Analog Devices Inc. AD7713ANZ

Overview

AD7713ANZ from Analog Devices is a 24-bit charge-balancing sigma-delta ADC optimized for loop-powered smart transmitters, featuring a 3-channel programmable gain front end (gains 1–128), dual differential inputs (AIN1/AIN2), one high-voltage single-ended input (AIN3, up to ±10 V at G=1), on-chip RTD excitation (2 × 200 µA), and self-calibration. It operates from a single 5–10 V analog supply with 3.5 mW typical power consumption.

For engineers reviewing the AD7713ANZ datasheet, AD7713ANZ pinout, AD7713ANZ application, or AD7713ANZ equivalent, key selection considerations include its 24-bit no-missing-codes performance, programmable digital filter notch (2–100 Hz), ±0.0015% integral nonlinearity, integrated transducer burn-out detection, and bidirectional serial interface supporting both self- and external-clocking modes.

Technical Context

The AD7713ANZ employs a proprietary analog modulator-based programmable gain amplifier (PGA) feeding a digitally programmable low-pass filter with configurable first-notch frequency (2 Hz to 100 Hz), enabling precise rejection of 50/60 Hz line interference. Its architecture integrates two independent 200 µA RTD current sources and on-chip calibration logic for zero-scale, full-scale, and background correction.

It supports three analog input configurations: two fully differential channels (AIN1±, AIN2±) with common-mode voltage range AGND to AVDD, and one high-level single-ended channel (AIN3) accepting up to 4×VREF (±10 V at VREF = 2.5 V, G = 1). The device uses a 24-bit control register to configure gain, polarity, filter cutoff, calibration mode, and channel selection via a bidirectional serial port.

Key Specifications

Pinout & Package

AD7713ANZ is housed in a 24-lead, 0.3-inch wide plastic DIP (PDIP) package (N-24), compatible with through-hole assembly and legacy industrial PCB layouts. Thermal impedance is 105°C/W; maximum power dissipation is 450 mW.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7713ANZ, AD7793BRUZ offers lower power and simpler integration but sacrifices dual RTD drive and high-voltage input flexibility, while ADS1248IPWR provides faster sampling yet requires external components to match AD7713ANZ's out-of-the-box 50/60 Hz rejection and diagnostic capabilities.

Availability

AD7713ANZ is available at Aetrix Electronics and suitable for loop-powered transmitters, RTD-based temperature instrumentation, and portable industrial calibrators requiring stable component supply, long-term obsolescence management, and traceable sourcing.

Supply support for AD7713ANZ 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, serving industrial, automotive, communications, and healthcare markets.

The AD7713ANZ belongs to Analog Devices' LC2MOS precision sigma-delta ADC product line, designed specifically for low-power, high-accuracy industrial measurement systems where loop power constraints, RTD interfacing, and robust 50/60 Hz rejection are critical.

FAQ

What is the maximum input voltage range supported by AD7713ANZ on its AIN3 pin?

The AD7713ANZ AIN3 pin accepts a single-ended input voltage range of 0 to +4×VREF. With a nominal 2.5 V reference, this yields ±10 V at gain = 1. Absolute voltage must remain within –0.3 V to +22 V relative to AGND, and the input must not exceed AVDD + 0.3 V or go below AGND – 0.3 V. This capability allows direct connection to industrial 0–10 V or ±10 V signals without external attenuation.

Does AD7713ANZ support true 24-bit resolution across all operating conditions?

Yes, AD7713ANZ guarantees 24-bit no-missing-codes performance for digital filter notches ≤12 Hz. At higher notches (e.g., 20 Hz, 50 Hz), resolution degrades to 22 bits and 18 bits respectively due to increased noise bandwidth - confirmed in the "No Missing Codes" specification table. System-level 24-bit integrity requires selecting appropriate filter settings per application noise requirements.

How does the AD7713ANZ implement RTD lead resistance compensation?

The AD7713ANZ implements RTD lead resistance compensation using its dual 200 µA current sources (RTD1 and RTD2). In a 3-wire RTD configuration, RTD1 excites the RTD element while RTD2 provides a matched current through the lead wire, enabling the ADC to measure and cancel lead resistance voltage drop. Matching between RTD1/RTD2 currents is ±1% at 25°C and drifts <3 ppm/°C, ensuring stable compensation over temperature.

Can AD7713ANZ operate with a 3.3 V digital supply (DVDD)?

No, AD7713ANZ requires DVDD = 5 V ±5% as specified in the Power Requirements section. The absolute maximum rating for DVDD is +6 V, and operation outside 4.75–5.25 V may cause timing violations or communication failure. While AVDD can range from 5–10 V, DVDD must be precisely 5 V and must not exceed AVDD by more than 0.3 V in normal operation.

What calibration modes are available on the AD7713ANZ and how are they triggered?

The AD7713ANZ supports three calibration modes: self-calibration (zero- and full-scale internal references), system calibration (two-step user-provided zero/full-scale voltages), and background calibration (continuous drift correction). All are controlled via the 24-bit control register's MD2–MD0 bits. Self-calibration is initiated by writing 001b; system calibration uses 010b (zero step) and 011b (full-scale step); DRDY pulses indicate completion of each phase.