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.There is a pullup
resistor, R1 (RENT), which connects between the VIN pin and the EN pin of 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 program the switching frequency for a RT
trim part. This jumper allows the user three programmable switching frequency
options:
Program the switching
frequency using the R8 (RT) resistor. This action allows for the
switching frequency to be tuned to any value between 200 kHz to 2.2 MHz.
Refer to the data sheet for the required RT resistor value for the
desired switching frequency. When using the RT resistor to program the
switching frequency, leave JRT open circuited.
Short circuit the RT pin
to GND by shunting pin 1 and 2. This action results in AUTO mode
operation with a maximum switching frequency of 2.2 MHz. Remove resistor
R8 (RT) for proper operation. Resistor R9 (RJM) must be populated.
Short circuit the RT pin
to the VCC pin by shunting pin 2 and 3. This action results in AUTO mode
operation with a maximum switching frequency of 1 MHz. Remove resistor
R8 (RT) for proper operation. Resistor R9 (RJM) must be populated.