Features

• 3-Phase Controller with Onboard MOSFET Drivers
• ±5% Output Current Matching Optimizes Thermal Performance and Size of Inductors and MOSFETs
• 4.5V </= V_CC </= 7V; 4.5V </= V_IN </= 32V
• Differential Amplifier Accurately Senses V_OUT
• Reduced Input and Output Capacitance
• Reduced Power Supply Induced Noise
• VID DAC Programmable from 1.1V to 1.85V (VRM9.0/9.1)
• ±10% Power Good Output Indicator
• 250kHz to 600kHz Per Phase, PLL, Fixed Frequency
• PWM, Stage Shedding™ or Burst Mode® Operation
• OPTI-LOOP® Compensation Minimizes C_OUT
• Adjustable Soft-Start Current Ramping
• Short-Circuit Shutdown Timer with Defeat Option
• Overvoltage Soft Latch
• Small 36-Lead Narrow (0.209 inch) SSOP Package
• QFN 5mm x 7mm 38-Lead Package

Typical Application

Description

The LTC3732 is a PolyPhase synchronous step-down switching regulator controller that drives all N-channel external power MOSFET stages in a phase-lockable fixed frequency architecture. The 3-phase controller drives its output stages with 120° phase separation at frequencies of up to 600kHz per phase to minimize the RMS current losses in both the input and output filter capacitors. The 3- phase technique effectively triples the fundamental frequency, improving transient response while operating each controller at an optimal frequency for high efficiency and ease of thermal design. Light load efficiency is optimized by using a choice of output Stage Shedding or Burst Mode technology.

A differential amplifier provides true remote sensing of both the high and low side of the output voltage at load points.

Soft-start and a defeatable, timed short-circuit shutdown protect the MOSFETs and the load. A foldback current circuit also provides protection for the external MOSFETs under short-circuit or overload conditions.

LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode, OPTI-LOOP and PolyPhase are registered trademarks of Linear Technology Corporation. Stage Shedding is a trademark of Linear Technology Corporation.