AD7490 Analog Devices, AD7490 Datasheet - Page 15

• Manufacturer Part Number: AD7490
• Description: 16-Channel, 1MSPS, 12-Bit ADC with Sequencer in 28-Lead TSSOP
• Manufacturer: Analog Devices

Specifications of AD7490

• Resolution (bits): 12bit
• # Chan: 16
• Sample Rate: 1MSPS
• Interface: Ser,SPI
• Analog Input Type: SE-Uni
• Ain Range: Uni (Vref),Uni (Vref) x 2
• Adc Architecture: SAR
• Pkg Type: CSP,SOP

Figure 14 shows how a sequence of consecutive channels can be
converted on without having to program the Shadow register or
write to the part on each serial transfer. Again, to exit this mode
of operation and revert back to the normal mode of operation
CS
CS
CS
Figure 14. SEQ Bit = 1, SHADOW Bit = 1 Flowchart
DIN: WRITE TO CONTROL REGISTER,
WRITE BIT = 1,
SELECT CODING, RANGE, AND POWER MODE
SELECT CHANNEL ADD3 TO ADD0 FOR
CONVERSION,
SEQ = 1 SHADOW = 1
DOUT: CONVERSION RESULT FROM
CHANNEL 0
CONTINUOUSLY CONVERTS ON A
CONSECUTIVE SEQUENCE OF CHANNELS
FROM CHANNEL 0 UP TO AND INCLUDING
THE PREVIOUSLY SELECTED ADD3 TO ADD0
IN THE CONTROL REGISTER
CONTINUOUSLY CONVERTS ON THE
SELECTED SEQUENCE OF CHANNELS BUT
WILL ALLOW RANGE, CODING, AND SO ON,
TO CHANGE IN THE CONTROL REGISTER
WITHOUT INTERRUPTING THE SEQUENCE
PROVIDED, SEQ = 1, SHADOW = 0
DUMMY CONVERSIONS
DIN = ALL 1s
Rev. C | Page 15 of 28
POWER ON
WRITE BIT = 1,
SEQ = 1,
SHADOW = 0
of a multichannel ADC (as outlined in Figure 12), ensure that
the WRITE = 1 and SEQ = SHADOW = 0 on the next serial
transfer.
WRITE
BIT = 0
WRITE BIT = 1,
SEQ = 1,
SHADOW = 0
AD7490