Circuit of TPS61040

Hi Takahiro:
I thought it's caused by the current limit. I have done the calculation that Vin=5Vm Vout=12, L=10uH, Efficiency=0.8, The Iomaxi couldn't reach 83mA.
I'll check with my team to fig out the solution.
May you share your simulation circuit with me?

Thank you for your support!

Our customer demand us the recommended circuit of TPS61040.
And we use the WEBENCH to show the circuit.
But we can't check the simulation result by webench.

Current Limit(min) of TPS61040 is 350mA.
We think current limit is no prpblem when Iout is 83mA.

We are waiting for your answer!


Best regards,

Takahiro Nishizawa

Hi Takahiro:
It's should be noticed that the current limit is aimed to the peak current of the inductance. The peak current is higher than the Iin or Io.
You could check the calculation follow the 8.2.2 of the datasheet.

TPS61040: 28-V, 400-mA Switch Boost Converter in SOT-23 for LCD and White LED Applications
Product Folder: www.ti.com/.../TPS61040
Data sheet (PDF): www.ti.com/.../slvs413i

Thank you for your answer!

Can we use TPS61040 under following conditions?
We think this condition is no problem.Only WEBENCH is not applied.

Vin=5V
Vout=12V
Iout=0.083A


Best regards,

Takahiro Nishizawa

Hi Takahiro:

Below is my calculation. And it seems the circuit couldn't supply 83mA. What's your application? I'm curious about the number of 83mA. 

			TPS61040/41 Worksheet Version 1.0
Input values			Calculated component values			Calculated design parameter
Vin/V	5		R1/kOhm	1414.64		Ipeak/mA	400.00
Vout/V	12					fsmax/kHz	729.17
L/uH	10					Ioutmax/mA	70.83
Vd/V
ILIM/mA	350
R2/kOhm	162
Cin/uF
Co/uF
Efficiency/%	85

Hi Takahiro:
How is it going? Have you done the calculation?