AN2495 datasheet(22/36 Pages) STMICROELECTRONICS

22 / 36 page

Efficiency, waveforms and experimental results

AN2495

22/36

Doc ID 13127 Rev 5

Efficiency, waveforms and experimental results

Overall efficiency variation versus output power is illustrated in Figure 9 for two different

values of input voltage.

Figure 9.

Overall efficiency versus output power for two different values of input

voltage

It is worth noting that with low input voltage (red curve), total efficiency is over 80%, and at

medium and high load working conditions, reaching almost 85%. Efficiency decreases with

input voltage. However, it is above 75% at loads higher than 30% even with maximum input

voltage.

Theoretical assumptions made so far have been validated with the use of a demonstration

board. A complete description of this board has been carried out and the most meaningful

waveforms in any working condition are shown in Figure 10 through Figure 15.

Figure 10, Figure 11 and Figure 12 show the prototype steady state behavior, by indicating

the gate voltage (blue waveform), the base current (violet waveform) and the collector

voltage (sky blue waveform) at maximum load for different input voltages.

AN2495 Datasheet(PDF) 22 Page - STMicroelectronics