Superpower Ripple Rejection
compared to newer regulators

How does Superpower compare with the latest generation of high performance voltage regulators? See the FFT spectra below and judge for yourself. Devices were tested using datasheet recommended application circuits, all devices use the same input supply. All were measured with 12V out with no load. A perfect spectrum would show only a noise floor—an ideal regulator never varies from its specified DC output voltage and ripple that transits from input to output appears as a vertical spike out of the noise floor.

This is a somewhat dreary page that shows many hours of measurement taking, and if you don't want to spend hours reviewing what it says, the data are summarized in our Ripple Rejection discussion page and in this summary graph. Ripple rejection comparison
120dBV represents 1µV and 100dBV is 10µV of ripple at the output.

Some of the individual spectra for higher frequency measurements have aliased artifacts that are "extra" to the PSRR measurement. The graphs have been modified to change the color of those elements to gray so you can focus on the peak of the ripple (such that it is). Also, some of the really great regulators have such low ripple that it is hidden by regulator noise at some frequencies.


Power Line Ripple Rejection

PSRR for good regulators is typically very high at low frequency, so to get an accurate measurement we put the regulator output through a gain of 1000 amplifier. Ripple frequency is chosen as 55Hz to make one measurement that's useful for most of the world's power line frequencies. The amplifier has a high-pass corner of 20Hz so it doesn't attenuate at 55Hz.

The choice of 55Hz also allows the ripple rejection to be visible away from the actual power line frequency of 60Hz in our lab. You can see some power line ripple that is either ground feedthrough in the test fixture or introduced in the 1000x amplifier. This can be ignored and you should focus on the voltage peak just to its left.

When comparing, be careful to notice not just the size of the peak but also its maximum on the vertical axis, because its height depends on the noise floor of the regulator. For example, the LT3045 and SPX both show -135dBV but the noise floor of the LT3045 is so low that its ripple appears to be more but it's not.


Test conditions

First, please note that we are measuring a few hundred nanovolts and this is difficult. We solved multiple problems with spurious signals and ground feed-through coming from several sources, including 60Hz added by a nearby oscilloscope, a 185Hz spike from an attached voltmeter (I have to assume that's the frequency of its internal integrator), and ground noise at the measurement frequency caused by inadequate internal grounding in several signal generators. We finally were able to use an old Wavetek Model 166 and a Tiepie HS3 that have less ground signal injection than two other generators on our bench (including the venerable HP model 200CD).

  • Vin = 16VDC/sub> + 0.5VACpk
  • Sample frequency = 2*max frequency
  • 16 bit resolution
  • 2k samples per sweep
  • 16 sweeps averaged
Any spurious unrelated voltages were colored gray, they are the result of test equipment anomalies or sampler aliasing and can be ignored.

New Belleson SPX78

SPX78 55Hz ripple rejection spectrum
135dBV

Older Belleson SPZ78

SPZ78 55Hz ripple rejection spectrum
133dBV

Texas Instruments TPS7A4700

TPS7A4700 55Hz ripple rejection spectrum
107dBV

Analog Devices LT3045

LT3045 55Hz ripple rejection spectrum
135dBV

Sparkos SS7812

Sparkos 55Hz ripple rejection spectrum
128dBV

NewClassD (Dexa) UWB2

NewClassD (Dexa) UWB2 55Hz Ripple Rejection Spectrum
65dBV


100Hz Ripple Rejection

New Belleson SPX78

SPX78 100Hz ripple rejection spectrum
131dBV [≤ noise floor]

Older Belleson SPZ78

SPZ78 100Hz ripple rejection spectrum
136dBV [≤ noise floor]

Texas Instruments TPS7A4700

TPS7A4700 100Hz ripple rejection spectrum
108dBV

Analog Devices LT3045

LT3045 100Hz ripple rejection spectrum
138dBV [≤ noise floor]

Sparkos SS7812

Sparkos 100Hz ripple rejection spectrum
130dBV [≤ noise floor]

NewClassD (Dexa) UWB2

NewClassD (Dexa) UWB2 100Hz Ripple Rejection Spectrum
67dBV


1kHz Ripple Rejection

New Belleson SPX78

SPX78 1kHz ripple rejection spectrum
130dBV

Older Belleson SPZ78

SPZ78 1kHz ripple rejection spectrum
133dBV [≤ noise floor]

