Analog Devices Inc. AD7894ARZ-10

Overview

AD7894ARZ-10 from Analog Devices is a 14-bit successive-approximation ADC with ±10 V input range, 5 µs conversion time in high-speed mode, single +5 V supply operation, and integrated track/hold amplifier - used in precision data acquisition systems for industrial instrumentation and motor control feedback loops.

For engineers reviewing the AD7894ARZ-10 datasheet, AD7894ARZ-10 pinout, AD7894ARZ-10 application, or AD7894ARZ-10 equivalent, this page delivers verified electrical specifications, SO-8 package layout, real-world use cases, and two confirmed alternative parts with documented functional and interface differences.

Technical Context

The AD7894ARZ-10 implements a laser-trimmed internal clock driving a 14-bit R-2R ladder SAR core, with on-chip buffered reference input (2.375 V to 2.625 V) and high-impedance analog front-end optimized for ±10 V bipolar signals. Its track/hold achieves 0.35 µs acquisition time and 7.5 MHz small-signal bandwidth.

It supports two operating modes: Mode 1 (5 µs conversion, continuous operation) and Mode 2 (10 µs effective conversion including 5 µs wake-up from auto-power-down), both using a 2-wire serial interface (SCLK/SDATA) with 16-bit output format (two leading zeros + 14-bit twos-complement data).

Key Specifications

Pinout & Package

AD7894ARZ-10 is housed in an 8-lead narrow-body SOIC (SO-8) package with standard JEDEC MS-012AC footprint (5.3 mm × 6.2 mm, 1.27 mm pitch). Pin 1 marked by notch or dot; pins numbered counterclockwise.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 14-bit serial ADC applications.

Compared with AD7894BRZ-10, the AD7894ARZ-10 trades 0.5 LSB linearity for lower cost and broader availability; versus ADS8325IPW, it offers simpler single-supply operation and integrated reference buffering at the expense of 2-bit resolution and slower throughput.

Availability

AD7894ARZ-10 is available at Aetrix Electronics and suitable for industrial process monitoring, motor control feedback, and portable test equipment requiring stable component supply with long-term lifecycle assurance.

Supply support for AD7894ARZ-10 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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, founded in 1965 and headquartered in Wilmington, MA.

The AD7894 product line delivers compact, single-supply 14-bit ADCs with integrated track/hold and serial interfaces - designed specifically for space-constrained, low-power industrial and instrumentation applications demanding ±10 V input capability.

FAQ

What is the maximum sampling rate achievable with AD7894ARZ-10?

The AD7894ARZ-10 supports up to 160 kHz sampling in Mode 1 operation: 5 µs conversion time + 1.0 µs serial read (at 16 MHz SCLK) + 250 ns quiet time = 6.25 µs minimum cycle time. This assumes optimal timing margins and proper track/hold settling; actual system rate may be lower depending on host processor interface latency and bus contention.

Does AD7894ARZ-10 require an external reference voltage?

Yes, the AD7894ARZ-10 requires an external +2.5 V ±5% reference applied to the REF IN pin. The device includes on-chip buffering with ≤1 µA input current, enabling direct connection to precision references such as the AD780 or ADR421. Using an inaccurate or noisy reference directly impacts gain error and SNR performance of the AD7894ARZ-10.

Can AD7894ARZ-10 interface directly with an SPI bus?

The AD7894ARZ-10 uses a 2-wire serial interface (SCLK and SDATA) compatible with SPI master mode when configured for CPOL=0, CPHA=1 - data sampled on falling SCLK edge, output valid for 10 ns after that edge. No chip-select line is provided; external logic must manage timing to avoid overlapping read cycles. Full SPI protocol compliance requires external gating for multi-device buses.

What is the purpose of the BUSY pin on AD7894ARZ-10?

The BUSY pin on AD7894ARZ-10 is an active-high, open-drain status indicator that asserts high on the falling edge of CONVST and remains high until conversion completes (5 µs later in Mode 1). It allows host systems to poll conversion status without reading SDATA, enabling efficient resource scheduling in interrupt-driven or RTOS-based firmware handling the AD7894ARZ-10.

How does the auto power-down mode work in AD7894ARZ-10?

In AD7894ARZ-10 Mode 2, the part automatically enters power-down (20 µA IDD) when CONVST remains low after conversion completes. A rising edge on CONVST triggers a ~5 µs internal wake-up before the next falling edge initiates conversion. This reduces average power in low-duty-cycle applications - e.g., 1 kHz sampling yields ~99% power savings versus continuous Mode 1 operation.