Analog Devices Inc. AD7718BRUZ-REEL7

Overview

AD7718BRUZ-REEL7 from Analog Devices is a 24-bit Σ-Δ analog-to-digital converter (ADC) with integrated programmable-gain amplifier (PGA), 10-channel pseudo-differential or 5-channel fully differential input capability, on-chip 32.768 kHz crystal oscillator and PLL, and SPI-compatible 3-wire serial interface. It delivers up to 18 bits peak-to-peak resolution at ±2.56 V input range with CHOP = 0 mode and supports simultaneous 50 Hz/60 Hz rejection for industrial sensor signal acquisition.

For engineers reviewing the AD7718BRUZ-REEL7 datasheet, AD7718BRUZ-REEL7 pinout, AD7718BRUZ-REEL7 application, or AD7718BRUZ-REEL7 equivalent, key selection criteria include its 24-bit resolution, factory-calibrated offset/gain performance, rail-to-rail input buffer, dual reference input flexibility (REFIN1/REFIN2), and TSSOP-28 package compatibility with space-constrained instrumentation designs.

Technical Context

The AD7718BRUZ-REEL7 implements a chopper-stabilized Σ-Δ modulator architecture with digital filtering, supporting two operational modes: CHOP = 0 (optimized for analog performance, 5.4–105 Hz update rate) and CHOP = 1 (optimized for throughput, 16.06 Hz–1.365 kHz). Its PGA offers gain settings from 1 to 128, enabling direct transducer interfacing without external signal conditioning.

It features dual configurable reference inputs (REFIN1 and REFIN2), each accepting 1 V to AVDD common-mode voltage and 1 V to 2.5 V differential range, and supports VREF Select™ for ratiometric or absolute measurement configurations. The device uses separate analog (AVDD/AGND) and digital (DVDD/DGND) supplies, with independent power domains and <±0.05 V AGND–DGND tolerance.

Key Specifications

Pinout & Package

TSSOP-28 package (RU-28), 4.4 mm × 9.7 mm body, 0.65 mm pitch, exposed pad optional for thermal enhancement.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7730BRUZ and ADS1258IPWR, the AD7718BRUZ-REEL7 uniquely integrates dual reference inputs with VREF Select™, on-chip 32.768 kHz oscillator, and selectable chopper mode - delivering superior 50/60 Hz rejection and reduced BOM count for precision sensor front-ends.

Availability

AD7718BRUZ-REEL7 is available at Aetrix Electronics and suitable for industrial process control, portable instrumentation, and smart transmitter designs requiring stable component supply, long-term lifecycle support, and RoHS-compliant TSSOP packaging.

Supply support for AD7718BRUZ-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, serving industrial, automotive, communications, and healthcare markets since 1965.

The AD7718BRUZ-REEL7 belongs to Analog Devices' precision Σ-Δ ADC product line, designed specifically for low-frequency, high-accuracy sensor signal acquisition in harsh industrial environments with stringent EMC and long-term stability requirements.

FAQ

What is the maximum achievable peak-to-peak resolution of the AD7718BRUZ-REEL7?

The AD7718BRUZ-REEL7 achieves up to 18 bits peak-to-peak resolution at ±2.56 V input range with CHOP = 0 mode and 20 Hz output update rate. At ±20 mV range under same conditions, it delivers 13 bits p-p. Resolution varies with gain setting, update rate, and CHOP configuration - values are specified in the AD7718BRUZ-REEL7 datasheet Tables I and II.

Does the AD7718BRUZ-REEL7 require an external crystal oscillator?

No, the AD7718BRUZ-REEL7 includes an on-chip buffer and PLL that accept a standard 32.768 kHz tuning-fork crystal directly on XTAL1/XTAL2 pins. No external oscillator circuitry is needed, reducing component count and board space - a key advantage of the AD7718BRUZ-REEL7 over alternatives like the AD7730.

How does the VREF Select™ feature work on the AD7718BRUZ-REEL7?

VREF Select™ on the AD7718BRUZ-REEL7 allows dynamic selection between REFIN1 and REFIN2 as the ADC reference source via register control. This enables one device to support both ratiometric measurements (e.g., bridge sensors using excitation as reference) and absolute measurements (e.g., thermocouples with external reference), eliminating need for multiple ADC variants.

What is the purpose of the P1 and P2 pins on the AD7718BRUZ-REEL7?

P1 and P2 are 2-bit general-purpose digital I/O ports on the AD7718BRUZ-REEL7, configurable as inputs or outputs via the I/O Control Register. They can drive LEDs, read pushbuttons, or interface with external logic - providing system-level flexibility without requiring additional GPIO expanders in compact sensor nodes.

Can the AD7718BRUZ-REEL7 operate from a single 3.3 V supply?

Yes, the AD7718BRUZ-REEL7 supports single 3 V operation (2.7–3.6 V) on both AVDD and DVDD rails. At 3 V, typical current consumption is 1.28 mA in normal mode and 30 µA in power-down mode with oscillator active - making the AD7718BRUZ-REEL7 suitable for low-voltage, battery-powered instrumentation.