AOZ1231-01 Datasheet, PDF (1/17 Pages) Alpha & Omega Semiconductors – 28V/4A Synchronous EZBuckTM Regulator

AOZ1231-01
28V/4A Synchronous EZBuck^TM Regulator
General Description
The AOZ1231-01 is high-efficiency, easy-to-use DC/DC
synchronous buck regulator that operates up to 28V.
The device is capable of supplying 4A of continuous
output current with an output voltage adjustable down to
0.8V (±1.0%).
The AOZ1231-01 integrates an internal linear regulator
to generate 5.3V V_CC from the input source. If the input
voltage is lower than 5.3V, the linear regulator operates
in low drop-output mode and the V_CC voltage is equal to
input voltage minus the drop-output voltage of the
internal linear regulator.
A proprietary constant on-time PWM control with input
feed-forward results in ultra-fast transient response while
maintaining relatively constant switching frequency over
the entire input voltage range. The switching frequency
can be externally set up to 1MHz.
The devices feature multiple protection functions such
as V_CC under-voltage lockout, cycle-by-current limit,
output over-voltage protection, short-circuit protection,
and thermal shutdown.
The AOZ1231-01 is available in a 5mm × 5mm
QFN-30L package and is rated over a -40°C to +85°C
ambient temperature range.
Features
 Wide input voltage range:
– 4.5V to 28V (internal V_CC)
– 2.7V to 28V (external V_CC)
 4A continuous output current
 Output voltage adjustable to 0.8V (±1.0%)
 Low R_DS(ON) internal NFETs
– 40m high-side
– 25m low-side
 Constant On-time with input feed-forward
 Programmable frequency up to 1MHz
 Internal 5.3V, 20mA linear regulator
 Ceramic capacitor stable
 Adjustable soft start
 Power Good output
 Over voltage protection
 Integrated bootstrap diode
 Cycle-by-cycle current limit
 Short-circuit protection
 Thermal shutdown
 Thermally enhanced 5mm × 5mm QFN-30L package
Applications
 Portable computers
 Compact desktop PCs
 Servers
 Graphics cards
 Set top boxes
 LCD TVs
 Cable modems
 Point of load DC/DC converters
 Telecom/Networking/Datacom equipment
Rev. 1.1 June 2012
www.aosmd.com
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