Teardown: White-Label 20 W USB-C Charger — LX3726 Primary Switch, LX1709 Synchronous Rectifier, JD6617 Protocol IC
2026-10-20 · Compiled by Best IT Parts from public industry reporting
A teardown of a white-label 20 W USB-C wall charger built for the India market shows how a low-cost PD adapter is assembled around two single-die controllers and an entry-level protocol IC. The unit, marked Adapto 20X, accepts AC 180–240 V at 50/60 Hz, 0.6 A maximum, and delivers 5 V/3 A, 9 V/2.22 A and 12 V/1.67 A for 20 W peak. The shell is flame-retardant white PC with moulded vertical ribs, a fixed two-pin India plug with nickel-plated pins and a single USB-C receptacle on an orange insert. Measured size is 42.73 x 41.73 x 29.30 mm at 41.6 g, close to Apple's 20 W charger.
Tested with a POWER-Z KM003C, the port advertises QC3+, FCP, SCP, AFC, PD3.0/PPS, QC4+ and DCP, with fixed PDOs of 5 V/3 A, 9 V/2.22 A and 12 V/1.67 A plus one 5.00–11.00 V/2.00 A PPS range. The PCBA keeps primary and secondary clearly separated, with white thermal adhesive bonding the high-voltage electrolytic, differential-mode inductor, transformer and output solid capacitor. Input protection is a fuse for overcurrent and an NTC thermistor for inrush limiting, followed by an ABS210 bridge in an ABS package, a 450 V/15 µF bulk capacitor and a 50 V/22 µF capacitor feeding the primary controller.
The primary side runs an LX3726 in SOP-8 with an integrated high-voltage switch, driving a transformer marked XED 1512-002 / XDWY 2637, with a TMY1102M SMD Y capacitor and an Everlight EL817 optocoupler for feedback. Secondary rectification uses an LX1709 in SOP-8 that integrates both the synchronous-rectification controller and the SR MOSFET. The protocol layer is a JADARD JD6617, a USB Type-C source controller covering PD 3.2 SPR with PPS and AVS, 5–21 V operation and 3 A output; a constant-voltage loop drives the optocoupler through its OPTO pin at up to 20 mV steps, and a single resistor on the RPDO pin sets power and PDO across a 15–60 W range.
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Technical details are reproduced as reported. Verify specifications against the original source before design or procurement decisions.