4
Copyright © 2012 Future Technology Devices International Limited
UMFT200XD
Version 1.1
Document Reference No.: FT_000543 Clearance No.: FTDI# 274
3.3 CBUS Signal Options
Output is low after the device has been configured by USB, then
high during USB suspend mode. This output can be used to control
power to external logic P-Channel logic level MOSFET switch.
Internal drive configuration consists of an open drain to GND with
no pull-up, specially designed for battery charging applications.*
Transmit data LED drive – pulses low when transmitting data via
USB.
Receive data LED drive – pulses low when receiving data via USB.
LED drive – pulses low when transmitting or receiving data via
USB.
Goes low during USB suspend mode. Typically used to power down
an external TTL to RS232 level converter IC in USB to RS232
converter designs.
CBUS bit bang mode option. A separate application note, AN232R-
01, available from FTDI website (www.ftdichip.com) describes in
more detail how to use CBUS bit bang mode.
Battery charge Detect, indicates when the device is connected to a
dedicated battery charger host. Active high output.
Synchronous and asynchronous bit bang mode WR# strobe output.
Synchronous and asynchronous bit bang mode RD# strobe output.
Transmit buffer empty, used to indicate to I2C master device
status of the FT200XD transmit buffer
Receive buffer full, used to indicate to I2C master device status of
FT200XD receive buffer
Input to detect when VBUS is present.
Toggle signal which changes state each time a USB SOF is received
Active Low input, prevents the chip from going into suspend.
Table 3.3 CBUS Configuration Control
* PWREN# must be used with a 10kΩ resistor pull up.
**When in USB suspend mode the outputs clocks are also suspended.
