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Product(s)

- Obsolete

Product(s)

Circuit description

TDA8133

6/14

3

Circuit description

The TDA8133 and the TDA8133D are dual-voltage regulators with reset and disable

functions.

The two regulation parts are supplied from a single voltage reference circuit trimmed by

zener zapping during EWS testing. Since the supply voltage of this voltage reference is

supplied.

The output stages are designed using a Darlington configuration with a typical dropout

voltage of 1.2 V.

The disable circuit will switch off pin OUTPUT2 if a voltage less than 0.8 V is applied to pin

DISABLE.

0.25 V (4.85 V Typ.), the "a" comparator (Figure 4) rapidly discharges the external capacitor

(Ce) and the reset output immediately switches to low. When the voltage at pin OUTPUT1

Afterwards, the reset output returns to high. To avoid glitches in the reset output, the second

comparator "b" has a large hysteresis (1.9 V).

Figure 4.

Reset diagram

t

RD

C

e

2.5V

×

10

μA

---------------------------

=

OUTPUT1

REG

-

+

50

a

+

-

Ce

0.6V

b

RESET

10 µA

3