Microchip Technology

The MIC281 is a digital thermal sensor capable of measuring the temperature of a remote PN junction. It is optimized for applications favoring low cost and small size. The remote junction may be an inexpensive commodity transistor, e.g., 2N3906, or an embedded thermal diode such as found in Intel Pentium\* II/III/IV CPUs, AMD Athlon\* CPUs, and Xilinx Virtex\* FPGAs. The MIC281 is 100% software and hardware backward compatible with the MIC280 and features the same industry-leading noise performance and small size. The advanced integrating A/D converter and analog front-end reduce errors due to noise for maximum accuracy and minimum guardbanding. A 2-wire SMBus 2.0-compatible serial interface is provided for host communication. The clock and data pins are 5V-tolerant regardless of the value of VDD. They will not clamp the bus lines low even if the device is powered down. Superior performance, low power, and small size make the MIC281 an excellent choice for cost-sensitive thermal management applications.

MIC28303 is synchronous step-down regulator module, featuring a unique adaptive ON-time control architecture. The module incorporates a DC/DC controller, power MOSFETs, bootstrap diode, bootstrap capacitor and an inductor in a single package. The MIC28303 operates over an input supply range from 4.5V to 50V and can be used to supply up to 3A of output current. The output voltage is adjustable down to 0.8V with a guaranteed accuracy of ±1%. The device operates with programmable switching frequency from 200kHz to 600kHz. The MIC28303-1 uses HyperLight Load® architecture for improved efficiency at light loads. The MIC28303-2 uses Hyper Speed Control™ for ultra-fast transient response. The MIC28303 offers a full suite of protection features. These include undervoltage lockout, internal soft-start, foldback current limit, 'hiccup' mode short-circuit protection, and thermal shutdown.

MIC28304 is synchronous step-down regulator module, featuring a unique adaptive ON-time control architecture. The module incorporates a DC-to-DC controller, power MOSFETs, bootstrap diode, bootstrap capacitor and an inductor in a single package. The MIC28304 operates over an input supply range from 4.5V to 70V and can be used to supply up to 3A of output current. The output voltage is adjustable down to 0.8V with a guaranteed accuracy of ±1%. The device operates with programmable switching frequency from 200kHz to 600kHz. HyperLight Load® architecture provides the same high-efficiency and ultra-fast transient response as the Hyper Speed Control™ architecture under the medium to heavy loads, but also maintains high efficiency under light load conditions by transitioning to variable frequency, discontinuous-mode operation. The MIC28304 offers a full suite of protection features to ensure protection of the IC during fault conditions. These include under-voltage lockout to ensure proper operation under power-sag conditions, internal soft-start to reduce inrush current, foldback current limit, "hiccup" mode short-circuit protection and thermal shutdown.

The MIC284 is a versatile digital thermal supervisor capable of measuring temperature using its own internal sensor and an inexpensive external sensor or embedded silicon diode such as those found in the Intel Pentium III® CPU. A 2-wire serial interface is provided to allow communication with either I2C or SMBus masters. Features include an open-drain over-temperature output with dedicated registers for implementing fan control or over-temperature shutdown circuits. Interrupt status and mask bits are provided for reduced software overhead. The open-drain interrupt output pin can be used as either an overtemperature alarm or a thermostatic control signal. A programmable address pin permits two devices to share the bus. (Alternate base addresses available-contact Micrel.) Superior performance, low power and small size makes the MIC284 an excellent choice for the most demanding thermal management applications. The MIC284 is part of the SilentSense® family of thermal supervisors. Data sheets and support documentation can be found on Micrel's web site at www.micrel.com.

The MIC2841A is a high efficiency White LED (WLED) driver designed to drive up to four WLEDs, greatly extending battery life for portable display backlighting, keypad backlighting and camera flash in mobile devices. The MIC2841A provides the highest possible efficiency as this architecture has no switching losses present in traditional charge pumps or inductive boost circuits. The MIC2841A provides four linear driver channels which maintain constant current for up to four WLEDs. It features a typical dropout of 40mV at 20mA. This allows the WLEDs to be driven directly from the battery eliminating switching noise/losses present with the use of boost circuitry. The MIC2841A features Dynamic Average Matching™ (DAM™) which is specifically designed to provide optimum matching across all WLEDs. The four channels are matched better than ±1.5% typical, ensuring uniform display illumination under all conditions. The brightness is controlled through an Ultra Fast PWM™ interface operating down to less than 1% duty cycle. The MIC2841A operates over a junction temperature range of -40°C to +125°C.