SparkFun Qwiic Power Switch

The SparkFun Qwiic Power Switch (QPS) gives you the power to manage your Qwiic devices more efficiently. Many Qwiic boards, especially high-power ones like our high-accuracy GNSS boards, draw significant current even in standby mode. With the QPS, you can selectively turn off these devices to conserve energy and extend your battery life.

However, the QPS offers even more functionality; it includes I2C bus isolation, allowing you to mix 100kHz and 400kHz I2C devices on the same bus without conflict. Isolate slower devices to avoid slowing down communication with faster ones.

For added flexibility, the QPS also provides two extra GPIO pins that can be used as inputs or outputs to control other components in your project. It works seamlessly with the SparkFun Qwiic Mux, enabling you to control and power multiple devices, even those sharing the same I2C address.

Our Arduino Library makes integrating the QPS into your projects easy, with comprehensive examples for power switching, bus isolation, and GPIO control. Enhance your Qwiic projects with the SparkFun Qwiic Power Switch and take control of your power management!


The SparkFun Qwiic Connect System is an ecosystem of I2C sensors, actuators, shields and cables that make prototyping faster and less prone to error. All Qwiic-enabled boards use a common 1mm pitch, 4-pin JST connector. This reduces the amount of required PCB space, and polarized connections mean you can’t hook it up wrong.


  • PCA9536
    • 4-Bit I2C to Parallel Port Expander
    • Operating Voltage (VCC): 2.3V to 5.5V
    • (Note: Qwiic operation must be limited to 3.3V)
    • Operating Temperature: -40°C to +85°C
    • 400kHz Fast I2C Bus
    • Input/Output Configuration Register
    • Polarity Inversion Register
    • Internal Power-On Reset
    • No Glitch on Power Up
    • Standby Current Consumption (Typical): 0.2μA
    • I2C Address: 0x41
  • PCA9306
    • Dual Bidirectional I2C Bus Voltage-Level Translator
    • Lockup-free Operation for Isolation
  • DMG2305UX P-Channel MOSFET
    • 52mΩ (0.052 Ohms) typical on-resistance
  • IN and OUT Qwiic Connection Ports
  • IN and OUT I2C Pull-Up Resistors
  • 2x Extra GPIO Pins
  • IN and OUT Power LEDs
    • Can be disabled for low power applications
  • Jumpers
    • IN power LED
    • OUT power LED
    • IN I2C Pull-Up Resistors
    • OUT I2C Pull-Up Resistors
  • Board Dimensions: 1.0in. x 1.0in. (25.4mm x 25.4mm)
  • Weight: 2.40g

Comments

Looking for answers to technical questions?

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  • What is the voltage drop? What is the relationship between current and voltage drop?

    • PaulZC / about 2 weeks ago / 2

      Hi. The "switch" is a DMG2305UX P-Channel MOSFET. Its on-resistance is around 52 milliOhms (0.052 Ohms). You can use Ohm's Law to calculate the drop... I hope this helps, Paul

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