Tool/software:
Hello everyone,
I am trying to write a setup for my TPS92518. I can calculate all registers except the register LEDx_PK_DAC.
According to the illustration (Datasheet TPS92518 SLUSCR7 –MAY 2017 p.43 ), this should be a register for the switching frequency
For me the setting of the switching frequency is not obvious, can someone help me, how the switching frequency is calculated. I would like to set a frequency of 800KHz.
Best regards
Andre
This is NOT a fixed frequency converter. We cover the process to select toff-min and then the conditions and the inductor value set the ON-time based on desired peak to peak inductor ripple current in the datasheet.
Are you using the EVM? If so, what is your load in other words number of LEDs are you using and Vf characteristics of them? Are you doing PWM dimming or shunt fet or analog dimming? (or combinations of dimming?) If so, what PWM frequency and duty cycle range?
Here is an example of calculations.
If the input voltage and output voltages doing change then you can setup the switching frequency to be close to what you want. If the input or output voltages vary alot then you will have varying switching frequency.
-fhoude
Hello Andre,
Sorry that the "th" isn't included in the equation but if you read the datasheet it would have been pretty self evident. Please try and read the datasheet when possible.
-fhoude
