Analog Devices Inc. AD7863ARZ-2

Overview

AD7863ARZ-2 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 (AD7863-3 variant), and integrated 2.5 V reference - used in motor control feedback loops where phase coherence between voltage and current sensing is critical.

For engineers reviewing the AD7863ARZ-2 datasheet, AD7863ARZ-2 pinout, AD7863ARZ-2 application, or AD7863ARZ-2 equivalent, key selection criteria include simultaneous sampling capability, aperture delay matching (<350 ps), channel-to-channel isolation (−86 dB), and low-power operation (70 mW typical) in industrial real-time control systems.

Technical Context

The AD7863ARZ-2 implements two independent successive approximation register (SAR) ADCs with matched track-and-hold amplifiers, enabling true simultaneous sampling across VA1/VA2 or VB1/VB2 pairs. Its internal 2.5 V reference and laser-trimmed oscillator eliminate external clocking components while maintaining 77 dB SNR at 80 kHz input.

Control logic uses CONVST falling edge to initiate concurrent hold and conversion, with BUSY signaling completion; data is read via 14-bit parallel bus (DB0–DB13) under CS/RD handshaking. Aperture delay matching (350 ps max) and 0.5 μs acquisition time ensure sub-degree phase fidelity for vector-controlled drives.

Key Specifications

Pinout & Package

AD7863ARZ-2 is housed in a 28-lead SOIC_W (Wide Body) package with 0.6 mm lead pitch and exposed pad for thermal management. Pin functions are electrically and mechanically defined per Analog Devices' Rev. B specification.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7863ARZ-2, AD7656ASTZ offers higher resolution and channel count but demands external reference design and consumes 57% more power; ADS8556IPMR delivers faster conversion but cannot accept ±2.5 V inputs or operate without an external reference - making AD7863ARZ-2 uniquely suited for compact, self-contained dual-channel signal acquisition at 14-bit precision.

Availability

AD7863ARZ-2 is available at Aetrix Electronics and suitable for motor control systems, industrial data loggers, and power quality analyzers requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for AD7863ARZ-2 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 product line delivers dual-channel simultaneous-sampling ADCs optimized for real-time industrial control, motor drive feedback, and power system monitoring where phase coherence and deterministic timing are essential.

FAQ

What is the input voltage range supported by the AD7863ARZ-2?

The AD7863ARZ-2 supports a ±2.5 V bipolar analog input range, with overvoltage protection up to ±7 V on all analog inputs. This range is fixed for the -3 variant and cannot be reconfigured to ±10 V or 0 V to 2.5 V without selecting a different part number. The internal 2.5 V reference scales the full-scale code accordingly, ensuring consistent 14-bit quantization across the specified range. AD7863ARZ-2 maintains this specification over its full operating temperature range of −40°C to +85°C.

How does the AD7863ARZ-2 achieve simultaneous sampling across two channels?

The AD7863ARZ-2 achieves true simultaneous sampling using two physically separate track-and-hold amplifiers that respond identically to the falling edge of the CONVST signal. Both amplifiers freeze their respective input voltages (e.g., VA1 and VA2) at precisely matched instants, with aperture delay matching specified at ≤350 ps maximum. This hardware-level synchronization preserves phase relationships between signals - a requirement unmet by multiplexed single-ADC architectures. AD7863ARZ-2's functional block diagram confirms independent signal paths through scaling, track/hold, and ADC stages for each channel.

Can the AD7863ARZ-2 operate with an external reference instead of the internal one?

Yes, the AD7863ARZ-2 can operate with an external 2.5 V reference applied to the VREF pin, overriding the internal bandgap source. The datasheet specifies REF IN input voltage range as 2.375 V to 2.625 V and input current as ±100 μA max. When using an external reference, system designers must ensure its temperature coefficient and noise performance meet the required gain accuracy - since reference errors directly translate to full-scale errors in AD7863ARZ-2's transfer function. The internal reference remains enabled unless externally driven.

What is the purpose of the A0 pin on the AD7863ARZ-2?

The A0 pin on the AD7863ARZ-2 selects which pair of analog inputs undergoes simultaneous conversion: when A0 is low, VA1 and VA2 are sampled; when A0 is high, VB1 and VB2 are sampled. This multiplexer control operates independently of the CONVST trigger and must be stable before the falling edge of CONVST to ensure correct channel selection. A0 is a TTL-compatible digital input with VIH ≥ 2.4 V and VIL ≤ 0.8 V, and it has no effect on the analog signal path outside of routing - all four inputs retain identical ±2.5 V range and overvoltage protection regardless of A0 state. AD7863ARZ-2's pin configuration diagram confirms A0 as Pin 20.

Does the AD7863ARZ-2 support power-down mode, and how is it activated?

Yes, the AD7863ARZ-2 supports automatic power-down mode (Mode 2), where it enters low-power sleep after conversion completion and wakes just before the next CONVST pulse. This mode reduces IDD to 20 μA max at 25°C and cuts power dissipation to 105 μW maximum. No external control signal is needed - activation is inherent to Mode 2 timing operation, which extends conversion time to 10.0 μs to accommodate wake-up latency. The datasheet specifies that power-down behavior is guaranteed only when VDD decoupling follows recommended layout: 0.1 μF + 10 μF ceramics on VDD and dual 0.1 μF on VREF, all referenced to AGND. AD7863ARZ-2's timing characteristics table explicitly defines t_CONV = 10.0 μs for Mode 2.