SC486 View Datasheet(PDF) - Semtech Corporation

Part Name

Description

Manufacturer

SC486

Complete DDR1/2/3 Memory Power Supply

Semtech Corporation 

POWER MANAGEMENT

Pin Configuration

Top View

SC486

Ordering Information

DEVICE

PACKAGE(1)

SC486IMLTRT(2)

MLPQ-24

SC486EVB

Evaluation Board

Note:

(1) Only available in tape and reel packaging. A reel

contains 3000 devices.

(2) Lead-free product. This product is fully WEEE and

RoHS compliant.

(MLPQ-24)

Pin Descriptions

Pin # Pin Name Pin Function

1

EN/PSV Enable/Power Save input pin. Tie to ground to disable VDDQ. Tie to +5V to enable VDDQ and

activate PSAVE mode. Float to enable VDDQ and activate continous conduction mode. If floated,

bypass to VSSA with a 10nF capacitor.

2

TON

This pin is used to sense VBAT through a pullup resistor, RTON, and set the top MOSFET on-

time. Bypass this pin with a 1nF capacitor to VSSA.

3

VDDQS Sense pin for VDDQ. Used to set the on-time for the top MOSFET and also to set VREF/VTT. Use

a 10Ω/1µF RC filter from VDDQ to VSSA.

4

VSSA Ground reference for analog circuitry. Connect directly to R9, C6, C7, C8, and C9 (see Page 1) on

same side of PCB as I.C. Connect to thermal pad.

5

VCCA Supply voltage input for the analog supply. Use a 10Ω/1µF RC filter from 5VSUS to VSSA.

6

FB

Feedback input for VDDQ. Connect to a resistor divider from the output to VSSA to set the output

voltage between 1.5V and VCCA.

7

PGD Power good output for VDDQ. PGD is low if VDDQ is outside the power good thresholds. This pin

is an open drain NMOS output and requires an external pull-up resistor.

8

REF Reference output. An internal resistor divider from VDDQS sets this voltage to 50% VDDQ

(nominal). Bypass this pin with a series 10Ω/1µF to VSSA. The connection to R6 (see Page 1)

should be made close to pin 8.

9

COMP Error amplifier compensation for VTT output.

10

VTTS Sense pin for VTT. Connect to VTT at the load.

11

VTTEN Enable pin for VTT. Pull this pin low to disable VTT (VREF remains present as long as VDDQ is

present).

12,13

VTTIN

Input supply for the high side switch for VTT regulator. Decouple this pin with a 1µF capacitor to

PGND2.

 2006 Semtech Corp.

6

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