Help for a voltage regulator

[stefano.luna]

Hello,

I need a voltage regulator to power a microphone at 1.3V from a 3V coin cell battery and I was looking for a regulator like the lm317, but with this one the minimum output voltage is 2.5V+input voltage, so it's not suitable for my application. Do you know other voltage regulatorthat fits with this?

Thank You

[RK]

I use the micrel LDOs for almost everything, they're cheap and reliable and did I say cheap?

The 1.3 one is MIC5365-1.3YC5-TR, mouser has them here but you can get them anywhere.

As guruprasad says you need to watch the power dissipated to make sure you don't overheat the regulator. The thermal resistance of those micrels is about 250W/C, the max junction temperature 150C. So if you're running at 25C you have 125C of headroom. That gives you 1/2W you can drop through the LDO which means a current of about 300mA max. That series is designed for 150mA output although the only actual limitation I've seen is the junction temperature.

From the regulator you mention in the original question it looks like you want < 100mA anyway so you're fine with this regulator. Oh and did I mention .. it's really cheap.

[stefano.luna]

Thank you for the reply. Is this available only in smd package? I was looking for a tht one.

[RK]

That one is SMD only - sorry I took the plunge a few years ago and never went back. There's a microchip one which comes in different packages including TO, I've used the SMD version of that one and it works also fine (I switched to micrel for cost reasons).

this is it but it seems hard to find.

[stefano.luna]

The one you suggest me seems to have only a fixed set of output voltages, but not 1.3V. I found the LP3966 and seems nice: the dropout voltage is 80-800mV and the output is adjustable via a voltage divider. I also found the LT1761 that seems nice, but only available in SMT. What do you think about the first one?