HIMNL9
0
- Joined
- May 26, 2009
- Messages
- 5,318
- Points
- 0
For the input voltage ..... remember that these are step-down linear regulators, so the input voltage must be higher than the LD voltage ..... anyway, those drivers have usually less than 1V of dropout ..... about the maximum input voltage, i'm not sure, anyway you can see that they have no tantalium capacitors on the input, so the only limit is given from the IC maximum power supply, and from the 10uF 6.3V tantalium capacitor at the output (LD side, marked J106) ..... as far as the output is not higher than 6V (no LDs with over 6V of FV), and the input remain under 12 / 13V, no problem for the voltage.
Only remember that a linear driver need to dissipate ALL the extra power in heat, so more the input voltage is near the FV of your LD, better it is ..... can say, if your LD have a FV of 2.8V or similar (red diodes, usually), a 3.7V Li-Ion cell will be enough.
Only remember that a linear driver need to dissipate ALL the extra power in heat, so more the input voltage is near the FV of your LD, better it is ..... can say, if your LD have a FV of 2.8V or similar (red diodes, usually), a 3.7V Li-Ion cell will be enough.