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鈥檚 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 鈥渞eset鈥?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
鈥渨atchdog鈥?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
Power supply transient immunity
No external components
Ordering Information
Part No.
TS823CX5
x
TS824CX5
x
TS825CX5
x
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
- 40 ~ +85 C
o
Operating Temp.
Package
SOT-25
Applications
Computers and Controllers
Embedded Controllers
Intelligent instruments
Critical uP monitoring
Portable / Battery powered equipment
Automotive Systems
Pin Assignment
Function
RESET
(Active-Low)
Ground
Manual Reset
(RESET)
(Active-High)
Watchdog Input
Supply Voltage (Vdd)
TS823
1
2
3
-
4
5
TS824
1
2
-
3
4
5
TS825
1
2
4
3
-
5
TS823/824/825
1-6
2003/12 rev. A
1
2
3
4
5
6
