Analog Devices Inc. AD7782BRUZ

Overview

AD7782BRUZ from Analog Devices is a 24-bit sigma-delta analog-to-digital converter (ADC) with two fully differential input channels, pin-configurable ±160 mV or ±2.56 V input ranges, fixed 19.79 Hz output update rate, and simultaneous 50 Hz/60 Hz rejection - designed for high-precision sensor front ends in industrial weighing and temperature measurement systems.

For engineers reviewing the AD7782BRUZ datasheet, AD7782BRUZ pinout, AD7782BRUZ application, or AD7782BRUZ equivalent, this page delivers verified technical context, real-world design meaning of key specs, validated pin functions, confirmed alternatives, and supply-ready procurement guidance - all grounded in Analog Devices' official AD7782B specification data.

Technical Context

The AD7782BRUZ implements a fixed-rate, read-only sigma-delta ADC architecture with an on-chip PLL locked to a 32.768 kHz crystal, generating a stable 4.194304 MHz internal clock. Its analog path includes rail-to-rail input buffers and a pin-programmable PGA (gain = 1 or 16), enabling direct connection to resistive sensors without external amplification.

Digital interface operation is strictly master/slave-selectable via the MODE pin, with no internal registers to configure. Channel selection (AIN1/AIN2) and input range (±160 mV / ±2.56 V) are set by dedicated logic pins (CH1/CH2, RANGE), eliminating firmware overhead and ensuring deterministic timing behavior across power cycles.

Key Specifications

Pinout & Package

AD7782BRUZ is housed in a 16-lead TSSOP (RU-16) package, 4.4 mm × 5.0 mm body size, 0.65 mm pitch, with exposed pad not electrically connected. Pin 1 marked by dot; thermal resistance θ_JA = 97.9°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 24-bit sigma-delta ADC applications.

Compared with AD7782BRUZ, AD7783BRUZ removes channel redundancy but adds excitation sources for RTDs, while LTC2418CGN#PBF trades hardware-based noise rejection for software-configurable flexibility - making AD7782BRUZ optimal for fixed-rate, dual-sensor, mains-immune industrial front ends.

Availability

AD7782BRUZ is available at Aetrix Electronics and suitable for industrial process control, weigh scale manufacturing, and portable instrumentation requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for AD7782BRUZ 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 and ISO 9001-certified manufacturing.

The AD778x family - including AD7782BRUZ - was engineered specifically for low-frequency, high-resolution sensor measurement in harsh industrial environments, emphasizing noise immunity, ratiometric accuracy, and minimal system-level design complexity.

FAQ

What is the maximum sample rate of the AD7782BRUZ?

The AD7782BRUZ has a fixed output update rate of 19.79 Hz - it does not support variable sampling. This rate is derived from its internal PLL locked to a 32.768 kHz crystal and is optimized for simultaneous 50 Hz and 60 Hz mains rejection. Attempting to force higher rates will violate timing specifications and degrade noise performance. The AD7782BRUZ is not intended for dynamic signal acquisition above ~5 Hz bandwidth.

Does the AD7782BRUZ require external configuration registers to operate?

No, the AD7782BRUZ is a read-only, pin-configured ADC with no internal registers to program. Channel selection (AIN1/AIN2), input range (±160 mV / ±2.56 V), and interface mode (master/slave) are all controlled by dedicated logic pins (CH1/CH2, RANGE, MODE). This eliminates firmware initialization code, reduces startup time, and ensures deterministic behavior across power cycles - a core design feature of the AD7782BRUZ.

Can the AD7782BRUZ interface directly with a 3.3 V microcontroller in slave mode?

Yes, the AD7782BRUZ supports 3 V operation (2.7–3.6 V range) and its digital I/Os are compatible with 3.3 V logic levels: VINH ≥ 2.0 V and VINL ≤ 0.4 V at VDD = 3 V. In slave mode, the Schmitt-triggered SCLK input accepts slow or noisy clocks, and DOUT/RDY drives VOH ≥ VDD − 0.6 V (≥2.4 V) and VOL ≤ 0.4 V - fully interoperable with standard 3.3 V MCUs without level shifters. The AD7782BRUZ datasheet confirms these values under "Logic Inputs" and "Logic Outputs" sections.

What reference voltage sources are recommended for use with the AD7782BRUZ?

Analog Devices explicitly recommends the AD780, REF43, and REF192 as reference voltage sources for the AD7782BRUZ. These devices provide low-noise, low-drift, and low-output-impedance performance required to maintain the ADC's 18.5-bit p-p resolution and ±10 ppm FSR integral nonlinearity. Using a high-impedance reference (e.g., resistor-divider) introduces gain errors due to the AD7782BRUZ's dynamic reference input loading - a key constraint documented in the "Reference Input" section of the AD7782BRUZ datasheet.

How does the AD7782BRUZ achieve simultaneous 50 Hz and 60 Hz rejection?

The AD7782BRUZ achieves simultaneous 50 Hz and 60 Hz rejection through its fixed 19.79 Hz output update rate and matched digital filter notch placement - not via software. The internal modulator sampling frequency (32.768 kHz) and decimation ratio produce inherent nulls at both frequencies, delivering ≥60 dB rejection at 50 Hz and ≥94 dB at 60 Hz without any user configuration. This hardware-based rejection is guaranteed across temperature and supply voltage - a defining characteristic of the AD7782BRUZ architecture.