SNVSCB1C December 2022 – February 2024 TPSM33615 , TPSM33625
PRODUCTION DATA
The following operating description of the TPSM336x5 refers to Functional Block Diagram. In CCM, the TPSM336x5 supplies a regulated output voltage by turning on the internal high-side (HS) and low-side (LS) switches with varying duty cycle (D). During the HS switch on time, the SW pin voltage, VSW, swings up to approximately VIN, and the inductor current increases with a linear slope. The HS switch is turned off by the control logic. During the HS switch off time, tOFF, the LS switch is turned on. Inductor current discharges through the LS switch, which forces the VSW to swing below ground by the voltage drop across the LS switch. The buck module converter loop adjusts the duty cycle to maintain a constant output voltage. D is defined by the on time of the HS switch over the switching period:
In an ideal buck module converter where losses are ignored, D is proportional to the output voltage and inversely proportional to the input voltage: