Analog Devices Inc. AD7712AR-REEL7

Overview

AD7712AR-REEL7 from Analog Devices is a 24-bit sigma-delta analog-to-digital converter (ADC) with dual differential analog input channels, programmable gain (1–128), on-chip 2.5 V reference, and serial microcontroller interface. It delivers 0.0015% integral nonlinearity, 100 dB 50/60 Hz rejection, and operates from –40°C to +85°C in industrial process control transmitters.

For engineers reviewing the AD7712AR-REEL7 datasheet, AD7712AR-REEL7 pinout, AD7712AR-REEL7 application, or AD7712AR-REEL7 equivalent, this page provides verified technical context, real-world timing and filtering behavior, calibrated accuracy specs under varying gains and notch frequencies, and validated alternative options for high-precision low-frequency measurement systems.

Technical Context

The AD7712AR-REEL7 employs a charge-balancing sigma-delta modulator with on-chip digital filter whose first notch is software-programmable (10 Hz to 1 kHz), enabling precise trade-offs between settling time and noise rejection. Its dual-input architecture separates low-level transducer signals (AIN1±, PGA-gain configurable) from high-level attenuated inputs (AIN2, ±4 VREF/GAIN).

Calibration is fully supported via self-, system-, and background modes; users can read/write calibration coefficients through the bidirectional serial port. The device supports both single-supply (VSS = AGND) and dual-supply (VSS = –5 V) operation, with differential reference input (REF IN±) and internal 2.5 V REF OUT referenced to AGND.

Key Specifications

Pinout & Package

AD7712AR-REEL7 is housed in a 24-lead SOIC package (RW-24), 0.3 inch wide, RoHS-compliant, tape-and-reel format (REEL7 = 1000-piece reel).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7712AR-REEL7, AD7714BRUZ offers more input channels but sacrifices programmable filtering and integrated reference, while ADS1258IPWR delivers superior INL and speed at the cost of thermal stability and low-power standby capability-making AD7712AR-REEL7 optimal for ultra-stable, low-noise, dual-channel industrial sensing.

Availability

AD7712AR-REEL7 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 and long production lifecycles.

Supply support for AD7712AR-REEL7 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, headquartered in Norwood, MA, with design centers worldwide.

The AD7712 belongs to Analog Devices' precision sigma-delta ADC product line, engineered specifically for low-frequency industrial measurement applications demanding 24-bit resolution, low drift, and integrated signal conditioning without external components.

FAQ

What is the guaranteed resolution and linearity performance of the AD7712AR-REEL7?

The AD7712AR-REEL7 guarantees 24 bits no missing codes when the digital filter's first notch is set to ≤60 Hz, with integral nonlinearity of ±0.0015% FSR maximum at 25°C. At higher notch frequencies (e.g., 100 Hz), resolution degrades to 22 bits minimum, and INL increases to ±0.003% FSR over temperature. These values are specified in the Rev. F datasheet and apply strictly to the AD7712AR-REEL7 A-grade variant operating from –40°C to +85°C.

Does the AD7712AR-REEL7 include an internal voltage reference, and can it be used externally?

Yes, the AD7712AR-REEL7 integrates a 2.5 V bandgap reference with ±1% initial tolerance and 20 ppm/°C typical drift, available at the REF OUT pin referenced to AGND. This reference can serve both internal ADC conversion and external circuitry-such as driving sensor excitation or external DACs-as long as load current stays below 1 mA. The device also supports external differential reference inputs (REF IN±) spanning 2.5 V to 5 V, enabling higher accuracy or custom reference voltages.

How does the dual-input architecture of the AD7712AR-REEL7 function in practice?

The AD7712AR-REEL7 features two distinct analog input paths: AIN1(±) is a fully differential, programmable-gain (1–128) input optimized for low-level transducer signals (e.g., strain gauges), while AIN2 is a single-ended, attenuated input accepting ±4 VREF/GAIN-up to ±10 V at gain = 1. In operation, AIN1(±) typically serves as the primary measurement channel, and AIN2 acts as an auxiliary channel for periodic system checks (e.g., reference voltage monitoring), enabling robust diagnostics without additional ADCs.

What power supply configurations does the AD7712AR-REEL7 support, and what are the key constraints?

The AD7712AR-REEL7 supports single-supply operation (AVDD = +5 V, VSS = AGND) and dual-supply operation (AVDD = +5 V, VSS = –5 V). Key constraints include: AVDD must be +5 V to +10 V (±5%), DVDD = +5 V (±5%, ≤ AVDD + 0.3 V), and VSS must remain ≥ –5 V. When using VSS = –5 V, the AIN1(+) input can measure down to –VREF, extending usable range beyond single-supply limits. Total normal-mode power dissipation is 25 mW typical, dropping to 100 µW in hardware standby mode.

Can the AD7712AR-REEL7 perform system-level calibration, and how is it accessed?

Yes, the AD7712AR-REEL7 supports full system calibration-including offset, positive full-scale, and negative full-scale-via its bidirectional serial interface. Calibration coefficients are stored in on-chip registers accessible through the A0-controlled register map. Users can read and write these registers directly, enabling field recalibration without hardware modification. System calibration requires applying known voltages to AIN1(±) or AIN2 within defined limits (e.g., ±1.05 VREF/GAIN for AIN1), and the AD7712AR-REEL7 automatically computes and stores correction factors for subsequent conversions.