DS1808 datasheet(2/17 Pages) DALLAS

2 / 17 page

DS1808

2 of 17

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

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

0dB

>90dB

60dB

VCC(+12VSupply)

SCL

Power Supply

VB (-12VSupply)

60dB

>90dB

SDA

GND

VDD(5VSupply)

Address Lines

A0 – A2

DS1808 датащи(PDF) 2 Page - Dallas Semiconductor