CAT9557 Datasheet, PDF (3/17 Pages) ON Semiconductor – 8-Bit I2C-Bus and SMBus I/O Port

CAT9557
CAT9557
A0
A1
A2
SCL
SDA
IO0
IO1
8−bit
IO2
INPUT
FILTER
I²C−BUS/SMBus
CONTROL
INPUT/
IO3
OUTPUT
IO4
write pulse
PORTS
IO5
IO6
V_DD
read pulse
IO7
V_SS
POWER−ON
RESET
RESET
Figure 2. Block Diagram of CAT9557
Data from
Shift Register
Data from
Shift Register
Configuration
Register
D
Q
FF
Write Configuration
Pulse
CK
Q
Write Pulse
Read Pulse
Data from
Shift Register
Write Polarity
Pulse
D
Q
FF
CK
Output Port
Register
Input Port
Register
D
Q
FF
CK
Polarity Inversion
Register
D
Q
FF
CK
Output Port
Register Data
IO0
Q2
ESD Protection
Diode
V_SS
Input Port
Register Data
Polarity Inversion
Register Data
On power−up or reset, all registers return to default values.
Figure 3. Simplified Schematic of IO0
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