Soft Power Switch with USB-C

This board adds a laptop-style power button to your project: a simple press turns the system on, and another press can turn it off cleanly when your microcontroller is involved. If things go wrong, pressing and holding the button for ~10 seconds forces a power-down.

This USB-C version has two USB Type C connectors and supports USB data feed-through, making it useful for enclosed builds where you still want a neat external power button. It is a good fit for projects using an enclosed Thing Plus board or similar microcontroller setup.

The design is based on a fully digital Texas Instruments circuit and includes a self-resetting 2A fuse for overcurrent protection, VIN and VOUT LEDs for visual feedback, and very low quiescent current draw. Connect the PUSH and OFF pins to your microcontroller to detect button presses and run a controlled shutdown sequence.

Documentation provided by SparkFun includes a schematic, KiCad files, 3D model, board dimensions, hookup guide, component datasheets, an example sketch, and the hardware repository.

Features:

• Software feedback and control: passive, hard on/off switching with MCU interaction.
• Press to power on: a simple press will turn the system on.
• Controlled shutdown: another press can, with MCU intervention, turn off the system.
• Hard override: pressing and holding the button for ~10 seconds will force a power-down.
• USB-C: this version has two USB-C connectors.
• USB data feed-through: supports USB data feed-through.
• Overcurrent protection: self-resetting 2A fuse.
• Visual feedback: input and output LEDs.
• Low standby draw: very low quiescent current draw to conserve battery power.
• MCU pins: PUSH and OFF pins for button monitoring and controlled shutdown.
• Timing customisation: wake-up and power-down times can be customised.

Specifications:

• Input voltage: 5.5V maximum, 1.8V minimum
• Typical input: Typically 5V from USB
• Maximum current draw: 2A continuous, 4A peak (fuse protected)
• MOSFET: SIL2308 N&P-Channel MOSFET
• P-Channel on-resistance: 70mΩ (0.070 Ohm) typical P-Channel on-resistance
• Quiescent current: <1µA @ 3.75V, with VIN LED disabled
• USB Type C connectors: 2x USB Type C Connectors
• VIN: VIN
• VOUT: VOUT
• USB data feed-through: USB data feed-through
• Built-in momentary push button: Built-in momentary push button
• Hard override: push and hold the button for ~10 seconds
• Breakout PTH GND: GND
• Breakout PTH VIN: VIN
• Breakout PTH VOUT: VOUT
• BTN: if desired, connect an external button between BTN and GND
• PUSH: open-drain output, requires pull-up, low indicates button is pushed
• OFF: drive high to turn the output off
• LEDs: VIN and VOUT (can be disabled if desired)
• Jumpers: Jumpers
• Input power LED: Input power LED
• Output power LED: Output power LED
• Dimensions: 1.0in. x 1.0in. (25.4mm x 25.4mm)
• Weight: 3.25g

Use it when you need a neat front-panel-style power button, USB-C pass-through, and microcontroller-aware shutdown control in a compact build.