July 2003
LM2591HV
SIMPLE SWITCHER®Power Converter 150 kHz 1A
Step-Down Voltage Regulator
current limit for the output switch and an over temperature
shutdown for complete protection under fault conditions.
General Description
The LM2591HV series of regulators are monolithic inte-
grated circuits that provide all the active functions for a
step-down (buck) switching regulator, capable of driving a
1A load with excellent line and load regulation. These de-
vices are available in fixed output voltages of 3.3V, 5V, and
an adjustable output version.
Features
n 3.3V, 5V, and adjustable output versions
n Adjustable version output voltage range, 1.2V to 57V
4% max over line and load conditions
n Guaranteed 1A output load current
n Available in 5-pin TO-220 and TO-263 (surface mount)
Package
This series of switching regulators is similar to the
LM2590HV, but without some of the supervisory and perfor-
mance features of the latter.
n Input voltage range up to 60V
n 150 kHz fixed frequency internal oscillator
n On/Off control
Requiring a minimum number of external components, these
regulators are simple to use and include internal frequency
†
compensation , improved line and load specifications and a
fixed-frequency oscillator.
n Low power standby mode, IQ typically 90 µA
n High Efficiency
n Thermal shutdown and current limit protection
The LM2591HV operates at a switching frequency of 150
kHz thus allowing smaller sized filter components than what
would be needed with lower frequency switching regulators.
Available in a standard 5-lead TO-220 package with several
different lead bend options, and a 5-lead TO-263 Surface
mount package.
Applications
n Simple high-efficiency step-down (buck) regulator
n Efficient pre-regulator for linear regulators
n On-card switching regulators
Other features include a guaranteed 4% tolerance on out-
put voltage under all conditions of input voltage and output
load conditions, and 15% on the oscillator frequency. Ex-
ternal shutdown is included, featuring typically 90 µA
standby current. Self protection features include a two stage
n Positive to Negative converter
†
Note: Patent Number 5,382,918.
Typical Application (Fixed Output Voltage Versions)
10129301
SIMPLE SWITCHER® and Switchers Made Simple® are registered trademarks of National Semiconductor Corporation.
© 2003 National Semiconductor Corporation
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