AD7782BRUZ-REEL7

Overview

The AD7782BRUZ-REEL7 is a 2-channel, 24-bit sigma-delta analog-to-digital converter (ADC) manufactured by Analog Devices Inc. It operates from a single 3 V or 5 V supply and features a fixed output update rate of 19.79 Hz, providing simultaneous 50 Hz and 60 Hz rejection. The device includes two fully differential analog input channels with pin-selectable ranges of ±160 mV or ±2.56 V via an internal programmable gain amplifier. It utilizes a read-only digital interface compatible with SPI, QSPI, Microwire, and DSP protocols, supporting both master and slave modes without requiring on-chip register programming.

Feature Summary

• Pin-configurable architecture eliminates the need for software register programming for channel selection and input range configuration.
• Integrated rail-to-rail input buffer and programmable gain amplifier support high-impedance sensor connections.
• Fixed 19.79 Hz update rate ensures simultaneous rejection of 50 Hz and 60 Hz power line interference.
• Read-only serial interface supports flexible master or slave operation modes.

Applications

• Sensor measurement systems
• Industrial process control instrumentation
• Temperature measurement applications
• Pressure transducer interfaces
• Weigh scale systems

Procurement Notes

Verify that the ordering suffix matches the required package type and RoHS compliance status. Confirm the specific reel quantity requirements against distributor specifications. Ensure the component version aligns with the latest datasheet revision to guarantee parameter accuracy. Cross-reference the manufacturer part number with authorized distribution channels to validate authenticity and supply chain integrity before finalizing procurement orders.

Selection Notes

Select this component when designing low-frequency measurement circuits requiring high resolution without complex digital configuration. The pin-programmable nature simplifies hardware design by removing the need for microcontroller initialization sequences. Consider the fixed 19.79 Hz data rate when determining system throughput requirements. Verify that the external reference voltage source meets the specified common-mode and noise requirements for optimal performance.

Part Context

This component belongs to the AD778x family of precision analog front ends designed for low-frequency signal acquisition. It shares architectural similarities with other members like the AD7783, which integrates current sources but offers only one differential channel. The AD7782 specifically targets applications needing dual-channel differential input capability with minimal external digital logic overhead.

Replacement Considerations

The AD7782BRU-REEL is a tube-packaged alternative within the same series. The AD7783 serves as a functional variant with integrated current sources and a single differential channel. Verify pin compatibility and channel count requirements when substituting these parts in existing designs.

FAQ

How are the input channels and voltage ranges configured?

Configuration is achieved through external logic pins rather than software registers. The CH1/CH2 pin selects between the two differential input pairs, while the RANGE pin sets the full-scale input range to either ±160 mV or ±2.56 V.

What crystal frequency is required for operation?

The device requires a 32.768 kHz watch crystal connected to the XTAL1 and XTAL2 pins. An internal phase-locked loop generates the necessary operating clock from this frequency.

Does the device support isolated communication interfaces?

Yes, the SCLK input in slave mode is Schmitt-triggered, making the interface suitable for opto-isolated applications where noise immunity is critical.