μs/DIV DC1669A F03
VIN (V) VOUT (V) COUT BULK COUT CERAMIC OTHER
12 1.8 330μF/6.3V
POSCAP
2 ×100μF, 6.3V C10 = 47pF
C19 = 330pF
Figure 3. Measured Load Transient Response
(7.5A to 15A Load Step)
Figure 4. Measured Thermal Capture
VIN (V) VOUT (V) IOUT (A) AIRFLOW AMBIENT (°C)
12 1.8 15 Natural
Convection
27
LOAD CURRENT (A)
0
65
EFFICIENCY (%)
70
75
80
85
95
246810
DC1669 F02a
12 14
90
18VIN
fSW = 500kHz
3.3VOUT
2.5VOUT
1.8VOUT
1.5VOUT
1.2VOUT
1VOUT
LOAD CURRENT (A)
0
65
EFFICIENCY (%)
70
75
80
85
95
246810
DC1669 F02b
12 14
90
12VIN
fSW = 500kHz
3.3VOUT
2.5VOUT
1.8VOUT
1.5VOUT
1.2VOUT
1VOUT

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DEMO MANUAL DC1669A
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 1 C5 CAP, 1210 22μF 10% 25V X5R MURATA GRM32ER61E226KE15L
3 1 C10 CAP, 0603 150pF 10% 25V NPO AVX 06033A151KAT2A
4 2 C11, C12 CAP, 1210 100μF 20% 6.3V X5R TAIYOYUDEN JMK325BJ107MM-T
5 1 C16 CAP, 7343 330uF 20% 6.3V POSCAP SANYO 6TPF330M9L
6 1 C19 CAP, 0603 82pF 5% 25V NPO AVX 06033A820JAT2A
7 1 R7 RES, 0603 0Ω JUMPER VISHAY CRCW06030000Z0ED
8 1 R9 RES, 0603 124k 5% 1/10W VISHAY CRCW0603124K0JNEA
9 1 R15 RES, 0603 30.1k 1% 1/10W VISHAY CRCW060330K1FKEA
10 2 R18, R19 RES, 0603 10Ω 5% 1/10W VISHAY CRCW060310R0JNEA
11 1 U1 IC, MICRO MODULE LINEAR TECH LTM4627EV
Additional Demo Board Circuit Components
1 1 C6 CAP, 150μF 35V ALUM SUNCON ELEC 35CE150AX
2 0 C3, C4, C13, C22, C23 CAP, 1210 OPTION OPTION
3 0 C7 CAP, 0805 OPTION OPTION
4 0 C14, C15, C17, C20, C21 CAP, 0603 OPTION OPTION
5 1 Q1 XSTR, MOSFET, N-CHANNEL 30V VISHAY SUD50N03-09P
6 4 R5, R6, R8, R11 RES, 0603 OPTION OPTION
7 3 C1, C2, C8 CAP, 0603 1μF 20% 10V X5R TAIYO YUDEN LMK107BJ105MA-T
8 1 C9 CAP, 0603 0.1μF 10% 50V X7R TDK C1608X7R1H104K
9 1 C18 CAP, 0603 1.5nF 5% 25V X7R AVX 06033A152JAT2A
10 1 R1 RES, 0603 10k 5% 1/10W VISHAY CRCW060310K0JNEA
11 1 R2 RES, 2512 0.015Ω 1% 1W VISHAY WSL2512R0150FEA
12 2 R3, R13 RES, 0603 60.4k 1% 1/10W VISHAY CRCW060360K4FKEA
13 2 R4, R12 RES, 0603 90.9k 1% 1/10W VISHAY CRCW060390K9FKEA
14 1 R10 RES. 0603 20k 5% 1/10W VISHAY CRCW060320K0JNEA
15 1 R14 RES, 0603 40.2k 1% 1/10W VISHAY CRCW060340K2FKEA
16 1 R16 RES, 0603 19.1k 1% 1/10W VISHAY CRCW060319K1FKEA
17 1 R17 RES, 0603 13.3k 1% 1/10W VISHAY CRCW060313K3FKEA
18 1 R20 RES. 0603 100k 5% 1/10W VISHAY CRCW0603100KJNEA
Hardware
1 10 E1-E3, E5-E11 TURRET MILL-MAX 2501-2-00-80-00-00-07-0
2 4 JP1, JP2, JP3, JP4 SHUNT SAMTEC 2SN-BK-G
3 2 JP1, JP2 HEADER, 3-PIN, 2mm SAMTEC TMM-103-02-L-S
4 1 JP3 HEADER, 4-PIN, DOUBLE ROW, 2mm SAMTEC TMM-104-02-L-D
5 1 JP4 HEADER, 6-PIN, DOUBLE ROW, 2mm SAMTEC TMM-106-02-L-D
6 4 J1, J2, J5, J6 JACK, BANANA KEYSTONE 575-4
7 2 J3, J4 CONN., VERT. PC-MNT, BNC 50Ω CONNEX 112404
8 4 STANDOFF, SNAP ON KEYSTONE_8834

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DEMO MANUAL DC1669A
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. LinearTechnology 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 DC1669A
Linear Technology Corporation
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[phone] ●FAX: [phone] ●www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2010
LT 1110 • PRINTED IN USA
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