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I have lipo battery 4.2V 3000mAh,

booster simulation ti power bench TPS55340QRTERQ1 ‑ 2.8V-4.2V to 8.00V @ 1.5A enter image description here

  • Vin 2.8V - 4.2V

  • Vout 8v

  • Iout 1.5A

simulation details

  • efficiency 84%
  • 1.43Mhz
  • duty 65%
  • total power dissipation 2.34W
  • Iin avg ic 5.13A

what if load is not connected, but booster is connected to battery, will battery drain over the time?

what would be the current consumption of booster circuit if load is not connected? how to determine this?

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    \$\begingroup\$ Can't you get a simulation result if you reduce the output current to 0 A? \$\endgroup\$ – Arsenal Sep 10 at 6:41
  • \$\begingroup\$ It depends on the convertor. You can put an upper bound on the power loss by using the full load efficiency figure, as 16% of rated output, but it'll likely be better than that. Some boost converters may go discontinuous, operating in short bursts, to save power, others may not. \$\endgroup\$ – Brian Drummond Sep 10 at 10:26
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Yes, battery will drain due to quiescent operating current the chip draws when it is working. It is listed in the datasheet, both in the cover page and in the electrical specifications, so open the datasheet and read the value from datasheet.

In addition to what the chip consumes, all external components consume current too. The feedback network obviously adds about 1mW of constant load.

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  • \$\begingroup\$ is that the only current that draws at all? Iq is 0.5mA \$\endgroup\$ – kobi89 Sep 10 at 5:18
  • \$\begingroup\$ but i have experienced such boosters draws more current than Iq when no load is connected around 5mA-7mA \$\endgroup\$ – kobi89 Sep 10 at 6:00
  • \$\begingroup\$ That is what the chip itself uses - I forgot it does not include everything needed to provide output voltage like linear regularors do. It will still actually use more energy to maintain the output voltage at 8V. If you build the circuit, you can just measure how much it consumes. The feedback network consumes constantly about 1mW extra. \$\endgroup\$ – Justme Sep 10 at 6:35

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