MIC24420 Datasheet, PDF (1/34 Pages) Micrel Semiconductor – 2.5A Dual Output PWM Synchronous Buck Regulator IC

MIC24420/MIC24421
2.5A Dual Output PWM Synchronous
Buck Regulator IC
General Description
Features
The MIC24420/MIC24421 are synchronous PWM dual
output step down converters with internal 2.5A high-side
switches. The MIC24420/MIC24421 has an integrated low-
side gate driver for synchronous step-down conversion by
connecting an external N-channel MOSFET to achieve
high efficiencies in low duty-cycle applications.
The MIC24420 switching frequency is 1MHz and the
MIC24421 switching frequency is 500kHz. A patented
control scheme allows the use of a wide range of output
capacitance from small ceramic capacitors to large
electrolytic types with only one compensation component.
A 2% output voltage tolerance over the temperature range
allows the maximum level of system performance. The
MIC24420/MIC24421 power good signal allows full control
for sequencing the output voltages with minimum external
components.
An adjustable current limit allows the use of smaller
inductors in lower current applications.
The MIC24420/MIC24421 is available in a ePad 24-pin
4mm x 4mm MLF^® package, and has an operating junction
temperature range of –40°C to +125°C.
• 4.5V to 15V input voltage range
• Adjustable output voltages down to 0.7V
• 2.5A per channel
• 180° out of phase operation
• Pre-biased output startup capability
• Low-side driver for synchronous operation
• 2% output voltage accuracy (over temperature)
• 500kHz (MIC24421) and 1MHz (MIC24420) switching
frequency
• Output voltage sequencing
• Programmable max current limit
• Power good output
• Ramp Control™ provides soft-start
• Low-side current sensing allows very low duty-cycle
• Works with ceramic output capacitors
• 24-pin 4mm x 4mm MLF^® package
• Junction temperature range of –40°C to +125°C
Applications
• Multi-output power supplies with sequencing
• DSP, FPGA, CPU and ASIC power supplies
• Telecom and networking equipment, servers
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Typical Application
MIC24420 Dual Output Buck Converter
Ramp Control is a trademark of Micrel, Inc.
MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel [phone] • fax + 1 [phone] • http://www.micrel.com
June 2012
M9999-062012-C