A multichannel temperature sensor makes use of a low-cost transistor, plus the primary Integrated Circuit (IC) to deliver 1°C accuracy for measuring multiple hot spots across your Printed Circuit Board (PCB). Each multichannel temperature sensor's primary IC has one temperature measurement on-board. Therefore, a two-channel temperature sensor has an additional temperature measured via the low-cost transistor in another location. In contrast, a single temperature sensor with a serial interface uses the same temperature measurement but has to replicate the digital interface and measurement at every point. The multichannel temperature sensor can get away with the simplest of transistors at every hot spot measurement. The device requires two traces to connect to the second location for heat measurement. Note the second channel is a Bipolar Junction Transistor (BJT), with the emitter and collector of the transistor connected. The primary IC can read temperature due to a relationship between the temperature of the BJT and current injected in the transistor.
Microchip offers antiparallel diodes, a unique method to minimize the number of pins required for multiple channels. This is the method shown in the figure of diode connections. This facilitates a five-channel part in a 2x2.5 mm package using a standard lead spacing of 0.5 mm pitch.