Features

• High Voltage Operation: Up to 60V
• Large 1Ω Gate Drivers
• No Current Sense Resistor Required
• Dual N-Channel MOSFET Synchronous Drive
• Extremely Fast Transient Response
• ±0.5% 0.8V Voltage Reference
• Programmable Soft-Start
• Generates 5.5V Driver Supply
• Selectable Pulse-Skipping Mode Operation
• Power Good Output Voltage Monitor
• Adjustable On-Time/Frequency: t_ON(MIN) < 100ns
• Adjustable Cycle-by-Cycle Current Limit
• Undervoltage Lockout On Driver Supply
• Output Overvoltage Protection
• Thermally Enhanced 16-Pin TSSOP Package

Typical Application

Description

The LTC3812-5 is a synchronous step-down switching regulator controller that can directly step down voltages from up to 60V input, making it ideal for telecom and automotive applications. The LTC3812-5 uses a constant on-time valley current control architecture to deliver very low duty cycles with accurate cycle-by-cycle current limit without requiring a sense resistor.

A precise internal reference provides 0.5% DC accuracy. A high bandwidth (25MHz) error amplifier provides very fast line and load transient response. Large 1Ω gate drivers allow the LTC3812-5 to drive large power MOSFETs for higher current applications. The operating frequency is selected by an external resistor and is compensated for variations in V_IN. A shutdown pin allows the LTC3812-5 to be turned off reducing the supply current to <230μA.

Integrated bias control generates gate drive power from the input supply during start-up and when an output short-circuit occurs, with the addition of a small external SOT23 MOSFET. When in regulation, power is derived from the output for higher efficiency.