AD7946BRMZRL7

Overview

The AD7946BRMZRL7 is a 14-bit, 500 kSPS PulSAR analog-to-digital converter (ADC) manufactured by Analog Devices Inc. It operates from a single 5 V supply with a digital interface supporting 1.8 V to 5 V logic levels via the VIO pin. The device features a pseudo-differential input range of 0 V to REF and includes an internal conversion clock. Key performance metrics include a typical Signal-to-Noise Ratio (SNR) of 85 dB at 20 kHz, Total Harmonic Distortion (THD) of −100 dB, and Integral Nonlinearity (INL) of ±0.4 LSB typical. Power dissipation scales linearly with throughput, reaching 3.3 mW at 100 kSPS and 19 mW at full speed.

Feature Summary

• Proprietary serial interface compatible with SPI, QSPI, Microwire, and DSP standards
• Daisy-chain capability for multiple ADCs on a single bus with optional BUSY indicator
• No pipeline delay or latency for immediate data availability after conversion
• Low power consumption with standby current of 1 nA

Applications

• Battery-powered equipment
• Data acquisition systems
• Instrumentation
• Medical instruments
• Process control

Procurement Notes

Verify the specific package variant, as the AD7946 series is available in both 10-lead MSOP and LFCSP formats. Confirm that the ordering suffix corresponds to the reel packaging required for automated assembly. Ensure compatibility with the host system's voltage levels, particularly the separate VIO supply for digital I/O.

Selection Notes

Select this component when a 14-bit resolution and 500 kSPS throughput are sufficient for the application. Consider the pseudo-differential input architecture if ground noise rejection is required. Verify that the external reference voltage can be supplied up to the VDD level, as the REF pin range extends from 0.5 V to VDD.

Part Context

The AD7946 belongs to Analog Devices' PulSAR ADC family, which utilizes charge redistribution successive approximation architecture. It is part of a broader lineup including 16-bit and 18-bit variants like the AD7686 and AD7980. The device is designed for applications requiring high accuracy with low power consumption in compact packages.

Replacement Considerations

The AD7946 is pin-for-pin compatible with the 16-bit AD7686. Designers upgrading from lower-resolution devices may consider this direct replacement, noting the change in bit resolution and potential differences in linearity specifications.