Audio chip connects directly to MEMS microphones

The device features a built-in interface for a MEMS digital microphone as well as a standard microphone input. Small size and low sensitivity to noise from LCDs and power components suit MEMS microphones for multi-function products such as smart phones. Direct connection of a MEMS microphone saves parts count and cost.

The audio chip has a second MEMS input that can be connected to a tiny sensor for detecting speaker movements. This allows designers to apply active-sound shaping using ST patented techniques to optimise speaker performance. In active-sound shaping, the processor compensates automatically for distortion or damage to the speaker enabling high-quality audio performance from over-driven speakers or from those with torn or restricted-movement cones.

Support for designers include complete development kits for MEMS-based systems, as well as the APWorkbench graphical development environment. APWorkbench helps designers configure Sound Terminal products intuitively, and includes features for setting up active sound shaping.

Main features of STA321MP are audio processing optimised for use with MEMS microphones; direct output to high-efficiency digital amplifier; PDM/analogue and dual-I²S input; low power consumption and a 1mm-high profile, being in a QFN package.

The STA321MP is available now in a 7 x 7mm QFN package, priced at Rs.137.60 ($3) in quantities of 1,000. Alternative pricing options are available for larger quantities.