Analog Devices Inc. AD7709BRUZ-REEL7

Overview

AD7709BRUZ-REEL7 from Analog Devices is a 16-bit sigma-delta ADC with integrated programmable gain amplifier (PGA), three switchable matched excitation current sources (200 µA, 200 µA, and 25 µA), low-side power switches, and a 4-bit digital I/O port - designed for precision sensor front-end applications including RTD, thermocouple, and bridge transducer measurement. It supports ±20 mV to ±2.56 V input ranges, simultaneous 50 Hz/60 Hz rejection at 19.79 Hz update rate, and operates from single 3 V or 5 V supply.

For engineers reviewing the AD7709BRUZ-REEL7 datasheet, AD7709BRUZ-REEL7 pinout, AD7709BRUZ-REEL7 application, or AD7709BRUZ-REEL7 equivalent, this page delivers verified technical context, real-world use cases, validated alternatives, and supply-ready availability details - all grounded in Analog Devices' official AD7709 Rev. A documentation and TSSOP-24 package specifications.

Technical Context

The AD7709BRUZ-REEL7 implements a chopper-stabilized sigma-delta ADC architecture with Sinc³ digital filtering, enabling 16-bit no-missing-codes performance and 13-bit p-p resolution at ±20 mV range with 20 Hz update rate. Its on-chip PLL locks to a 32.768 kHz crystal to generate internal timing, supporting programmable output data rates from 5.35 Hz to 105 Hz via an 8-bit filter register (SF = 13–255).

It integrates rail-to-rail input buffering, selectable reference inputs (REFIN1/REFIN2), and dual-purpose pins (P1/SW1, P2/SW2) configurable as digital I/O or low-side power switches (RON ≤ 7 Ω). The excitation current sources feature ±2.5% matching (IEXC1/IEXC2) and ±5% matching to 8×IEXC3, enabling precise ratiometric V_BE and 3-wire RTD measurements.

Key Specifications

Pinout & Package

The AD7709BRUZ-REEL7 is housed in a 24-lead TSSOP (RU-24) package with exposed pad, optimized for low thermal resistance (θ_JA = 97.9°C/W) and high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7709BRUZ-REEL7, AD7190BRUZ offers superior resolution but requires external components for RTD biasing, while ADS1248IPWR simplifies layout with internal clocking yet sacrifices the precise current matching and low-side switching needed for robust industrial sensor interfacing.

Availability

AD7709BRUZ-REEL7 is available at Aetrix Electronics and suitable for temperature measurement, pressure transducer readout, and portable instrumentation requiring stable component supply across extended temperature ranges (–40°C to +85°C) and long product lifecycles.

Supply support for AD7709BRUZ-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, headquartered in Norwood, MA, with design and manufacturing expertise spanning precision data conversion, power management, and RF technologies.

The AD7709BRUZ-REEL7 belongs to Analog Devices' precision sigma-delta ADC product line, engineered specifically for low-frequency, high-accuracy sensor signal conditioning in industrial, medical, and test equipment applications.

FAQ

What is the maximum update rate of the AD7709BRUZ-REEL7, and how is it configured?

The AD7709BRUZ-REEL7 supports a maximum update rate of 105 Hz, achieved by programming the Sinc³ filter register (SF) to 13. This value sets the decimation factor to 104 (SF × 8), yielding the highest output data rate. The update rate is software-configurable via the 8-bit Filter Register, with each increment in SF increasing conversion time by 0.732 ms. At 105 Hz, the AD7709BRUZ-REEL7 delivers 16-bit p-p resolution over ±2.56 V input range.

Does the AD7709BRUZ-REEL7 support both 3 V and 5 V operation, and what are the power consumption implications?

Yes, the AD7709BRUZ-REEL7 is fully specified for single-supply operation at either 3 V (2.7–3.6 V) or 5 V (4.75–5.25 V). At 3 V, typical supply current is 1.25 mA in normal mode and 7 µA in power-down mode with crystal active. At 5 V, typical current rises to 1.45 mA normal and 6.5 µA power-down. Power dissipation is 3.75 mW at 3 V - making AD7709BRUZ-REEL7 suitable for portable instrumentation where supply headroom and battery life are constrained.

How does the AD7709BRUZ-REEL7 achieve simultaneous 50 Hz and 60 Hz rejection, and what configuration is required?

The AD7709BRUZ-REEL7 achieves simultaneous 50 Hz and 60 Hz rejection through its Sinc³ digital filter architecture when operated at an update rate of 19.79 Hz (SF = 82). At this rate, the filter's notches align to reject both frequencies with ≥100 dB attenuation. This capability is intrinsic to the modulator/filter design and requires no external components. The AD7709BRUZ-REEL7 must be configured with appropriate gain and reference settings - no firmware or hardware modifications beyond register programming are needed to activate this feature.

Can the AD7709BRUZ-REEL7's P1/SW1 and P2/SW2 pins be used simultaneously as GPIO and power switches?

No - each of the P1/SW1 and P2/SW2 pins on the AD7709BRUZ-REEL7 is functionally exclusive: it operates either as a general-purpose digital output bit (P1 or P2) or as a low-side NMOS power switch (SW1 or SW2), but not both concurrently. Configuration is controlled via on-chip registers. When used as SW1/SW2, they sink up to 20 mA each to PWRGND with R_ON ≤ 7 Ω (B grade, 3 V); as GPIO, they support standard logic levels with weak internal pull-ups. The AD7709BRUZ-REEL7 does not support time-multiplexed or hybrid operation of these pins.

What are the absolute voltage limits for the analog input pins (AIN1–AIN4) of the AD7709BRUZ-REEL7?

The AD7709BRUZ-REEL7 specifies absolute voltage limits for AIN1–AIN4 as GND + 100 mV minimum and VDD – 100 mV maximum under normal operation. Exceeding these limits risks latch-up or permanent damage. These constraints apply regardless of PGA gain setting or input mode (differential or pseudo-differential). The AINCOM pin has wider tolerance: GND – 30 mV to VDD + 30 mV. All analog inputs also require adherence to the differential input voltage range: ±(1.024 × REFIN)/GAIN, where GAIN = 1 to 128.