DS1616 datasheet(4/29 Pages) DALLAS

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DS1616

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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.

I/O (3-Wire Input/Output) - The I/O pin is the data Input/Output signal for the 3-wire synchronous

communications channel.

RST

(3-Wire Reset Input) - The RST pin is the communications reset pin for the 3-wire synchronous

communications channel.

(Interrupt Output) - The INT pin is an open drain active low output that can be connected to an

interrupt input of a microprocessor. The INT output remains low as long as the status bit causing the

interrupt is present and the corresponding interrupt-enable bit is set.

INSPEC

(Open Drain In-Specification Output) - This pin, in conjunction with the OUTSPEC pin, is

used to signal the status of the operation and data of the DS1616.

OUTSPEC

(Open Drain Out-of-Specification Output) - This pin, in conjunction with the INSPEC pin,

is used to signal the status of the operation and data of the DS1616.

(Start/Status Button Input) - The ST pin provides two functions. First, when enabled as the datalog

start source (SE bit in Control 1 register is a logic 1), the ST pin is used to instruct the DS1616 to begin

recording data based on the programmed start delay and data sample rate. The ST pin must be held low

for at least 0.5 seconds for a datalog mission to begin.

Secondly, the ST pin can be used to poll the status of the recorded data. After datalogging has begun, the

pin instructs the DS1616 to report the status of the recorded data via the INSPEC and OUTSPEC pins.

AIN1, AIN2, AIN3 (Analog Inputs) - The AINx pins are the mux’ed inputs to the ADC.

X1, X2 - Connections for a standard 32.768 kHz quartz crystal, Daiwa part number DT-26S or

equivalent. For greatest accuracy, the DS1616 must be used with a crystal that has a specified load

capacitance of 6 pF. There is no need for external capacitors or resistors. Note: X1 and X2 are very high

impedance nodes. It is recommended that they and the crystal be guard-ringed with ground and that high

frequency signals be kept away from the crystal area. For more information on crystal selection and

crystal layout considerations, please consult Application Note 58, “Crystal Considerations with Dallas

Real Time Clocks.”

NC (No Connect) - These pins should be left unconnected or tied to ground.

DS1616 Datasheet(PDF) 4 Page - Dallas Semiconductor