This page describes the Plug & Program PNP-USB2Serial USB interface and power supply module

Quick Look

  • provides 3.3V to Plug & Program hardware solution sourced from the host workstation via USB
  • connects your Plug & Program hardware solution to a workstation virtual comms port via USB


  • Dual function Power supply (3.3V only) and USB to serial interface
  • Each function is independent of the other
    • USB to serial
      • Provides virtual comm port on the connected workstation for simple comunications
      • 1 IO data socket
    • Power Plug & Program hardware solution from USB
      • Convenient
      • 1 Plug & Program Eco System compatible power distribution socket onboard
  • FTDI FR232RL USB UART interface Integrated Circuit Devices
    • Simple UART interface on Mainboard
    • Connect to any Mainboard UART IO socket
  • 3.3V USB power supply
    • Low dropout 3.3v 500mA regulator
    • Conform to USB standards:
      • Current limited to ~350Ma via self resetting polyfuse
      • Mosfet switched on/off by FT232RL Active signal to respond to workstation USB Suspend signal
      • USB source diode protection to ensure no voltage fed back through host USB connection
    • Can co-exist in a Plug & Program hardware solution with another power supply module connected (PN-DCPWR1) with both turned on, either turned on
  • Conforms to the Plug & Program Ecosystem

IO Connectors

    • IO-UART.1 = CTS
    • IO-UART.2 = TX
    • IO-UART.3 = RX
    • IO-UART.4 = RTS

Plug & Program Resources

  • Schematic
  • PCB
  • BOM

External Resources

USB Suspend mode

When powering a Plug & Program hardware solution using the PNP-USB2SERIAL:

The onboard FT232RL by default has its USB config descriptor as:

  • 90mA current draw
  • Do not pull down IO pins in USB suspend mode

This is reprogrammed by Plug & Program on every PNP-USB2Serial to:

  • 500mA max current draw
  • Do not pull down IO pins in USB suspend mode

This result of this is that the USB2SERIAL will stop providing power if the host workstation issues a suspend command, until such a time as it issues a USB wakeup command.