Analog Devices Inc. AD7712ARZ

Overview

AD7712ARZ from Analog Devices is a 24-bit sigma-delta analog-to-digital converter (ADC) with integrated programmable-gain amplifier (PGA), dual analog input channels (low-level differential AIN1 and high-level single-ended AIN2), internal 2.5 V reference, and serial microcontroller interface. It delivers 0.0015% integral nonlinearity, 100 dB 50/60 Hz rejection, and operates at 25 mW typical power in industrial process control transmitters.

For engineers reviewing the AD7712ARZ datasheet, AD7712ARZ pinout, AD7712ARZ application, or AD7712ARZ equivalent, this page provides verified technical context, real-world design meaning of specifications, validated pin functions, confirmed alternative parts with documented functional differences, and supply-chain support for embedded instrumentation designs requiring high-precision, low-drift, multi-channel signal conditioning.

Technical Context

The AD7712ARZ implements a charge-balancing sigma-delta architecture with on-chip digital filtering, where the first notch frequency is software-programmable (10–1000 Hz) to optimize noise rejection and settling time per application. Its dual-input front end uses a proprietary PGA for AIN1 (gain 1–128) and a precision resistor attenuator for AIN2 (±4 V_REF/gain), both feeding the same modulator core.

Calibration is fully configurable via serial interface: self-calibration removes zero- and full-scale drift; system calibration supports external voltage standards; background calibration enables continuous error correction without interrupting conversion. The device supports both single-supply (VSS = AGND) and dual-supply (VSS = –5 V) operation, enabling true bipolar input ranges down to –V_REF on AIN1.

Key Specifications

Pinout & Package

AD7712ARZ is housed in a 24-lead SOIC (RW-24) package, 0.3 inch wide, RoHS-compliant, with exposed pad not electrically connected.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-precision sigma-delta ADC applications.

Compared with AD7799BRUZ and ADS1258IPWR, the AD7712ARZ uniquely combines dual-input topology (low-level differential + high-level single-ended), integrated 2.5 V reference, and programmable digital filter notch - making it irreplaceable in space-constrained, single-IC transmitter designs requiring ±10 V compatibility and field recalibration.

Availability

AD7712ARZ is available at Aetrix Electronics and suitable for process control transmitters, portable industrial instruments, and smart sensor modules requiring stable component supply across extended temperature ranges (–40°C to +85°C) and long product lifecycles.

Supply support for AD7712ARZ 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 AD7712ARZ belongs to Analog Devices' precision sigma-delta ADC product line, engineered specifically for low-frequency industrial measurement applications demanding 24-bit accuracy, low drift, and integrated signal conditioning - eliminating discrete op-amps, references, and filters.

FAQ

What is the maximum sample rate of the AD7712ARZ?

The AD7712ARZ achieves a maximum output data rate of 120 samples per second when the digital filter notch is set to 10 Hz. At higher notch frequencies (e.g., 100 Hz), the output rate drops to 12 SPS, and at 1 kHz, it falls to 1.2 SPS. This trade-off is inherent to its sigma-delta architecture and enables precise 50/60 Hz line rejection. The AD7712ARZ does not support oversampling beyond these programmed notch settings.

Does the AD7712ARZ require an external crystal oscillator?

No, the AD7712ARZ supports both crystal and external CMOS clock inputs. A 10 MHz crystal can be connected between MCLK IN (Pin 2) and MCLK OUT (Pin 3); alternatively, a 10 MHz (or 400 kHz–10 MHz) CMOS-compatible clock may be driven directly into MCLK IN with MCLK OUT left unconnected. The AD7712ARZ contains internal clock generation circuitry that derives all internal timing from this source.

Can the AD7712ARZ operate from a single +5 V supply?

Yes, the AD7712ARZ supports single-supply operation by tying VSS (Pin 11) to AGND. In this configuration, the AIN1(+) input must remain > –30 mV relative to VSS, and the device maintains full 24-bit performance with 0.0015% nonlinearity. For true bipolar input ranges extending to –2.5 V, VSS must be set to –5 V - but the single-supply mode is fully validated and widely used in 4–20 mA transmitter designs.

How does the AD7712ARZ handle transducer open-circuit detection?

The AD7712ARZ integrates a 4.5 µA nominal current source on the AIN1(+) pin (Pin 7), controllable via the control register. When enabled, this source pulls current through the external transducer; if the sensor lead opens, the resulting voltage shift at AIN1(+) exceeds the input range, triggering a detectable overflow condition in the conversion result. This eliminates the need for external burnout resistors or comparators in strain gauge and RTD applications.

Is the internal 2.5 V reference of the AD7712ARZ available for external use?

Yes, the AD7712ARZ provides its internal 2.5 V reference at Pin 16 (REF OUT), rated at ±1% initial tolerance and 20 ppm/°C drift. It can drive up to 1 mA load and is commonly used to bias external circuitry such as sensor excitation or op-amp reference inputs. Using REF OUT avoids adding a discrete reference IC, reducing board area and cost in compact transmitter modules containing the AD7712ARZ.