BQ25504 - Transducer current

Tzern Toh

Other Parts Discussed in Thread: BQ25504

Hello,

I am testing the BQ25504 evaluation kit, using an external power supply to mimic the voltage from a thermoelectric generator. A 10 ohm resistor is connected in series between the power supply and Vin pin of the BQ25504.

When the MPPT function is enabled, should the input current drawn from the power supply (transducer) equal V_in/(2*R_in)? where V_in is the generated voltage from the transducer and R_in is the source resistance from the transducer.

Tzern

over 13 years ago

0 Charles Mauney over 13 years ago

TI__Mastermind 31120 points

That looks like the current at maximum power transfer, but don't think you are set up to opperating there. One would have to set the MPPT to half the lab supply voltage. If the lab supply is set for 2V and the MPPT is set for 1V. May hit some peak power limitations and may need to use a 20 ohm resistor.

Another way to calculate input current is the average voltage dropacross input resistor divided by its resistance.

0 Chao Chen6 over 8 years ago in reply to Charles Mauney

Prodigy 20 points

How can we get the input resistance？

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BQ25504 - Transducer current