Analog Devices Inc. AD7783BRUZ-REEL7

Overview

AD7783BRUZ-REEL7 from Analog Devices is a read-only, pin-configured 24-bit sigma-delta ADC with integrated 200 µA excitation current sources, rail-to-rail input buffer, and programmable gain amplifier (PGA) supporting ±160 mV or ±2.56 V input ranges. It delivers simultaneous 50 Hz/60 Hz rejection at a fixed 19.79 Hz update rate and operates from single 3 V or 5 V supply. It is used in high-precision weigh scales and RTD-based temperature measurement systems where low-noise, ratiometric bridge sensing is required.

For engineers reviewing the AD7783BRUZ-REEL7 datasheet, AD7783BRUZ-REEL7 pinout, AD7783BRUZ-REEL7 application, or AD7783BRUZ-REEL7 equivalent, key selection considerations include its no-missing-codes 24-bit performance, pin-selectable input range and current source routing, fixed-output-rate architecture eliminating firmware register configuration, and TSSOP-16 package compatibility with industrial sensor front-end layouts.

Technical Context

The AD7783BRUZ-REEL7 implements a fully differential sigma-delta modulator with on-chip PLL locked to a 32.768 kHz crystal, generating a stable 4.194304 MHz internal clock. Its analog path includes a buffered input stage followed by a PGA with gain of 1 (±2.56 V range) or 16 (±160 mV range), enabling direct connection to resistive sensors without external amplification.

Digital interface operation is strictly read-only: no registers are programmable. Input range and current source routing are controlled solely via hardware pins RANGE and IPIN. The device supports master mode (SCLK output) or slave mode (SCLK input), with Schmitt-triggered SCLK enabling opto-isolated communication, and DOUT/RDY serving dual RDY/data functions with precise timing alignment to conversion completion.

Key Specifications

Pinout & Package

AD7783BRUZ-REEL7 is housed in a 16-lead TSSOP (RU-16) package, RoHS-compliant, with 0.65 mm pitch and JEDEC MO-153-AB compliant outline dimensions (4.4 mm × 5.0 mm × 1.2 mm max height).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7783BRUZ-REEL7, AD7782BRUZ-REEL7 removes excitation capability while preserving pin compatibility, whereas ADS124S08IPBSR trades deterministic timing and inherent notch filtering for configurability and speed-making AD7783BRUZ-REEL7 optimal for fixed-rate, mains-immune, self-contained sensor interfaces.

Availability

AD7783BRUZ-REEL7 is available at Aetrix Electronics and suitable for industrial weigh scales, RTD temperature transmitters, and portable pressure instrumentation requiring stable component supply across long production lifecycles.

Supply support for AD7783BRUZ-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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA, with design centers worldwide.

The AD778x family-including AD7783BRUZ-REEL7-is engineered for low-frequency, high-accuracy sensor measurement applications, emphasizing simplicity, noise immunity, and integration of excitation and digitization in a single chip.

FAQ

What is the primary function of the AD7783BRUZ-REEL7 in sensor signal chains?

The AD7783BRUZ-REEL7 serves as a complete analog front end for precision low-frequency measurements, integrating a 24-bit sigma-delta ADC, programmable gain amplifier, rail-to-rail input buffer, and dual 200 µA excitation current sources. Its role is to directly digitize mV-level outputs from resistive sensors like strain gages and RTDs while rejecting mains-frequency interference-eliminating the need for external amplifiers, references, or excitation circuitry in AD7783BRUZ-REEL7-based designs.

Does the AD7783BRUZ-REEL7 require firmware configuration to operate?

No, the AD7783BRUZ-REEL7 is a read-only, pin-configured device with no programmable registers. All operational parameters-including input voltage range (±160 mV or ±2.56 V), current source routing (via IPIN), and master/slave interface mode (via MODE)-are set by external logic levels. This eliminates firmware initialization overhead and ensures deterministic behavior from power-on, making AD7783BRUZ-REEL7 ideal for safety-critical or resource-constrained embedded systems.

How does the AD7783BRUZ-REEL7 achieve simultaneous 50 Hz and 60 Hz rejection?

The AD7783BRUZ-REEL7 achieves simultaneous 50 Hz and 60 Hz rejection through its on-chip digital filter, which places fixed notches at both frequencies. This is enabled by the device's fixed 19.79 Hz output update rate-derived from a 32.768 kHz crystal and internal PLL-which synchronizes the modulator sampling to produce inherent rejection without external clock synchronization or software tuning. As a result, AD7783BRUZ-REEL7 delivers ≥60 dB rejection at 50 Hz and ≥94 dB at 60 Hz in a single measurement cycle.

What are the absolute voltage limits for the AIN(+) and AIN(–) inputs on the AD7783BRUZ-REEL7?

The AD7783BRUZ-REEL7 specifies absolute analog input voltage limits of GND + 100 mV minimum and VDD – 100 mV maximum for both AIN(+) and AIN(–). Exceeding these limits degrades linearity and noise performance. For example, with a 3 V supply, the valid input common-mode range is 0.1 V to 2.9 V. This constraint applies regardless of selected input range (±160 mV or ±2.56 V), and must be respected during sensor biasing and PCB layout of AD7783BRUZ-REEL7 circuits.

Can the AD7783BRUZ-REEL7 operate from a 3.3 V supply?

Yes, the AD7783BRUZ-REEL7 is specified to operate from a single supply of 2.7 V to 3.6 V (3 V nominal) or 4.75 V to 5.25 V (5 V nominal). A 3.3 V supply falls within the 2.7–3.6 V range and is fully supported. At 3.3 V, power consumption remains near 1.3 mA typical, and all specifications-including 24-bit no missing codes, 18.5-bit p-p resolution at ±2.56 V, and 50/60 Hz rejection-are guaranteed across the –40°C to +85°C temperature range for AD7783BRUZ-REEL7.