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

Figures

Measurement setup

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