The TPS63810 is a buck-boost converter with an I²C interface. The ability of the buck-boost converter to increase or decrease the input voltage can be used to drive a TEC with positive or negative voltage. In this way, the heat flow through the TEC can be controlled in order to heat or cool the target device. Figure 4-1 shows how the TEC can be driven using the buck-boost converter. When the converter operates in buck mode, V_OUT is lower than V_IN, and V_TEC and I_TEC are therefore positive. It should be noted that in this mode, I_TEC flows from V_IN into V_OUT pin of the TPS63810, therefore the TPS63810 output is sinking the TEC current. When the converter operates in boost mode, V_OUT is higher than V_IN, and V_TEC and I_TEC are therefore negative. It should be noted that in this mode, I_TEC flows from V_OUT pin of the TPS63810 back to the power source V_IN, therefore the TPS63810 output is sourcing the TEC current.

With the TPS63810, the TEC voltage can be easily changed via I²C interface. This reduces the component count when compared to conventional voltage scaling approaches, where a dedicated DAC or a PWM signal with associated filters and scaling resistors is used.