Step down regulator powers ddr1, ddr2 and ddr3 memory
1 min read
Linear Technology's LTC3634 is a dual channel monolithic synchronous step down regulator, which provides power supply and bus termination rails for ddr1, ddr2 and ddr3 SDRAM controllers.
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The device operates from an input voltage from 3.6 to 15V and is targeted at dual cell Li-Ion applications as well as 5 and 12V intermediate bus systems. It incorporates a constant frequency/controlled on time, current mode architecture, which is suitable for powering ddr applications from a 12V input supply at high switching frequencies. Its termination voltage is set to ½ of VDDQ down to 0.6V with an accuracy rated at ±1.6%.
Each channel uses internal switches with Rds(on) of 65 and 130Mohms to deliver efficiencies up to 95%. The two channels run 180° out of phase, minimising the size of both input and output capacitance. An on-chip buffer capable of driving a 10mA load is optimised to provide a low noise reference output also at VDDQ/2. Additional features include power good voltage monitors, input overvoltage and overtemperature protection, as well as short circuit protection.