MAX6655

· Three Temperature Channels
    Two Remote PN Junctions
    One Local Sensor
· Four Voltage Channels
    +12V, +5V, +3.3V, +2.5V
    Three External Monitors
    One Internal Supply Monitor
· 11-Bit, 0.125°C Resolution
· High Accuracy: ±1°C Over +60°C to +100°C  Temperature Range
· Programmable Under/Over-Threshold Alarms
· Programmable Power-Saving Mode
· No Calibration Required
· SMBus/I2C™-Compatible Interface
· OVERT Output for Fan Control and System Shutdown

Vcc to GND..............................................................-0.3V to +6V
DXN_ to GND ........................................................-0.3V to +0.8V
SMBCLK, SMBDATA,ALERT, STBY,
OVERT to GND...........................................................-0.3V to +6V
VIN1 to GND............................................................-0.3V to +16V
VIN2 to GND..............................................................-0.3V to +6V
_VIN3 to GND..............................................................-0.3V to +6V
All Other Pins to GND..................................-0.3V to (VCC + 0.3V)
SMBDATA, ALERT, OVERT Current....................-1mA to +50mA
DXN_ Current.....................................................................±1mA
ESD Protection (all pins, Human Body Model) ...................2000V
Continuous Power Dissipation (TA = +70°C)
16-Pin QSOP (derate 8.30mW/°C above +70°C)..........667mW
Operating Temperature Range .......................-55°C to +125°C
Junction Temperature......................................................+150°C
Storage Temperature Range ...........................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C

Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and  unctional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

The MAX6655/MAX6656 are precise voltage and temperature monitors. The digital thermometer reports the temperature of two remote sensors and its own die temperature. The remote sensors aMAX6655 re diode-connected transistors-typically a low-cost, easily mounted 2N3906 PNP type-that replace conventional thermistors or thermocouples. Remote accuracy is ±1°C for multiple transistor manufacturers with no calibration necessary. The remote channels of MAX6655 can also measure the die temperature of other ICs, such as microprocessors, that contain a substrate-connected PNP with its collector grounded and its base and emitter available for temperature- sensing purposes. The temperature is digitized with 11-bit resolution.

The MAX6655/MAX6656 also measure their own supply oltage and three external voltages with 8-bit resolution. Each voltage input's sensitivity is set to give approximately 3/4-scale output code when the input voltage is at its nominal value. The MAX6655 operates at +5V supply and its second voltage monitor is 3.3V. The MAX6656 operates on a +3.3V supply and its second voltage monitor is 5V.

The 2-wire serial interface accepts standard SMBus™ Write Byte, Read Byte, Send Byte, and Receive Byte commands to program the alarm thresholds and to read data. The MAX6655/MAX6656 also provide SMBus alert response and timeout functions. The MAX6655/MAX6656 measure automatically and autonomously, with the conversion rate programmable. The adjustable rate allows the user to control the supply current.

In addition to the SMBus ALERT output, the MAX6655/ MAX6656 feature an OVERT output, which is used as a temperature reset that remains active only while the temperature is above the maximum temperature limit. The OVERT output is optimal for fan control or for system shutdown.