Lt3042 anything better ?

[Frederico Acardi]

Hello. I need a low current regulator for a dual supply +15 -15v opamp, the lt3042 seems perfect for the task, and the 3094 is for the negative.


But is there a better specs (lower noise and pssr at audio frequencies) than this, in a single chip form factor ?

I know i can parallel chips but i am looking for a single chip solution.

Thank you.

 

[Rudi_Ratlos]

What about the Texas Instruments TPS7A4700?

Using a transformer with 2 independent secondaries will easily give you a "+/-" PSU - with the lowest ripple current (Output Voltage Noise: 4 µVRMS (10 Hz, 100 kHz) that I know.

Regards - Rudi_Ratlos

 

[Joseph K]

lt3042/3094 is one of the highest quality solution..

 

[Frederico Acardi]

Would you say its better than the TPS7A4700 version ? I am building from scratch so i can go either way. Thank you.


Edit : forgot to say thank you very much Rudi_Ratlos

 

[Joseph K]

they are similar. But 3042 /94 is lower noise, and a bit faster.. then, I found it produces less peaking in the transition from regulator output to bypass cap impedance..
The parameter in which the TPS7A could be a bit better (slightly) is the output impedance.

Ciao, George

 

[Frederico Acardi]

Thank you very much guys.

 

[avtech]

I've used TPS7A4700 LDO modules before with good results.

 

[Frederico Acardi]

Thank you. The good thing with the tps7a is that they are 1A. The lt are 0.2A and 0.5A. But for a single opamp its better going for lowest noise.



I wonder if the tps7a get better at low current ?

 

[bohrok2610]

It all depends on your use case.
LT30xx:
+ lower noise below 100kHz
+ more diy-friendly package available (MSOP)
- only up to 15V/500mA
- higher output impedance

TPS7Axx:
+ lower output impedance so it may work better with load transients
+ up to 34V/1A
- higher noise

 

[Joseph K]

All these regulators does need a substantial amount of load current, for performing to datasheet values!!

So don't even dream of piloting only one opamp..
the LT series I have seen to come up, work ok cca above 50mA. more is better.
So a partial extra load resistor is usually needed, to bring them into the right regime..

 

[Frederico Acardi]

Thank you very much.


bohrok2610. So the lt is lower noise. Thanks.


Joseph K. I knew about this but i completely forgot this... Thank you so much because i was going to build it without adding a load resistor. You saved me a pcb redesign, thanks.