3.3V
TXD
RXD
Figure 4.
7
8
9
Bus-Powered
5V System with
3.3 Volt Logic Interface
Figure 4 shows how to configure the DLP-USB1232H to interface with a 3.3V logic device via
the ASYNC serial mode. In this example, the target electronics provide the 3.3 volts to power
the microcontroller.
9.0 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 Suspend current requirement (including external logic):
P-Channel
Power MOSFET
S
D
G
.1uF
10K
1K
Microcontroller
Figure 4.
VCC
PWREN#
7
8
9
Power Controlled by
PWREN#
Figure 4 shows how to use a discrete P-Channel MOSFET to control the power to external logic
circuits. This “soft-start” circuit accommodates designs that draw more than 100mA at power
up.
Rev. 1.3 (December 2009)
11
? DLP Design, Inc.
相关PDF资料
DLP-USB232M-G MODULE USB-TO-TTL SRL UART CONV
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DLP-USB245M-G MODULE USB-TO-TTL PARL FIFO CONV
DLP-USB245R MODULE USB-TO-PARL FIFO 18-DIP
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相关代理商/技术参数
DLP-USB232M 功能描述:界面模块 USB-UART Adapter RoHS:否 制造商:4D Systems 产品:Serial Converters 通道/端口数量: 数据速率: 接口类型:USB, UART 工作电源电压:3.3 V, 5 V 最大工作温度:
DLP-USB232M-G 功能描述:界面模块 USB-UART Adapter RoHS:否 制造商:4D Systems 产品:Serial Converters 通道/端口数量: 数据速率: 接口类型:USB, UART 工作电源电压:3.3 V, 5 V 最大工作温度:
DLP-USB232M-G2 功能描述:MODULE USB-TO-TTL SRL UART CONV 制造商:dlp design inc. 系列:- 零件状态:在售 类型:USB 至串行 转换自(适配器端):USB - B 2.0 母头 转换至(适配器端):DIL(Dual Inline) 接口:UART 特性:- 包括:- 标准包装:1
DLP-USB232R 功能描述:界面模块 USB-TO-SERIAL UART INTERFACE MODULE RoHS:否 制造商:4D Systems 产品:Serial Converters 通道/端口数量: 数据速率: 接口类型:USB, UART 工作电源电压:3.3 V, 5 V 最大工作温度:
DLP-USB245M 功能描述:界面模块 USB-FIFO Adapter RoHS:否 制造商:4D Systems 产品:Serial Converters 通道/端口数量: 数据速率: 接口类型:USB, UART 工作电源电压:3.3 V, 5 V 最大工作温度:
DLP-USB245M-G 功能描述:界面模块 USB-FIFO Adapter RoHS:否 制造商:4D Systems 产品:Serial Converters 通道/端口数量: 数据速率: 接口类型:USB, UART 工作电源电压:3.3 V, 5 V 最大工作温度:
DLP-USB245R 功能描述:界面模块 USB-TO-PARALLEL FIFO INTERFACE MODULE RoHS:否 制造商:4D Systems 产品:Serial Converters 通道/端口数量: 数据速率: 接口类型:USB, UART 工作电源电压:3.3 V, 5 V 最大工作温度:
DLP-UT1 功能描述:工业温度传感器 TEMPERATURE SENSOR RoHS:否 制造商:Texas Instruments 准确性:1 C 功能:Temperature Sensing 25 摄氏度时的电阻: 温度范围:- 55 C to + 127 C 电源电流: 电源电压:2.7 V to 5.5 V