
Linear Technology
DESCRIPTION
The LTC®3831 is a high power, high efficiency switching regulator controller designed for DDR memory termination. The LTC3831 generates an output voltage equal to 1/2 of an external supply or reference voltage. The LTC3831 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.
FEATURES
◾ High Power Switching Regulator Controller
for DDR Memory Termination
◾ VOUT Tracks 1/2 of VIN or External VREF
◾ No Current Sense Resistor Required
◾ Low Input Supply Voltage Range: 3V to 8V
◾ Maximum Duty Cycle >91% Over Temperature
◾ Drives All N-Channel External MOSFETs
◾ High Efficiency: Over 95% Possible
◾ 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
APPLICATIONS
◾ DDR SDRAM Termination
◾ SSTL_2 Interface
◾ SSTL_3 Interface