The LM27402 evaluation board is setup with a tracking connection (SS/TK). The SS/TK terminal is also the soft-start pin. If a voltage source is connected to the SS/TK connection of the board, the output can be controlled up to 1.5 V (voltage set by the feedback resistors). The LM27402 will stop tracking when the SS/TK voltage exceeds 0.6 V. Please refer to the data sheet for more details of the tracking function.