Direct drive led lighting

A direct drive LED lighting circuit comprising:

• a LED current control circuit with a power switching device;
• a current sensing device, an averaging circuit, and a three input error amplifier;
• wherein
• the power switching device with a control terminal to control the amount of current flowing through the switching channel, a current inflow terminal and a current outflow terminal as the positive channel terminal and the negative channel terminal of the power switching device respectively;
• and
• a current sensing device for sensing the current flowing through the power switching device is connecting between the negative channel terminal of the power switching device and the reference node (lowest voltage) of the control circuit. The output of the current sensing circuit (or negative channel terminal of the power switching device for particular implementation) is also connecting to the input of an averaging circuit;
• and
• the averaging circuit with an input connected to the output of the current sensing device, and an output connected to one of the inputs of a three input error amplifier;
• and
• the three input error amplifier with the output of the averaging circuit as one of the inputs, and reference voltage serving for setting of an average LED current as another input, and phase (or instantaneous voltage) information of the rectified AC as the third input for instantaneous AC current waveform shaping, and an output connected to the control terminal of the power switching device, and
• a LED chain circuit by connecting several LEDs in series with a capacitor connecting in parallel with the series of LEDs, with a current flowing in terminal as a positive terminal, and a current leaving terminal as a negative terminal;
• the LED chain circuit and the LED current control circuit are connecting in series and the whole circuit is connected between the positive and negative terminals of a rectified AC power source.