WM8862: Multi Channel HDA CODEC with Integrated Speaker Driver

Description

The WM8862 is a high performance PC audio subsystem for use in notebook, netbook, MID and tablet devices where a high level of audio performance is demanded. It is designed to minimise supporting components and board area, and enables the system designer to improve audio performance of a PC system while minimising design and implementation time.

The WM8862 is fully compliant with the High Definition Audio (HDA) interface specification (Revision 1.0), and also with the low-power DCN HDA015-B and dual-voltage DCN HDA024-A.

The device supports two stereo, single-ended analogue microphone/line inputs. This enables support for up to two analogue microphones inbuilt to a notebook screen, with simultaneous support for external microphone/line input connections. Microphone pre-amps are available, providing up to +30dB boost gain; a further pair of analogue PGAs provide an additional ±12dB of fine gain control. Two independent low-noise ECM bias sources are provided, further reducing the external system component count. The analogue inputs are digitised using high-performance multi-bit sigma-delta stereo ADCs.

Up to four digital microphones can be connected to the WM8862, providing support for advanced microphone arrays, eg. built into the lid of a portable PC system. Configurable notch filters are provided for the analogue or digital inputs, enabling known system noise sources (such as optical drives or fans) to be filtered from the audio input paths.

The WM8862 provides two stereo, 24-bit sigma-delta hi-fi DACs, supporting sample rates up to 192kHz. A ground-referenced headphone driver is provided, powered by an integrated charge pump, providing a true hi-fi performance output.

A stereo 2W/channel high-efficiency Class D speaker driver is also provided. Advanced digital signal processing is incorporated in the speaker path, enabling loudspeaker compensation to be realised using Wolfson's ReTune™ feature. Programmable compression / loudness control is also possible using the Dynamic Range Controller (DRC). This can be used at a hardware level to prevent very loud signals being applied to the speakers, avoiding distortion and damage.

Jack detect, GPIO functionality and an S/PDIF transmitter fully-compatible with IEC-60958-3 are also provided.

The CODEC and output drivers can operate from a single +5V supply, deriving all other necessary voltages using integrated regulators. The WM8862 supports separate I/O domains for the HDA interface and for the other digital interface pins, providing maximum system flexibility. The WM8862 is supplied in a small 48-pin QFN package.