ADAU1977WBCPZ-R7

Overview

The ADAU1977WBCPZ-R7 is a quad analog-to-digital converter (ADC) with integrated diagnostics, designed for automotive audio applications. It features four direct-coupled differential inputs capable of handling 10 V rms line-level signals or connecting directly to electret microphones via a programmable 5 V to 9 V bias generator. The device utilizes a multibit sigma-delta architecture with a continuous-time front end to minimize electromagnetic interference (EMI). Key performance metrics include a 109 dB dynamic range and -95 dB THD+N at a 48 kHz sample rate. An on-chip phase-locked loop (PLL) derives the master clock from an external input or frame clock, eliminating the need for separate high-frequency clocks.

Feature Summary

• Quad ADCs with 24-bit resolution supporting sample rates from 8 kHz to 192 kHz
• Integrated boost converter providing programmable microphone bias from 5 V to 9 V
• Comprehensive diagnostic circuitry detecting shorts to battery, ground, MICBIAS, and open circuits
• On-chip PLL for flexible clock generation from MCLKIN or LRCLK

Applications

• Automotive audio systems
• Active noise cancellation systems

Procurement Notes

Verify that the component matches the specific Rev. D datasheet specifications. Confirm the package type is the 40-lead LFCSP. Ensure the ordering suffix corresponds to the reel packaging format required by the assembly process. Cross-reference the part number against the manufacturer's current product status to confirm availability.

Selection Notes

Select this component when designing systems requiring high-performance audio digitization with built-in fault detection. The internal boost converter simplifies power management for microphone arrays. Ensure the system voltage supports the specified 3.3 V AVDDx supply and that the digital interface logic levels match the IOVDD requirements.

Part Context

This part belongs to the Analog Devices ADAU1977 family of audio data converters. The 'R7' suffix indicates the unit is supplied in a tape and reel configuration suitable for automated surface-mount assembly. The device is qualified for automotive applications, adhering to specific reliability standards required for vehicle electronics.

Replacement Considerations

Consult the manufacturer's official documentation for verified substitute part numbers. Do not assume functional equivalence with other quad ADCs without verifying pinout compatibility, electrical specifications, and diagnostic feature sets.

FAQ

How does the ADAU1977 handle microphone bias?

The device includes an integrated DC-to-DC boost converter that generates a programmable microphone bias voltage ranging from 5 V to 9 V in 0.5 V steps, allowing direct connection to electret condenser microphones.

What diagnostic faults can be detected?

The on-chip diagnostics detect short to battery, short to microphone bias, short to ground, short between positive and negative input pins, and open input terminals. These faults can trigger an IRQ flag.

What is the function of the on-chip PLL?

The phase-locked loop (PLL) generates the necessary internal master clock signals. It can derive the clock from an external MCLKIN input or from the serial audio frame clock (LRCLK), removing the need for a separate high-frequency oscillator.