TPS54201EVM-818: Help Testing EVM voltage delivery

Part Number: TPS54201EVM-818

 I had used the circuit provided in the datasheet, 12V, 1.5A, 3-Piece IR LEDs, but instead of the LEDs staying on continuously, the LEDs were blinking rapidly, and we cannot maintain a consistent flow of power at 100% PWM. We had used the PWM nodes, as well as the Vo and Vi inputs only. I am using an Arduino Uno board, using a PWM signal frequency of 960 Hz, with a 100% duty cycle, resulting in a voltage of 5V. I have also tested the Vout wave, with and without load and so far. Without load it was 4.17V, with the load it was 3.38V.