Features

• High Voltage Operation: Up to 100V
• 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 Output Voltage Tracking/Soft-Start
• Generates 10V Driver Supply from Input Supply
• Synchronizable to External Clock
• Selectable Pulse Skip Mode Operation
• Power Good Output Voltage Monitor
• Adjustable On-Time/Frequency: t_ON(MIN) < 100ns
• Adjustable Cycle-by-Cycle Current Limit
• Programmable Undervoltage Lockout
• Output Overvoltage Protection
• 28-Pin SSOP Package

Typical Application

Description

The LTC3810 is a synchronous step-down switching regulator controller that can directly step-down voltages from up to 100V, making it ideal for telecom and automotive applications. The LTC3810 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 LTC3810 to drive multiple MOSFETs for higher current applications. The operating frequency is selected by an external resistor and is compensated for variations in V_IN and can also be synchronized to an external clock for switching-noise sensitive applications. A shutdown pin allows the LTC3810 to be turned off, reducing the supply current to 240μA.

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.