Datasheet

DS1808
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DS1808 BLOCK DIAGRAM Figure 1
PIN DESCRIPTIONS
V
CC
– Power Supply Terminal. This pin acts as the positive rail. The DS1808 will support positive supply
voltages ranging from 5 to 13.2 volts. When V
CC
–V
B
is less than 8 volts the series wiper resistance will
increase up to 1kW. The value of V
DD
should never exceed V
CC
.
V
B
– Substrate Bias Supply. This pin acts as a negative rail. The DS1808 will support negative voltages
ranging from 0 to -13.2 volts. When V
CC
–V
B
is less than 8 volts the series wiper resistance will increase
up to 1kW.
V
DD –
DC Supply Terminal. 5V DC voltage supply. The value of V
DD
should never exceed V
CC
.
GND – Ground Terminal.
SDA – 2-wire serial data interface. The serial data pin is for serial data transfer to and from the DS1808.
The pin is open drain and may be wire-ORed with other open drain or open collector interfaces.
SCL – 2-wire serial clock interface. The serial clock input is used to clock data into the DS1808 on rising
edges and clock data out on falling edges.
/CE – Port Enable Pin. When active (/CE=0), the port inputs SDA and SCL are recognized by the device.
If inactive (/CE=1), the port input pins SDA and SCL are disabled making 2-wire communication
impossible.
Control Logic
W
0
L
0
H
0
L
1
H
1
W
1
0dB0dB
>90dB
60dB
V
CC
(+12V Supply)
SCL
Power Supply V
B
(-12V Supply)
60dB
>90dB
SDA
GND
CE
V
DD
(5V Supply)
Address Lines
A0 – A2