USB-PD 3.1 EPR Workbench

Apple 140W USB-C Power Adapter Simulator

Interactive simulation of Apple's Model A2457 140W GaN power adapter. Sequence the Rev. 2026.09.08-EPR firmware payload, upgrade protocol negotiation to 28V / 5A EPR mode, and observe live dynamic wattage and thermal curves.

Firmware Sequencer Firmware: 1.4.73 (Legacy)
Adapter Model A2457 (140W) GaN Architecture
Negotiated PD USB-PD 3.0 Max 20V / 5A (100W)
Firmware Build 1.4.73 Target: 1.4.90
Flashing Sequence Ready to Flash
[00:00:00] Model A2457 initialized. Firmware Rev 1.4.73 active. Operating in fallback USB-PD 3.0 mode (100W limit).
Operating Telemetry Host: MacBook Pro 16"
Actual Output 100.0W 20.00V @ 5.00A
Thermal Output 43.8°C GaN Stage Sensing
Ripple & Noise 38 mVp-p Spec: <100mVp-p
Select Connected Host Device
MacRumors Release Note Dispatch & Payload Analysis

Source Dispatch: Apple has released an over-the-air firmware update for its standalone 140W USB-C Power Adapter (Model A2457). The firmware revs from build 1.4.73 to 1.4.90 (internal release: Rev. 2026.09.08-EPR).

  • USB-PD 3.1 EPR Protocol: Unlocks optimized power contracts up to 28V at 5A (140W) when coupled with Apple's MagSafe 3 or 240W USB-C EPR cables.
  • Thermal Stabilization: Enhanced GaN switching frequency curve stabilizes operating temperature at 41.2°C under sustained 140W saturation load.
  • Autonomous Deployment: Apple power adapters flash automatically in the background when tethered to macOS Sequoia / iOS hosts while connected to AC power.