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.
標(biāo)簽: channel 9548A 9548 PCA
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.
標(biāo)簽: C-bus SMBus reset port
上傳時間: 2014-01-18
上傳用戶:bs2005
The ISO7220 and ISO7221 are dual-channel digital isolators. To facilitate PCB layout, the channels are orientedin the same direction in the ISO7220 and in opposite directions in the ISO7221. These devices have a logic inputand output buffer separated by TI’s silicon-dioxide (SiO2) isolation barrier, providing galvanic isolation of up to4000 V. Used in conjunction with isolated power supplies, these devices block high voltage, isolate grounds, andprevent noise currents on a data bus or other circuits from entering the local ground and interfering with ordamaging sensitive circuitry.
標(biāo)簽: ISOLATORS DIGITAL DUAL
上傳時間: 2013-10-24
上傳用戶:hbsunhui
摘要:本水位監(jiān)測報警器使用5V低壓直流電源(也可以用3節(jié)5號電池代替)就可以對5~15厘米的水位進(jìn)行監(jiān)測,用LED顯示和數(shù)碼管顯示水位,并可以對不再此范圍內(nèi)的水位發(fā)出報警。主要采用CD4066、74LS86、74LS32、CD4511芯片,再加上數(shù)碼管、蜂鳴器、發(fā)光二極管、電阻這些器件組成一個簡單而靈敏的監(jiān)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(shù)字電路,所以本水位監(jiān)測報警器還具有耗能低、準(zhǔn)確性高的特點。關(guān)鍵字:譯碼電路 報警電路 監(jiān)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
標(biāo)簽: 水位 監(jiān)測報警 系統(tǒng)原理
上傳時間: 2013-11-05
上傳用戶:王慶才
基于PIC單片機(jī)的低功耗讀卡器硬件設(shè)計:本文提出了一個完整的基于串口的智能讀卡器子系統(tǒng)設(shè)計方案并將其實現(xiàn)。讀卡器的設(shè)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(shè)計中還使用了串口竊電的技術(shù),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(shè)計,采用了省電的集成電路,并大膽簡化了許多傳統(tǒng)的設(shè)計電路。關(guān)鍵字: 讀卡器, 單片機(jī), 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(tǒng)保存了加密算法所需要的工作密鑰,供加密算法對網(wǎng)絡(luò)上傳輸?shù)臄?shù)據(jù)加密使用,是整個系統(tǒng)網(wǎng)絡(luò)安全的核心。在IC 卡子系統(tǒng)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(wǎng)絡(luò)計算機(jī)間傳遞數(shù)據(jù)的重要作用。本文以一片PIC單片機(jī)為核心完成了基于RS232 串口的讀卡器的硬件設(shè)計。
上傳時間: 2014-04-14
上傳用戶:wanghui2438
基于單片機(jī)控制的二氧化碳濃度測試計:基于CDM4161二氧化碳?xì)怏w濃度測試模塊以及ATtiny26單片機(jī),提出了一種二氧化碳濃度測試計的設(shè)計方案。該方案具有硬件電路簡單、成本低、可靠性高、測量準(zhǔn)確等優(yōu)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
The P90CL301 is a highly integrated 16/32 bit micro-controller especially suitable for applications requiring lowvoltage and low power consumption. It is fully software compatible with the 68000. Furthermore, it provides bothstandard as well as advanced peripheral functions on-chip.One of these peripheral functions is the I2C bus. This report describes worked-out driver software (written in C) toprogram the P90CL301 I2C interface. It also contains interface software routines offering the user a quick start inwriting a complete I2C system application.
上傳時間: 2014-01-06
上傳用戶:氣溫達(dá)上千萬的
The MC68HC05K0 is a low cost, low pin countsingle chip microcomputer with 504 bytes of userROM and 32 bytes of RAM. The MC68HC05K0 isa member of the 68HC05K series of devices whichare available in 16-pin DIL or SOIC packages.It uses the same CPU as the other devices in the68HC05 family and has the same instructions andregisters. Additionally, the device has a 15-stagemulti-function timer and 10 general purposebi-directional I/0 lines. A mask option is availablefor software programmable pull-downs on all ofthe I/O pins and four of the pins are capable ofgenerating interrupts.The device is ideally suited for remote-controlkeyboard applications because the pull-downs andthe interrupt drivers on the port pins allowkeyboards to be built without any externalcomponents except the keys themselves. There isno need for external pull-up or pull-down resistors,or diodes for wired-OR interrupts, as these featuresare already designed into the device.
標(biāo)簽: Infra-red Remote Cont 05K
上傳時間: 2014-01-24
上傳用戶:zl5712176
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