A thermoelectric generator induces DC current, but a transformer cannot directly step up DC voltage. Instead, the transformer operates by creating an AC current through a switch in the primary circuit, typically functioning at frequencies between 10 kHz and 100 kHz. This AC current is then stepped up in voltage to power the circuit. The chip also features a charge pump and allows for user-programmable output voltages of 2.35V, 3.3V, 4.1V, or 5V. The datasheet provides further insights into its functionalities.