Universal input-voltage-compatible switched-mode power supply

A switched-mode power supply (SMPS), comprising:

• a direct current (DC)-to-DC step-down converter having an input terminal, a positive output terminal, and a negative output terminal, the DC-to-DC step-down converter being:
• configured for operation in a boundary conduction mode;
• and configured for receiving a DC input current having an input voltage at the input terminal;
• and configured for causing a DC output current having an output voltage to flow from the positive output terminal through an output load to the negative output terminal;
• and configured for being integrated with a controller including a transistor having a channel being coupled between a cathode and an anode, the anode being coupled with a grounded current sense resistor, the controller being configured for applying a pulse-width-modulated voltage to the channel of the transistor for controlling a duty cycle of the DC output current, the duty cycle having an on-time period (T-On) and an off-time period (T-Off), the controller being coupled with a T-On capacitor having a T-On voltage, the controller being configured for charging the T-On capacitor during the T-On period by a regulated T-On current for setting a maximum limit of the T-On period, the controller being configured for initiating the T-Off period when the T-On capacitor becomes charged to a selected maximum limit of the T-On voltage;
• a voltage divider being coupled with the input terminal for receiving the input voltage and for reducing the input voltage to a signal voltage being within a selected voltage signal range;
• a voltage-to-current converter having a connection with the voltage divider, the voltage-to-current converter including another output terminal being coupled with another transistor having another channel being coupled between another cathode and another anode, the voltage-to-current converter including a grounded precision resistor configured for generating a transconductance voltage, the voltage-to-current converter being configured for inputting the signal voltage and for outputting an error correction voltage being applied to the another channel for generating a signal current appearing at the another anode and defining a transconductance of the voltage-to-current converter and having a current signal value being within a selected current signal range representing the selected voltage signal range;
• and
• a current mirror being coupled with the another cathode and being configured for receiving and combining a regulated supply current having a supply voltage together with the signal current as forming a T-On modulation current, with the current mirror being configured for causing the T-On modulation current to be combined with the regulated T-On current to charge the T-On capacitor.

A switched-mode power supply (SMPS) integrated circuit, comprising:

• a direct current (DC)-to-DC step-down converter, a switch, and an element being configured for storage of potential energy in an electric field and having a T-On voltage;
• wherein the SMPS is configured to receive a DC input current having an input voltage and to output, through an output load, a DC output current having an output voltage;
• wherein the SMPS is configured to operate in a boundary conduction mode by applying a pulse-width-modulated voltage to the switch for controlling a duty cycle of the DC output current, the duty cycle having an on-time period (T-On) and an off-time period (T-Off);
• wherein the SMPS is configured to generate a regulated T-On current for setting a maximum limit of the on-time period (T-On) of the duty cycle;
• wherein the SMPS is configured to monitor the input voltage by reducing the input voltage to a signal voltage being within a selected voltage signal range;
• wherein the SMPS is configured to convert the signal voltage to a signal current having a current signal value being within a selected current signal range representing the selected voltage signal range;
• wherein the SMPS is configured to output a T-On modulation current including the signal current;
• wherein the SMPS is configured to combine together the T-On modulation current with the regulated T-On current during the T-On period to store potential energy in the element, while causing the SMPS to monitor the T-On voltage of the element;
• and
• wherein the SMPS is configured to initiate the T-Off period when the potential energy stored in the element reaches a selected maximum limit of the T-On voltage.

A method of operating a switched-mode power supply (SMPS), comprising:

• providing an SMPS including a direct current (DC)-to-DC step-down converter, a switch, and an element being configured for storage of potential energy in an electric field and having a T-On voltage;
• causing the SMPS to receive a DC input current having an input voltage and to output, through an output load, a DC output current having an output voltage;
• causing the SMPS to operate in a boundary conduction mode by applying a pulse-width-modulated voltage to the switch for controlling a duty cycle of the DC output current, the duty cycle having an on-time period (T-On) and an off-time period (T-Off);
• causing the SMPS to generate a regulated T-On current for setting a maximum limit of the on-time period (T-On) of the duty cycle;
• causing the SMPS to monitor the input voltage by reducing the input voltage to a signal voltage being within a selected voltage signal range;
• causing the SMPS to convert the signal voltage to a signal current having a current signal value being within a selected current signal range representing the selected voltage signal range;
• causing the SMPS to output a T-On modulation current including the signal current;
• causing the SMPS to combine together the T-On modulation current with the regulated T-On current during the T-On period to store potential energy in the element, while causing the SMPS to monitor the T-On voltage of the element;
• and
• causing the SMPS to initiate the T-Off period when the potential energy stored in the element reaches a selected maximum limit of the T-On voltage.

A switched-mode power supply (SMPS) integrated circuit, comprising:

• a direct current (DC)-to-DC step-down converter, a switch, and an element being configured for storage of potential energy in an electric field and having a T-On voltage;
• wherein the SMPS is configured to receive a DC input current having an input voltage and to output, through an output load, a DC output current having an output voltage;
• wherein the SMPS is configured to operate in a boundary conduction mode by applying a pulse-width-modulated voltage to the switch for controlling a duty cycle of the DC output current, the duty cycle having an on-time period (T-On) and an off-time period (T-Off), the SMPS setting a maximum T-On voltage of the element;
• wherein the SMPS is configured to monitor the input voltage by reducing the input voltage to a signal voltage being within a selected voltage signal range;
• wherein the SMPS is configured to convert the signal voltage to a signal current having a current signal value being within a selected current signal range representing the selected voltage signal range;
• wherein the SMPS is configured to generate a T-On current having an amperage taking into account the current signal value to set the on-time period (T-On) of the duty cycle;
• wherein the SMPS is configured for causing the T-On current to store potential energy in the element during the T-On period, while causing the SMPS to monitor the T-On voltage of the element;
• and
• wherein the SMPS is configured to initiate the T-Off period when the potential energy stored in the element reaches the maximum T-On voltage.

A switched-mode power supply (SMPS) integrated circuit, comprising:

• a direct current (DC)-to-DC step-down converter, a switch, and an element being configured for storage of potential energy in an electric field and having a T-On voltage;
• wherein the SMPS is configured to receive a DC input current having an input voltage and to output, through an output load, a DC output current having an output voltage;
• wherein the SMPS is configured to operate in a boundary conduction mode by applying a pulse-width-modulated voltage to the switch for controlling a duty cycle of the DC output current, the duty cycle having an on-time period (T-On) and an off-time period (T-Off);
• wherein the SMPS is configured for causing a T-On current to store potential energy in the element during the T-On period while monitoring a T-On voltage of the element;
• wherein the SMPS is configured to monitor the input voltage by reducing the input voltage to a signal voltage being within a selected voltage signal range;
• wherein the SMPS is configured to set a maximum T-On voltage taking into account the signal voltage;
• and
• wherein the SMPS is configured to initiate the T-Off period when the potential energy stored in the element reaches the maximum T-On voltage.