FT201XQ-R FTDI, FT201XQ-R Datasheet - Page 25

• Manufacturer Part Number: FT201XQ-R
• Description: USB Interface IC USB to I2C IC QFN-16
• Manufacturer: FTDI

Specifications of FT201XQ-R

• Rohs: yes
• Product: USB 2.0
• Data Rate: 12 Mbps, 480 Mbps
• Interface Type: I2C, USB
• Operating Supply Voltage: 2.97 V to 5.5 V
• Operating Supply Current: 6.4 mA to 8.65 mA
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: QFN-16
• Tradename: X-Chip

8
The following sections illustrate possible applications of the FT201X. The illustrations have omitted pin
numbers for ease of understanding since the pins differ between the FT201XS and FT201XQ package
options.
8.1 USB to I
Figure 8.1 Application Example showing USB to I
An example of using the FT201X as an I
the I
Therefore the clock supplied to the SCL pin must come from the I
standard I
mode plus (FM+), and 3.4 Mbit/s High Speed mode (HS).
The data line SDA is bi- directional.
The master is initially in master transmit mode by sending a start bit followed by the 7-bit address of the
slave it wishes to communicate with, which is finally followed by a single bit representing whether it
wishes to write(0) to or read(1) from the slave.
If the slave (FT201X) exists on the bus then it will respond with an ACK bit (active low for acknowledged)
for that address. The master then continues in either transmit or receive mode (according to the
read/write bit it sent), and the slave continues in its complementary mode (receive or transmit,
respectively).
The address and the data bytes are sent most significant bit first. The start bit is indicated by a high-to-
low transition of SDA with SCL high; the stop bit is indicated by a low-to-high transition of SDA with SCL
high.
If the master wishes to write to the slave then it repeatedly sends a byte with the slave sending an ACK
bit. (In this situation, the master is in master transmit mode and the slave is in slave receive mode.)
If the master wishes to read from the slave then it repeatedly receives a byte from the slave, the master
sending an ACK bit after every byte but the last one. (In this situation, the master is in master receive
mode and the slave is in slave transmit mode.)
The master then ends transmission with a stop bit, or it may send another START bit if it wishes to retain
control of the bus for another transfer (a "combined message").
I²C defines three basic types of message, each of which begins with a START and ends with a STOP:


Application Examples
2
C bus.
SHIELD
Single message where a master writes data to a slave;
Single message where a master reads data from a slave;
2
C data rates such as 100 kbit/s standard mode (SM), 400 kbit/s fast mode (FM), 1 Mbit/s Fast
5
1
2
3
4
2
Copyright © 2013 Future Technology Devices International Limited
C Converter
100nF
GND
10nF
47pF
Ferrite
Bead
VCC
GND
+
GND
4.7uF
2
47pF
C peripheral is shown in Figure 8.1. The FT201X is the slave on
VCC
GND
27R
27R
2
C Converter
100nF
FT201X USB I2C SLAVE IC Datasheet
USBDM
USBDP
VCC
RESET#
VCCIO
3V3OUT
Document No.: FT_000627 Clearance No.: FTDI# 264
FT201X
2
C Master. The device will support
SDA
SCL
1k
VCCIO
SCL
SDA
1k
Version 1.3
I2C MASTER DEVICE
25