UMFT231XE Datasheet, PDF (8/18 Pages) Future Technology Devices International Ltd. – UMFT231XE USB to Full-Handshake UART Development Module

UMFT231XE
Version 1.0
Document Reference No.: FT_000652 Clearance No.: FTDI# 294
5.2 Bus Powered Configuration
Alternative
connection
Current Flow
GND
VCCIO
3V3OUT
GND
VCC
VBUS
Alternative
connection
Self-Sourced
3V3 TTL Mode
Jumper JP1 - Closed
Bus Powered
Mode
Jumper JP2- Closed
Figure 5.1 – Bus Powered Configuration
A bus powered configuration draws its power from the USB host/hub. The UMFT231XE is configured by
default to be in bus powered mode.
Figure 5.1 illustrates the UMFT231XE module in a typical USB bus powered design configuration. By
default VCCIO is connected to 3V3OUT, and VCC is connected to VBUS.
For a bus power configuration power is supplied from the USB VBUS:
+5V VBUS power is sourced from the USB bus and is connected to the FT231X power input (VCC)
+3.3V power is sourced from the FT231X‟s voltage regulator output and is connected to the FT231X IO
port‟s power input (VCCIO).
Interfacing the UMFT231XE module to a microcontroller (MCU), or other logic devices for bus powered
configuration is done the same way as a self-powered configuration (see Section 3), except it is possible
for the MCU or external device to take its power supply from the USB bus (either the 5V from the USB
pin, or 3.3V from the 3V3OUT pin).
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