Analog Devices Inc. AD7899AR-2REEL

Overview

AD7899AR-2REEL from Analog Devices is a 14-bit, 400 kSPS successive-approximation ADC operating from a single 5 V supply, featuring an integrated 2.5 V reference, track/hold amplifier, and high-speed parallel interface. It supports unipolar input ranges of 0 V to 2.5 V or 0 V to 5 V, delivers ±2 LSB INL, and consumes 80 mW typical power-used in precision data acquisition systems for industrial process monitoring.

For engineers reviewing the AD7899AR-2REEL datasheet, AD7899AR-2REEL pinout, AD7899AR-2REEL application, or AD7899AR-2REEL equivalent, key selection criteria include unipolar input range support, 14-bit resolution with straight binary coding, 2.2 µs conversion time, and compatibility with both 3 V and 5 V digital interfaces via VDRIVE pin.

Technical Context

The AD7899AR-2REEL implements a laser-trimmed internal clock oscillator (enabling 400 kSPS throughput) or accepts external CLKIN up to 6.5 MHz for precise timing control. Its track/hold acquires to ±1/2 LSB in 0.3 µs, supporting full-scale sine wave inputs up to 500 kHz (–0.1 dB bandwidth).

Conversion is initiated by CONVST rising edge, which places the track/hold into hold mode and triggers BUSY/EOC assertion; data is latched and read via 14-bit parallel bus (DB0–DB13) using CS and RD strobes, with VDRIVE configurable for 3 V or 5 V logic levels.

Key Specifications

Pinout & Package

AD7899AR-2REEL 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-2REEL, AD7899AR-1 lacks unipolar range support and uses two's complement, making it unsuitable for 0–5 V sensor interfaces without software remapping; ADS8325IPW trades parallel speed and integration for higher resolution and serial simplicity but increases design complexity and reduces maximum sampling rate by 75%.

Availability

AD7899AR-2REEL is available at Aetrix Electronics and suitable for industrial process monitoring, automated test equipment, portable data loggers, and motor drive current sensing requiring stable component supply and long-term obsolescence management.

Supply support for AD7899AR-2REEL 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 since 1965.

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

FAQ

What input voltage ranges does the AD7899AR-2REEL support?

The AD7899AR-2REEL 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 in sensor interface circuits. The AD7899AR-2REEL does not support bipolar ranges like ±5 V or ±10 V-those are handled by the AD7899AR-1 variant.

How does the AD7899AR-2REEL handle reference voltage sourcing?

The AD7899AR-2REEL integrates a 2.5 V ±20 mV reference with 25 ppm/°C temperature coefficient, accessible at the VREF pin. A 0.1 µF capacitor must be placed between VREF and AGND to stabilize the internal reference. Alternatively, an external 2.5 V ±5% reference (e.g., AD780 or REF43) can overdrive the internal source via the same VREF pin, enabling system-level reference synchronization. The AD7899AR-2REEL reference output has 6 kΩ source impedance and is intended for internal use unless buffered.

What is the function of the VDRIVE pin on the AD7899AR-2REEL?

The VDRIVE pin supplies power to the AD7899AR-2REEL's digital I/O circuitry-including DB0–DB13, BUSY/EOC, RD, CS, CONVST, CLKIN, and STBY-and determines logic threshold levels. It may be tied to 5 V for standard TTL/CMOS compatibility or to 3 V ±10% to interface directly with 3 V microcontrollers and FPGAs without level shifters. VDRIVE decoupling with a 0.1 µF capacitor to GND is mandatory. The AD7899AR-2REEL maintains full 14-bit performance regardless of VDRIVE voltage.

Does the AD7899AR-2REEL support external clocking, and what are the timing requirements?

Yes, the AD7899AR-2REEL supports external clocking via the CLKIN pin. When CLKIN is high on the rising edge of CONVST, the external clock drives conversion; otherwise, the internal laser-trimmed oscillator is used. The external clock must have ≤60/40 duty cycle and start no sooner than 100 ns after CONVST rising edge. Maximum recommended frequency is 6.5 MHz, yielding 400 kSPS throughput. The AD7899AR-2REEL requires 16 clock cycles per conversion, and timing parameters (e.g., t9, t10, t11) are specified in the datasheet for robust synchronization.

What packaging and compliance information applies to the AD7899AR-2REEL?

The AD7899AR-2REEL is supplied in a 28-lead SOIC (R-28) package with RoHS-compliant lead finish and JEDEC-standard dimensions. It operates across the industrial temperature range of –40°C to +85°C and features ESD protection rated to 4000 V HBM. Absolute maximum ratings include VDD = –0.3 V to +7 V, analog input = –1 V to +18 V, and junction temperature ≤150°C. Thermal impedance is 95°C/W (θJA), and power dissipation is rated at 450 mW for the SOIC package.