0
\$\begingroup\$

I'm currently using a charge pump ic chip (http://www.digikey.com/product-detail/en/microchip-technology/MCP1252-33X50I-MS/MCP1252-33X50I-MS-ND/529831) for stepping up a 3V coin cell to a 3.3V regulated supply.

I originally chose this chip seeing as how, "it got the job done". However, I've realized that operating in this range (3V -> 3.3V) is only 60% efficient. I've also learned that high current draw from a coincell should be avoided seeing as coin cells have high internal resistance. I'm afraid that implementing this regulator is going to strain my battery even more than it already is.

The coin cell I'm using is a CR2032, but there's a chance I'm going to be switching to a different battery type soon.

So I'm curious, is anyone aware of a more efficient method for doing this?

Ideal solutions feature:

  • Purchasable IC package (i.e. I don't feel like designing my own regulator circuit).
  • Something of a small form factor (surface mount chip height).
\$\endgroup\$
  • \$\begingroup\$ What is your average power consumption? Because if it's in the uA range rather than mA (e.g. a low power MCU sleeping most of the time), you care more about quiescent current than efficiency. \$\endgroup\$ – dim Oct 28 '16 at 17:01
1
\$\begingroup\$

Google, or do a parametric search for, "Synchronous Boost Regulator" and you will find many parts. For example, the TPS61020 claims 96% efficiency, though probably not under your operating conditions.

Boost regulator because that what you need.

Synchronous because you need synchronous rectification to get high efficiency with relatively low output voltage compared to a diode drop.

\$\endgroup\$
  • \$\begingroup\$ Very good stuff! I was just looking at the TPS61025 and it shows that it will yield near peak efficiency around ~3V. As long as I don't surpass 3.3V, I should be good to go. \$\endgroup\$ – Izzo Oct 28 '16 at 17:33
  • \$\begingroup\$ Question for you, why do some of these data sheets refer to certain battery types? For example, the TPS61020 mentions lithium-ion batteries as an example source to be regulated, yet when looking at a different series (TPS6101x, digikey.com/product-detail/en/texas-instruments/TPS61016DGS/…), it only mentions Alkaline batteries in the data sheet. Why is this? \$\endgroup\$ – Izzo Oct 28 '16 at 17:48
  • \$\begingroup\$ Probably the combination of input/output voltages and currents it's intended to work with. Some of them have a mode to regulate slightly downward if fresh cells are inserted that exceed the desired output voltage, which is a very nice feature. \$\endgroup\$ – Spehro Pefhany Oct 28 '16 at 17:53

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.