LX1732 Datasheet, PDF (1/12 Pages) Microsemi Corporation – High Current PFM Boost Converter

INTEGRATED PRODUCTS
LX1732
High Current PFM Boost Converter
PRODUCTION DATA SHEET
DESCRIPTION
The LX1732 is a compact, high
efficiency, step-up DC-DC boost
regulator implemented in a
BiCMOS process technology. This
device features variable frequency
operation and a built in N-channel
MOSFET power switch for
optimal functioning in low voltage
portable systems.
Start-up operation is guaranteed
from 1.1V inputs (at light load)
and the input voltage can be as low
as 0.7V after start-up. This
attribute allows the LX1732 to
operate in an extended power-
savings mode, supplying (data)
critical system components, even
after battery capacity no longer
supports normal operation.
The output voltage programming
range of 2.2V to 5V, requires only
two external resistors via the
feedback pin (see Figure 1.0).
Output load currents of up to
200mA are achievable and the
internal MOSFET is capable of
switching up to a 1A current limit.
Quiescent current during operation
is 200µA (max) and in shutdown-
mode drops to a mere 1µA thus
maximizing overall battery life-
time.
The LX1732 features a low
battery-detect circuitry that alerts
system power management of low
input voltages thus allowing
portable systems to enter a power-
savings mode (e.g., to protect data)
IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com
KEY FEATURES
ƒ 88% Efficiency
ƒ 200µA Quiescent Current
ƒ 0.1µA Logic Shutdown
ƒ Low-Battery Detector
ƒ 8-Pin MSOP Package
APPLICATIONS/BENEFITS
ƒ Pagers
ƒ Wireless Phones
ƒ Hand-Held Computers
ƒ PDAs
ƒ RF Tags
ƒ Two-cell Alkaline Battery
Applications
ƒ Single-cell Lithium Ion 5V
Boost
V_BAT
C_IN
R₃
R₄
PRODUCT HIGHLIGHT
L
IN
SW
SHDN
VC
LX1732
LBI
FB
LBO
GND
D
R₁
R₂
V_OUT
C_OUT
100%
90%
80%
70%
60%
50%
0
25 50 75 100 125 150 175 200
Output Current
Copyright © 2000
Rev. 1.1c, 2005-03-03
Figure 1 – LX1732 General Circuit Topology and Typical Efficiency Performance
PACKAGE ORDER INFO
T_A (°C)
Plastic MSOP
DU _8-Pin
RoHS Compliant / Pb-free
Transition DC: 0432
0 to 70
LX1732CDU
Note: Available in Tape & Reel. Append the letters “TR” to the part
number. (i.e. LX1732CDU-TR)
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: [phone]
Page 1