Dynamic slope - power supply test you overlooked problem
When do the dc dc power supply response speed test, load test in the dynamic capabilities. But how to get the dynamic parameters of load up the slope and down slope?
First of all, slope is defined as the curve tangent slope itself. In other words, refers to the load switch change when the maximum speed of two state. But in waveform measurement, it’s uneasy to achieve some point slope, so the oscilloscope etc waveform measuring instruments, the slope signal generator defined as the change of the values divided by the change of time by 10% to 90% for the slope. A high-end oscilloscope will automatically help you hustle and measurement.
As the picture:
Slope error: the definition of the oscilloscope bandwidth, such as 100M, means the oscilloscope will get worse and more than 3 db attenuation if higher than 100m of signal amplitude.The probe, etc. So does the bandwidth definition. So general measure, to amplitude, slope of measurement, the error of 3 db is allowed within the scope. The frequency, time accuracy involves higher. If there is no tagging precision control of the waveform, generally the default for plus or minus 3 db, plus or minus 30%.
Slope control: the working principle of the electronic load is controlled by the DAC voltage signal to the linear conduction performance of the MOS (this work way and the control of switch power supply switch mode is difference, load using the linear MOS). General load includes two manufacturers in Taiwan, in order to save costs, will design into several fixed resistor capacitor circuit to simulate the control of the slope. This will lead to load can be achieved only a few fixed slope, generally for four. Although can be set, but within the period set in large range, no matter how to set up, the slope, the slope is not big changes.
CHONDA slope load controlled by the special slope control DAC, so to ensure the load slope is really can control. Both to ensure the precision of the normal load, and ensure the continuous adjustable slope.