Hi I would like to know which negative regulator would you recommend for a Linear PSU with a bridge rectifier (120Hz) ? And which one would performs the best ?
I need 1Amp or more, it has to be LDO.
I don't care about the package. But I do somewhat care about the number of added parts to make it operational.
Does any of those 2 has any flaw I should be aware of ? Should I focus on other LDOs maybe ?
Thank you.
I need 1Amp or more, it has to be LDO.
I don't care about the package. But I do somewhat care about the number of added parts to make it operational.
Does any of those 2 has any flaw I should be aware of ? Should I focus on other LDOs maybe ?
Thank you.
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Hi here is the datasheet of the tps7a33 and some key specs :
https://www.ti.com/lit/gpn/tps7a33Vin (V) -36
Iout (A) 1
Noise (uVrms) 16
Dropout voltage (Typ) (mV) 290
PSRR @ 120 Hz (dB) 70
PSRR @ 100 KHz (dB) 64
PSRR @ 1 MHz (dB) 50
For the Lt3091
https://www.analog.com/media/en/technical-documentation/data-sheets/3091fa.pdfVin (V) -36
Iout (A) 1.5
Noise (uVrms) 18
Dropout voltage (Typ) (mV) 300
PSRR @ 120 Hz (dB) 85
PSRR @ 100 KHz (dB) 35
PSRR @ 1 MHz (dB) 30
https://www.ti.com/lit/gpn/tps7a33Vin (V) -36
Iout (A) 1
Noise (uVrms) 16
Dropout voltage (Typ) (mV) 290
PSRR @ 120 Hz (dB) 70
PSRR @ 100 KHz (dB) 64
PSRR @ 1 MHz (dB) 50
For the Lt3091
https://www.analog.com/media/en/technical-documentation/data-sheets/3091fa.pdfVin (V) -36
Iout (A) 1.5
Noise (uVrms) 18
Dropout voltage (Typ) (mV) 300
PSRR @ 120 Hz (dB) 85
PSRR @ 100 KHz (dB) 35
PSRR @ 1 MHz (dB) 30
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You omitted the most important information - what will this feed?
When I compared the LT and tps specs (positive regs!), my conclusion was that the LT seemed more suitable for audio and the tps better for digital (HF/MHz) circuits. This was primarily due to the PSSR "frequency response". Noise at audio freq. was not my first prio. The design/implementation around the regs is as usual easy to screw up and lose all that performance of the LDO component. This is my limited level of knowledge view and there are far more skilled persons in this topic and I'm sure they will correct me if I'm wrong..
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When I compared the LT and tps specs (positive regs!), my conclusion was that the LT seemed more suitable for audio and the tps better for digital (HF/MHz) circuits. This was primarily due to the PSSR "frequency response". Noise at audio freq. was not my first prio. The design/implementation around the regs is as usual easy to screw up and lose all that performance of the LDO component. This is my limited level of knowledge view and there are far more skilled persons in this topic and I'm sure they will correct me if I'm wrong..
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If you already built a LT3045 positive regulator then LT3094 is the best match and better than TPS7A33 or LT3091 if -15V@500mA output and -20V input voltage is sufficient. TPS7A33 datasheet noise is given at low voltage (Vref) so expect higher noise at higher output voltages. LT3094 noise stays about the same regardless of output voltage.
Thank you for the help.
Hi i am building a dual stage power supply, I already built the lt3045/lt3094 psu and I will add one of those as preregulator before the lt94. Mainly, only PSRR is important in this case.
But I also plan on using them when I need more current than 500ma, so they need be able to power high load quietly when used as standalone (when only the tps7a33 or lt3091 are used alone, not as pre reg).
But to be fair I am starting to realize the superiority of Posititive regulators (low noise high psrr), and I will try to see if I can gain much by using a dual secondary with 2 positive regs, instead of one center tapped secondary with 1positive and 1 negative reg. It will also be cheaper and easier to order...
Thank you.
Hi i am building a dual stage power supply, I already built the lt3045/lt3094 psu and I will add one of those as preregulator before the lt94. Mainly, only PSRR is important in this case.
But I also plan on using them when I need more current than 500ma, so they need be able to power high load quietly when used as standalone (when only the tps7a33 or lt3091 are used alone, not as pre reg).
But to be fair I am starting to realize the superiority of Posititive regulators (low noise high psrr), and I will try to see if I can gain much by using a dual secondary with 2 positive regs, instead of one center tapped secondary with 1positive and 1 negative reg. It will also be cheaper and easier to order...
Thank you.
Yes, but there is a difference where in the frequency band you need your PSRR depending on if you are to DC feed an oscillator/clock or a unity input gain stage...
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Does the lt3091 noise stay the same too regardless of output ? because I read the datasheet and it is not specified.
If anyone cares, some people prefer the TPS7A regulators over LT30xx for analog audio circuits. It has been claimed they "sound better." I would not disagree. Then again, other people seem to prefer the specs of LT30xx.
Which doesn't mean anything to those who weren't there unless such claim is accompanied by supporting evidence.
Are these "some people" the same the former POTUS referred to with "many people are saying"?