High-Efficiency Drop-in Power Delivery Solution for Commodore 64 / 64C / VIC-20CR and SukkoPera's LittleSixteen (Enhanced Plus/4)

This board is a modern, high-performance drop-in replacement for the aging original power supplies of the Commodore home computer.

It delivers clean, stable power with exceptional efficiency — keeping your retro machine cool, safe, and reliable for years to come.

Inspired by the work of Vittorio Pascucci (SPL).

📐 Dimensions & Form Factor

Mounting: Vertical direct-mount on Commodore models.

Board Size: 60 x 91 mm (L x W).

Height: 14 mm (excluding the DIN connector), overall 31 mm.

Weight: 45 grams (no enclosure, excluding the USB-C power supply unit and cable).

PCB stack: 2 layers, 1.6 mm thickness, 1 oz.

Compact and portable.

⚡ High-Efficiency Performance

Engineered for minimal heat generation and maximum power conversion:

94% efficiency @ 5.15V / 0.5A

95% efficiency @ 5.15V / 0.8A

96% efficiency @ 5.15V / 1.5A (Peak efficiency)

94% efficiency @ 5.15V / 3.0A

92% efficiency @ 5.15V / 4.0A

94% efficiency @ 9VAC / 1.2A (25W clean power)

🎯 Precision Regulation & Transient Response

Maintains rock-solid output under varying conditions, keeping the total deviation within ±0.25%:

Line Regulation: Exceptional stability across a wide input range (11V to 13V DC) at full load.

Load Regulation & Transient Response: Handles rapid load steps (0.4A to 4A, Rise/Fall time 40µs, duration 300ms) with minimal deviation.

🛡️ Comprehensive Protection Suite

Advanced safety features to safeguard both the power supply and your vintage computer:

Overvoltage Protection (OVP - 5V Rail): Triggers at >5.49V ±0.30V.

Undervoltage Protection (UVP - 5V and 9V AC Rails): Triggers at <6.96V ±0.12V.

Overload & Short-Circuit Protection (OCP / SCP) – Automatic shutdown to prevent damage, no hiccup.

Thermal Shutdown – Prevents overheating under extreme conditions.

Soft-start with Inrush Current limit and Fast Discharge after Shutdown – The main power switch remains ON while the board controls power ON / OFF condition carefully.

EMI filters – High Frequency noise reduction.

Transil™ transient voltage surge suppressor (TVS) diode – to protect from electrostatic discharge and voltage spikes.

Power Good & Fail Monitoring – Provides status signaling for diagnostic purposes.

🔌 Compatibility & Power Delivery

Designed for global retro-computing use with flexible AC frequency selection:

Frequency Selection: User-selectable 50 Hz (PAL) or 60 Hz (NTSC) AC voltage output with jitter-free performance.

Continuous Output Capability (requires an adequate USB-C power source):

5V DC: 4.0A continuous (Peak 4.2A) – Step-down (buck) DC-DC conversion with no-load output voltage set to 5.15V

9V AC: 1.2A continuous (Peak 1.5A) – Quasi-sinusoidal waveforms with a 50% duty cycle and a no-load peak-to-peak voltage of 10.6V

As a reference, a Commodore 64C equipped with a joystick, running a game cartridge, and using an SD2IEC interface consumes 7W from a 12V USB-PD power supply.

Combined power cannot exceed power available from the USB-C power source (36W = 12V x 3A on delivery):

https://www.amazon.co.jp/dp/B0982VFYYJ?ref=ppx_yo2ov_dt_b_fed_asin_title

The USB-C cable can be 200 cm long (max):

https://www.amazon.co.jp/dp/B07V529BXP?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

✅ Perfect for Retro Enthusiasts

Revive your beloved Commodore 64, VIC-20 and the newest LittleSixteen with a cutting-edge, reliable power solution

that respects the original hardware while providing modern performance and safety.

BoM list: 

https://www.digikey.com/en/mylists/list/W7VXTF13QF

DIN 7 male connector:

https://ja.aliexpress.com/item/1005004612689660.html?spm=a2g0o.order_list.order_list_main.10.3e6d18021nvKtD&gatewayAdapt=glo2jpn

CH224K integrated circuit:

https://ja.aliexpress.com/item/1005007591739411.html?spm=a2g0o.order_list.order_list_main.46.360e1802T9A4Hb&gatewayAdapt=glo2jpn

Others:

Pick'n'Place files (centroid), Assembly diagrams (.pdf), STM32C0 firmware (.bin, .hex, .elf) are available for downloading.

No 3D enclosure is currently available. If any community member would like to contribute a design,

please contact me to collaborate on a plastic enclosure in FCStd and STL formats (FreeCAD).

The author is not an Amazon affiliate and may not receive a commission from products sold through links on this project page.

The schematic, layout and firmware are not AI-generated.

Designed circuit solutions based on public application notes and datasheets, followed by simulation and bench testing.

The firmware and Gerber files are provided 'as is' without warranty of any kind, and are subject to future improvements and development.

Inspired by the work of Vittorio Pascucci (SPL).