Analog Devices Inc. AD7893ARZ-2

Overview

AD7893ARZ-2 from Analog Devices is a 12-bit, serial-output analog-to-digital converter with 6 µs conversion time, single +5 V supply operation, and integrated track/hold amplifier. It accepts 0 V to +2.5 V unipolar input range, delivers straight binary output coding, and targets precision data acquisition in space-constrained industrial and portable systems.

For engineers reviewing the AD7893ARZ-2 datasheet, AD7893ARZ-2 pinout, AD7893ARZ-2 application, or AD7893ARZ-2 equivalent, key selection criteria include its 6 µs conversion time, 0 V to +2.5 V input range, SOIC-8 package, 70 dB SNR at 10 kHz, and ±1 LSB relative accuracy - all critical for high-speed, low-power embedded sensing and control interfaces.

Technical Context

The AD7893ARZ-2 implements a successive-approximation ADC core with an on-chip R-2R ladder DAC and laser-trimmed internal clock oscillator. Its track/hold amplifier acquires signals to 12-bit accuracy within 1.5 µs and supports input bandwidth exceeding 58 kHz at 117 kHz sampling.

It uses a two-wire serial interface: SCLK clocks data out on rising edges, SDATA provides 16-bit frames (4 leading zeros + 12-bit result), with data valid on falling SCLK edges. The part requires an external +2.5 V reference applied to REF IN and operates with AGND/DGND separation for noise immunity.

Key Specifications

Pinout & Package

AD7893ARZ-2 is housed in an 8-pin SOIC (SO-8) package with 1.27 mm pitch, 5.0 mm × 6.2 mm body size, and gull-wing leads. Thermal impedance θ_JA = 170°C/W supports operation up to +85°C ambient.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-bit serial ADC applications.

Compared with AD7893BR-2, the AD7893ARZ-2 trades 0.5 LSB accuracy and 2 dB SNR for lower unit cost and broader availability; versus ADS7822U, it offers faster conversion and simpler 2-wire interface but lacks supply flexibility and multi-channel synchronization support.

Availability

AD7893ARZ-2 is available at Aetrix Electronics and suitable for industrial process monitoring, portable medical sensors, automated test equipment, and energy metering front-end designs requiring stable component supply, long-lifecycle support, and RoHS-compliant sourcing.

Supply support for AD7893ARZ-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, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The AD7893 product line delivers compact, single-supply 12-bit ADCs with integrated track/hold and serial interface for space- and power-constrained data acquisition systems in industrial, medical, and test equipment.

FAQ

What is the maximum sampling rate achievable with the AD7893ARZ-2?

The AD7893ARZ-2 achieves a maximum throughput rate of 117 kSPS when operated with optimal timing: 6 µs conversion time, 1.92 µs serial read (16 clocks at 8.33 MHz), and 0.6 µs acquisition guard band. Higher rates up to 133 kSPS are possible but incur ~1.5 dB SNR degradation and increased code flicker, as documented in the AD7893 performance section.

Does the AD7893ARZ-2 require an external reference voltage?

Yes, the AD7893ARZ-2 requires an external +2.5 V reference applied to the REF IN pin. The device features an on-chip buffered reference input with ≤1 µA input current and ±5% voltage tolerance. Precision references such as the AD780 or AD680 are recommended to maintain specified gain accuracy and full-scale error limits.

What is the purpose of the CONVST pin on the AD7893ARZ-2?

The CONVST pin on the AD7893ARZ-2 serves as the convert-start trigger: its rising edge initiates the track-to-hold transition and starts the 6 µs conversion sequence, while its falling edge resets the internal serial output shift register. It can also function as an interrupt signal to synchronize microcontroller read operations, ensuring data validity and timing compliance.

Can the AD7893ARZ-2 interface directly with standard SPI peripherals?

The AD7893ARZ-2 uses a two-wire serial interface (SCLK and SDATA) that is SPI-compatible in timing but lacks dedicated chip select (CS) and MOSI lines. It requires bit-banged or semi-custom SPI configuration - specifically, SCLK must go low between reads, and SDATA is three-stated after 16 clock edges. Standard hardware SPI masters may need firmware adaptation to meet these protocol constraints.

What is the input impedance of the VIN pin on the AD7893ARZ-2?

The VIN pin of the AD7893ARZ-2 presents a high-impedance input with ≤500 nA bias current, as confirmed in the Absolute Maximum Ratings and Analog Input sections of the datasheet. This allows direct connection to low-current sources like thermocouples or bridge sensors without significant signal attenuation or offset error from loading effects.