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