J1 – connect J1: 1-2 to set the IC operation to auto mode or J2: 2-3 to FPWM
(fixed frequency) mode. If synchronization to an external clock source is
required, remove the J2 jumper and hook the clock up to TP7 and TP8.
J2 – connect J2: 2-3 to enable the device or J2: 1-2 to disable the device.
J3 – connect J3: 1-2 for a VCC pullup voltage on PGOOD. The PGOOD signal can
also be connected to an external supply of up to 20V using pin 2 of this
jumper.