Features

• V_OUT as Low as 0.4V
• High Power Switching Regulator Controller for DDR Memory Termination
• V_OUT Tracks 1/2 of V_IN or External V_REF
• No Current Sense Resistor Required
• Low V_CC Supply: 3V to 8V
• Maximum Duty Cycle > 91% Over Temperature
• Drives All N-Channel External MOSFETs
• High Efficiency: Up to 95%
• Programmable Fixed Frequency Operation:
  100kHz to 500kHz
• External Clock Synchronization Operation
• Programmable Soft-Start
• Low Shutdown Current: <10µA
• Overtemperature Protection
• Available in 16-Pin Narrow SSOP Package

Typical Application

Description

The LTC3831-1 is a high power, high efficiency switching regulator controller designed for DDR memory termination. The LTC3831-1 generates an output voltage equal to 1/2 of an external supply or reference voltage. The LTC3831-1 uses a synchronous switching architecture with N-channel MOSFETs. Additionally, the chip senses output current through the drain-source resistance of the upper N-channel FET, providing an adjustable current limit without a current sense resistor.

The LTC3831-1 operates with input supply voltage as low as 3V and with a maximum duty cycle of >91%. It includes a fixed frequency PWM oscillator for low output ripple operation. The 300kHz free-running clock frequency can be externally adjusted or synchronized with an external signal from 100kHz to above 500kHz. In shutdown mode, the LTC3831-1 supply current drops to <10µA.