I want to design a USB-JTAG Programmer with FT2232D. And I want to program Xilinx spartan3 FPGA with it, so I need 3.3 volt logic for VCCIO. Datasheet indicates that FT2232D has an internal regulator to convert 5v to 3.3v:

"It‟s prime purpose is to provide the internal 3.3V supply to the USB transceiver cell and the RSTOUT# pin. A small amount of current (<= 5mA) can be drawn from this pin to power external 3.3V logic if required."

I don't know wheather I can connect this pin to VCCIO, and how much current is required for this purpose (programming).

  • \$\begingroup\$ So what does the Xilinx spartan3 datasheet say it's 3.3V current requirement is? The datasheet will specify that information. \$\endgroup\$ – gbulmer Aug 24 '14 at 19:35
  • \$\begingroup\$ You want to use level shifters - FPGAs use lower voltages and may not like JTAG signals at 3.3 Volts. \$\endgroup\$ – Turbo J Aug 25 '14 at 12:10

According to the datasheet of a standart programmer, you need around 10mA. You can check it by yourself Here's a link!


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