I'm looking to use TPS61021A in a LED driver circuit powered by a AAA battery and wanted to model the setup for optimization. The model that I developed gives me results that are inconsistent with the actual circuit. I downloaded the Spice model for the LED from the manufacturer and got the TPS61021A model from a TI representative.
Any tips, or is there an example Pspice setup that I could reference for something like this?
Model:
Actual measured values:
Hi Jarrod,
Sorry, I don't understand why you're connecting the circuit like this. Ususlly for a LED load, the boost circuit is connected like this:
Best Regards,
Travis
The designer of the original circuit followed the TI white paper found here (Figure 11): Single LED Driver in AA Battery-Powered Systems (ti.com)
You can see above that the original circuit was built and measured and does not align with the simulation. Regardless of the optimal circuit configuration, I'm still concerned about why the numbers aren't very close to each other.
Below is what I get from simulating the circuit you suggested.
It appears that the voltage on the anode side of the LED is around 1.5 V which is less than the forward voltage for the LED (2-2.6 V from the datasheet). The current through R3 is also showing a negative value.
Any advice based on this new information?
It looks like I had a wire placed over the LED, shorting it out. After simulating the circuit you suggested, it yielded results that make sense (80 mA through the LED with a 10 ohm resistor. When I tried to re-simulate the original circuit, however, I am getting a convergence error.
Hi Jarrod,
PSPICE is a case-insensitive software. Both 1M and 1m means 1 Milli while 1MEG means 1Megohm.
Best Regards,
Travis
