SLUSDX1 September 2020 TPS563211
The device requires a mode resistor to select the operations mode under light load and configure the function of pin 1. Table 7-1 shows the MODE pin settings.
|MODE RESISTOR RANGE||RECOMMENDED MODE RESISTOR VALUE||OPERATION MODE IN LIGHT LOAD||FUNCTION OF PG/SS PIN|
|[0, 12] kΩ||0||Eco-mode||Power Good|
|[30, 50] kΩ||47 kΩ||Eco-mode||Soft Start|
|[83, 120] kΩ||100 kΩ||FCCM||Soft Start|
|[180, ∞] kΩ||Float||FCCM||Power Good|
Figure 7-1 shows the typical start-up sequence of the device once the enable signal triggers the EN turnon threshold. After the voltage of VIN crosses the UVLO rising threshold, it takes about 110 μs to finish reading and setting of the MODE pin. After this process, the MODE status is latched and does not change until VIN or EN toggles to restart-up this device. Then, the soft-start function begins to ramp up the reference voltage to the PWM comparator.