Analog Devices Inc. AD7719BR-REEL7

Overview

AD7719BR-REEL7 from Analog Devices is a factory-calibrated, dual-channel sigma-delta ADC with 24-bit main and 16-bit auxiliary channels, programmable gain amplifier, on-chip excitation current sources (200 µA), and integrated temperature sensor. It operates from single 3 V or 5 V supply, delivers simultaneous 50/60 Hz rejection at 20 Hz update rate, and targets precision sensor front ends in weigh scales and RTD-based temperature systems.

For engineers reviewing the AD7719BR-REEL7 datasheet, AD7719BR-REEL7 pinout, AD7719BR-REEL7 application, or AD7719BR-REEL7 equivalent, key selection criteria include dual-channel synchronized sampling, ±20 mV/±2.56 V p-p resolution scalability, rail-to-rail buffered input architecture, and 3-wire SPI-compatible serial interface with RDY status signaling.

Technical Context

The AD7719BR-REEL7 integrates two independent Σ-Δ modulators: a 24-bit main ADC with PGA (gain 1–128) and 13–18-bit p-p resolution, and a 16-bit auxiliary ADC with ±2.5 V or ±1.25 V range. Both channels share a 32.768 kHz crystal oscillator and on-chip PLL for internal clock generation, enabling software-programmable output data rates from 5.4 Hz to 105 Hz in 0.732 ms increments.

It features dual switchable 200 µA excitation current sources (IEXC1/IEXC2), low-side power switches (SW1/SW2, R_ON ≤ 7 Ω @ 3 V), reference detect circuitry, and a 4-bit digital I/O port referenced to AVDD/AGND. The device supports unipolar/bipolar differential inputs, burnout detection, and system-level calibration via on-chip offset/gain registers.

Key Specifications

Pinout & Package

AD7719BR-REEL7 is housed in a 28-lead SOIC package (R-28), RoHS-compliant, with standard JEDEC MS-012AC footprint (17.9 mm × 7.5 mm, 1.27 mm pitch).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-channel precision ADC applications.

Compared with AD7719BR-REEL7, AD7190BRUZ offers superior noise floor but sacrifices integrated dual-channel functionality and excitation matching, while ADS1248IPWR provides lower-cost sensor interface capability at the expense of factory calibration traceability and simultaneous sampling assurance.

Availability

AD7719BR-REEL7 is available at Aetrix Electronics and suitable for pressure transmitters, weigh scales, RTD temperature controllers, and portable instrumentation requiring stable component supply with long-term manufacturing continuity.

Supply support for AD7719BR-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, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The AD7719BR-REEL7 belongs to Analog Devices' precision sigma-delta ADC product line, designed specifically for low-frequency industrial and instrumentation sensor front ends requiring factory-traceable calibration and integrated excitation resources.

FAQ

What is the maximum update rate supported by the AD7719BR-REEL7?

The AD7719BR-REEL7 supports an output update rate from 5.4 Hz to 105 Hz in 0.732 ms increments. At the maximum rate of 105 Hz, the main ADC achieves 16-bit effective resolution; resolution increases with slower rates - e.g., 18-bit p-p at 20 Hz for ±2.56 V input range. This programmability allows optimization for noise vs. speed in each application.

Does the AD7719BR-REEL7 require external calibration after power-up?

No, the AD7719BR-REEL7 is factory-calibrated across temperature and supply voltage, and does not require field calibration. System zero or full-scale calibration can further reduce offset and gain errors, but the device meets all published specifications - including ±10 µV full-scale error and ±3 µV offset - immediately after power-on at –40°C to +85°C.

How does the AD7719BR-REEL7 handle reference voltage faults?

The AD7719BR-REEL7 includes a dedicated reference detect circuit that monitors REFIN1. When the differential reference voltage falls below 0.3 V, the NOXREF bit in the status register is asserted. The bit clears only when REFIN1 exceeds 0.65 V, providing hysteresis to prevent chatter. This feature enables robust fault handling in systems where reference integrity is critical to measurement validity.

Can the AD7719BR-REEL7 drive a 4-wire RTD directly?

Yes - the AD7719BR-REEL7 integrates two matched 200 µA excitation current sources (IEXC1/IEXC2) and low-side power switches (SW1/SW2), enabling direct 4-wire RTD connection. IOUT1 and IOUT2 connect to RTD leads, while AIN1–AIN4 provide Kelvin sense inputs. Matching better than ±1% at 25°C and drift tracking within 20 ppm/°C ensure accurate ratio-metric conversion without external components.

What digital interface protocols is the AD7719BR-REEL7 compatible with?

The AD7719BR-REEL7 features a 3-wire serial interface compatible with SPI, QSPI, MICROWIRE, and generic DSP protocols. It uses CS, SCLK, DIN, DOUT, and RDY signals; SCLK includes a Schmitt trigger for noise immunity. The interface supports both CS-framed and CS-tied-low modes, allowing flexible integration with microcontrollers (e.g., ARM Cortex-M) and DSPs (e.g., ADSP-2105) without protocol translation logic.