The TMP421-Q1, TMP422-Q1, and TMP423-Q1 devices are single, dual, and triple remote, automotive-qualified temperature sensor monitors with a built-in local temperature sensor. The remote temperature sensor diode-connected transistors are typically low-cost, NPN- or PNP-type transistors or diodes that are an integral part of microcontrollers, microprocessors, or field-programmable gate arrays (FPGAs). Remote accuracy is ±1°C for multiple device manufacturers, with no calibration needed. The two-wire serial interface accepts SMBus write byte, read byte, send byte, and receive byte commands to configure the device. The TMP421-Q1, TMP422-Q1, and TMP423-Q1 include series resistance cancellation, programmable non-ideality factor, wide remote temperature measurement range (up to +150°C), and diode fault detection. The TMP421-Q1, TMP422-Q1, and TMP423-Q1 are all available in an 8-pin SOT-23 package.