AN1344

Thermal consideration

11/14

5

Thermal consideration

Temperature measurement was taken at room ambient of 24 °C, convection air-cooled

Results may vary depending on final application.

6

Overcurrent limiting

This power supply was designed for an audio application where music peaks can exceed

the maximum current of the power supply. In a sound entertainment system it is imperative

for the power supply to not shut down during such peaks. It is acceptable for the voltage to

decrease as the current increases. This maintains constant power for the unit. Under a short

circuit condition, this unit cycles on and off or "hiccup mode". In Figure 8 the output voltage

versus the output current is shown. Maximum output power reached is 163 W. The

VIPer100A-E also has thermal shutdown with hysteresis that is located close to the Power

MOSFET portion of the die, which protects it from exceeding the temperature limit of the I.C.

Figure 8.

Output voltage versus the output

current

Figure 9.

Transient Response 50% step

change

Figure 10.

Output Ripple

Figure 11.

EMI measurement