General Description

The MIC2155 and MIC2156 are a family of two-phase, single-output synchronous buck control ICs featuring small size, high efficiency, and a high level of flexibility. The ICs implement a 500kHz (MIC2155) and 300kHz (MIC2156) voltage mode PWM control, with the outputs switching 180° out of phase. The result of the out-of-phase operation is 1MHz (or 600kHz) input ripple with ripple current cancellation, minimizing the required input filter capacitance. A 1 output voltage tolerance allows the maximum level of system performance. Internal drivers with adaptive gate drive allow the highest efficiency with the minimum external components.

Features

? Synchronous buck control ICs with outputs switching 180° out-of-phase

? Remote sensing with internal differential amplifier

? 4.5V to 14.5V input voltage range

? Adjustable output voltages down to 0.7V

? 1 output voltage accuracy

? Starts up into a pre-biased output

? 500kHz PWM operation (MIC2155)

? 300kHz PWM operation (MIC2156)

? Adaptive gate drive allows efficiencies over 95

? Adjustable current limit with no sense resistor

? Senses low-side MOSFET current

? Internal drivers allow 25A per phase

? Power Good output allow simple sequencing

? Dual enables with micro-power shutdown and UVLO

? Programmable soft-start pin

? Output over-voltage protection

? Works with ceramic output capacitors

? Multi-input supply capability

? Single-output high-current capability with master/slave current sharing

? External synchronization

? Small footprint 32-pin 5mm × 5mm MLF?

? Junction temperature range of -40°C to +125°C

Applications

? Multi-output power supplies with sequencing

? DSP, FPGA, CPU and ASIC power supplies

? DSL modems

? Telecom and networking equipment

? Servers