AAC242 Datasheet, PDF (1/8 Pages) List of Unclassifed Manufacturers – Current Mode PWM Contoller

Power Management AAC242/243
AAC242/243
Current Mode PWM Contoller
PRELIMINARY DATA
DESCRIPTION
The AAC242 and AAC243 are part of AAI’s new
family of specialty products for Power Management
applications. The AAC242 and AAC243 are high
performance integrated circuits designed for Off-line
or DC to DC converters using peak current mode
control. The AAC24X has a current sense of 250mV
in comparison to 1V for AAC14X parts.
In offline AC designs the startup is improved by the
low start-up current of the family. The integrated
soft-start function adds to the easy of using the
AAC24X parts in offline applications.
The AAC242 and AAC243 are identical except for the
Under Voltage Lockout. The AAC242 has UVLO_on
threshold of 16V and off of 10V making it easy to use
in offline supplies where startup requirements for
energy storage is necessary. For applications using
lower supply voltages the AAC243 has UVLO_on of
8.4V and UVLO_off of 7.6V.
The AAC24X family is offered in DIP and SMD
packages. The packages are industry standards and
are ROHS compliant. Extended temperature is
standard with the AAC24X family.
The greater than 1A output driver is ideal for driving
MOSFETs and low power IGBTs. Rise and fall times
are typically less that 30ns with a 1000pF load. The
improvements in switching speed can provide
improvements in efficiency, higher operating
frequency and over current protection.
The AAC24X family has a minimum pulse width of
0.4% allowing operation at very low power without
pulse skipping or erratic operation. The narrower
pulse width capibilities enhances operation at higher
frequencies and voltages.
FEATURES
• Low Start-up current
• Pulse by pulse current limiting
• On board voltage reference
• Under Voltage Lockout with hysteresis
• Simple oscillator circuit
• Over Voltage protection zener
• High current output driver
• Less than 30ns rise and fall times
• Operation to over 1MHz
• Peak Current Mode control
• Integrated Soft-Start Function (~330 Clock
Cycles)
• 100ns leading edge current blanking for reduced
filtering
• 250mV current sense
PIN CONFIGURATION: 8-Lead DIP and SOIC8
View of the AAC24X shown from the top.
COMP 1 8 VREF
VFB ^AAC242 VCC
ISENSE ^AAC243 OUT
Rt/Ct 4 5 GND
© Copyright 2010- ASIC Advantage, Inc. – AADS00012 / R127B - Preliminary - October 2010 1 / 8