Other Parts Discussed in Thread: TPS543C20
I have a stand alone TPS543B20, configured similar to the eval board;
Mode resistor: open
RT : 28.7K
ss: 34.8K
VSEL: 51.1K
ILIM: 24.9K
RAMP: 187K
When I enable this regulator, I do not get any output when I have no signal on SYNC (it is held low by inactive clock driver).
When I apply an external 700KHz on SYNC, I do get the expected 0.9V output.
Why does this not come up using the internal frequency set by RT?
8.4.9 Synchronization and Stackable Configuration
The TPS543C20 device can synchronize to an external clock which must be equal to or higher than internal
frequency setting. For stand alone device, the external clock should be applied to the SYNC pin. A sudden
change in synchronization clock frequency causes an associated control loop response, resulting in an overshoot
or undershoot on the output voltage.
