Spark Logic

FT232H Hi-Speed USB bridge connection guide

FT232H Hi-Speed USB bridge LQFP-48 wiring guide with power, signal assignments, and bench checks.

LQFP-48

48 contacts Current package
QFN-48 49 contacts

FTDI · FT232HL · gull-wing leads

Verify the USB power and reference circuit

Required

Use an assembled UM232H or the complete Figure 6.1 design. Compare the power groups below against Figure 6.1, including the PLL/PHY filter, oscillator circuit, connector and reset wiring.

100 nF between Analog regulator and ReturnAnalog regulator100 nFReturn
100 nF between Core regulator and ReturnCore regulator100 nFReturn
12 kΩ ±1% between PHY current reference and ReturnPHY current reference12 kΩ ±1%Return

Bench checks

  • Check that the USB-powered board reads approximately 5 V at VREGIN, 3.3 V at VCCD and 1.8 V at the two regulator outputs.
  • Confirm USB enumeration and UART mode before connecting the loopback jumper.

FTDI FT_000288, version 2.2, Tables 3.1–3.2 and Fig. 6.1.

Connection scenarios

Test the UART in loopback

Unplug USB and jumper the bridge transmit output to its own receive input. Plug USB back in, open the enumerated port and disable local echo and flow control.

Bench checks

  • Send a short string at 9,600 bit/s, 8 data bits, no parity and 1 stop bit. The received bytes should match the transmitted bytes.
  • Remove the jumper before connecting another UART. Cross the two data lines, share ground and check the logic levels first.

FTDI FT_000288, version 2.2, UART signal descriptions. Loopback is a bench test.

LQFP-48 wiring map

Highlighted contacts are used in the required step or selected circuit. Select a contact to inspect it.

LQFP-48
Top view. Match pin 1 to the package mark. The numbers advance counterclockwise. Scroll the map to reach all contacts.
Selected pin details

3 · VPHY

Supply input · Power

USB PHY power. Use the filtered 3.3 V rail in Figure 6.1.

FTDI FT_000288, version 2.2, §§3.2–3.3 and 8.2

Electrical limits · Pin in the reference

Models and documents

The two interactive maps cover the FT232HL LQFP-48 and FT232HQ QFN-48. Start with the FTDI reference circuit or the UM232H evaluation module. The companion covers power verification and UART loopback.

FT232HL
FT232HL · gull-wing leads