The PCA9519 is a 4-channel level translating I2C-bus/SMBus repeater that enables theprocessor low voltage 2-wire serial bus to interface with standard I2C-bus or SMBus I/O.While retaining all the operating modes and features of the I2C-bus system during thelevel shifts, it also permits extension of the I2C-bus by providing bidirectional buffering forboth the data (SDA) and the clock (SCL) lines, thus enabling the I2C-bus or SMBusmaximum capacitance of 400 pF on the higher voltage side. The SDA and SCL pins areover-voltage tolerant and are high-impedance when the PCA9519 is unpowered.
標簽: 4channel transla level 9519
上傳時間: 2013-11-19
上傳用戶:jisiwole
The PCA9544A provides 4 interrupt inputs, one for each channeland one open drain interrupt output. When an interrupt is generated byany device, it will be detected by the PCA9544A and the interruptoutput will be driven LOW. The channel need not be active fordetection of the interrupt. A bit is also set in the control byte.Bits 4 – 7 of the control byte correspond to channels 0 – 3 of thePCA9544A, respectively. Therefore, if an interrupt is generated byany device connected to channel 2, the state of the interrupt inputs isloaded into the control register when a read is accomplished.Likewise, an interrupt on any device connected to channel 0 wouldcause bit 4 of the control register to be set on the read. The mastercan then address the PCA9544A and read the contents of thecontrol byte to determine which channel contains the devicegenerating the interrupt. The master can then reconfigure thePCA9544A to select this channel, and locate the device generatingthe interrupt and clear it. The interrupt clears when the deviceoriginating the interrupt clears.
標簽: 4channel multiple 9544A 9544
上傳時間: 2014-12-28
上傳用戶:潛水的三貢
The PCA9549 provides eight bits of high speed TTL-compatible bus switching controlledby the I2C-bus. The low ON-state resistance of the switch allows connections to be madewith minimal propagation delay. Any individual A to B channel or combination of channelscan be selected via the I2C-bus, determined by the contents of the programmable Controlregister. When the I2C-bus bit is HIGH (logic 1), the switch is on and data can flow fromPort A to Port B, or vice versa. When the I2C-bus bit is LOW (logic 0), the switch is open,creating a high-impedance state between the two ports, which stops the data flow.An active LOW reset input (RESET) allows the PCA9549 to recover from a situationwhere the I2C-bus is stuck in a LOW state. Pulling the RESET pin LOW resets the I2C-busstate machine and causes all the bits to be open, as does the internal power-on resetfunction.
上傳時間: 2014-11-22
上傳用戶:xcy122677
The PCA9555 is a 24-pin CMOS device that provides 16 bits of General Purpose parallelInput/Output (GPIO) expansion for I2C-bus/SMBus applications and was developed toenhance the NXP Semiconductors family of I2C-bus I/O expanders. The improvementsinclude higher drive capability, 5 V I/O tolerance, lower supply current, individual I/Oconfiguration, and smaller packaging. I/O expanders provide a simple solution whenadditional I/O is needed for ACPI power switches, sensors, push buttons, LEDs, fans, etc.The PCA9555 consists of two 8-bit Configuration (Input or Output selection); Input, Outputand Polarity Inversion (active HIGH or active LOW operation) registers. The systemmaster can enable the I/Os as either inputs or outputs by writing to the I/O configurationbits. The data for each Input or Output is kept in the corresponding Input or Outputregister. The polarity of the read register can be inverted with the Polarity Inversionregister. All registers can be read by the system master. Although pin-to-pin and I2C-busaddress compatible with the PCF8575, software changes are required due to theenhancements, and are discussed in Application Note AN469.
上傳時間: 2013-11-13
上傳用戶:fredguo
The PCA9548A is an octal bidirectional translating switch controlled via the I2C-bus. TheSCL/SDA upstream pair fans out to eight downstream pairs, or channels. Any individualSCx/SDx channel or combination of channels can be selected, determined by thecontents of the programmable control register.An active LOW reset input allows the PCA9548A to recover from a situation where one ofthe downstream I2C-buses is stuck in a LOW state. Pulling the RESET pin LOW resets theI2C-bus state machine and causes all the channels to be deselected as does the internalPower-on reset function.
