- 您现在的位置：买卖IC网 > PDF目录3765 > FT232RQ-REEL (FTDI, Future Technology Devices International Ltd)IC USB FS SERIAL UART 32-QFN PDF资料下载
参数资料
| 型号： | FT232RQ-REEL |
| 厂商： | FTDI, Future Technology Devices International Ltd |
| 文件页数： | 18/43页 |
| 文件大小： | 0K |
| 描述： | IC USB FS SERIAL UART 32-QFN |
| 产品培训模块： | USB Introduction USB-UART Interface Solutions |
| 标准包装： | 1 |
| 系列： | USBmadeEZ-UART |
| 特点： | USB 至 UART |
| 通道数： | 1，UART |
| FIFO's： | 256 字节 |
| 规程： | RS232，RS422，RS485 |
| 电源电压： | 3.3 V ~ 5.25 V |
| 带自动流量控制功能： | 是 |
| 带调制解调器控制功能： | 是 |
| 带CMOS： | 是 |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 32-VFQFN 裸露焊盘 |
| 供应商设备封装： | 32-QFN 裸露焊盘（5x5） |
| 包装： | 标准包装 |
| 产品目录页面： | 634 (CN2011-ZH PDF) |
| 配用： | 768-1023-ND - MOD USB RS232 DEV/EVAL FT232RL 768-1022-ND - MOD USB UART MINI B DEV FT232R 768-1021-ND - MOD USB UART MINI DEV FT232R 768-1019-ND - MOD USB UART DEV FT232R |
| 其它名称： | 768-1008-6 |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页当前第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页
Copyright 2010 Future Technology Devices International Limited
25
Document No.: FT_000053
FT232R USB UART IC Datasheet Version 2.10
Clearance No.: FTDI# 38
6.3 USB Bus Powered with Power Switching Configuration
FT232R
GND
100nF
VCC
USBDM
USBDP
VCCIO
NC
RESET#
NC
OSCI
OSCO
3V3OUT
A
G
N
D
G
N
D
G
N
D
G
N
D
T
E
S
T
TXD
RXD
RTS#
CTS#
DTR#
DSR#
DCD#
RI#
CBUS0
CBUS1
CBUS2
CBUS3
CBUS4
1
2
3
4
GND
SHIELD
GND
100nF
4.7uF
+
5
10nF +
Ferrite Bead
s
d
g
P-Channel Power
MOSFET
PWREN#
1K
Switched 5V Power
To External Logic
Soft Start
Circuit
0.1uF
5V VCC
10K
Figure 6.3 Bus Powered with Power Switching Configuration
A requirement of USB bus powered applications, is when in USB suspend mode, the application draws a
total current of less than 2.5mA. This requirement includes external logic. Some external logic has the
ability to power itself down into a low current state by monitoring the PWREN# signal. For external logic
that cannot power itself down in this way, the FT232R provides a simple but effective method of turning
off power during the USB suspend mode.
Figure 6.3 shows an example of using a discrete P-Channel MOSFET to control the power to external
logic. A suitable device to do this is an International Rectifier (www.irf.com) IRLML6402, or equivalent. It
is recommended that a “soft start” circuit consisting of a 1kΩ series resistor and a 0.1μF capacitor is used
to limit the current surge when the MOSFET turns on. Without the soft start circuit it is possible that the
transient power surge, caused when the MOSFET switches on, will reset the FT232R or the USB host/hub
controller. The soft start circuit example shown in Figure 6.3 powers up with a slew rate of
approximaely12.5V/ms. Thus supply voltage to external logic transitions from GND to +5V in
approximately 400 microseconds.
As an alternative to the MOSFET, a dedicated power switch IC with inbuilt “soft-start” can be used. A
suitable power switch IC for such an application is the Micrel (www.micrel.com) MIC2025-2BM or
equivalent.
With power switching controlled designs the following should be noted:
i) The external logic to which the power is being switched should have its own reset circuitry to
automatically reset the logic when power is re-applied when moving out of suspend mode.
ii) Set the Pull-down on Suspend option in the internal FT232R EEPROM.
iii) One of the CBUS Pins should be configured as PWREN# in the internal FT232R EEPROM, and used
to switch the power supply to the external circuitry. This should be pulled high through a 10 k
resistor.
iv) For USB high-power bus powered applications (one that consumes greater than 100mA, and up
to 500mA of current from the USB bus), the power consumption of the application must be set in
the Max Power field in the internal FT232R EEPROM. A high-power bus powered application uses
the descriptor in the internal FT232R EEPROM to inform the system of its power requirements.
v) PWREN# gets its VCC from VCCIO. For designs using 3V3 logic, ensure VCCIO is not powered
down using the external logic. In this case use the +3V3OUT.
相关PDF资料 |
PDF描述 |
|---|---|
| SC16C550BIA44,512 | IC UART SINGLE W/FIFO 44-PLCC |
| SC16C550BIA44,518 | IC UART SINGLE W/FIFO 44-PLCC |
| SC16IS750IPW,128 | IC UART I2C/SPI 24-TSSOP |
| SC16IS740IPW/Q900, | IC UART SINGLE W/FIFO 16-TSSOP |
| XR16L788CQ-F | IC UART 64B 3.3V OCTAL 100QFP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| FT232RQ-TRAY | 制造商:Future Technology Devices International (FTDI Chip) 功能描述: |
| FT-23-43 | 制造商:Amidon 功能描述:Bulk |
| FT234XD-R | 制造商:Future Technology Devices International (FTDI Chip) 功能描述:IC USB SERIAL BASIC UART 12DFN 制造商:Future Technology Devices International (FTDI Chip) 功能描述:USB to Serial UART Interface |
| FT234XD-T | 功能描述:USB 接口集成电路 USB to Basic Serial UART IC RoHS:否 制造商:Cypress Semiconductor 产品:USB 2.0 数据速率: 接口类型:SPI 工作电源电压:3.15 V to 3.45 V 工作电源电流: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:WLCSP-20 |
| FT-23-77 | 制造商:Amidon 功能描述: |
发布紧急采购，3分钟左右您将得到回复。