LTC3728 Dual 550kHz 2-Phase Synchronous Step-Down Switching Regulator

32 pin plastic QFN package. Manufactured by Linear Technology

Description

The LTC®3728 is a dual high performance step-down switching regulator controller that drives all N-channel synchronous power MOSFET stages. A constant-frequency current mode architecture allows phase-lockable frequency of up to 550kHz. Power loss and noise due to the ESR of the input capacitors are minimized by operating the two controller output stages out of phase.

Features

• Dual, 180° Phased Controllers Reduce Required Input Capacitance and Power Supply Induced Noise
• OPTI-LOOP® Compensation Minimizes C_OUT
• ±1% Output Voltage Accuracy
• Power Good Output Voltage Indicator
• Phase-Lockable Fixed Frequency 250kHz to 550kHz
• Dual N-Channel MOSFET Synchronous Drive
• Wide VIN Range: 3.5V to 36V Operation
• Very Low Dropout Operation: 99% Duty Cycle
• Adjustable Soft-Start Current Ramping
• Foldback Output Current Limiting
• Latched Short-Circuit Shutdown with Defeat Option
• Output Overvoltage Protection
• Remote Output Voltage Sense
• Low Shutdown IQ: 20μA
• 5V and 3.3V Regulators
• 3 Selectable Operating Modes: Constant-Frequency, Burst Mode® Operation and PWM
• Supplied in 32-Pin 5mm × 5mm QFN

Applications

Notebook and Palmtop Computers
Telecom Systems
Portable Instruments
Battery-Operated Digital Devices
DC Power Distribution Systems