The Inter IC bus or I2C bus is a simple bidirectional two wire bus designed primarily for general control
and data transfer communication between ICs.
Some of the features of the I2C bus are:
• Two signal lines, a serial data line (SDA) and a serial clock line (SCL), and ground are required. A
12V supply line (500mA max.) for powering the peripherals often may be present.
• Each device connected to the bus is software addressable by a unique address and simple
master/ slave relationships exist at all times masters can operate as master-transmitters or as
master-receivers.
• The I2C bus is a true multi-master bus including collision detection and arbitration to prevent data
corruption if two or more masters simultaneously initiate data transfer systems.
• Serial, 8-bit oriented, bidirectional data transfers can be made at up to 100 KBit/s in the standard
mode or up to 400 KBit/s in the fast mode.
The MAX4968/MAX4968A are 16-channel, high-linearity,high-voltage, bidirectional SPST analog switches with18I (typ) on-resistance. The devices are ideal for use inapplications requiring high-voltage switching controlledby a low-voltage control signal, such as ultrasound imagingand printers. The MAX4968A provides integrated40kI (typ) bleed resistors on each switch terminal todischarge capacitive loads. Using HVCMOS technology,these switches combine high-voltage bilateral MOSswitches and low-power CMOS logic to provide efficientcontrol of high-voltage analog signals.
The LTC®4099 high effi ciency USB power manager andLi-Ion/Polymer battery charger seamlessly managespower distribution from multiple sources in portableapplications. It is differentiated from other USB powermanagers by its bidirectional I2C port that allows the hostmicroprocessor to control and monitor all aspects of theUSB power management and battery charging processes.In addition, a programmable interrupt generation functionalerts the host microprocessor to changes in device statusand provides unprecedented control of power managementfunctions. This high degree of confi gurability allowspost-layout changes in operation, even changes in thefi eld, and it allows a single qualifi ed device to be usedin a variety of products, thus reducing design time andeasing inventory management.
The PCF8578 is a low power CMOS1 LCD row and column driver, designed to drive dotmatrix graphic displays at multiplex rates of 1:8, 1:16, 1:24 or 1:32. The device has40 outputs, of which 24 are programmable and configurable for the following ratios ofrows/columns: 32¤8, 24¤16, 16¤24 or 8¤32. The PCF8578 can function as a stand-alone LCDcontroller and driver for use in small systems. For larger systems it can be used inconjunction with up to 32 PCF8579s for which it has been optimized. Together these twodevices form a general purpose LCD dot matrix driver chip set, capable of driving displaysof up to 40960 dots. The PCF8578 is compatible with most microcontrollers andcommunicates via a two-line bidirectional bus (I2C-bus). Communication overhead isminimized by a display RAM with auto-incremented addressing and display bankswitching.
The SN65LBC170 and SN75LBC170 aremonolithic integrated circuits designed forbidirectional data communication on multipointbus-transmission lines. Potential applicationsinclude serial or parallel data transmission, cabledperipheral buses with twin axial, ribbon, ortwisted-pair cabling. These devices are suitablefor FAST-20 SCSI and can transmit or receivedata pulses as short as 25 ns, with skew lessthan 3 ns.These devices combine three 3-state differentialline drivers and three differential input linereceivers, all of which operate from a single 5-Vpower supply.The driver differential outputs and the receiverdifferential inputs are connected internally to formthree differential input/output (I/O) bus ports thatare designed to offer minimum loading to the buswhenever the driver is disabled or VCC = 0. Theseports feature a wide common-mode voltage rangemaking the device suitable for party-lineapplications over long cable runs.
The PCA9674/74A provide general purpose remote I/O expansion for most
microcontroller families via the two-line bidirectional bus (I2C-bus) and is a part of the
Fast-mode Plus (Fm+) family.
The PCA9517 is a CMOS integrated circuit that provides level shifting between lowvoltage (down to 0.9 V) and higher voltage (2.7 V to 5.5 V) I2C-bus or SMBus applications.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 two buses of 400 pF. Usingthe PCA9517 enables the system designer to isolate two halves of a bus for both voltageand capacitance. The SDA and SCL pins are over voltage tolerant and arehigh-impedance when the PCA9517 is unpowered.
