General Description Typical Performance Characteristics
(Circuit of Figure 2)
The LM2576 series of regulators are monolithic integrated
circuits that provide all the active functions for a step-down
(buck) switching regulator, capable of driving 3A load with
excellent line and load regulation. These devices are avail-
able in fixed output voltages of 3.3V, 5V, 12V, 15V, and an
adjustable output version.
Requiring a minimum number of external components, these
regulators are simple to use and include internal frequency
compensation and a fixed-frequency oscillator.
The LM2576 series offers a high-efficiency replacement for
popular three-terminal linear regulators. It substantially re-
duces the size of the heat sink, and in some cases no heat
sink is required.
A standard series of inductors optimized for use with the
LM2576 are available from several different manufacturers.
This feature greatly simplifies the design of switch-mode
power supplies.
Other features include a guaranteed ±4% tolerance on out-
put voltage within specified input voltages and output load
conditions, and ±10% on the oscillator frequency. External
shutdown is included, featuring 50 µA (typical) standby cur-
rent. The output switch includes cycle-by-cycle current limit-
ing, as well as thermal shutdown for full protection under
fault conditions.
Features
♦ 3.3V, 5V, 12V, 15V, and adjustable output versions
♦ Adjustable version output voltage range,
1.23V to 37V (57V for HV version) ±4% max over
line and load conditions
♦ Guaranteed 3A output current
♦ Wide input voltage range, 40V up to 60V for
HV version
♦ Requires only 4 external components
♦ 52 kHz fixed frequency internal oscillator
♦ TTL shutdown capability, low power standby mode
♦ High efficiency
♦ Uses readily available standard inductors
♦ Thermal shutdown and current limit protection
♦ P+ Product Enhancement tested
Applications
♦ Simple high-efficiency step-down (buck) regulator
♦ Efficient pre-regulator for linear regulators
♦ On-card switching regulators
♦ Positive to negative converter (Buck-Boost)
Product Tags:
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SIMPLE SWITCHER 3A Step Down Voltage Regulator LM2576S-5.0 Images
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