AMS2576 Datasheet, PDF (1/9 Pages) Advanced Monolithic Systems Ltd – 3.3V, 5V, 12Vand adjustable versions

3A Step-Down Voltage Regulator
AMS2576
GENERAL DESCRIPTION
The AMS2576 Series are step-down switching
regulators with all required active functions. It is
capable of driving 3A load with excellent line and
load regulations. These devices are available in
fixed output voltages of 3.3V, 5V, 12V and an
adjustable output version.
The AMS2576 series offers a high-efficiency
replacement for popular three-terminal linear
regulators. Also it requires a minimum number of
external components. It substantially not only
reduces the area of board size but also the size of
heat sink, and in some cases no heat sink is
required. The ±4% tolerance on output voltage
within specified input voltages and output load
conditions is guaranteed. Also, the oscillator
frequency accuracy is within ±10%. External
shutdown is included. Featuring 80µA (typical)
standby current. The output switch includes
cycle-by-cycle current limiting, as well as thermal
shutdown for full protection under fault conditions.
This series are offered in 5-pin TO-263,
TO-220 package.
Block Diagram
FEATURES
‹ 3.3V, 5V, 12Vand adjustable versions
‹ Wide input voltage range, up to 40V
‹ Internal oscillator of 52KHz fixed frequency
‹ Guaranteed 3A output current
‹ Wide adjust version output voltage range
from 1.23V to 37V ±4% max. at over line and
load conditions
‹ Low standby current, typ. 80µA, at shutdown
mode
‹ Requires only 4 external components
‹ Thermal shutdown and current limit
protection
APPLICATIONS
„ LCD Monitors.
„ ADD-ON Cards Switching Regulators
„ High Efficiency Step-Down Regulators
„ Efficient Pre-regulator for Linear Regulators
„ Positive to Negative converter (Buck-Boost)
Vin
DC Input
1
+
Internal
Regulator
Enable
Enable
5
4
Feed
Back
R2
+_-
R1
1K
1.23V
Band-Gap
Reference
Fixed Gain
3Amp.
Error amp. Comparator _{Driver Switch}
+_-
Thermal
Shutdown
Output
2
3
L1
+
Cout
D1
52KHz
Oscillator
Reset
Current
Limited
1
Advanced Monolithic Systems http://www.ams-semitech.com