AQ1541 Datasheet, PDF (1/10 Pages) Acutechnology Semiconductor – Low Dropout 1 Amp Voltage Regulator with Enable Function

Product Specification
Revision 2.2
AQ1541
Low Dropout
1 Amp Voltage Regulator
with Enable Function
September 13, 2006
General Description
The AQ1541 is a low dropout three terminal
voltage regulator, offered in popular fixed options
or an adjustable version that can set a precise
voltage from 1.22V to 12V with two external
resistors.
It drops into the footprint of the popular LM1117
SOT-223 and provides a true fourth pin
separated from the output tab. The extra pin
allows for an enable function that provides a
remote turn-off for low power consumption. It
draws virtually zero current in shutdown mode.
The Enable pin implements Sequential, Ratio-
metric, or Simultaneous sequencing schemes.
To assure accuracy within 1.5% over
temperature the heart of the AQ1541 is a self-
correcting AcuRef™ bandgap reference.
On-chip current limit and thermal shutdown with
hysteresis protects against any combination of
overload and ambient temperature that might
cause the junction temperature to exceed safe
limits.
The AQ1541 is featured in the new
SOT223 4-lead TetraPack^TM package.
Applications
• Graphic cards
• PC motherboards
• Switching power supply post-regulation
• Telecom equipment
• DVD video player
Features
• Enable pin implements sequencing in
SOT223-3 footprint
• Vout tolerance 1.5% over temperature
• Eliminates expensive components
• Stable with low cost 1uF capacitor
• Low dropout voltage (1V at 1 Amp)
• Thermal protection with hysteresis
• Short circuit protection
• Offered with 1.8V, 2.5V, and 3.3V fixed or
adjustable output
• RoHS compliant available
Typical Application
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AQ1541