ECONOMONITOR™ – 3-PIN SYSTEM SUPERVISOR
WITH POWER SUPPLY MONITOR AND WATCHDOG
1
2
3
4
5
6
7
8
TC32M
tST
VDD
RS
VRST
VSTH (MIN)
VSTL (MAX)
V
(MIN)
STL
tTD
tRST
tRPD
RS
VIH
VIL
Note: tTD is the maximum elapsed time between strobes which
will keep the watchdog timer from forcing RS LOW.
(A STROBE is defined as a high-to-low transition from VSTH to VSTL).
Figure 3. Power Up / Down Reset Timing
Figure 1. Watchdog Strobe
PB OPEN
PB CLOSED
RS
VIH
VIL
tRST
Figure 2. RS Pulled Low by Push-button Reset
PIN DESCRIPTION
Pin No.
Symbol
Description
1
2
3
GND
VDD
RS
Ground.
The +5V power supply input.
RESET/STROBE (Bidirectional). The open drain goes active if:
1. VDD falls below 4.5V nominal.
2. If pulled low by an external electronic signal or switch closure.
3. If the watchdog is not strobed within the minimum watchdog timeout period.
4. During power-up and power-down.
In the input mode, RS connects to a voltage level shift network (typically a resistor divider
to VDD.) The watchdog timer is reset when processor causes a voltage level ≤ VSTL to be
applied to RS.
4
VDD
The +5V power supply input. (SOT-223 only).
TELCOM SEMICONDUCTOR, INC.
5-5
TELCOM [ TELCOM SEMICONDUCTOR, INC ]
