Other Parts Discussed in Thread: TPS54308EVM-876, TPS54308, TPS54302
Dear TI Team
On our PCBA's we use the TPS54308 Step-Down Converter for our 5V power supply. The PCBA and the Step-Down Converter itself gets powered by 24V. We expected an voltage ripple around 20mVpp. But on our PCBA we had voltage ripple around 100mVpp. We decided to order 2 evaluation boards. The TPS54308EVM-876 for 3.3V and the TPS54302EVM716 for 5V. We powered both of them with 24V and put an resistor on them to pull 300mA. The result on the TPS54308EVM-876 for 3.3V looked like the picture 7 in the datasheet. But on the TPS54302EVM716 for 5V we had a voltage ripple around 100mVpp. While we measured the voltage we checked the current constantly and recalibrated the oscilloscope before we measured. We havent changed anything on the evaluation board and measured in AC mode. Am i missing an information in the datasheet or is there something wrong with the mV/div. scale in the figure 22? The signal looks exactly the same, but the voltage is a lot bigger.
Thank you for answering and have a great week
Ramon Sidler