TL7770-5, TL7770-12
DUAL POWER-SUPPLY SUPERVISORS
SLVS019F – OCTOBER 1987 – REVISED JULY 1999
APPLICATION INFORMATION
VS
16
5
Reset Input
(from system)
RT
(see Note B)
1
1RESIN
VCC
1VSU
1RESET
4
To System Reset
10 kΩ
System Supply
2
1CT
1RESET
GND
8
3
To System Reset
10 kΩ
CT
NOTE B: When VCC and 1VSU are connected to the same point, it is recommended that series resistance (RT) be added between the time-delay
programming capacitor (CT) and the voltage-supervisor device terminal (1CT). The suggested RT value is given by:
R
T
V
u
V
*
10
**
,
1
I
IT
3
where V
I
+
the lesser of 7.1 V or V
R
T
C
T
S
When this series resistor is used, the td calculation is as follows:
t
d
+
1.3
*
(6.5E
*
5)
6.5
10
*
5
10
*
5
Figure 4. System Reset Controller With Undervoltage Sensing
8
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
TI [ TEXAS INSTRUMENTS ]
