Datasheet AD7739 (Analog Devices) - 10

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Data Sheet AD7739 Pin No. Mnemonic Description
19 AGND Ground Reference Point for Analog Circuitry. 20 RDY Logic Output. Used as a status output in both conversion mode and calibration mode. In conversion mode, a falling edge on this output indicates that either any channel or all channels have unread data available, according to the RDYFN bit in the I/O port register. In calibration mode, a falling edge on this output indicates that calibration is complete (see the Digital Interface Description section for details). 21 DOUT Serial Data Output. Serial data is read from the output shift register on the part. This output shift register can contain information from any AD7739 register, depending on the address bits of the communications register. 22 DIN Serial Data Input (Schmitt Triggered). Serial data is written to the input shift register on the part. Data from this input shift register is transferred to any AD7739 register, depending on the address bits of the communications register. 23 DVDD Digital Supply Voltage, 3 V or 5 V Nominal. 24 DGND Ground Reference Point for Digital Circuitry. Rev. A | Page 9 of 32 Document Outline Features Applications Functional Block Diagram General Description Table of Contents Revision History Specifications Timing Specifications Timing Diagrams Absolute Maximum Ratings ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics Output Noise and Resolution Specification Chopping Enabled Chopping Disabled Register Descriptions Register Access Communications Register 8 Bits, Write-Only Register, Address 0x00 I/O Port Register 8 Bits, Read/Write Register, Address 0x01, Default Value 0x30 + Digital Input Value × 0x40 Revision Register 8 Bits, Read-Only Register, Address 0x02, Default Value 0x09 + Chip Revision × 0x10 Test Register 24 Bits, Read/Write Register, Address 0x03 ADC Status Register 8 Bits, Read-Only Register, Address 0x04, Default Value 0x00 Checksum Register 16 Bits, Read/Write Register, Address 0x05 ADC Zero-Scale Calibration Register 24 Bits, Read/Write Register, Address 0x06, Default Value 0x80 0000 ADC Full-Scale Calibration Register 24 Bits, Read/Write Register, Address 0x07, Default Value 0x80 0000 Channel Data Registers 16-Bit/24-Bit, Read-Only Registers, Address 0x08 to Address 0x0F, Default Width 16 Bits, Default Value 0x8000 Channel Zero-Scale Calibration Registers 24 Bits, Read/Write Registers, Address 0x10 to Address 0x17, Default Value 0x80 0000 Channel Full-Scale Calibration Registers 24 Bits, Read/Write Registers, Address 0x18 to Address 0x1F, Default Value 0x20 0000 Channel Status Registers 8 Bits, Read-Only Registers, Address 0x20 to Address 0x27, Default Value 0x20 × Channel Number Channel Setup Registers 8 Bits, Read/Write Registers, Address 0x28 to Address 0x2F, Default Value 0x00 Channel Conversion Time Registers 8 Bits, Read/Write Registers, Address 0x30 to Address 0x37, Default Value 0x91 Mode Register 8 Bits, Read/Write Register, Address 0x38 to Address 0x3F, Default Value 0x00 Digital Interface Description Hardware Reset Access the AD7739 Registers Single Conversion and Reading Data Dump Mode Continuous Conversion Mode Continuous Read (Continuous Conversion) Mode Circuit Description Analog Inputs Sigma-Delta ADC Chopping Multiplexer, Conversion, and Data Output Timing Frequency Response Extended Voltage Range of the Analog Input Voltage Reference Inputs Reference Detect I/O Port Calibration ADC Zero-Scale Self-Calibration ADC Full-Scale Self-Calibration Per Channel System Calibration Outline Dimensions Ordering Guide