This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

  • TI Thinks Resolved

LM43601: Start up problem with inverting application SNVA722B

Prodigy 10 points

Replies: 1

Views: 101

Part Number: LM43601

Dear all

I used LM43601 in our application and had very serious issues with unreliable start up. The device locks up to a positive voltage of approximately 0.5V.

My conclusion is that it has something to do with the BIAS pin. If I connect the BIAS pin to device ground (which is the negative output rail of the circuit in this case) the circuit seems to work reliably. It tested with different loads through a temperature range of 0°C to 100°C and it always powers up properly and can deliver currents much higher than needed for our application. 

Is this an error on the application note or something that I have overlooked in the design? Is the circuit reliable with the BIAS pin connected to device ground? I have attached the actual circuit from our application with the component values I used.

LM43601-problem.pdf

  • This issue is sometimes seen in IBB applications.
    One solution is to connect the BIAS to the GND node of the LM43601 (-Vout of system).
    Or a diode can be placed across the output (anode to -Vout, cathode to system ground).

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.