Abstract: A control circuit for a switch mode power supply (SMPS) includes a power switch for coupling to a primary winding of the power supply and a startup resistor coupled to an external input voltage and to a control terminal of the power switch. The control circuit also includes a controller. During startup, the controller is configured to cause the power switch to amplify a startup current from an external input voltage through the startup resistor and provide a startup power to the controller. During normal operation, the controller is configured to provide a power switch control signal to turn on and off the power switch for controlling a current flow in the primary winding and regulating an output of the power supply. The controller is configured to provide a current signal for driving an NPN power switch and to provide a voltage signal for driving an NMOS power switch.

Abstract: A control circuit for a switch mode power supply (SMPS) includes a power switch for coupling to a primary winding of the power supply and a startup resistor coupled to an external input voltage and to a control terminal of the power switch. The control circuit also includes a controller. During startup, the controller is configured to cause the power switch to amplify a startup current from an external input voltage through the startup resistor and provide a startup power to the controller. During normal operation, the controller is configured to provide a power switch control signal to turn on and off the power switch for controlling a current flow in the primary winding and regulating an output of the power supply. The controller is configured to provide a current signal for driving an NPN power switch and to provide a voltage signal for driving an NMOS power switch.

Abstract: A control circuit for a switch mode power supply (SMPS) includes a power switch for coupling to a primary winding of the power supply and a startup resistor coupled to an external input voltage and to a control terminal of the power switch. The control circuit also includes a controller. During startup, the controller is configured to cause the power switch to amplify a startup current from an external input voltage through the startup resistor and provide a startup power to the controller. During normal operation, the controller is configured to provide a power switch control signal to turn on and off the power switch for controlling a current flow in the primary winding and regulating an output of the power supply. The controller is configured to provide a current signal for driving an NPN power switch and to provide a voltage signal for driving an NMOS power switch.

Abstract: A control circuit for a switch mode power supply (SMPS) includes a power switch for coupling to a primary winding of the power supply and a startup resistor coupled to an external input voltage and to a control terminal of the power switch. The control circuit also includes a controller. During startup, the controller is configured to cause the power switch to amplify a startup current from an external input voltage through the startup resistor and provide a startup power to the controller. During normal operation, the controller is configured to provide a power switch control signal to turn on and off the power switch for controlling a current flow in the primary winding and regulating an output of the power supply. The controller is configured to provide a current signal for driving an NPN power switch and to provide a voltage signal for driving an NMOS power switch.

Abstract: A switching mode power supply (SMPS) includes a power transistor coupled to the primary winding of transformer and a resistor coupled between the input power source and a control terminal of the power transistor for triggering a primary current flow through the power transistor for providing startup power. A primary side control circuit is configured to regulate the output of the SMPS. A secondary side control circuit is coupled to the secondary winding and being configured to provide a first electrical signal to the secondary winding when an output voltage of the SMPS is less than a first reference voltage, whereupon an awakening signal is induced in the auxiliary winding and causes the primary side control circuit to provide a turn-on signal to the power transistor. The primary side control circuit is configured to enter a standby mode or a normal operating mode in response to the awakening signal.

Abstract: A control circuit for a switch mode power supply (SMPS) includes a power switch for coupling to a primary winding of the power supply and a startup resistor coupled to an external input voltage and to a control terminal of the power switch. The control circuit also includes a controller. During startup, the controller is configured to cause the power switch to amplify a startup current from an external input voltage through the startup resistor and provide a startup power to the controller. During normal operation, the controller is configured to provide a power switch control signal to turn on and off the power switch for controlling a current flow in the primary winding and regulating an output of the power supply. The controller is configured to provide a current signal for driving an NPN power switch and to provide a voltage signal for driving an NMOS power switch.

Abstract: A switching mode power supply (SMPS) includes a power transistor coupled to the primary winding of transformer and a resistor coupled between the input power source and a control terminal of the power transistor for triggering a primary current flow through the power transistor for providing startup power. A primary side control circuit is configured to regulate the output of the SMPS. A secondary side control circuit is coupled to the secondary winding and being configured to provide a first electrical signal to the secondary winding when an output voltage of the SMPS is less than a first reference voltage, whereupon an awakening signal is induced in the auxiliary winding and causes the primary side control circuit to provide a turn-on signal to the power transistor. The primary side control circuit is configured to enter a standby mode or a normal operating mode in response to the awakening signal.

Abstract: A calibrator circuit and method for VCOM voltage adjustment for an LCD includes using integrated programmable resistive arrays. The method uses two DACs and three integrated circuit arrays to provide all of the advantages of VCOM calibrator circuits using external resistive voltage-dividers. The integrated circuit resistor arrays reduce the number of external components and PCB space. The method used is suitable for higher resolution adjustment of the VCOM voltage and no calculation is required in the whole adjustment procedure, which saves labor cost, time and enables automation of the calibrator fabrication.

Abstract: A calibrator circuit and method for VCOM voltage adjustment for an LCD includes using integrated programmable resistive arrays. The method uses two DACs and three integrated circuit arrays to provide all of the advantages of VCOM calibrator circuits using external resistive voltage-dividers. The integrated circuit resistor arrays reduce the number of external components and PCB space. The method used is suitable for higher resolution adjustment of the VCOM voltage and no calculation is required in the whole adjustment procedure, which saves labor cost, time and enables automation of the calibrator fabrication.