Date: 5/25/04

SP691A/693A/800L/800M Low Power Microprocessor Supervisor with Battery Switch-Over © Copyright 2004 Sipex Corporation

15

Input Supply Voltage

via a parallel diode and a large PMOS switch.

The switch carries the entire current load for

currents less than 250mA. The parallel diode

carries any current in excess of 250mA. Both

the switch and the diode have impedances

less than 1

Ω each. Refer to Figure 24. The

maximum continuous current is 250mA, but

power-on transients may reach a maximum of 1A.

Backup-Battery Input

diode are much smaller. Refer to Figure 24.

Accordingly, the on-resistances of the diode and

the switch are each approximately 10

Ω.

Table 2. Input and Output Status in Battery-Backup Mode; to enter the Battery-Backup Mode, V

reset threshold and less than V

Figure 24. V

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