Datasheet

TL7770-5, TL7770-12
DUAL POWER-SUPPLY SUPERVISORS
SLVS019F – OCTOBER 1987 – REVISED JULY 1999
8
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
APPLICATION INFORMATION
V
S
10 kΩ
1VSU
1RESIN
GND
1RESET
1RESET
V
CC
1CT
To System Reset
10 kΩ
R
T
(see Note B)
C
T
System Supply
Reset Input
(from system)
To System Reset
5
1
4
32
8
16
NOTE B: When V
CC
and 1VSU are connected to the same point, it is recommended that series resistance (R
T
) be added between the time-delay
programming capacitor (C
T
) and the voltage-supervisor device terminal (1CT). The suggested R
T
value is given by:
R
T
V
I
V
IT
1 10
3
, where V
I
the lesser of 7.1 V or V
S
When this series resistor is used, the t
d
calculation is as follows:
t
d
1.3
(
6.5E 5
)
10
5
R
T
6.5 10
5
C
T
Figure 4. System Reset Controller With Undervoltage Sensing