Analog Devices Inc. AD7713SQ

Overview

AD7713SQ from Analog Devices is a 24-bit charge-balancing analog-to-digital converter (ADC) designed for loop-powered smart transmitters and RTD-based process instrumentation. It integrates a 3-channel programmable-gain front end (gains 1–128), on-chip 200 µA RTD excitation current sources, self-calibration, and bidirectional serial interface - enabling direct transducer interfacing without external signal conditioning. Its 0.0015% integral nonlinearity and 150 µW standby power support high-accuracy, low-power industrial sensing.

For engineers reviewing the AD7713SQ datasheet, AD7713SQ pinout, AD7713SQ application, or AD7713SQ equivalent, key selection considerations include its 24-bit no-missing-codes performance at ≤12 Hz filter notch, ±0.0015% INL, dual differential + single-ended high-voltage input architecture, RTD excitation capability, and extended temperature range (–55°C to +125°C) in CERDIP package.

Technical Context

The AD7713SQ employs a sigma-delta modulator with on-chip digital filtering, where the first notch frequency is software-programmable via control register bits FS0–FS11, enabling configurable rejection of 50/60 Hz interference. Its analog front end includes two differential inputs (AIN1, AIN2) and one high-level single-ended input (AIN3, up to ±10 V at G=1), all routed through a programmable gain amplifier (PGA) with gains from 1 to 128.

It features dual 200 µA matched RTD excitation currents (RTD1/RTD2) for 3-/4-wire configurations, hardware-controlled STANDBY mode reducing supply current to 150 µW typical, and a bidirectional serial interface supporting both self-clocking (SCLK output) and external-clocking modes. Calibration is supported via on-chip self-, system-, and background calibration routines accessible through the 24-bit control register.

Key Specifications

Pinout & Package

The AD7713SQ is housed in a 24-lead CERDIP (Q-24) package with 0.3-inch width, rated for –55°C to +125°C operation and compatible with standard through-hole assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-precision, low-power ADC applications.

Compared with AD7713SQ, AD7714SQ offers superior linearity and lower power while maintaining pin and register compatibility, whereas ADS1248IPWR provides integrated reference and oscillator but lacks on-chip RTD excitation and extended temperature rating - making AD7713SQ uniquely suited for ruggedized, self-contained RTD transmitter designs.

Availability

AD7713SQ is available at Aetrix Electronics and suitable for loop-powered transmitters, RTD temperature monitoring systems, and portable industrial data loggers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for AD7713SQ 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, serving industrial, automotive, communications, and healthcare markets since 1965.

The AD7713SQ belongs to Analog Devices' LC2MOS precision ADC product line, engineered specifically for low-power, high-accuracy sensor signal conditioning in harsh industrial environments - emphasizing integrated excitation, self-calibration, and loop-compatible power efficiency.

FAQ

What is the operating temperature range of the AD7713SQ?

The AD7713SQ is specified for operation from –55°C to +125°C, qualifying it for extended industrial, aerospace, and downhole applications. This S-grade temperature range is implemented in the hermetically sealed CERDIP (Q-24) package and is validated per Analog Devices' extended temperature testing protocols. The AD7713SQ maintains full 24-bit no-missing-codes performance and ±0.0015% INL across this entire range when used with appropriate external components and layout practices.

Does the AD7713SQ include built-in RTD excitation current sources?

Yes, the AD7713SQ integrates two matched 200 µA constant-current sources (RTD1 and RTD2) with ±1% initial matching and 3 ppm/°C drift matching. These are controllable via the on-chip control register and enable direct 3-wire RTD configurations by driving separate leads to cancel lead resistance errors. No external current sources or precision resistors are required for basic RTD interfacing - a key differentiator of the AD7713SQ in transmitter design.

How does the AD7713SQ achieve 50/60 Hz rejection in noisy industrial environments?

The AD7713SQ achieves >100 dB normal-mode and >150 dB common-mode 50/60 Hz rejection through its programmable digital filter architecture. The first notch frequency is set via FS0–FS11 bits in the control register - selecting exact frequencies like 2 Hz, 6 Hz, 30 Hz, or 60 Hz ensures deep nulls at line frequency and harmonics. Combined with high CMRR (>100 dB at DC) and differential input structure, this enables robust operation in electrically noisy plants without external notch filters.

Can the AD7713SQ operate from a single 5 V supply?

Yes, the AD7713SQ supports single-supply operation with AVDD = DVDD = 5 V (±5%). In this configuration, it draws ≤0.6 mA AVDD current and ≤0.5 mA DVDD current at 1 MHz MCLK, resulting in ~3.5 mW total power - well within 4–20 mA loop budgets. The device also supports AVDD up to 10 V for higher input voltage headroom, while DVDD must remain at 5 V and not exceed AVDD by more than 0.3 V.

What calibration modes does the AD7713SQ support, and how are they triggered?

The AD7713SQ supports three calibration modes: self-calibration (zero + full-scale on internal references), system calibration (two-step zero then full-scale on external inputs), and background calibration (continuous zero correction during normal operation). All are initiated by writing specific values to MD2–MD0 bits in the 24-bit control register. DRDY pulses indicate completion, and calibration coefficients are stored in on-chip registers accessible via the serial interface - enabling full recalibration without external equipment.