I have a TPS61222 Buck boost voltage converter, in a circuit intended to boost a 3.7V battery source to 5V. The output voltage however, is consistently less than 5V - scoping shows a 4V signal with spikes up to 6v at about 90kHz, low duty cycle.
The current draw is 56mA nominal (into the converter). The converter powers a charge pump inverter, to generate -5V, along with a number of other devices. The feedback pin voltage should be o.5V, with about 13mV tolerance (as per data sheet) - the value it is showing is more like 0.35-0.42V.
Full schematic and PCB layout are here