Data Sheet

2

Rev. 1.4, 2009-01-12

TLE 4287 G

The device has two logic inputs, EN and H. It is turned ON by a voltage > 4 V at EN, for

example by the ignition and remains active in case H is set LOW, even if the voltage at

EN goes LOW. This makes it possible to implement a self-holding circuit without external

components. When the device is turned OFF, the output voltage drops to 0 V and current

consumption tends towards 0

Design Notes for External Components

The input capacitor

C

circuit consisting of lead inductance and input capacitance can be damped by a resistor

of approx. 1

regulating circuit. Stability is guaranteed for

C

Q

≥ 100 nF within the operating

temperature range.

Table 1

State Table for Turn-On/Turn-Off Logic

Enable EN

Hold H

V

Q

Remarks

L

X

0 V

Initial state

H

X

5 V

Regulator switched on via pin 6, by ignition for

example

H

L

5 V

Pin 9 clamped active to GND by controller while

pin 6 is still HIGH

X

L

5 V

Previous state remains, even ignition is shut off:

self-holding state

L

L

5 V

Ignition shut off while regulator is in self-holding

state

L

H

0 V

Regulator shut down by releasing of pin 9 while pin

6 remains LOW, final state. No active clamping

required by external self-holding circuit (

µC) to

keep regulator shut off