The LED driver boad can be supplied from 1V to 4V so its perfectly suitable for one cell lithium ionen battery use. I designed 8 high power LED's (3535 size, Cree or equivalent) with an constant current of 350mA.
On my first prototype i equipped four Cree LED XLAMP XPG3 4000K (RS-Online number: 1223595) with 179lm (at 25°C) -> 716lm.
The board should be driven by an 2.3V Lithium Titanate Cell (LTO).
As an step up driver i decided to use the LTC3490.
Key characteristics of the LTC3490:
- 350mA Constant Current Output
- 2.8V to 4V Output Compliance
- 1- or 2-Cell NiMH or Alkaline Input or LTO battery
- Synchronous Rectification: Up to 90% Efficiency
- Fixed Frequency Operation: 1.3MHz
- Low Quiescent Current: <1mA
- Very Low Shutdown Current: <50μA
- Open LED Output Limited to 4.7V
- VIN Range: 1V to 3.2V
- Dimming Control
- Undervoltage Lockout to Protect Batteries
The efficiency is in my application around 85%-90%!
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Robert (Wednesday, 09 February 2022 23:27)
Looks like a good idea!
Will it drain the LTO battery past its 1.8v discharge limit? Or can you use resister or inductor to set the low voltage?
Thanks