A stereo audio codec (coder-decoder) with built-in digital audio processing capabilities, the ADAU1761BCPZ consumes little power. Developed by Analog Devices, this codec is designed to cater to a broad range of portable applications, such as cellular phones, digital cameras, portable media players, and other devices that have recording and playback functionalities. Here are its key features:

1.Stereo Audio Codec: The ADAU1761BCPZ has both Analog-to-Digital Converters (ADC's) and Digital-to-Analog Converters (Days) to enable stereo audio recording and playback.

2. Integrated Digital Signal Processor (DSP): It includes a Sigma DSP core for signal processing tasks, such as equalization, dynamic range compression, and filtering.

3. Flexible Audio I/O: It supports multiple audio input and output channels with various analog and digital interfaces.

4. Hapless Headphone Driver: This reduces component count and system cost as it eliminates the need for DC-blocking capacitors.

5. Integrated PLL: The on-chip PLL can be used to generate the required system clock from an external reference clock.

6. I2C and SPI Control Interfaces: These interfaces allow a microcontroller or other device to control the ADAU1761BCPZ.

In terms of the circuit connection, here are several important pins:

- ADD, DVD, IOV DD, PADD, DVD_CORE: These are power supply pins for the analog, digital I/O, PLL, and core digital sections of the device, respectively.

- MP0/MP1: These are mode pins used to configure the operating mode of the device.

- Digital audio data is inputted and outputted using these pins, designated DATA_IN, DATA_OUT.

- BULK, LACK: These are clocking signals for the digital audio interface.

- ADC, DAC: These are the analog inputs and outputs for the ADC's and Days.

- MACIAS: This is a power output for elected microphones.

- SCL, SDA/SDI, SDO, SILK: These pins are used for I2C or SPI control interfaces.

- CATCH, CCK, DATA: These are used for control port interfaces.

For a detailed understanding of its functionalities and connections, it's crucial to refer to the ADAU1761BCPZ's data sheet. Additionally, it is recommended to use the SigmaStudio software, which provides a graphical interface for developing and tuning audio processing algorithms for the ADAU1761BCPZ's DSP.