AW87319 Audio IC

Every GSM technician runs into the "no sound" or "low volume" complaint on Xiaomi boards, and most of the time the AW87319 audio IC sits at the root of it. Awinic designed this chip as a K-class Class D power amplifier, meaning it drives the speaker with a high-voltage synchronous boost stage instead of pulling straight from the battery rail. That boost stage runs at up to 84% efficiency, which keeps the output steady at 4.1W into an 8Ω speaker and 4.6W into 6Ω, even as the lithium battery voltage sags between 3.3V and 4.35V during a call or a game session.The chip carries Awinic's Triple-Level Triple-Rate AGC algorithm, a feature that boosts bass response and expands dynamic range while it protects the speaker coil from over-excursion at high volume. On the technician side, this shows up as fewer "buzzing speaker" complaints coming back after a repair, because the AGC clamps output before the coil gets stressed. Noise floor sits at 47μV with a 102dB signal-to-noise ratio and 0.015% THD+N, so the audio stays clean instead of muddy or crackly once you swap the chip in.AW87319 ships in a CSP-19 package measuring 2.76mm × 2.36mm, small enough that reballing needs a steady hand, flux, and the right stencil size. The chip talks to the main audio codec over I2C, and the board firmware controls boost output voltage, Class D gain, and AGC parameters through internal registers, so a straight IC swap without a matching firmware or EEPROM mismatch restores function on a working donor board. On Redmi 4A, Redmi Note 4, and Redmi Note 4X boards, this chip sits close to the speaker connector, and a short trace run helps keep GSM 217Hz interference out of the audio path — worth checking if the replaced chip still picks up noise during a call.Dead phone boards after liquid contact often show a shorted AW87319 pulling the whole audio rail low, and a jumper lagana fix without replacing the burnt IC rarely holds. Common bench scenarios include: complete dead speaker with the display and touch still working, one-sided audio where receiver works but loud speaker stays silent (or the reverse), speaker output that plays at a fixed low volume regardless of the volume rocker, and a hang on logo or bootloop board where diagnostics later trace back to a shorted amplifier pulling down PMIC output. Before you order a replacement, check chipset markings against the board — counterfeit stock circulating in the market carries the same top marking without matching internal specs, and that mismatch shows up as a repeat comeback within days.Handle this IC with standard BGA reballing practice: preheat the board, control hot air temperature to avoid lifting neighboring components, and confirm ball alignment under a microscope before reflow. A software marna step alone will not fix a physically shorted or cracked chip — this component needs a hardware swap. Once reballed and reflowed, test speaker output at low, medium, and full volume before you close the board back up, since a cold joint on a 19-ball CSP package can pass a quick beep test and still fail under load later.KB GSM Store stocks genuine AW87319 units sourced for accuracy against the original chip markings, so your repair shop gets consistent results job after job instead of chasing comeback repairs from mismatched stock.