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TLV61046A: draws to much current

geen gene1
Prodigy 30 points
Part Number: TLV61046A
Other Parts Discussed in Thread: TLV61046,

We have a piezo buzzer that runs on a coin cell at 3V. But we want to boost the voltage to get some more sound.

When I use a 12V power supply it draws about 2mA, but when I use the TLV61046ADBVR it drwas 28mA !?

I would expect it would draw 12V/3V*2mA = 8mA plus some extra for the TLV so lets say 10mA.

We used 10uH and 4,7uF for both Vin and Vout capacitors. ENA and FBA are connected to Vin.

Also the 12V of the TLV61046 is stable, so it has not trouble generating the 12V. 

The 10uH is special for DCDC converters with low R.

  • 0
    TI__Mastermind 21565 points

    Hi Geen:

    Is there anything else as the load for coil cell? Please share the schematic with us. And how you measure the current?

    May you replace the coil cell with a DC voltage source, and replace the load with a 6k ohm resistance to reduce the external influence?

    We did the efficiency test in our lab before. For Vin=3V, Vout=12V, Io=2mA. The efficiency is higher than 8mA before.

  • 0 in reply to Minqiu Xie
    Prodigy 30 points

    I tested it with a 10K load and it worked like expected. Then I measured the current at 12V with a power source again with another meter. Now I see almost 5mA as cuurent. So that would mean 5*4 = 20mA at 3V. Thats is already close to the 28mA.  I think because the load is a switching circuit the meter on the power supply just could not measure the exact current.  Thanks for the reply but I think the circuit itself with the TLV61046A is ok!

  • 0 in reply to geen gene1
    TI__Mastermind 21565 points

    Hi Geen:

    I'm confused what's the 5mA means? And how do you measure it? For 10K load, the current should be 12V/10K=1.2mA.

    Is there any other load?