
TS823/824/825
1-6
2003/12 rev. A
TS823/824/825
Microprocessor Supervisory Circuit with
Watchdog Timer & Manual Reset
7 Voltage Threshold Voltage Option
From 2.19V ~ 4.63V
General Description
The TS823/824/825 family allows the user to customize the CPU monitoring function without any external components.
The user has a large choice of reset voltage thresholds and output driver configurations, all of which are present ant
the factory. Each wafer is trimmed to the customer’s specifications.
These circuits will ignore fast negative going transients on Vdd. The state of the reset output is guaranteed to be
correct down to 1V. After Vdd crosses above a factory present threshold, the TS823/824/825 assert a reset signal.
After a predetermined time (the “reset” interval) the reset is deasserted. If Vdd ever drops below the threshold voltage
a reset is asserted immediately. In addition to a supply monitoring function the TS823/824/825 also monitor transitions
at the watchdog (WDI) input. If a logic transition does not occur at the WDI pin within a certain time interval (the
“watchdog” interval) then a reset is asserted. The reset deasserts after the reset interval, as explained earlier.
The TS823/824/825 can both assert a reset manually by pulling the MR input to ground, and the micro-power
quiescent current make this family a natural for portable battery powered equipment.
The TS823/824/825 is available in a 5-pin SOT-25 package.
Features
Precision monitoring of +3V, +3.3V and +5V
power supply voltage
Tight voltage threshold tolerance +/-1.5%
Fully specified over temperature
210mS min. power-on reset pulse width
3uA(typ) supply current
Guaranteed reset valid to Vdd = +1V
No external components
Power supply transient immunity
Ordering Information
Note:
x
is the threshold voltage type, option as
A: 4.63V
B: 4.38V
D: 3.08V
E: 2.93V
F: 2.63V
G: 2.32V
H: 2.19V
Part No.
Operating Temp.
Package
TS823CX5
x
TS824CX5
x
TS825CX5
x
- 40 ~ +85
o
C
SOT-25
Applications
Computers and Controllers
Embedded Controllers
Intelligent instruments
Critical uP monitoring
Automotive Systems
Portable / Battery powered equipment
Pin Assignment
Function
TS823
TS824
TS825
RESET
(Active-Low)
1
1
1
Ground
2
2
2
Manual Reset
3
-
4
(RESET)
(Active-High)
-
3
3
Watchdog Input
4
4
-
Supply Voltage (Vdd)
5
5
5