AD7321 Analog Devices, AD7321 Datasheet - Page 22

• Manufacturer Part Number: AD7321
• Description: 500 kSPS, 2-Channel, Software-Selectable, True Bipolar Input, 12-Bit Plus Sign ADC
• Manufacturer: Analog Devices

Specifications of AD7321

• Resolution (bits): 13bit
• # Chan: 2
• Sample Rate: 500kSPS
• Interface: Ser,SPI
• Analog Input Type: Diff-Uni,SE-Uni
• Ain Range: Bip 10V,Bip 2.5V,Bip 5.0V,Uni 10V
• Adc Architecture: SAR
• Pkg Type: SOP

AD7321
REGISTERS
The AD7321 has two programmable registers: the control register and the range register. These registers are write only registers.
ADDRESSING REGISTERS
A serial transfer on the AD7321 consists of 16 SCLK cycles. The three MSBs on the DIN line during the 16 SCLK transfer are decoded to
determine which register is addressed. The three MSBs consist of the write bit, a ZERO bit, and the register select bit. The register select
bit is used to determine which of the two on-board registers is selected. The write bit determines if the data on the DIN line following the
register select bit loads into the addressed register. If the write bit is 1, the bits load into the register addressed by the register select bit. If
the write bit is 0, the data on the DIN line does not load into any register.
Table 8. Decoding Register Select Bits and Write Bit
Write
0
1
1
ZERO
0
0
0
Register Select
0
0
1
Description
Data on the DIN line during this serial transfer is ignored.
This combination selects the control register. The subsequent 12 bits are loaded into
the control register.
This combination selects the range register. The subsequent 6 bits are loaded into the
range register.
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