DS1808
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DS1808 BLOCK DIAGRAM Figure 1
PIN DESCRIPTIONS
VCC – 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 VCC–VB is less than 8 volts the series wiper resistance will
increase up to 1k
W. The value of VDD should never exceed VCC.
VB – Substrate Bias Supply. This pin acts as a negative rail. The DS1808 will support negative voltages
ranging from 0 to -13.2 volts. When VCC–VB is less than 8 volts the series wiper resistance will increase
up to 1k
W.
VDD – DC Supply Terminal. 5V DC voltage supply. The value of VDD should never exceed VCC.
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
W0
L0
H0
L1
H1
W1
0dB
>90dB
60dB
VCC(+12VSupply)
SCL
Power Supply
VB (-12VSupply)
60dB
>90dB
SDA
GND
CE
VDD(5VSupply)
Address Lines
A0 – A2