Analog Devices Inc. AD7863ARSZ-3

Overview

AD7863ARSZ-3 from Analog Devices is a dual-channel, simultaneous-sampling 14-bit analog-to-digital converter (ADC) operating from a single 5 V supply. It delivers 175 kSPS throughput per channel with 5.2 μs conversion time, ±2.5 V input range, and integrated 2.5 V reference - enabling high-fidelity phase-coherent acquisition in motor control feedback loops.

For engineers reviewing the AD7863ARSZ-3 datasheet, AD7863ARSZ-3 pinout, AD7863ARSZ-3 application, or AD7863ARSZ-3 equivalent, key selection criteria include simultaneous dual-channel sampling accuracy, aperture delay matching (<350 ps), bipolar ±2.5 V input compatibility, and parallel interface timing compliance with microcontrollers such as ADSP-2100 or MC68000.

Technical Context

The AD7863ARSZ-3 integrates two independent successive approximation ADCs, each paired with a track-and-hold amplifier and sharing a common internal 2.5 V reference. Its dual-channel architecture supports simultaneous sampling of VA1/VA2 or VB1/VB2 via A0 multiplexer control, preserving inter-channel phase integrity for dynamic signal analysis.

Conversion is initiated by a falling edge on CONVST, triggering both track-and-holds into hold mode and starting parallel 14-bit conversions. Results are read sequentially over a 14-bit parallel bus (DB0–DB13) using CS and RD strobes, with BUSY indicating completion after 5.2 μs in high-speed mode.

Key Specifications

Pinout & Package

AD7863ARSZ-3 is housed in a 28-lead SOIC_W (Wide) package with 0.3 inch body width and standard 1.27 mm pitch. Pin layout supports compact PCB routing for analog/digital partitioning and decoupling.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-channel simultaneous-sampling ADC applications.

Compared with AD7863ARSZ-3, AD7656ASTZ offers greater channel count and resolution but sacrifices ±2.5 V native support and adds SPI complexity, while ADS8556IPM delivers higher speed and range flexibility at the cost of board space, power, and procurement lead time.

Availability

AD7863ARSZ-3 is available at Aetrix Electronics and suitable for motor control systems, industrial PLC analog input modules, power quality analyzers, and digital oscilloscope front-ends requiring stable component supply and long-term obsolescence management.

Supply support for AD7863ARSZ-3 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The AD7863 belongs to Analog Devices' precision high-speed data acquisition product line, designed specifically for applications demanding phase-coherent multichannel sampling in industrial automation, energy, and test equipment.

FAQ

What is the maximum sampling rate supported by the AD7863ARSZ-3?

The AD7863ARSZ-3 supports a maximum sustained sampling rate of 175 kSPS per channel in high-speed mode, with 5.2 μs conversion time. This rate is achievable only when read operations are timed to avoid the 400 ns quiet period before the next CONVST pulse, as specified in the timing diagram (Figure 2). The AD7863ARSZ-3 maintains this throughput while delivering 14-bit resolution and 77 dB SNR at 80 kHz input frequency.

Does the AD7863ARSZ-3 require an external reference voltage?

No, the AD7863ARSZ-3 includes an internal 2.5 V reference with ±10 mV accuracy at 25°C and 25 ppm/°C temperature coefficient. The VREF pin serves as both output and input: it delivers the internal reference by default, but accepts an external 2.5 V source if higher stability or lower noise is required. Using the internal reference eliminates external components and simplifies layout for the AD7863ARSZ-3 in cost-sensitive applications.

How does the AD7863ARSZ-3 handle simultaneous sampling of two analog inputs?

The AD7863ARSZ-3 uses two matched track-and-hold amplifiers that switch to hold mode simultaneously on the falling edge of CONVST, capturing VA1/VA2 or VB1/VB2 in lockstep. Aperture delay matching is guaranteed ≤350 ps, ensuring phase coherence between channels. This capability is fundamental to the AD7863ARSZ-3's role in vector control and power measurement where relative timing between signals must be preserved within sub-nanosecond tolerance.

What is the purpose of the A0 pin on the AD7863ARSZ-3?

The A0 pin on the AD7863ARSZ-3 selects which pair of analog inputs is converted during a given cycle: when A0 is low at CONVST falling edge, VA1 and VA2 are sampled; when A0 is high, VB1 and VB2 are sampled. This multiplexer control allows the AD7863ARSZ-3 to serve four distinct analog sources with only two ADC cores, reducing silicon area and power while maintaining simultaneous sampling integrity within each selected channel pair.

Can the AD7863ARSZ-3 operate from a single 5 V supply?

Yes, the AD7863ARSZ-3 is fully specified for single-supply operation at VDD = 5 V ±5%. It draws 16 mA typical in normal mode, resulting in 70 mW typical power dissipation. The device also features an auto power-down mode consuming ≤105 μW, making the AD7863ARSZ-3 suitable for portable and battery-powered instrumentation where supply headroom and efficiency are constrained.