LX13088A Datasheet, PDF (1/12 Pages) Microsemi Corporation – Dual 1A Step-Down Converters

LX13088A
TM
®
Dual 1A Step-Down Converters
PRODUCTION DATASHEET
DESCRIPTION
The LX13088A is a highly integrated
dual output voltage regulator ideal for
low power applications that require
minimal board space. The two current
mode buck converters include integrated
high side control switches, synchronous
rectifiers, and internal compensation.
The outputs of each converter are both
rated for up to 1A, and the output
voltages are adjustable using external
resistive dividers.
The LX13088A step down converters
operate at 1.3MHz fixed switching
frequency under normal load, reducing
external output filter component values
and size. Under light load conditions, the
converters operate in a pulse-skipping
mode for improved efficiency.
The LX13088A incorporates out of
phase switching, where converter 2
switches 180° out of phase from
converter 1 in order to minimize the input
ripple effects. The controller also
features an E/S pin that provides an
enable input function, or allows the
converter to be synchronized to an
external clock. With the E/S input held
low, the LX13088A draws less than
10uA.
Both converters have controlled soft
start, in addition to power up sequencing.
In the start-up sequence, the output of
converter 1 is designed to precede the
output of converter 2.
Power On Reset function is provided
by means of an open-drain output at the
POR pin. The Power On Reset function
monitors the voltages at the VMON, FB1
and FB2 pins, and pulls low if any of
these voltages drop below the stated POR
threshold. The POR is internally
deglitched and provides a delayed
recovery and reset time.
The LX13088A provides peak over
current protection, short circuit protection
and thermal shutdown. Discharge-Before-
Turn-On discharges the outputs
completely before soft starting to always
bring them up in the proper sequence at
start up or after a POR event.
KEY FEATURES
• Outputs Can Be Set From 1V to
3.6V @ 1A, VIN Dependent
• 3.0V to 5.5V Operating Input
Voltage Range
• No Rectifier Diode required
• 1.3MHz Switching
• 180° Phase Shifted Switching
• Optional External Clocking (2x
clock required)
• Light load Pulse Skipping
• Enable/Sleep state
• Internal Soft Start
• Open-drain Power On Reset
Monitors Input and Outputs
• Discharge Before-Turn-On
• Peak Over-Current Protection
• Short Circuit Protection
• Over Temperature Shutdown
APPLICATIONS
• Hard Disk Drives
• Set- Top Boxes
IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com
Product Highlight
PACKAGE ORDER INFO
T_A (°C)
LD ^{Plastic 3x3 mm DFN 10-pin}
RoHS Compliant / Pb-free
0 to +70
LX13088ACLD
Note: Available in Tape & Reel. Append the letters “TR” to the part number.
(i.e. LX13088ACLD-TR)
THERMAL DATA
θ_JA = 33 °C/W
THERMAL RESISTANCE-JUNCTION TO AMBIENT
Junction Temperature Calculation: T_J = T_A + (P_D x θ_JA).
The θ_JA numbers are guidelines for the thermal performance of the
device/pc-board system. All of the above assume no ambient airflow.
Copyright © 2010
Rev. 1.0, 2010-09-23
Microsemi
Analog Mixed Signal Group
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: [phone]
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