Regulator generates DDR2, 3, 3L & 4 SDRAM voltages

3rd October 2014

Siobhan O'Gorman

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Datasheet

Capable of generating the bus termination voltages needed by DDR 2, 3, 3L and 4 SDRAM memory systems, a low-dropout linear regulator has been released by Diodes Incorporated. The AP2303 regulator, which is suitable for next-gen set-top boxes, mother boards and graphics cards, continuously sources and sinks current up to 1.75A.

A regulated VTT output voltage to DDR standards with an accuracy of ±2% up to full load is provided by the regulator. An external resistor sets the required DDR memory termination supply. This is outputted via a standard MLCC, which simplifies assembly processes and reduces component cost and PCB size. The regulator operates from an input voltage range of 1.2-5.5V and a temperature range of -40 to +85ºC.

A soft-start facility, which is activated by a rising voltage on either VCNTL or VREFEN pins, minimises inrush currents generated by large capacitive loads. The regulator also shuts down if a falling voltage is applied to VIN, VCNTL or VREFEN pins, reducing power consumption. When current exceeds 1.75A, current limit protection provided on both source and sink sides drops the output voltage to 0V. Temperature protection is also provided and turns off the regulator's output when the junction temperature exceeds +160ºC.

Available in 8-pin SO and PSOP packages, the AP2303 regulator is sold in 4,000 unit quantities and priced at $0.10 each.