CAT811_05 Datasheet, PDF (7/9 Pages) Catalyst Semiconductor – 4-Pin Microprocessor Power Supply Supervisors with Manual Reset

VALID RESET WITH V_CC UNDER 1.0 V
To ensure that the CAT811 RESET pin is in a known
state when V_CC is under 1.0 V, a 100 kΩ pull-down
resistor between RESET pin and GND is recommended;
the value is not critical. For the CAT812, a pull-up
resistor from RESET pin to V_CC is needed.
Power
Supply
Power
Supply
VCC
CAT811
MR
RESET
GND
100kΩ
CAT811, CAT812
VCC
CAT812
MR
RESET
GND
100kΩ
Figure 3. RESET Valid with V_CC Under 1.0 V
Figure 4. RESET Valid with V_CC Under 1.1 V
BI-DIRECTIONAL RESET PIN INTERFACING
The CAT811/812 can interface with µP/µC bi-directional
reset pins by connecting a 4.7 kΩ resistor in series with
the CAT811/812 reset output and the µP/µC bi-directional
reset pin.
Power
Supply
VCC
BUF
Buffered
RESET
CAT811
4.7kΩ
µP
MR
RESET
RESET
INPUT
GND
Bi-directional
I/O Pin
GND
(For example: 68HC11)
Figure 5. Bi-directional Reset Pin Interfacing
© 2005 by Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
7
Doc No. 3005, Rev. R