40-Pin IO Protector

EDATEC's 40-pin IO protector features a tiny switch on the left board edge to control the 5 V and 3.3 V power supplies of a daughter board. To switch off a daughter board, turn the switch to the 'off' position. To install a daughter board on the 40-pin connector, switch off the power of the device, which protects the Pi 400 from damage from the hot plug without having to shut it down. The ESD immunity IC protects the 40 signals including power signals from the Pi 400. The ESD immunity IC will absorb the ESD energy from the daughter board.

The GPIO signals are protected by 33 Ω current-limit resistors and a short-circuit between the GPIOs and GPIO to GND. 5 V or 3.3 V won’t damage the IO of the Pi 400. The PMU provides overcurrent protection. However, the Pi400 won’t properly work when the PMU is in protection mode. The overcurrent protection limits current to 2 A at 5 V and 1.5 A at 3.3 V maximum draw from the Pi 400, avoiding the PMU shutting down the system due to a short-circuit or overcurrent on the daughter board. The green LED indicates the status of the 3.3 V power supply of the daughter board and the red LED indicates the status of the 5 V power. When the daughter board draws too much power from the Pi 400, the LEDs will blink. Two 220 µF capacitors stabilize the 5 V and 3.3 V power supplies respectively, 5*40-pin breadboard allows the user to experiment without additional cost.

The IO board comes with a 40-pin ribbon cable that offers gray and multi-color options, as well as a 40-pin black male connector with anti-reverse insertion at one end that connects to a 40-pin female connector on the back of the Pi 400 enabling the user to install a daughter board on the IO board. The device materials are RoHS-compliant.