參數(shù)資料
型號(hào): FT245BL
廠商: Electronic Theatre Controls, Inc.
英文描述: FT245BL USB FIFO ( USB - Parallel ) I.C.
中文描述: FT245BL USB先進(jìn)先出(USB端口-并行)集成電路
文件頁(yè)數(shù): 21/24頁(yè)
文件大小: 505K
代理商: FT245BL
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
FT245BL/TR 制造商:Future Technology Devices International (FTDI Chip) 功能描述:IC USB FIFO SMD LQFP32 245 制造商:Future Technology Devices International (FTDI Chip) 功能描述:IC, USB FIFO, SMD, LQFP32, 245 制造商:Future Technology Devices International (FTDI Chip) 功能描述:IC, USB FIFO INTERFACE, 480MBPS, LQFP-32; USB Type:FIFO; USB Version:1.1, 2.0; Supply Voltage Min:4.35V; Supply Voltage Max:5.25V; Digital IC Case Style:LQFP; No. of Pins:32; Data Rate:480Mbps; No. of Ports:2; MSL:MSL 3 - 168 hours ;RoHS Compliant: Yes
FT245BL-REEL 功能描述:USB 接口集成電路 USB to Parallel FIFO IC LQFP-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
FT245BL-TRAY 制造商:Future Technology Devices International (FTDI Chip) 功能描述:USB FIFO ( USB - PARALLEL ) I.C.
FT245BM 功能描述:先進(jìn)先出 Obsolete See FT245RL RoHS:否 制造商:IDT 電路數(shù)量: 數(shù)據(jù)總線寬度:18 bit 總線定向:Unidirectional 存儲(chǔ)容量:4 Mbit 定時(shí)類型:Synchronous 組織:256 K x 18 最大時(shí)鐘頻率:100 MHz 訪問(wèn)時(shí)間:10 ns 電源電壓-最大:3.6 V 電源電壓-最小:6 V 最大工作電流:35 mA 最大工作溫度:+ 85 C 封裝 / 箱體:TQFP-80 封裝:
FT245BM-TRAY 功能描述:USB 接口集成電路 Obsolete See FT245RL 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