See Figure 1-2 for jumper locations.

• JEN - This jumper allows the ENABLE input to be connected to GND in order to disable the IC. By default, this jumper is left open since there is a pullup resistor R2 (RENT) to VIN to enable the IC.
• JPGOOD - Use this jumper to select how the PGOOD pin is connected. A jumper can be used to connect pin 2 and 3. In this configuration, the PGOOD pin is pulled up to VOUT through R7 (RPGOOD) with a value of 100 kΩ. When connecting the jumper between pin 1 and 2, the PGOOD pin is pulled up to VCC through R7 (RPGOOD) with a value of 100 kΩ. By default, this jumper is not populated.
• JRT - Use this jumper to set the switching frequency. Connecting this jumper from pin 1 and pin 2 sets the switching frequency to 2.2 MHz and connecting this jumper from pin 2 and pin 3 sets the switching frequency to 1 MHz. Leaving this jumper floating results in the frequency being set by the RT resistor. An RT resistor must be present if the JRT jumper is left floating. By default, the jumper is connected between pin 1 and pin 2. Pin 1 is indicated by the dot on the PCB.

Figure 1-2 Jumper Locations