UMFT240XA-01 FTDI, UMFT240XA-01 Datasheet - Page 11

• Manufacturer Part Number: UMFT240XA-01
• Description: Interface Development Tools USB to Parallel FIFO Dev Mod for FT240X
• Manufacturer: FTDI
• Type: USB to FIFOr

Specifications of UMFT240XA-01

• Rohs: yes
• Product: Development Modules
• Tool Is For Evaluation Of: FT240XQ
• Interface Type: USB
• Operating Supply Voltage: 3.3 V
• Dimensions: 37 mm x 12.2 mm x 2.2 mm
• Tradename: X-Chip

5.6
Figure 5.4 – USB Bus Powered 3.3V Logic Drive
The FT240X can process signals at CMOS/TTL logic levels in the range of 1.8V to 3.3V. This section
describes how to utilise this feature.
Figure 5.4 shows a configuration where the FT240X is interfaced to a device with IOs operating in the
range of 1.8V - 3.3V. The IO ports of this module need to be powered with a voltage level that is equal to
the level of the signals it is processing. Since the FT240X‟s embedded voltage regulator only outputs 3V3
the IO ports will need to be powered from another power source when operating at voltage levels other
than 3.3V. (Note that Figure 5.4 is for illustration only and that the pins do not actually go all the way
through the PCB)
By default, a short is present between 3V3OUT (embedded voltage regulator) and VCCIO (IO port‟s
power input) by solder links JP1. If an external power supply is used to power the IO ports this solder
links needs to be open. This can be done by removing the solder linking the two pads of the solder links.
The configuration described in this section can be implemented in either bus-powered mode or self-
powered mode.
Note 1: The CBUS and DBUS pins are 5V tolerant; however these signals cannot drive signals at 5V
TTL/CMOS. VCCIO is not 5V tolerant; applying 5V to VCCIO will damage the chip.
Note 2: If power is applied to VCCIO and no power is applied to VCC all IOs will be at an unknown state,
this however will not damage the chip. The FT240X also has protective circuitry to prevent the chip being
damaged by a voltage discrepancy between VCCIO and the level of the signal being processed.
Note 3: When using VCCIO less than 3V3 on a chip from FTDI‟s X-chip range, it is recommended to uses
pull up resistors (47K) to VCCIO on the data lines, all of the UMFT2xxXA devices include an on-board
pull-up for these lines.
Variable IO Voltage Supply
Vcc = 1.8V – 3.3V
MCU
DATA0-7
RXF#
TXE#
Solder Link JP1 - Open
WR#
RD#
Copyright © 2012 Future Technology Devices International Limited
GND
Document Reference No.: FT_000520
Viewing pins thourgh the board
3V3OUT
VCCIO
from the top.
VBUS
VCC
Solder Link JP2 - Closed
Clearance No.: FTDI#
11
UMFT240XA
Version 1.1
GND
271