上傳時間: 2013-10-13
上傳用戶:bakdesec
The PCA9557 is a silicon CMOS circuit which provides parallel input/output expansion for SMBus and I2C-bus applications. The PCA9557 consists of an 8-bit input port register, 8-bit output port register, and an I2C-bus/SMBus interface. It has low current consumption and a high-impedance open-drain output pin, IO0. The system master can enable the PCA9557’s I/O as either input or output by writing to the configuration register. The system master can also invert the PCA9557 inputs by writing to the active HIGH polarity inversion register. Finally, the system master can reset the PCA9557 in the event of a time-out by asserting a LOW in the reset input. The power-on reset puts the registers in their default state and initializes the I2C-bus/SMBus state machine. The RESET pin causes the same reset/initialization to occur without de-powering the part.
上傳時間: 2014-01-18
上傳用戶:bs2005
摘要:本水位監測報警器使用5V低壓直流電源(也可以用3節5號電池代替)就可以對5~15厘米的水位進行監測,用LED顯示和數碼管顯示水位,并可以對不再此范圍內的水位發出報警。主要采用CD4066、74LS86、74LS32、CD4511芯片,再加上數碼管、蜂鳴器、發光二極管、電阻這些器件組成一個簡單而靈敏的監測報警電路,操作簡單,接通電源即可工作。因為大部分電路采用數字電路,所以本水位監測報警器還具有耗能低、準確性高的特點。關鍵字:譯碼電路 報警電路 監測電路 Abstract: The water level alarm monitoring the use of 5 V low-voltage DC power (can also use three batteries replaced on the 5th) will be able to 5 to 15 centimeters of water level monitoring, with LED display and digital display of water level, and this can no longer Within the scope of a water level alarm. Mainly CD4066, 74LS86, 74LS32, CD4511 chips, coupled with digital control, buzzer, light-emitting diode, the resistance of these devices composed of a simple and sensitive monitoring alarm circuits. Because the majority of circuits using digital circuitry, so the water level monitored alarm system also has low energy consumption, high accuracy of the characteristics. Keyword: Decoding circuit alarm circuit monitoring circuit
上傳時間: 2013-11-05
上傳用戶:王慶才
基于PIC單片機的低功耗讀卡器硬件設計:本文提出了一個完整的基于串口的智能讀卡器子系統設計方案并將其實現。讀卡器的設計突出了小型化的要求,全部器件使用貼片封裝。為了減小讀卡器的體積,設計中還使用了串口竊電的技術,使用串口信號線直接給讀卡器供電。為此,讀卡器使用了省電的設計,采用了省電的集成電路,并大膽簡化了許多傳統的設計電路。關鍵字: 讀卡器, 單片機, 串口竊電 Abstract: This paper aims to put forward a complete design of Smart IC card reader based onSerial Port and propose the way of realizing it for the purpose of Network Security. SMD isadopted to make Smart IC reader smaller in this design. To reduce the volume of Smart ICreader, Serial Port powered technology is employed to get power from the signal line of Serial Port. For this reason, low-power consumption components are adopted in the design and some traditional designs are simplified to reduce the power consumption.Keywords: Card Reader; Single-chip Computer; Serial Port Powered IC 卡系統保存了加密算法所需要的工作密鑰,供加密算法對網絡上傳輸的數據加密使用,是整個系統網絡安全的核心。在IC 卡子系統中,讀卡器是一個重要的部分。它起著管理IC卡、在IC 卡和PC或網絡計算機間傳遞數據的重要作用。本文以一片PIC單片機為核心完成了基于RS232 串口的讀卡器的硬件設計。
上傳時間: 2014-04-14
上傳用戶:wanghui2438
基于單片機控制的二氧化碳濃度測試計:基于CDM4161二氧化碳氣體濃度測試模塊以及ATtiny26單片機,提出了一種二氧化碳濃度測試計的設計方案。該方案具有硬件電路簡單、成本低、可靠性高、測量準確等優點,具有較高的實用價值。 Abstract: Abstract:A desigh scheme of CO2 concentration meter based on CDM4161carbon dioxide concentration test module and ATtiny26micro-controller is presented in this paper.The design scheme features simple hardware circuit,low-cost,high reli-ability,accurate measurement and it has a high practical value.
上傳時間: 2013-11-14
上傳用戶:zjwangyichao
The solution presented in this paper and in the attached source files emulates the mostimportant SSC functions by using SW routines implemented in C. The code is focused onthe SAB C513, but will fit to all C500 derivatives.Beyond the low level software drivers a test shell is delivered. This shell allows a quicktest of the software drivers by an emulator or a starter kit demo board.
上傳時間: 2013-11-24
上傳用戶:363186