HMP4030/4040: Output ripple (ID #595)

The HMP series is a power supply with a very low ripple voltage. Due to the high output currents and the wide voltage ranges circuit-related disorders cannot completely avoided.

HAMEG specified in the datasheet HMP4030/4040 following values​​:

Please note that it is an indication of the voltage RMS value terms, such as used by other manufacturers.

Please also note that a very short ground connection is needed to measure the ripple voltage, otherwise the measured disturbance would be intensify by the resonant circuit behavior of the ground line. Additionally, common mode interference from the internal GND connection of the oscilloscope are measured. These disorders are irrelevant for a DC circuit.

To simulate a measurement, we have used a 350MHz oscilloscope of the series HMO.

On the first of the two screenshots you can see the test result over the measured full range. The second screenshot shows the same measurement with activated bandwidth filter of 20MHz. In this case, all disturbances over 20MHz are filtered .

Please note that the indication of the RMS voltage down below:

On the Screnshots you can see that the device is complying with the specification by enabled bandwidth limitation. Considering the data sheet specification of 20MHz, the ripple voltage is even far below the data sheet specifications.