Tool/software:
Dear Sir,
Because I want to use SDIM to turn on/off LED immediately, so TPS92641 is good fo this purpose, but LED VF is about 2.0V （current about 5A）， which is lower then 3.05V,(an internal reference), it can't work!
So can you give me some suggestion or other choice?
Best regards!
David
Hi David,
I do not see any problem for TPS92641 to drive a 2V 5A LED. Please clarify why it does not work.
For the 3.05V as you mentioned, does it refer to VOUT overvoltage threshold?
Best Regards,
Steven
it refer to VOUT overvoltage threshold，Ron is also mixed with Vout!
How to deal with it ?
Hi David,
Sorry for the late response.
Although the common practice to set the voltage of the VOUT pin at 2.5V (Please refer to Section 8.2.1.2.1 Set Output Voltage Feedback Ratio from the datasheet), it is also ok to design it direct at your output voltage without the resistor divider if your output voltage is less than 2.5V. (i.e., R_OUT1 = 0ohm, R_OUT2 = open). Additional measures may need to be taken to avoid the voltage of the VOUT pin from exceeding its voltage ratings.
When doing so, you can substitute the "R_VOUT2 / (R_VOUT1 +R_VOUT2)" with "1" in equation (2) from the datasheet and you will get a new equation, which is f_SW = 1 / (R_ON * C_ON).
Best Regards,
Steven
