Analog Devices Inc. AD7893ARZ-3

Overview

AD7893ARZ-3 from Analog Devices is a 12-bit successive-approximation ADC with on-chip track/hold amplifier, serial interface, and ±2.5 V analog input range. It operates from a single +5 V supply, delivers 6 µs conversion time, 70 dB SNR at 10 kHz, and consumes 25 mW typical power. Used in precision data acquisition systems requiring compact, low-power, high-speed digitization of bipolar sensor signals.

For engineers reviewing the AD7893ARZ-3 datasheet, AD7893ARZ-3 pinout, AD7893ARZ-3 application, or AD7893ARZ-3 equivalent, this page provides verified technical context, real-world design meaning for key specs, validated pin functions, confirmed alternative parts with functional differences, and supply support details for industrial embedded and test equipment designs.

Technical Context

The AD7893ARZ-3 implements a laser-trimmed internal clock driving a 12-bit R-2R ladder SAR core, with integrated track/hold acquiring to ±1/2 LSB in ≤1.5 µs. Its analog front end uses resistor scaling (R1 = R2 = 6.5 kΩ, R3 open) to condition ±2.5 V inputs into the ADC core while maintaining 4 kΩ minimum input resistance.

It employs a two-wire serial interface: SCLK controls timing, and SDATA outputs 16-bit frames (four leading zeros + 12-bit twos-complement result), with data valid on SCLK falling edges. No BUSY or EOC signal is provided-timing coordination relies on fixed 6 µs conversion latency and strict 600 ns pre-CONVST read window management.

Key Specifications

Pinout & Package

AD7893ARZ-3 is housed in an 8-pin SOIC package (SO-8, 150 mil width), RoHS-compliant, with standard JEDEC MS-012AC footprint and 1.27 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7893BRZ-3, AD7893ARZ-3 trades 0.5 LSB linearity for lower cost and broader availability; compared with ADS7822U, it provides native bipolar input capability and integrated reference buffer-reducing external component count by three in ±2.5 V applications.

Availability

AD7893ARZ-3 is available at Aetrix Electronics and suitable for industrial process monitoring, portable test equipment, and automotive sensor interface applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for AD7893ARZ-3 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, founded in 1965 and headquartered in Wilmington, MA.

The AD7893 product line delivers compact, single-supply 12-bit serial ADCs optimized for space-constrained, low-power data acquisition in industrial, medical, and test equipment-prioritizing integration, ease of interface, and dc/dynamic accuracy.

FAQ

What is the absolute maximum analog input voltage for AD7893ARZ-3?

The absolute maximum analog input voltage for AD7893ARZ-3 is –5 V to +10 V referenced to AGND. Exceeding these limits-even momentarily-may cause permanent damage. The specified operating range remains ±2.5 V; the wider absolute rating accommodates transient overvoltage events but does not guarantee functionality or accuracy beyond ±2.5 V. Always use external clamping or protection circuits if input transients are expected in the target application.

Does AD7893ARZ-3 require an external clock source?

No, AD7893ARZ-3 does not require an external clock for conversion-it uses an internal laser-trimmed oscillator for the 6 µs conversion cycle. However, an external serial clock (SCLK) is mandatory to read data from the SDATA pin. SCLK must be supplied by the host controller at up to 8.33 MHz to shift out the 16-bit frame; the part has no internal serial clock generator.

Can AD7893ARZ-3 operate with a reference voltage other than +2.5 V?

AD7893ARZ-3 is specified and characterized for +2.5 V ±5% reference input. While the REF IN pin accepts voltages from 2.375 V to 2.625 V, using values outside this range invalidates all accuracy specifications-including full-scale error, offset, and SNR. Gain error scales linearly with reference deviation; for example, a 2.4 V reference reduces full-scale range to ±2.4 V and introduces ~4% gain error.

What is the purpose of the four leading zeros in AD7893ARZ-3's serial data frame?

The four leading zeros in AD7893ARZ-3's 16-bit serial frame provide synchronization and alignment for host processors with 8-bit or 16-bit shift registers. They ensure the 12-bit twos-complement result (DB11–DB0) always occupies consistent bit positions regardless of bus width, simplifying firmware parsing. These zeros are fixed and do not carry signal information-they are part of the defined protocol, not padding for variable-length data.

How is the track/hold acquisition time used in system timing for AD7893ARZ-3?

The 1.5 µs track/hold acquisition time defines the minimum delay required after conversion completion (6 µs post-CONVST rising edge) before initiating the next CONVST pulse. This ensures the internal track/hold settles to ±1/2 LSB before sampling the next input. Violating this timing causes gain and linearity errors. In practice, systems enforce a 600 ns guard band before the next CONVST, making the total inter-conversion interval ≥8.1 µs for full-spec operation.