CAT811_08 Datasheet, PDF (7/11 Pages) Catalyst Semiconductor – 4-Pin Microprocessor Power Supply Supervisors with Manual Reset

CAT811, CAT812
VALID RESET WITH V_CC UNDER 1.0V
To ensure that the CAT811 R¯¯E¯S¯E¯T¯ pin is in a known
state when V_CC is under 1.0V, a 100kΩ pull-down
resistor between R¯¯E¯S¯E¯T¯ 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
V_CC
CAT811
MR RESET
GND
100kΩ
Power
Supply
V_CC
CAT812
MR RESET
GND
100kΩ
Figure 3. R¯¯E¯S¯E¯T¯ Valid with V_CC under 1.0V
Figure 4. RESET Valid with V_CC under 1.1V
BI-DIRECTIONAL RESET PIN INTERFACING
The CAT811/812 can interface with µP/µC bi-
directional reset pins by connecting a 4.7kΩ resistor in
series with the CAT811/812 reset output and the
µP/µC bi-directional reset pin.
Power
Supply
BUF
Buffered
RESET
CAT811
MR RESET
GND
4.7kΩ
V_CC
(for example: 68HC11)
µP
RESET
INPU_CT_AT811
GND
Bi-directional I/O Pin
Figure 5. Bi-directional Reset Pin Interfacing
© Catalyst Semiconductor, Inc.
7
Characteristics subject to change without notice
Doc. No. MD-3005 Rev. S