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Rainbow Electronics MAX1231 User Manual

Page 18

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MAX1227/MAX1229/MAX1231

12-Bit 300ksps ADCs with FIFO,
Temp Sensor, Internal Reference

18

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Internally Timed Acquisitions and

Conversions Using the Serial Interface

Performing Conversions in Clock Mode 10

In clock mode 10, the wake-up, acquisition, conversion,
and shutdown sequences are initiated by writing an
input data byte to the conversion register, and are per-
formed automatically using the internal oscillator. This is
the default clock mode upon power-up. See Figure 6
for clock mode 10 timing.

Initiate a scan by writing a byte to the conversion regis-
ter. The MAX1227/MAX1229/MAX1231 then power up,
scan all requested channels, store the results in the
FIFO, and shut down. After the scan is complete, EOC
is pulled low and the results are available in the FIFO. If
a temperature measurement is requested, the tempera-
ture result precedes all other FIFO results. EOC stays
low until CS is pulled low again.

CS

DOUT

SCLK

CNVST

EOC

(CONVERSION2)

MSB1

LSB1

MSB2

(ACQUISITION1)

(ACQUISITION2)

(CONVERSION1)

REQUEST MULTIPLE CONVERSIONS BY SETTING CNVST LOW FOR EACH CONVERSION.

Figure 5. Clock Mode 01

(UP TO 514 INTERNALLY CLOCKED ACQUISITIONS AND CONVERSIONS)

MSB1

LSB1

MSB2

(CONVERSION BYTE)

CS

DOUT

SCLK

DIN

EOC

THE CONVERSION BYTE BEGINS THE ACQUISITION. CNVST IS NOT REQUIRED.

Figure 6. Clock Mode 10