Pololu RC Switch with Small Low-Side MOSFET

The Pololu RC switch with a small low-side MOSFET can be used with commercially available hobby radio control systems for radio control switching applications or simple interface applications. Examples include converting additional RC receiver or servo controller outputs into simple high/low signals to control LEDs or relays, and connecting RC systems to microcontroller projects that lack the resources to decode the RC interface. Two outputs indicate the presence of a valid signal and the on/off state of the switch. An integrated low-side MOSFET turns on when the switch is open, allowing the board to directly drive small loads. The switch also features a flyback (or freewheeling) diode across the load outputs, enabling you to connect an inductor, such as a motor or relay, without additional external components.

The board requires a 2.5–5.5 V power supply, which is connected to VCC. The board's MOSFET can deliver up to approximately 3 A at 5 V VCC and handle load supply voltages up to 30 V.

The RC switch measures the width of incoming RC pulses and compares them to a user-configurable threshold (with ±64 µs hysteresis) to determine whether to turn on the MOSFET. By default, the threshold is approximately 1700 µs, with longer pulses triggering the switch. However, the switch features a learning mode that allows you to change the threshold and the activation direction. A safe-start function reduces the likelihood of unexpected activation.

This compact device measures 0.4" x 0.6" and weighs just over 0.5 g (0.02 oz) without the included pin headers.

Dimensions:

• Size: 0.4" x 0.6"
  
• Weight: 0.5 g

General specifications:

• Maximum output current: 3 A
  
• Minimum logic voltage: 2.5 V
  
• Maximum logic voltage: 5.5 V

Links:

• User manual