DS1615 datasheet(3/24 Pages) DALLAS

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DS1615

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DS1615 BLOCK DIAGRAM Figure 1

SIGNAL DESCRIPTIONS

The following paragraphs describe the function of each pin.

VCC- VCC is a +5V input supply. Communication with the DS1615 can take place only when VCC is

connected to a +5V supply.

Vbat- Battery input for standard lithium cell or other energy source. All functions of the DS1615 with the

exception of the serial interface circuitry are powered by Vbat when VCC< Vbat. All functions are powered

by VCC when VCC > Vbat. If a battery or other energy source is not used, the Vbat pin should be connected

directly to GND.

GND - Ground

COMSEL (Communication Select Input) - This pin determines whether serial communication is

asynchronous or synchronous. When pulled high to VCC, communication is synchronous and will take

place via the SCLK, I/O, and RST pins. When COMSEL is tied to ground, asynchronous communication

utilizing the TX and RX pins is selected.

If this pin is floated, the DS1615 will operate in the

asynchronous communications mode since the COMSEL pin has a weak internal pulldown resistor.

Tx (Transmit Output) - Transmit output of the asynchronous serial interface. Tx is tri-stated whenever

VCC < Vbat.

Rx (Receive Input) - Receive input of the asynchronous serial interface.

SCLK (3-wire Serial Clock Input) - The SCLK pin is the serial clock input for the 3-wire synchronous

communications channel.

DS1615 Datasheet(PDF) 3 Page - Dallas Semiconductor