STM1068 datasheet(8/22 Pages) STMICROELECTRONICS

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Operation

STM1068

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Operation

The STM1068 device monitors supply voltage VCC and logic states of EN and INH inputs.

According to detected states is the output OUT connected to VIN or GND and the pass gate

between PKX and POX is either enabled or disabled (see Table 2, Table 3 , and Figure 11

for more details).

2.1

Output, OUT

If the enable input is in a logic high state and inhibit input is in a logic low state, the output

will be connected to VIN input as VCC rises above the VTH+ voltage threshold. Otherwise, the

output is connected to ground GND. The output is current limited (see Table 6).

2.2

Enable input, EN

A logic low on the enable input disconnects the output, OUT, from VIN, the POX will follow

the PKX and the device enters a standby mode with very low current consumption (see

Table 6).

2.3

Inhibit input, INH

A logic high on the inhibit input disconnects the output, OUT, from VIN and the POX will

follow the PKX.

2.4

Pass gate, PKX and POX

Pass gate between PKX and POX is disabled only if enable input is in logic high, inhibit input

is in logic low and the supply voltage is below the voltage threshold.

Table 2.

Truth table for output, OUT

EN(1)

Once the device is disabled by EN input, the VCC must be above VTH+ to reconnect output to VIN.

INH

VCC

OUT

connected to GND

<VTH+ (rising edge)

<VTH- (falling edge)

connected to GND

>VTH+ (rising edge)

>VTH- (falling edge)

connected to VIN

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