MAX6642应用电路

Figure 4. A remote temperature sensor, the MAX6642, monitors the temperature of a sensing transistor (or thermal diode) on the die of an external IC.

There is an important advantage to remote temperature sensors: they allow you to monitor more than one hot spot with a single IC. A basic single remote sensor like the MAX6642 in Figure 4 can monitor two temperatures: its own and an external temperature. The external location can be on the die of a target IC, as in Figure 4, or a hot spot on a board that it monitors with a discrete transistor. Some remote sensors monitor as many as seven external temperatures. Thus, eight locations, consisting of ICs and board hot spots, are monitored from a single chip. Consider the MAX6602 as an example. This temperature sensor has four remote diode inputs so it can monitor the temperatures of a pair of FPGAs with integrated thermal diodes, two board hot spots using discrete transistors, and the temperature of the board at the MAX6602's location. Both the MAX6602 and the MAX6642 mentioned here achieve ±1°C accuracy when reading external thermal diodes.