International Rectifier IR3637 User Manual

IR3637 EVALUATION BOARD USER GUIDE

DESCRIPTION

The IR3637 controller IC is designed to
provide a low cost synchronous Buck
regulator for on-board
applications in a small 8-pin SOIC. The
output voltage can be precisely regulated
using the internal 0.8V reference voltage
for low voltage applications.
The IR3637 operates at a fixed internal
400KHz switching frequency to reduce the
component size.
The device features under-voltage lockout
for both input supplies, an external
programmable soft-start function as well as
output under-voltage detection that latches
off the device when an output short is
detected.

INPUT / OUTPUT CONNECTIONS

The following is the input / output connections:
Inputs:
JP1: Input (+5V) and GND
JU1: V
c
Outputs:
JP2: V (+1.8V) and GND
out
Other Connections:
J1: Scope connection for V
J2: Scope connection for Inductor Point
Rev1.0
4/29/2005
DC to DC
out

PACKAGE INFORMATION

Fb
1
Vcc
2
LDrv
3
Gnd
4
IRDC3637EVAL
The reference board is designed for
1.8V output using +5V and +12V
supplies. This will demonstrate the
main features of IC.
This user guide contains the schematic
and bill of materials, the design
guidelines are described in data sheet.

SPECIFICATION DATA

V = 12V
c
V =V =5V
cc in
V =1.8V
out
Iout =7A
Output Ripple = 50mV
F = 400KHz
s
The connection points are shown in
Figure1. Connect the power supply
cables according
minimizing wire lengths to reduce
losses in the wire. Test points J1 and
J2 provide easy
oscilloscope voltage probe to monitor
the inductor points and output voltage.
SS/SD
8
Comp
7
Vc
6
HDrv
5
to this figure,
connection for
1