PDM microphone to I²S bridge — what it does on the board
The ADAU7002ACBZ-R7 from Analog Devices is a dedicated sample rate converter that takes a PDM (pulse-density modulation) input from a digital microphone and outputs a standard I²S signal. This is the chip you reach for when you need to interface a PDM mic — common in consumer audio gear like smart speakers, soundbars, and voice-triggered devices — to a codec or DSP that only speaks I²S. It handles the clock-domain crossing and decimation filtering internally, so the host processor doesn't have to burn MIPS on PDM decoding. The supply range spans 1.62V to 3.6V, which covers the common 1.8V and 3.3V digital rails used in battery-powered and USB-bus-powered designs. Operating temperature covers -40°C to 85°C, fine for indoor consumer gear and most automotive cabin environments, though not rated for under-hood or extended industrial.
8-WLCSP — what the tiny package means for assembly
The part comes in an 8-bump WLCSP (wafer-level chip-scale package) measuring 0.76 x 1.56 mm. That is small — about the size of a grain of rice — which is the whole point for space-constrained audio boards. But it means the PCB footprint needs a fine-pitch BGA-style layout with microvias or at least tight trace escapes. No lab, no bench, let us go: this is not a hand-solder part; you want a stencil and a reflow oven with a profile tuned for WLCSP.
Active lifecycle — no LTB clock ticking
The ADAU7002ACBZ-R7 is listed as Active and ROHS3 compliant. For a BOM line, that means you can qualify it into a new design without worrying about a sudden discontinuation mid-production. The ROHS3 compliance covers the latest EU exemption rules, so no conflict with current environmental regulations.