AD7329 Analog Devices, AD7329 Datasheet - Page 29

• Manufacturer Part Number: AD7329
• Description: 1 MSPS , 8-Channel, Software Selectable True Bipolar Input, 12-Bit Plus Sign A/D Converter
• Manufacturer: Analog Devices

Specifications of AD7329

• Resolution (bits): 13bit
• # Chan: 8
• Sample Rate: 1MSPS
• Interface: Ser,SPI
• Analog Input Type: Diff-Bip,Diff-Uni,SE-Uni
• Ain Range: Bip (Vref),Bip (Vref) x 2,Bip (Vref) x 4,Bip 10V,Bip 2.5V,Bip 5.0V,Uni (Vref),Uni 10V
• Adc Architecture: SAR
• Pkg Type: SOP

SEQUENCER OPERATION
The AD7329 can be configured to automatically cycle through
a number of selected channels using the on-chip sequence
register with the SEQ1 bit and the SEQ2 bit in the control
register. Figure 48 shows how to program the AD7329 register
to operate in sequence mode.
After power-up, the four on-chip registers contain default
values. Each analog input has a default input range of ±10 V. If
different analog input ranges are required, a write to the range
registers is necessary. This is shown in the first two serial
transfers of Figure 48.
CS
SEQUENCE, SEQ1 = 0, SEQ2 = 0.
FROM CHANNEL IN SEQUENCE.
DOUT: CONVERSION RESULT
DIN: WRITE TO CONTROL
REGISTER TO STOP THE
CS
CS
CS
CS
CS
CS
Figure 48. Programmable Sequence Flowchart
A SEQUENCE.
DIN: TIE DIN LOW/WRITE BIT = 0 TO CONTINUE TO CONVERT
DIN: WRITE TO RANGE REGISTER 1 TO SELECT THE RANGE
DIN: WRITE TO RANGE REGISTER 2 TO SELECT THE RANGE
DOUT: CONVERSION RESULT FROM FIRST CHANNEL IN
DIN: WRITE TO SEQUENCE REGISTER TO SELECT THE
DIN: WRITE TO SEQUENCE REGISTER TO SELECT THE
DOUT: CONVERSION RESULT FROM CHANNEL 0, ±10V
STOP
DIN: WRITE TO CONTROL REGISTER TO START THE
DOUT: CONVERSION RESULT FROM CHANNEL X IN
DOUT: CONVERSION RESULT FROM CHANNEL 0,
DOUT: CONVERSION RESULT FROM CHANNEL 0,
DOUT: CONVERSION RESULT FROM CHANNEL 0,
ANALOG INPUT CHANNELS TO BE INCLUDED IN
SINGLE-ENDED MODE, RANGE SELECTED IN
SINGLE-ENDED MODE, RANGE SELECTED IN
SINGLE-ENDED MODE, RANGE SELECTED IN
THROUGH THE SEQUENCE OF CHANNELS.
Rev. A | Page 29 of 40
SELECT A NEW SEQUENCE.
FOR EACH ANALOG INPUT CHANNEL.
FOR EACH ANALOG INPUT CHANNEL.
SEQUENCE, SEQ1 = 0, SEQ2 = 1.
RANGE, SINGLE-ENDED MODE.
THE FIRST SEQUENCE.
RANGE REGISTER 1.
RANGE REGISTER 1.
RANGE REGISTER 1.
NEW SEQUENCE.
THE SEQUENCE.
THE SEQUENCE.
POWER ON.
These two initial serial transfers are required only if input ranges
other than the default ranges are required. After the analog input
ranges are configured, a write to the sequence register is necessary
to select the channels to be included in the sequence. After the
channels for the sequence have been selected, the sequence can
be initiated by writing to the control register and setting SEQ1
to 0 and SEQ2 to 1. The AD7329 continues to convert the selected
sequence without interruption if the sequence register remains
unchanged and SEQ1 = 0 and SEQ2 = 1 in the control register.
ON THE SELECTED SEQUENCE
CONTINUOUSLY CONVERT
OF CHANNELS.
DIN TIED LOW/WRITE BIT = 0.
AD7329