參數(shù)資料
型號： FT245BQ
廠商： Electronic Theatre Controls, Inc.
英文描述： FT245BQ USB FIFO ( USB - Parallel ) I.C.
中文描述： FT245BQ USB先進(jìn)先出（USB端口-并行）集成電路
文件頁數(shù)： 21/24頁
文件大小： 505K
代理商： FT245BQ
DS245BL Version 1.6 Future Technology Devices Intl. Ltd. 2005
Page 21 of 24
FT245BL USB FIFO ( USB - Parallel ) I.C.
Figure 11
Bus Powered Circuit with Power Control
USB Bus powered circuits need to be able to power down in USB suspend mode in order to meet the <= 500uA total
suspend current requirement (including external logic). Some external logic can power itself down into a low current
state by monitoring the PWREN# pin. For external logic that cannot power itself down in that way, the FT245BL
provides a simple but effective way of turning off power to external circuitry during USB suspend.
Figure 11 shows how to use a discrete P-Channel Logic Level MOSFET to control the power to external logic
circuits. A suitable device could be a Fairchild NDT456P, or International Rectifier IRLML6402, or equivalent. It is
recommended that a “soft start” circuit consisting of a 1K series resistor and a 0.1 uF capacitor are used to limit the
current surge when the MOSFET turns on. Without the soft start circuit there is a danger that the transient power
surge of the MOSFET turning on will reset the FT245BL, or the USB host / hub controller. The values used here
allow attached circuitry to power up with a slew rate of ~12.5 V per millisecond, in other words the output voltage will
transition from GND to 5 V in approximately 400 microseconds.
Alternatively, a dedicated power switch I.C. with inbuilt “soft-start” can be used instead of a MOSFET. A suitable
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
FT245BQ-REEL 功能描述:USB 接口集成電路 USB to Parallel FIFO IC QFN-32 RoHS:否 制造商:Cypress Semiconductor 產(chǎn)品:USB 2.0 數(shù)據(jù)速率: 接口類型:SPI 工作電源電壓:3.15 V to 3.45 V 工作電源電流: 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:WLCSP-20
FT245R 制造商:FTDI 制造商全稱:FTDI 功能描述:USB FIFO I.C. Incorporating FTDIChip-ID⑩ Security Dongle
FT245R_10 制造商:FTDI 制造商全稱:FTDI 功能描述:USB FIFO IC - Single chip USB to parallel FIFO bidirectional data transfer interface
FT245RL 制造商:Future Technology Devices International 功能描述:USB FIFO IC 28-Pin SSOP 制造商:Future Technology Devices International (FTDI Chip) 功能描述:IC USB TO FIFO SMD SSOP28 245 制造商:Future Technology Devices International (FTDI Chip) 功能描述:IC, USB TO FIFO, SMD, SSOP28, 245 制造商:Future Technology Devices International (FTDI Chip) 功能描述:IC, USB FIFO INTERFACE, SSOP-28; USB Type:USB FIFO; USB Version:2.0; Supply Voltage Min:1.8V; Supply Voltage Max:5.25V; Digital IC Case Style:SSOP; No. of Pins:28; Data Rate:1Mbps; No. of Ports:2; Operating Temperature Min:-40C ;RoHS Compliant: Yes
FT245RL-2000 制造商:FTDI 制造商全稱:FTDI 功能描述:USB FIFO IC - Single chip USB to parallel FIFO bidirectional data transfer interface
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