ADS8519_08 Datasheet, PDF (15/27 Pages) Texas Instruments – 16-Bit, 250kSPS, Serial, CMOS, Sampling ANALOG-TO-DIGITAL CONVERTER

ADS8519
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SLAS462A – JUNE 2007 – REVISED MARCH 2008
TYPICAL CHARACTERISTICS (continued)
INL
10000
20000
30000
40000
Code
Figure 26.
DNL
50000
60000
70000
10000
20000
30000
40000
Code
Figure 27.
50000
60000
70000
BASIC OPERATION
Two signals control conversion in the ADS8519: CS and R/C. These two signals are internally ORed together. To
start a conversion, the chip must be selected (CS low) and the conversion signal must be active (R/C low). Either
signal can be brought low first. Conversion starts on the falling edge of the second signal. BUSY goes low when
conversion starts and returns high after the data from that conversion are shifted into the internal storage
register. Sampling begins when BUSY goes high.
To reduce the number of control pins, CS can be tied low permanently. The R/C pin then controls conversion and
data reading exclusively. In the external clock mode, this configuration means that the ADS8519 clocks out data
whenever R/C is brought high and the external clock is active. In the internal clock mode, data are clocked out
every convert cycle, regardless of the states of CS and R/C. The ADS8519 provides a TAG input for cascading
multiple converters together.
READING DATA
The conversion result is available as soon as BUSY returns to high; therefore, data always represent the
conversion previously completed, even when it is read during a conversion. The ADS8519 outputs serial data in
either straight binary or binary two’s complement format. The SB/BTC pin controls the format. data are shifted
out MSB first. The first conversion immediately following a power-up does not produce a valid conversion result.
Data can be clocked out with either the internally-generated clock or with an external clock. The EXT/INT pin
controls this function. If an external clock is used, the TAG input can be used to daisy-chain multiple ADS8519
data pins together.
Copyright © 2007–2008, Texas Instruments Incorporated
Product Folder Link(s): ADS8519
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