AD7783BRU

Overview

The AD7783BRU is a read-only, pin-configured 24-bit sigma-delta analog-to-digital converter (ADC) from Analog Devices. It features a single fully differential input channel with an integrated programmable gain amplifier and two 200 mA excitation current sources. The device operates at a fixed update rate of 19.79 Hz, providing simultaneous 50 Hz and 60 Hz rejection. It supports dual supply voltages: 2.7 V to 3.6 V or 4.75 V to 5.25 V. Power consumption is typically 1.3 mA at 3 V in normal mode. The component is housed in a 16-lead TSSOP package and functions without programmable registers, relying on hardware pins for configuration.

Feature Summary

• Pin-configurable input ranges and current source routing eliminate the need for software programming or register access.
• Integrated dual 200 mA constant current sources facilitate direct excitation of resistive bridge sensors and RTDs.
• Fixed output data rate ensures precise simultaneous rejection of power line interference frequencies.

Applications

• Weigh scales
• Industrial process control
• Temperature measurement

Procurement Notes

Verify component authenticity through authorized distribution channels. Confirm that the specific ordering suffix matches the required packaging format, such as tube or reel variants. Ensure compliance with environmental standards like RoHS if applicable to the specific revision. Check for obsolescence status prior to finalizing procurement plans.

Selection Notes

Select this component for applications requiring high-resolution measurements without complex digital interface programming. Consider the fixed 19.79 Hz update rate when designing system timing. Evaluate the ±160 mV and ±2.56 V input range options against sensor signal levels. Verify that the external crystal oscillator frequency matches the internal PLL requirements for proper operation.

Part Context

The AD7783 belongs to the AD778x family of precision ADCs designed for low-frequency measurement. Unlike other members such as the AD7782, it includes integrated excitation current sources but offers only one differential input channel. It shares the same pinout and interface characteristics with similar devices in the series, simplifying design transitions within the product line.

Replacement Considerations

The AD7783BRUZ is a RoHS-compliant version of the same functional device. Other family members like the AD7782 offer multiple channels but lack the integrated current sources found in the AD7783.

FAQ

How is the input voltage range configured?

The input range is set via the RANGE logic pin. A logic low selects the ±160 mV range, while a logic high selects the ±2.56 V range.

What is the function of the MODE pin?

The MODE pin determines the serial interface operation. A logic low configures the device for master mode, where it generates the clock, while a logic high sets it to slave mode.

Can the excitation current sources be swapped?

Yes, the IPIN logic input controls the routing of the internal current sources between the IOUT1 and IOUT2 pins.