ChargerLab: Teardown of Lenovo Legion 135W USB-C GaN Charger

Lenovo’s Legion 5 and 5 Pro Gen 7 laptops are significant gaming machines, featuring AMD Rembrandt Ryzen 9 or Intel 12th-gen Alder Lake Core CPUs, AMD Radeon Vega or NVIDIA RTX GPUs, 32 GB of DDR5 memory, 1 TB of solid-state drive, up to 16” screens with 240 Hz refresh rates, and a mighty 80 Whr battery.

The 135 W-rated GaNFast charger measures only 66 x 65 x 31 mm (133 cc) – 40% smaller than legacy chargers – so the C135 achieves a power density over 1 W/cc. The power conversion topology is a PFC stage followed by an isolating high-frequency, quasi-resonant (HFQR) flyback using Navitas’ NV6136A GaNFast power IC with GaNSense technology. This eliminates the system-current-sensing resistor, avoids a high-temperature ‘hot-spot’ and delivers an additional 10% of energy savings with increased system reliability. Peak charging efficiency is over 92%, enabling the high power density.

The C135 adopts Lenovo’s proprietary protocol to reach the full 135W rating and a 0-100% charge time of only 65 minutes. Also equipped with universal, industry-standard protocols (USB-PD, USB-PPS and QC) at 100W and below, the C135 can also fast-charge any number of laptop, tablet, phone and audio models from Lenovo and any other manufacturer.

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