The TPS631010 and TPS631011 are constant frequency peak current mode control buck-boost converters in tiny wafer chip scale package. They have a 3A peak current limit (typical) and 1.6V to 5.5V input voltage range, and provide a power supply solution for system pre-regulators and voltage stabilizers. Depending on the input voltage, the TPS631010 and TPS631011 automatically operate in boost, buck, or in 3-cycle buck-boost mode when the input voltage is approximately equal to the output voltage. The transitions between modes happen at a defined duty cycle and avoid unwanted toggling within the modes to reduce output voltage ripple. 8µA quiescent current and power save mode enable the highest efficiency for light to no-load conditions. The devices offer a very small solution size in WCSP.