Analog Devices Inc. AD7795BRUZ-REEL

Overview

AD7795BRUZ-REEL from Analog Devices is a 16-bit, low-noise, low-power Σ-Δ analog-to-digital converter with integrated instrumentation amplifier, on-chip band gap reference (4 ppm/°C drift), six differential analog inputs, and programmable excitation current sources. It operates from 2.7 V to 5.25 V, consumes 400 μA typical supply current, and supports update rates from 4.17 Hz to 470 Hz - optimized for high-precision industrial sensor measurement in weigh scales and pressure transducers.

For engineers reviewing the AD7795BRUZ-REEL datasheet, AD7795BRUZ-REEL pinout, AD7795BRUZ-REEL application, or AD7795BRUZ-REEL equivalent, key selection considerations include its 16-bit resolution with 23 effective bits, simultaneous 50/60 Hz rejection, internal clock oscillator, 24-lead TSSOP package, and support for unipolar/bipolar configurations with buffered or unbuffered analog input modes.

Technical Context

The AD7795BRUZ-REEL implements a chopper-stabilized Σ-Δ modulator with digital filter capable of 4.17 Hz to 470 Hz output data rates and up to 23 effective bits of resolution. Its on-chip instrumentation amplifier provides programmable gain (1–128) and supports both buffered and unbuffered input paths with defined common-mode voltage constraints.

It integrates dual excitation current sources (10/210/1000 μA), a bias voltage generator (AVDD/2), reference detect circuitry, burnout currents, and a low-side power switch (RON ≤ 9 Ω at 3 V) for bridge sensor power management - all controlled via a 3-wire SPI-compatible serial interface with Schmitt-triggered SCLK.

Key Specifications

Pinout & Package

AD7795BRUZ-REEL is housed in a 24-lead TSSOP package (4.4 mm × 7.8 mm, 0.65 mm pitch) with exposed pad for thermal performance. Pin functions are validated per Analog Devices Rev. D datasheet Figure 5 and Table 4.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar precision ADC applications.

Compared with AD7794BRUZ-REEL, AD7795BRUZ-REEL trades resolution for lower cost and marginally reduced power; versus ADS124S08IPWR, it offers superior 50/60 Hz rejection and simpler calibration but lacks integrated CRC and has higher supply current.

Availability

AD7795BRUZ-REEL is available at Aetrix Electronics and suitable for weigh scales, pressure transducers, and temperature measurement systems requiring stable component supply, long-lifecycle assurance, and guaranteed traceability for industrial OEM deployments.

Supply support for AD7795BRUZ-REEL 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.

The AD779x series was designed specifically for high-precision, low-power sensor front ends in industrial process control, instrumentation, and smart transmitter applications - emphasizing integrated functionality, noise immunity, and ease of calibration.

FAQ

What is the maximum update rate supported by the AD7795BRUZ-REEL?

The AD7795BRUZ-REEL supports an output data rate from 4.17 Hz to 470 Hz. At 470 Hz, the device achieves 16-bit no-missing-codes performance with chop disabled; at lower rates (e.g., 4.17 Hz), it delivers up to 23 effective bits with chop enabled. The update rate is configured via the Mode Register's FS[3:0] bits and is independent of whether the internal or external clock is used.

Does the AD7795BRUZ-REEL require an external crystal or oscillator?

No, the AD7795BRUZ-REEL includes an internal 64 kHz ±3% clock oscillator, eliminating the need for external timing components. The CLK pin can be configured to output this internal clock or accept an external 64 kHz (or 128 kHz with divide-by-2) signal - enabling synchronization across multiple ADCs in multi-channel systems without added BOM cost.

Can the AD7795BRUZ-REEL drive a 4-wire RTD directly?

Yes, the AD7795BRUZ-REEL integrates two programmable excitation current sources (IOUT1/IOUT2) delivering 10 μA, 210 μA, or 1 mA with ±5% initial accuracy and 200 ppm/°C drift. These can be routed to AIN5(−)/AIN5(+) pins to bias 4-wire RTDs, while the on-chip instrumentation amplifier and 2.5 V reference enable ratiometric measurement - no external current sources or references needed.

What is the purpose of the PSW pin on the AD7795BRUZ-REEL?

The PSW (power switch) pin on the AD7795BRUZ-REEL is a low-side switch with RON ≤ 9 Ω (at 3 V) that controls power to external bridge sensors. It allows the ADC to disconnect the bridge between conversions, reducing average system power consumption - especially valuable in battery-operated weigh scales or portable pressure sensors where idle current must be minimized.

How does the AD7795BRUZ-REEL handle 50 Hz and 60 Hz interference?

The AD7795BRUZ-REEL achieves simultaneous 50 Hz and 60 Hz rejection up to 80 dB minimum (90 dB typical) using its digital filter architecture and selectable update rates. When configured for 4.17 Hz, 5.21 Hz, or 6.25 Hz output rates, the filter nulls both line frequencies inherently - no external hardware filtering required. This is implemented in firmware via the Mode Register and requires no additional components.