77645-11 IC

When a Xiaomi Mi 5C comes into your shop with a dead network, no signal bars, or intermittent 4G drop, the SKY77645-11 power amplifier is one of the first components you check on the RF section of the board. This IC is Skyworks' SkyLiTE multimode multiband power amplifier module, built to handle the transmit path for 3G and 4G LTE handsets in a single compact package. You're not dealing with a generic clone here — this is the same part number that OEM boards use, so a working replacement restores original network performance instead of a workaround fix.The module covers a wide spread of bands, which is why you see it across so many different network-issue repairs. On the CDMA side it supports BC0, BC1, BC4, BC6, BC10, and BC15. For WCDMA you get bands I, II, III, IV, V, VIII, and IX. TD-SCDMA coverage includes bands 34 and 39. On LTE, the FDD side supports bands 1, 2, 3, 4, 5, 7, 8, 9, 12, 13, 17, 20, 25, 26, 28, and 30, while the TDD side covers bands 38, 39, 40, and 41. When you're chasing a "network issue" complaint where the phone locks onto 2G only, drops LTE, or shows no service in specific areas, this band list tells you exactly which frequencies run through this single IC — so a fault here explains a lot of network symptoms in one shot.Internally, the PA module is built from an InGaP die and a silicon die mounted together with passive components on a multi-layer laminate substrate, then encapsulated into a compact 4.0mm x 6.8mm x 0.75mm, 42-pad MCM SMT package. That small footprint means precise reflow work under the microscope — you need clean pad alignment, correct paste application, and a controlled hot air profile to avoid tombstoning or bridging on such a tight pad pitch. This isn't a component you rework with a basic iron; a hot air station with fine nozzle control and steady temperature is the right tool for removing and reballing this IC.One feature technicians should know before quoting a repair: the SKY77645-11 is MIPI programmable, meaning the internal Multi-Function Control block talks to the baseband processor over the Mobile Industry Processor Interface to switch between bias modes for different bands and power levels. If you replace the IC but the phone still won't hold network, don't assume the part is faulty first — check that MIPI communication lines to the IC aren't damaged from a board short or corrosion, since a good IC with a broken control line will show the same symptoms as a bad IC.This part is common on Xiaomi Mi 5C repairs specifically, and boards using the same SkyLiTE PA design family will show identical failure patterns — dead after flash with no network return, signal drop after a fall or liquid exposure, or a phone that connects to WiFi fine but shows no SIM network. Keep in mind Skyworks has marked this part number as discontinued at the manufacturer level, so genuine new-old-stock and tested pulls are what's available in the repair parts market — factor that into your sourcing and testing before you commit to a board-level repair job.For your repair bench, stock a few of these alongside your existing PA and network IC inventory. Network complaints are recurring work, and having a verified working 77645-11 ready means you close the repair the same day instead of waiting on parts.