AD7863ARZ-10

Overview

The AD7863ARZ-10 is a dual 14-bit analog-to-digital converter (ADC) from Analog Devices, operating on a single 5 V supply. It features two simultaneous sampling channels with four total input lines, supporting an analog input range of ±10 V. The device utilizes successive approximation architecture with a conversion time of 5.2 μs and a throughput rate up to 175 kSPS. Key specifications include a typical signal-to-noise ratio of 78 dB, differential nonlinearity of +2/-1 LSB, and integral nonlinearity of ±2.5 LSB. Power consumption is 70 mW in normal mode, dropping to 105 μW maximum in power-down mode.

Feature Summary

• Simultaneous sampling and conversion across two independent channels to preserve relative phase information between inputs.
• Integrated internal 2.5 V reference voltage source with provision for external reference connection.
• High-speed parallel interface compatible with standard microprocessor control signals.
• Analog input overvoltage protection allowing tolerance beyond the specified input range limits.

Applications

• Vector motor control systems requiring precise phase data.
• Battery-powered or portable applications utilizing automatic power-down modes.
• Industrial data acquisition systems interfacing with microprocessors or DSPs.

Procurement Notes

Verify the specific suffix '10' confirms the ±10 V input voltage range capability. Confirm package type matches system requirements, as the component is available in SOIC_W and SSOP formats. Ensure ordering documentation aligns with the manufacturer's current revision standards to guarantee functional compatibility.

Selection Notes

Select this component when simultaneous multi-channel sampling is required without external synchronization hardware. Consider the ±10 V input range specifically for industrial sensor interfaces. Evaluate the 175 kSPS throughput against system bandwidth needs and verify that the parallel interface timing meets the host processor's constraints.

Part Context

The AD7863 serves as a 14-bit upgrade path for the AD7862 family while maintaining pin compatibility. It integrates two complete ADC functions into a single 28-lead package. The device is fabricated using LC2MOS technology, combining precision bipolar circuits with low-power CMOS logic for optimized performance.

Replacement Considerations

The AD7862 is a related 12-bit predecessor. Verify if the increased resolution and simultaneous sampling capabilities of the AD7863 are necessary for the application before substitution.

FAQ

How does the A0 pin affect channel selection?

The A0 multiplexer select input determines which pair of channels is converted. If A0 is low during conversion initiation, Channel A (VA1/VA2) is selected; if high, Channel B (VB1/VB2) is selected.

What is the function of the BUSY signal?

The BUSY output goes high upon the falling edge of CONVST and remains high until the conversion process is complete, indicating when data is ready to be read.

Can the internal reference be used externally?

Yes, the internal 2.5 V reference is accessible via the VREF pin, but it should be buffered externally due to a nominal source impedance of 5.5 kΩ caused by an internal FET switch.