Analog Devices Inc. AD7899ARSZ-3REEL

Overview

AD7899ARSZ-3REEL from Analog Devices is a 14-bit, 400 kSPS successive-approximation ADC with ±2.5 V input range, internal 2.5 V reference, and high-speed parallel interface. It operates from a single 5 V supply, delivers 78 dB SNR at 100 kHz input, and features 2.2 µs conversion time and 0.3 µs track/hold acquisition-enabling precision data acquisition in industrial process control systems.

For engineers reviewing the AD7899ARSZ-3REEL datasheet, AD7899ARSZ-3REEL pinout, AD7899ARSZ-3REEL application, or AD7899ARSZ-3REEL equivalent, key selection criteria include bipolar ±2.5 V full-scale range, two's complement output coding, STBY-controlled power-down mode (20 µA standby current), and compatibility with both 3 V and 5 V digital logic via VDRIVE pin.

Technical Context

The AD7899ARSZ-3REEL implements a laser-trimmed internal clock oscillator (enabling 400 kSPS throughput without external timing components) and supports optional external clocking via CLKIN. Its track/hold amplifier achieves 4.5 MHz –3 dB bandwidth and 25 ps aperture jitter, ensuring accurate sampling of fast-changing analog signals up to 200 kHz.

Conversion control uses edge-triggered CONVST to initiate hold mode and start conversion; BUSY/EOC serves dual function-high during conversion, low at completion-and interfaces directly with standard microprocessor read cycles using CS and RD strobes. Output data is latched and presented on a 14-bit three-state parallel bus (DB0–DB13).

Key Specifications

Pinout & Package

AD7899ARSZ-3REEL is housed in a 28-lead Shrink Small Outline Package (SSOP), RoHS-compliant, with 0.65 mm lead pitch and exposed pad for thermal enhancement. Pin 14 (OPGND) must be connected to analog ground to minimize digital switching noise coupling into the ADC core.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS8860IDRCT and MAX11100ETK+, the AD7899ARSZ-3REEL provides deterministic parallel read timing, integrated ±2.5 V scaling, and lower system-level component count-making it optimal for legacy microprocessor buses and deterministic real-time control loops.

Availability

AD7899ARSZ-3REEL is available at Aetrix Electronics and suitable for industrial process monitoring, avionics sensor interfaces, and motor drive current feedback requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for AD7899ARSZ-3REEL 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 SAR ADCs with integrated references and flexible digital interfaces-designed specifically for precision data acquisition in harsh, resource-constrained environments.

FAQ

What input voltage range does the AD7899ARSZ-3REEL support?

The AD7899ARSZ-3REEL supports a bipolar ±2.5 V analog input range. This is fixed for the -3 variant and configured via external connections: VINA accepts the signal while VINB is tied to AGND. The part guarantees no missing codes and ±2 LSB integral nonlinearity across this range, with 610.4 µV per LSB resolution. Input overvoltage tolerance extends to –4 V to +18 V, protecting against field-induced transients without external clamping.

Does the AD7899ARSZ-3REEL require an external clock source?

No, the AD7899ARSZ-3REEL includes a laser-trimmed internal clock oscillator enabling full 400 kSPS throughput without external timing components. An external clock may be applied via CLKIN only if precise synchronization or non-standard sampling rates are needed; the internal oscillator is factory trimmed to ±0.5% accuracy and eliminates BOM cost and layout complexity. The AD7899ARSZ-3REEL automatically selects the internal clock when CLKIN is low at CONVST rising edge.

How does the VDRIVE pin affect digital interface operation of the AD7899ARSZ-3REEL?

The VDRIVE pin on the AD7899ARSZ-3REEL sets the logic threshold and output drive strength for all digital pins (CS, RD, CONVST, BUSY/EOC, DB0–DB13). It may be tied to either 3 V ±10% or 5 V ±5%, allowing direct interfacing with 3 V microcontrollers or 5 V legacy systems without level-shifting circuitry. When VDRIVE = 3 V, output high voltage is ≥2.6 V and input high threshold is ≥1.9 V-ensuring reliable signaling across voltage domains while maintaining specified timing margins.

What is the purpose of the OPGND pin on the AD7899ARSZ-3REEL?

The OPGND (Output Driver Ground) pin on the AD7899ARSZ-3REEL is the dedicated return path for the digital output drivers (DB0–DB13 and BUSY/EOC), electrically isolated from AGND and DGND. It must be connected to the system's analog ground plane to prevent digital switching noise from modulating the ADC's reference or analog front-end. Improper OPGND routing causes increased harmonic distortion and degraded SNR-particularly critical when driving heavy capacitive loads or long PCB traces.

Can the AD7899ARSZ-3REEL operate in power-saving mode, and how is it controlled?

Yes, the AD7899ARSZ-3REEL supports a hardware-controlled power-saving mode activated by pulling the STBY pin low. In standby, supply current drops to 20 µA max while preserving internal reference stability and register state. Wake-up time is ≤5 µs from STBY rising edge to valid CONVST response. This mode is ideal for battery-powered data loggers or systems requiring periodic burst-mode acquisition, as it eliminates software initialization delays and maintains calibration integrity across sleep cycles.