MIC284-0YM Microchip

MIC284 Micrel, Inc. MIC284 Two-Zone Thermal Supervisor General Description The MIC284 is a versatile digital thermal supervisor capable of SilentSense measuring temperature using its own internal sensor and an inexpensive external sensor or embedded silicon diode such Features as those found in the Intel Pentium III CPU. A 2-wire serial Optimized for CPU Thermal Supervision in Computing 2 interface is provided to allow communication with either I C Applications or SMBus masters. Features include an open-drain over- Measures Local and Remote Temperature temperature output with dedicated registers for implementing Sigma-Delta ADC for 8-Bit Temperature Results fan control or over-temperature shutdown circuits. 2-Wire SMBus-compatible Interface Interrupt status and mask bits are provided for reduced soft- Programmable Thermostat Settings for both Internal and ware overhead. The open-drain interrupt output pin can be External Zones used as either an overtemperature alarm or a thermostatic Open-Drain Interrupt Output Pin control signal. A programmable address pin permits two Open-Drain Over Temperature Output Pin for Fan Con- devices to share the bus. (Alternate base addresses avail- trol or Hardware Shutdown able-contact Micrel.) Superior performance, low power and Interrupt Mask and Status Bits small size makes the MIC284 an excellent choice for the most Low Power Shutdown Mode demanding thermal management applications. The MIC284 Failsafe response to diode faults is part of the SilentSense family of thermal supervisors. 2.7V to 5.5V Power Supply Range 8-Lead SOIC and MSOP Packages Data sheets and support documentation can be found on Micrels web site at www.micrel.com. Applications Desktop, Server and Notebook Computers Power Supplies Test and Measurement Equipment Wireless Systems Networking/Datacom Hardware Typical Application 3.3V 0.1F 4 10k pull-ups MIC284 DATA VDD FROM SERIAL BUS CLK T1 REMOTE HOST DIODE /INT A0 2200pF OVER-TEMP /CRIT GND SHUTDOWN 2-Channel SMBus Temperature Measurement System SMBus and Pentium III are trademarks of Intel Corporation. 2 I C is a trademark of Philips Electronics, N.V. SilentSense is a trademark of Micrel, Inc. Micrel, Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel + 1 (408) 944-0800 fax + 1 (408) 474-1000 MIC284 Micrel, Inc Ordering Information Part Number Base Address (*) Junction Temp. Range Package Availability Standard Pb-Free MIC284-0BM MIC284-0YM 100 100x -55C to +125C 8-Lead SOIC MIC284-1BM MIC284-1YM 100 101x -55C to +125C 8-Lead SOIC Contact Factory MIC284-2BM MIC284-2YM 100 110x -55C to +125C 8-Lead SOIC Contact Factory MIC284-3BM MIC284-3YM 100 111x -55C to +125C 8-Lead SOIC Contact Factory MIC284-0BMM MIC284-0YMM 100 100x -55C to +125C 8-Lead MSOP MIC284-1BMM MIC284-1YMM 100 101x -55C to +125C 8-Lead MSOP Contact Factory MIC284-2BMM MIC284-2YMM 100 110x -55C to +125C 8-Lead MSOP Contact Factory MIC284-3BMM MIC284-3YMM 100 111x -55C to +125C 8-Lead MSOP Contact Factory * The least-signicant bit of the slave address is determined by the state of the A0 pin. Pin Conguration DATA 1 8 VDD CLK 2 7 A0 /INT 3 6 T1 GND 4 5 /CRIT Pin Description Pin Number Pin Name Pin Function 1 DATA Digital I/O: Open-drain. Serial data input/output. 2 CLK Digital Input: The host provides the serial bit clock on this input. 3 /INT Digital Output: Open-drain. Interrupt or thermostat output. 4 GND Ground: Power and signal return for all IC functions. 5 /CRIT Digital Output: Open-Drain. Over-temperature indication 6 T1 Analog Input: Connection to remote temperature sensor (diode junc- tion) 7 A0 Digital Input: Slave address selection input. See Table 1. MIC284 Slave Address Settings. 8 VDD Analog Input: Power supply input to the IC. MIC284 2 September 2005