Analog Devices Inc. AD7899ARSZ-2

Overview

AD7899ARSZ-2 from Analog Devices is a 14-bit, 400 kSPS successive-approximation ADC operating from a single 5 V supply, featuring a 0 V to 2.5 V or 0 V to 5 V unipolar input range, on-chip 2.5 V reference, and high-speed parallel interface. It delivers 77 dB SNR (min, TMIN to TMAX), ±2 LSB INL, and 0.3 µs track/hold acquisition time for precision data acquisition in industrial control and test equipment.

For engineers reviewing the AD7899ARSZ-2 datasheet, AD7899ARSZ-2 pinout, AD7899ARSZ-2 application, or AD7899ARSZ-2 equivalent, key selection considerations include unipolar input support, straight binary output coding, 3 V/5 V digital interface compatibility via VDRIVE, and standby power consumption of 20 µA typical.

Technical Context

The AD7899ARSZ-2 implements a laser-trimmed internal clock oscillator (2.2 µs conversion time) or accepts external CLKIN up to 6.5 MHz, with mode selection determined by CLKIN state at CONVST rising edge. Its track/hold amplifier achieves full-scale settling within 0.3 µs and supports ±18 V analog overvoltage tolerance on VINA/VINB.

Conversion control uses asynchronous CONVST-triggered hold mode initiation and BUSY/EOC dual-function signaling. Data readout employs standard CS/RD strobes across a 14-bit three-state parallel bus (DB0–DB13), with timing validated for both 3 V and 5 V VDRIVE operation.

Key Specifications

Pinout & Package

AD7899ARSZ-2 is housed in a 28-lead Shrink Small Outline Package (SSOP), RoHS-compliant, with 0.65 mm lead pitch and exposed pad not electrically connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7899AR-2, AD7899ARSZ-2 offers identical performance in a smaller SSOP package with equal thermal resistance, while ADS8320U trades parallel simplicity for resolution and serial flexibility-neither is pin-compatible, but both serve overlapping unipolar acquisition use cases.

Availability

AD7899ARSZ-2 is available at Aetrix Electronics and suitable for industrial process monitoring, automated test equipment, medical instrumentation, and motor drive feedback requiring stable component supply and long-term obsolescence management.

Supply support for AD7899ARSZ-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, single-supply ADCs with integrated references and flexible input ranges-designed specifically for precision data acquisition in space- and power-constrained embedded systems.

FAQ

What input voltage ranges does the AD7899ARSZ-2 support?

The AD7899ARSZ-2 supports two unipolar analog input ranges: 0 V to 2.5 V (with VINA and VINB tied together) or 0 V to 5 V (with VINB grounded). It does not support bipolar ranges like ±5 V or ±10 V-those are exclusive to AD7899-1 variants. The internal 2.5 V reference scales both ranges, and output coding is straight binary, not two's complement.

How does the AD7899ARSZ-2 handle digital interface voltage mismatch?

The AD7899ARSZ-2 resolves digital voltage mismatch via its dedicated VDRIVE pin, which accepts either 3 V ±10% or 5 V ±5% to power all digital I/O (CS, RD, DB0–DB13, BUSY/EOC). This allows direct connection to 3 V microcontrollers or 5 V FPGAs without external level shifters-timing parameters remain valid across both supply levels per the datasheet's VDRIVE = 3 V and 5 V test conditions.

Can the AD7899ARSZ-2 operate without an external reference?

Yes, the AD7899ARSZ-2 operates fully autonomously using its internal 2.5 V reference. A 0.1 µF decoupling capacitor from VREF to AGND is required. The internal reference has ±10 mV error at 25°C and ±20 mV over temperature, with 25 ppm/°C drift-sufficient for most industrial applications. External reference override is optional and supported via the same VREF pin.

What is the minimum acquisition time required between conversions for the AD7899ARSZ-2?

The AD7899ARSZ-2 requires a minimum track/hold acquisition time of 0.3 µs after BUSY/EOC goes low (end of conversion) before the next CONVST rising edge. This ensures the internal track/hold settles to ±1/2 LSB accuracy. Attempting a new conversion sooner risks code-dependent errors exceeding ±2 LSB INL specification.

Does the AD7899ARSZ-2 support external clocking, and what are the requirements?

Yes, the AD7899ARSZ-2 supports external clocking via the CLKIN pin. An external clock must be applied ≥100 ns after the CONVST rising edge, with duty cycle ≤60/40. When CLKIN is high at CONVST edge, the external clock is used; when low, the internal laser-trimmed oscillator (2.2 µs conversion time) activates. Maximum CLKIN frequency is 6.5 MHz for full 400 kSPS throughput.