LM9070

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SNVS130E – DECEMBER 1999 – REVISED APRIL 2013

ON/OFF, KEEP-ALIVE AND SAFETY LATCH-OFF CONTROL DIAGRAMS

Note: If Keep-Alive is provided by a microprocessor powered by the output voltage of the LM9070, the logic “1”

(Keep-Alive input must be high to turn OFF output)

Turn ON with ON/OFF control, Keep output biased with Keep-Alive

input, Turn OFF with Keep-Alive (Keep-Alive low keeps output ON,

Keep-Alive going high turns output OFF)

Figure 17. Simple ON/OFF control

Figure 18. Keep-Alive Mode

Keep output biased with Keep-Alive; Hold ouput ON with ON/OFF;

(ON/OFF going high required to turn Output back ON)

Turn OFF with ON/OFF input. (Temporary Keep-Alive Mode)

Figure 19. Switch ON with ON/OFF input

Alive Mode

Control Logic Truth Table

ON/OFF

Keep-Alive

Output

Reset

Operating Condition

Input

Input

Voltage

Output

L

X

0V

L

Low quiescent current standby (OFF) condition

↑

X

5V

↑ after delay

Output turns ON

H

X

5V

H

Normal ON condition

↓

H

0V

L

Output turns OFF

↓

L

5V

H

Output kept ON by Keep-Alive Input

↑

L

5V

H

Output remains ON (or turns ON)

H

X

L

Output pulled out of regulation, reset flag generated

L

L

L

Output latches OFF

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