CAT803 Datasheet, PDF (7/14 Pages) Catalyst Semiconductor – 3-Pin Microprocessor Power Supply Supervisors

Valid reset with V_CC under 1.0V
To ensure that the CAT809 RESET pin is in a known
state when V_CC is under 1.0V, a >10kΩ pull-down resistor
between RESET pin and GND is recommended. For
the CAT810, a pull-up resistor from RESET pin to V_CC
is needed.
Power
Supply
V_CC
CAT809
RESET
GND
Power
Supply
10kΩ
CAT803, CAT809, CAT810
V_CC
CAT810
RESET
GND
10kΩ
Figure 3. RESET Valid with V_CC Under 1.0V
Figure 4. RESET Valid with V_CC Under 1.1V
Bi-directional reset pin interfacing
The CAT809/810 can interface with µP/µC bi-directional
reset pins by connecting a 4.7kΩ resistor in series with
the CAT809/810 reset output and the µP/µC bi-directional
reset pin.
Power
Supply
V_CC
BUF
Buffered
RESET
CAT809
RESET
V_CC
µP
RESET
INPUT
GND
Bi-directional
I/O Pin
GND
(For example:
68HC11)
Figure 5. Bi-directional Reset Pin Interfacing
© 2010 SCILLC. All rights reserved.

Characteristics subject to change without notice
Doc. No. MD-3004, Rev. AA