LTM4637_15 Datasheet, PDF (1/30 Pages) Linear Technology – 20A DC/DC Module Step-Down Regulator

LTM4637
20A DC/DC µModule
Step-Down Regulator
Features
n _{Complete 20A Switch Mode Power Supply}
n _{4.5V to 20V Input Voltage Range}
n _{0.6V to 5.5V Output Voltage Range}
n _{±1.5% Total DC Output Voltage Error}
(–40°C to 125°C)
n _{Differential Remote Sense Amplifier for Precision}
Regulation for (V_OUT ≤ 3.3V)
n _{Current Mode Control/Fast Transient Response}
n _{Parallel Current Sharing (Up to 80A)}
n _{Frequency Synchronization}
n _{Selectable Pulse-Skipping or Burst Mode}^® _Operation
n _{Soft-Start/Voltage Tracking}
n _{Up to 88% Efficiency (12VIN, 1.8VOUT)}
n _{Overcurrent Foldback Protection}
n _{Output Overvoltage Protection}
n _{Internal Temperature Monitor}
n _{Overtemperature Protection}
n _{15mm × 15mm × 4.32mm LGA and}
15mm × 15mm × 4.92mm BGA Packages
n _{SnPb (BGA) or RoHS Compliant (LGA and BGA) Finish}
Applications
n _{Telecom Servers and Networking Equipment}
n _{Industrial Equipment}
n _{Medical Systems}
n _{High Ambient Temperature Systems}
Description
The LTM^®4637 is a complete 20A output high efficiency
switch mode step-down DC/DC µModule (micromodule)
regulator. Included in the package are the switching control-
ler, power FETs, inductor and compensation components.
Operating over an input voltage range from 4.5V to 20V,
the LTM4637 supports an output voltage range of 0.6V
to 5.5V, set by a single external resistor. Only a few input
and output capacitors are needed.
Current mode operation allows precision current sharing
of up to four LTM4637 regulators to obtain up to 80A
output. High switching frequency and a current mode
architecture enable a very fast transient response to line
and load changes without sacrificing stability. The device
supports frequency synchronization, multiphase/current
sharing, Burst Mode operation and output voltage tracking
for supply rail sequencing. A diode-connected PNP transis-
tor is available for use as an internal temperature monitor.
The LTM4637 is offered in 15mm × 15mm × 4.32mm LGA
and 15mm × 15mm × 4.92mm packages. The LTM4637
is available with SnPb (BGA) or RoHS compliant terminal
finish. The LTM4637 is pin compatible with the LTM4627,
a 15A DC/DC µModule regulator.
L, LT, LTC, LTM, PolyPhase, Burst Mode, µModule, Linear Technology, the Linear logo are
registered trademarks and LTpowerCAD is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners. Protected by U.S. Patents,
including 5481178, 5847554, 6580258, 6304066, 6476589, 6774611, 6677210, 8163643.
Typical Application
12V_IN, 1.2V_OUT, 20A DC/DC µModule^® Regulator
2.2µF
V_IN
12V
22µF
16V 10k
×4
V_IN EXTV_CC INTV_CC PGOOD
0.1µF COMP
V_OUT
TRACK/SS
V_{OUT_LCL}
RUN
LTM4637
f_SET
MODE_PLLIN
DIFF_OUT
V_OSNS+
V_OSNS–
330pF
100µF*₊
6.3V
×2
V_OUT
1.2V
20A
470µF
6.3V
×2
TEMP
* SEE TABLE 5
** SEE TABLE 1
SGND GND
VFB
R_FB**
60.4k
4637 TA01a
For more information www.linear.com/LTM4637
12V_IN Efficiency vs Load Current
100 _1.2VOUT
95
250kHz
CCM
90
85
80
75
70
65
0 2 4 6 8 10 12 14 16 18 20
OUTPUT CURRENT (A) 4637 TA01b
4637fc
1