Data Sheet

16

Rev. 1.6, 2009-02-03

TLE 4471

The reset delay time

t

calculated as follows:

(1)

Definitions:

•

C

•

t

•

V

•

I

For a delay capacitor

C

The undervoltage reset circuitry supervises the output voltage. In case

V

the reset threshold the reset output is set LOW after the reset reaction time

t

of the reset delay capacitor). The reset LOW signal is held down to an output voltage

V

Q1

of 1 V. Both, the reset reaction time and the reset delay time are defined by the capacitor

value.

The reset reaction time

t

LOW after the output voltage has dropped below the reset threshold. The reset reaction

time can be calculated using the following equation:

(2)

t

rd

C

DR

V

DR dt

,

,

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

×

=

t

rr

C

DR

,

,

–

I

DR dis

,

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

×

=