參數(shù)資料
型號: FT245BL-REEL
廠商: FTDI, Future Technology Devices International Ltd
文件頁數(shù): 11/24頁
文件大?。?/td> 0K
描述: IC USB FS PARALLEL FIFO 32-LQFP
標(biāo)準(zhǔn)包裝: 1,000
系列: *
類型: *
應(yīng)用: *
安裝類型: 表面貼裝
封裝/外殼: 32-LQFP
供應(yīng)商設(shè)備封裝: 32-LQFP(7x7)
包裝: 帶卷 (TR)
DS245BL Version 1.7
Future Technology Devices Intl. Ltd. 2005
Page 19 of 24
FT245BL USB FIFO ( USB - Parallel ) I.C.
Figure 9
Bus Powered Circuit with 3.3V logic drive / supply voltage
Ferrite Bead
470R
0.1uF
VCC
27R
USB "B"
Connector
27R
USB DM
8
FT245BM
USB DP
7
V
C
V
C
V
C
I
O
3
26
13
1
2
3
4
33nF
3v3OUT
6
A
V
C
30
10nF
0.1uF
In
Out
Gnd
3.3v LDO Regulator
3.3v Power to External
Logic
Figure 9 shows how to congure the FT245BL to interface with a 3.3V logic device. In this example, a discrete
3.3V regulator is used to supply the 3.3V logic from the USB supply. VCCIO is connected to the output of the 3.3V
regulator, which in turn will cause the FIFO interface IO pins to drive out at 3.3V level. For USB bus powered circuits
some considerations have to be taken into account when selecting the regulator –
a) The regulator must be capable of sustaining its output voltage with an input voltage of 4.35 volts. A Low Drop Out
(LDO) regulator must be selected.
b) The quiescent current of the regulator must be low in order to meet the USB suspend total current requirement of
<= 500uA during USB suspend.
An example of a regulator family that meets these requirements is the MicroChip (Telcom) TC55 Series. These
devices can supply up to 250mA current and have a quiescent current of under 1uA.
In some cases, where only a small amount of current is required (< 5mA) , it may be possible to use the in-built
regulator of the FT245BL to supply the 3.3V without any other components being required. In this case, connect
VCCIO to the 3V3OUT pin of the FT245BL.
Note : It should be emphasised that the 3.3V supply for VCCIO in a bus powered design with a 3.3V logic interface
should come from an LDO which is supplied by USB bus, or from the 3V3OUT pin of the FT245BL, and not from any
other source.
FT245BL
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
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
FT245BQ 制造商:未知廠家 制造商全稱:未知廠家 功能描述:FT245BQ USB FIFO ( USB - Parallel ) I.C.
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