Texas Instruments TPS7A4700

TPS7A4700 1kHz ripple rejection spectrum
107dBV

Analog Devices LT3045

LT3045 1kHz ripple rejection spectrum
145dBV [≤ noise floor]

Sparkos SS7812

Sparkos 1kHz ripple rejection spectrum
127dBV

NewClassD (Dexa) UWB2

NewClassD (Dexa) UWB2 1kHz Ripple Rejection Spectrum
68dBV


10kHz Ripple Rejection

New Belleson SPX78

SPX78 10kHz ripple rejection spectrum
128dBV [≤ the noise floor]

Older Belleson SPZ78

SPZ78 10kHz ripple rejection spectrum
132dBV [≤ the noise floor]

Texas Instruments TPS7A4700

TPS7A4700 10kHz ripple rejection spectrum
107dBV

Analog Devices LT3045

LT3045 10kHz ripple rejection spectrum
121dBV

Sparkos SS7812

Sparkos 10kHz ripple rejection spectrum
118dBV

NewClassD (Dexa) UWB2

NewClassD (Dexa) UWB2 10kHz Ripple Rejection Spectrum
70dBV


50kHz Ripple Rejection

New Belleson SPX78

SPX78 50kHz ripple rejection spectrum
119dBV

Older Belleson SPZ78

SPZ78 50kHz ripple rejection spectrum
104dBV

Texas Instruments TPS7A4700

TPS7A4700 50kHz ripple rejection spectrum
97dBV

Analog Devices LT3045

LT3045 50kHz ripple rejection spectrum
94dBV

Sparkos SS7812

Sparkos 50kHz ripple rejection spectrum
100dBV

NewClassD (Dexa) UWB2

NewClassD (Dexa) UWB2 50kHz Ripple Rejection Spectrum
72dBV


80kHz Ripple Rejection

New Belleson SPX78

SPX78 80kHz ripple rejection spectrum
120dBV

Older Belleson SPZ78

SPZ78 80kHz ripple rejection spectrum
95dBV

Texas Instruments TPS7A4700

TPS7A4700 80kHz ripple rejection spectrum
95dBV

Analog Devices LT3045

LT3045 80kHz ripple rejection spectrum
95dBV

Sparkos SS7812

Sparkos 80kHz ripple rejection spectrum
91dBV.

NewClassD (Dexa) UWB2

NewClassD (Dexa) UWB2 80kHz Ripple Rejection Spectrum
67dBV


Notes

Measurements are taken in the same test socket, with the same input stimulus and output sense for all devices. Measurements may differ from those you see in manufacturers' data sheets because of different setup, e.g. input or output capacitance, placement of sense device, wire lengths, etc.

The LT3045 and TPS7A4700 are both surface mount monolithic devices that require a PCB to allow them to be plugged into a TO-220 style test socket. The tested devices were, when purchased, already mounted on a PCB with MLCC capacitors connected. Replacing the MLCCs with tantalum on the TPS7A4700 PCB significantly improved performance, and the measurements you see here are with 10µF tantalum.

The king is dead,
long live the King!

SPX has replaced SPZ

  • Variable output 5V to 30V
  • World's lowest output impedance
  • Better ripple rejection (135dBV@60Hz!)
  • Faster step response
  • Same low noise
  • Same TO-220 size physical form factor
  • No thermal pad needed
Order now from our store.

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SPHP—1000 Watts for your music server!

SPHP, a 10A Superpower with adjustable output voltage from 5V to 100V

  • Same low noise
  • Same blazing step response
  • Same great ripple rejection.
Just lots more current and much higher output voltage. For sale on our order page See more information in the data sheet here.

Build a power supply

A PCB and parts list for building a compact dual positive or positive+negative power supply are on this new page.

Transformer Calculator!

Use the Belleson Transformer Calculator to calculate the minimum Vrms voltage of a transformer for your Superpower based supplies.

It's Official

We're proud to announce the U.S. Patent and Trademark Office has granted patent 8,294,440 to the Superpower design.

Use the Superpower regulator in...

  • Headphone amps
  • DACs
  • Buffers
  • Clocks and reclockers
  • Preamps
  • Microphone preamps
  • Phono stages
  • Phono motors
  • Tube preamps and input stages
  • Line powered guitar effects boxes
  • Anywhere an extremely clean, quiet, dynamic power source is needed