摘要 |
A cost-effective driver circuit for an LED background lighting unit includes a buck circuit with an upper transistor is driven via two further transistors. The first transistor is connected with its reference electrode to the positive terminal of a DC voltage source, with its working electrode to the control electrode of the buck transistor and with its control electrode, via a capacitor, to a signal contact, which can be driven externally. The second transistor is connected with its reference electrode to ground, with its working electrode to the control electrode of the buck transistor and with its control electrode to a signal contact, which can be driven externally. The buck transistor can be switched on via a corresponding gate signal at the terminal for the purpose of operating the light-emitting diodes. Advantageously, cost-effective standard transistors for operating voltages below 100 V can be used for the switching controller. |