SparkFun Soft Power Switch – USB-C

The SparkFun Soft Power Switch is a passive, hard on/off switch with software feedback and control. In other words, it’s like a laptop on/off switch. A simple press will turn the system on. Another press can (with MCU intervention) turn off the system. And if things go wrong, pressing and holding the button for ~10 seconds will force a power-down. If you’re building something with an enclosed Thing Plus board and need a good power button, this is the board you need. This version has two USB-C connectors, but we also have a version with JST 2mm battery connectors.

The Soft Power Switch is reliable and efficient, based on a robust, fully digital design from Texas Instruments. It features a self-resetting 2A fuse for overcurrent protection, input and output LEDs for visual feedback, and an incredibly low quiescent current draw to conserve battery power.

Connect the PUSH and OFF pins to your microcontroller to monitor button presses and initiate a controlled shutdown sequence, ensuring a smooth power-down process. You can customise the wake-up and power-down times to create the perfect user experience. The Soft Power Switch also supports USB data feed-through.

Get Started with the Sparkfun Soft Power Switch – USB-C Guide

Features

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

Resources

• Schematic
• KiCad Files
• 3D Model
• Board Dimensions
• Hookup Guide
• Component Datasheets
  • SN74LVC1G14
  • SN74LVC1G17
  • SN74LVC1G175
  • Texas Instruments Application Report: Push-Button Circuit SCEA048B
• Example Sketch
• GitHub Hardware Repo