The MAX11300 integrates one internal and two external temperature sensors which monitor programmable conditions of minimum and maximum temperature limits, using the interrupt to notify the host if one or more conditions occur. The temperature measurement results are made available through the serial interface. The external sensors are diode-connected transistors, typically a low-cost, easily mounted 2N3904 NPN type, that replace conventional thermistors or thermocouples. The external sensors’ accuracy is typically ±1°C over the -40°C to +150°C temperature range with no calibration necessary. Use of a transistor with a different ideality factor produces a proportionate difference in the absolute measured temperature. Parasitic series resistance results in a temperature reading error of about 0.25°C per Ohm of resistance. The MAX11300 features a series resistance cancellation mode (RS_CANCEL) that eliminates this error for resistances up to 10 Ohms. The external sensors can also measure the die temperature of other ICs, such as microprocessors, that contain a substrate-connected diode available for temperature-sensing purposes. Temperature data can be read from the temperature data registers. The temperature data format is in two’s complement, with one LSB representing 0.125°C.