Analog Devices Inc. AD7899AR-2

Overview

AD7899AR-2 from Analog Devices is a 14-bit, 400 kSPS successive-approximation ADC operating from a single 5 V supply, featuring unipolar input ranges of 0 V to 2.5 V or 0 V to 5 V, internal 2.5 V reference, and high-speed parallel interface. It integrates track/hold, signal scaling, and power-down via STBY pin, used in precision data acquisition systems for industrial process monitoring.

For engineers reviewing the AD7899AR-2 datasheet, AD7899AR-2 pinout, AD7899AR-2 application, or AD7899AR-2 equivalent, key selection criteria include unipolar input range support, 2.2 µs conversion time, 0.3 µs track/hold acquisition, straight binary output coding, and 3 V/5 V logic compatibility via VDRIVE.

Technical Context

The AD7899AR-2 implements a laser-trimmed internal clock oscillator (enabling 400 kSPS throughput) or accepts external CLKIN up to 6.5 MHz, with conversion initiated by CONVST rising edge. Its track/hold amplifier achieves ±1/2 LSB settling in 0.3 µs and supports full-scale sine wave inputs up to 500 kHz (–0.1 dB bandwidth).

Signal conditioning includes overvoltage protection (–1 V to +18 V on analog inputs), programmable VDRIVE (3 V or 5 V) for interfacing with mixed-voltage processors, and dual-mode BUSY/EOC signaling determined by CONVST state at conversion end.

Key Specifications

Pinout & Package

AD7899AR-2 is housed in a 28-lead SOIC (R-28) package with standard 0.3-inch body width and gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7899AR-2, AD7892AR-2 trades resolution and integration for speed and cost, while ADS8325IPW sacrifices parallel throughput and supply flexibility for higher resolution and smaller footprint-selection depends on whether system priority is speed+integration, cost+speed, or resolution+size.

Availability

AD7899AR-2 is available at Aetrix Electronics and suitable for industrial process monitoring, automated test equipment, medical instrumentation, and motor drive current sensing requiring stable component supply and long-term production continuity.

Supply support for AD7899AR-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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The AD7899 product line delivers high-speed, low-power, precision ADCs with integrated references and flexible input configurations-designed for demanding data acquisition in space-, power-, and accuracy-constrained systems.

FAQ

What input voltage ranges does the AD7899AR-2 support?

The AD7899AR-2 supports two unipolar input ranges: 0 V to 2.5 V and 0 V to 5 V. Configuration is achieved by tying VINB to GND for the 0 V–5 V range or connecting VINA and VINB together for the 0 V–2.5 V range. This eliminates external scaling components and simplifies design for sensor interfaces and DAC feedback paths in the AD7899AR-2.

Does the AD7899AR-2 include an internal voltage reference?

Yes, the AD7899AR-2 integrates a 2.5 V reference with ±10 mV initial error at 25°C and ±20 mV max error over temperature. The VREF pin provides access to this reference and accepts external 2.5 V ±5% sources. This internal reference reduces system component count and improves gain stability-key for consistent performance in the AD7899AR-2 across varying thermal conditions.

How does the AD7899AR-2 handle digital interface voltage levels?

The AD7899AR-2 uses the VDRIVE pin to set logic voltage levels: it may be tied to 3 V ±10% or 5 V ±5%, allowing direct interfacing with both 3 V microcontrollers and legacy 5 V systems. Input thresholds scale with VDRIVE (e.g., VINH = VDRIVE/2 + 0.4 V), and outputs drive to VDRIVE – 0.4 V (high) or 0.4 V (low)-ensuring robust communication without level shifters in the AD7899AR-2.

What is the conversion timing behavior of the AD7899AR-2?

The AD7899AR-2 completes conversion in 2.2 µs max using its internal laser-trimmed oscillator, achieving 400 kSPS throughput. After conversion ends, the track/hold requires 0.3 µs to reacquire the input signal before the next CONVST. To meet datasheet specifications, the next CONVST must occur ≥150 ns after BUSY/EOC goes low-this timing discipline ensures full 14-bit accuracy in every sample of the AD7899AR-2.

Can the AD7899AR-2 operate in low-power mode?

Yes, the AD7899AR-2 supports standby mode via the STBY pin: pulling STBY low reduces supply current to 20 µA typical (5 µA typ). In this state, the internal oscillator and track/hold are disabled, but the part retains configuration and wakes within 2 µs of STBY going high. This feature enables energy-efficient burst-mode acquisition in portable or battery-powered systems using the AD7899AR-2.