ZHCSB85F November 2011 – October 2021 TPS62140 , TPS62140A , TPS62141 , TPS62142 , TPS62143
PRODUCTION DATA
The TPS6214x can be used as inverting power supply by rearranging external circuitry as shown in Figure 9-42. As the former GND node now represents a voltage level below system ground, the voltage difference between VIN and VOUT has to be limited for operation to the maximum supply voltage of 17V (see Equation 16).
The transfer function of the inverting power supply configuration differs from the buck mode transfer function, incorporating a Right Half Plane Zero additionally. The loop stability has to be adapted and an output capacitance of at least 22µF is recommended. A detailed design example is given in Using the TPS6215x in an Inverting Buck-Boost Topology Application Report.