© 2000 SEMTECH CORP.

652 MITCHELL ROAD NEWBURY PARK CA 91320

500mA SmartLDO

Signal Sequencing

SC1545

PRELIMINARY - January 17, 2000

6

TIMING DIAGRAMS

Power up signal sequencing is shown in Figure 1. BF_CUT, PDR and NDR follow the power rails up to their final

values. SLP goes to its high value when the power rails have stabilized, ~25msec after power on. BF_CUT is

pulled low a period T1 after SLP goes high. T1 can be as short as 1msec. Typical measured values are

~200msec. The 2.5V LDO output stays OFF through this sequence.

Figure 1: Power Up Signal Sequencing

TYPICAL CHARACTERISTICS (Cont.)

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255075

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125

VDO Current Limit vs.

Junction Temperature