Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 7
Copyright © 2000
Rev. 1.1c, 2005-03-03
WWW.Microsemi .COM
LX1732
Hi
h Current PFM Boost Converter
INTEGRATED PRODUCTS
EVALUATION BOARD
O
VERVIEW
The LXE1732 evaluation board is available from
Microsemi for assessing overall circuit performance. The
evaluation board, shown in Figure 6, is 3 by 3 inches (i.e.,
7.6 X 7.6cm) square and factory calibrated for optimal
performance over a wide load range. Circuit designers can
easily modify output voltage to suit their particular
application. Moreover, inductor, capacitors, and diode are
easily swapped out to promote design verification of a
circuit that maximizes efficiency and minimizes cost for a
wide variety of applications. The input and output
connections are described in Table 1.
E
LECTRICAL
C
ONNECTIONS
Apply the DC input voltage directly to the VIN pin and
connect the test load to the VOUT pin. The output voltage
is factory programmed at 3.0V, however, the user may
adjust this value by changing the R1 and R2 values
accordingly. Install a wire loop at JU1 to close the circuit
connection and to examine the inductor current using a
suitable current probe.
The LX1732 exhibits a low quiescent current (I
Q
<
1µA: typ) during shutdown mode. This pin is pulled-up to
VIN via a 10K resistor. Grounding the SHDN test point
shuts down the IC however, the load is still capable of
drawing current through the inductor & diode circuit path.
Hence, V
OUT
during shutdown will be approximately the
input voltage minus the inductor and diode forward voltage
drop.
The LXE1732 evaluation board provides an easy and
cost effective solution for evaluation of the LX1732. The
factory installed component list for the evaluation board is
provided in Table 2 and the schematic is shown in Figure 7.
Figure 6 – LX1732 Evaluation Board
Table 1: Input and Output Pin Assignments
Pin
Name
Allowable
Range
Description
VIN 0 to 6V Input power supply connection.
LBI V < VIN
Low Battery Input voltage threshold sense pin: Programmed for 0.93V
nominal.
LBO N/A Low Battery Output voltage: Connect a DVM to LBO to observe voltage.
/SHDN 0 to VIN Ground to inhibit the LX1732
VOUT V > VIN Programmed for 3.0V nominal output, adjustable via R1 and R2.
GND 0V Circuit Ground
E
E
V
V
A
A
L
L
U
U
A
A
T
T
I
I
O
O
N
N
