FT245RQ-REEL FTDI, FT245RQ-REEL Datasheet - Page 15

• Manufacturer Part Number: FT245RQ-REEL
• Description: USB Interface IC USB to Parallel FIFO Enhanced IC QFN-32
• Manufacturer: FTDI

Specifications of FT245RQ-REEL

• Mounting Style: SMD/SMT
• Package / Case: QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Document No.: FT_000052
FT245R USB FIFO IC Datasheet Version 2.10
Clearance No.: FTDI# 39
4
Function Description
The FT245R is a USB to parallel FIFO interface device which simplifies USB to FIFO designs and reduces
external component count by fully integrating an external EEPROM, USB termination resistors and an
integrated clock circuit which requires no external crystal, into the device. It has been designed to
operate efficiently with a USB host controller by using as little as possible of the total USB bandwidth
available.
4.1 Key Features
Functional Integration. Fully integrated EEPROM, USB termination resistors, clock generation, AVCC
filtering, power-on-reset (POR) and LDO regulator.
Asynchronous Bit Bang Mode. In asynchronous bit-bang mode, the eight FIFO lines can be switched
from the regular interface mode to an 8-bit general purpose I/O port. Data packets can be sent to the
device and they will be sequentially sent to the interface at a rate controlled by an internal timer
(equivalent to the baud rate pre-scaler. This option will be described more fully in a separate application
note available from FTDI website (www.ftdichip.com).
Synchronous Bit Bang Mode. The FT245R supports synchronous bit bang mode. This mode differs from
asynchronous bit bang mode in that the interface pins are only read when the device is written to. This
makes it easier for the controlling program to measure the response to an output stimulus as the data
returned is synchronous to the output data. An application note, AN232R-01, available from FTDI website
(www.ftdichip.com) describes this feature.
FTDIChip-ID™. The FT245R also includes the new FTDIChip-ID™ security dongle feature. This
FTDIChip-ID™ feature allows a unique number to be burnt into each device during manufacture. This
number cannot be reprogrammed. This number is only readable over USB and forms a basis of a security
dongle which can be used to protect any customer application software being copied. This allows the
possibility of using the FT245R in a dongle for software licensing. Further to this, a renewable license
scheme can be implemented based on the FTDIChip-ID™ number when encrypted with other information.
This encrypted number can be stored in the user area of the FT245R internal EEPROM, and can be
decrypted, then compared with the protected FTDIChip-ID™ to verify that a license is valid. Web based
applications can be used to maintain product licensing this way. An application note, AN232R-02,
available from FTDI website (www.ftdichip.com) describes this feature.
High Output Drive Option. The parallel FIFO interface and the four FIFO handshake pins can be made
to drive out at three times the standard signal drive level thus allowing multiple devices to be driven, or
devices that require a greater signal drive strength to be interfaced to the FT245R. This option is
configured in the internal EEPROM.
Programmable FIFO RX Buffer Timeout. The FIFO RX buffer timeout is used to flush remaining data
from the receive buffer. This timeout defaults to 16ms, but is programmable over USB in 1ms increments
from 2ms to 255ms, thus allowing the device to be optimised for protocols that require fast response
times from short data packets.
Wake Up Function. If USB is in suspend mode, and remote wake up has been enabled in the internal
EEPROM (it is enabled by default), the RXF# pin becomes an input. Strobing this pin low for a minimum
of 20ms will cause the FT245R to request a resume from suspend on the USB bus. Normally this can be
used to wake up the host PC from suspend.
The FT245R is capable of operating at a voltage supply between +3.3V and +5V with a nominal
operational mode current of 15mA and a nominal USB suspend mode current of 70µA. This allows greater
margin for peripheral designs to meet the USB suspend mode current limit of 2.5mA. An integrated level
converter within the FIFO interface allows the FT245R to interface to FIFO logic running at +1.8V, 2.5V,
+3.3V or +5V.
Copyright © 2010 Future Technology Devices International Limited
15