Performance of UniversalStepdown 5V version

This page provides evaluation of RB0005 – UniversalStepdown shown in the photo below:

You can use the step-down regulator with input voltage up to 18 V. Without an active cooling the step-down is able to deliver 3 A continuously on the output. The step-down shows a voltage drop on the output when it is loaded with 4 A continuously. This is probably caused by a high die temperature inside the driver IC which leads to a shift in the internal voltage reference. Once you introduce extra cooling, it can deliver over 4 A continuously. We do not recommend to source more than 4 A continuously as higher currents trigger the internal over-temperature protection leading to a regulator shut-down.

The ripple on the output is less than 100 mV peak-to-peak in the worst case. In loads less than 2 A the output ripple is less than 50 mV.

The voltage drop on the step-down is 420 mV under 100 mA load. When the load increases to 4 A the drop increases to 900 mV.

You can examine our test setup in the bottom of the page.

RB0005 – UniversalStepdown properties

The following tables provides raw data from testing the step-down converter. Please note that the oscilloscope screenshots can differ in voltage per division.

The chip and coil temperature was measured by a K-type thermocoupler after 5 minutes of operation for a 1 minute. In one of the cases the temperature did not rise, therefore, the measurement should reflect conditions during continuous operation.

Parameters for input voltage 14.0 V

Load Output voltage Output ripple Input current Temperature chip, coil Output voltage waveform
0.1 A 5.03 V 80 mV 0.04 A 22 °C, 23°C waveform
0.5 A 5.03 V 50 mV 0.19 A 26 °C, 28°C waveform
1 A 5.03 V 90 mV 0.38 A 31 °C, 35°C waveform
2 A 5.03 V 110 mV 0.77 A 40 °C, 45°C waveform
3 A 4.97 V 140 mV 1.16 A 50 °C, 65°C waveform
4 A 4.74 V 70 mV 1.5 A 83 °C, 93°C waveform

Parameters for input voltage 7.4 V

Load Output voltage Output ripple Input current Temperature chip, coil Output voltage waveform
0.1 A 5.03 V 60 mV 0.07 A 22 °C, 23°C waveform
0.5 A 5.03 V 60 mV 0.35 A 24 °C, 26°C waveform
1 A 5.03 V 70 mV 0.7 A 28 °C, 29°C waveform
2 A 5.05 V 60 mV 1.43 A 33 °C, 36°C waveform
3 A 5.07 V 70 mV 2.22 A 45 °C, 51°C waveform
4 A 5.01 V 80 mV 3.04 A 65 °C, 84°C waveform


Measurement setup

The measurements above were taken in an ambient temperature 24°C using the following equipment: