Abstract: An apparatus, such as a Buck converter system, for generating an output voltage while at the same time monitoring whether an overload or over current condition occurs at the output, and protecting the system if the overload or over current condition occurs. The apparatus includes a first circuit adapted to monotonically change a control voltage from a first voltage (e.g., approximately ground potential) towards a second voltage (e.g., a reference voltage VREF); a second circuit adapted to generate the output voltage based on the control voltage; a third circuit adapted to detect whether a magnitude of an output current exceeds a current threshold; and a fourth circuit adapted to change the control voltage from the second voltage towards the first voltage in response to the third circuit detecting that the magnitude of the output current exceeds the current threshold.

Abstract: An LED driver circuit and method are disclosed where a plurality of arrays of light emitting diodes each have a transistor connected to each respective array of light emitting diodes. A PWM controller has an input for receiving a voltage reference and an output connected to selected transistors for driving the selected transistors and setting a PWM duty cycle for the selected arrays of light emitting diodes to determine the brightness of selected light emitting diodes. An oscillator is connected to the PWM controller for driving the PWM controller.

Abstract: A synchronous rectifier circuit operates as a high-efficiency DC/DC converter for mixed step-up/step-down applications, and includes an input terminal receiving a voltage signal, a second input terminal node connected to an external inductor, and an output terminal. A power switch may be connected between the second input terminal node and the output terminal to generate on its output a voltage at one terminal of the inductor. A driver circuit is provided for driving the power switch, and a comparator senses the potential difference between the output and input terminals and produces an enable signal for the driver circuit. The comparator may be a wide pass-band comparator forcing prompt triggering of the regulation loop in the rectifier.

Abstract: An LED driver circuit and method are disclosed where an array of light emitting diodes have a transistor connected to each respective array of light emitting diodes. A PWM controller has an input for receiving a voltage reference and an output connected to selected transistors for driving selected transistors and setting a PWM duty cycle for the selected arrays of light emitting diodes to determine the brightness of selected light emitting diodes. An oscillator is connected to the PWM controller for driving the PWM controller.

Abstract: An LED driver circuit and method are disclosed where an array of light emitting diodes have a transistor connected to each respective array of light emitting diodes. A PWM controller has an input for receiving a voltage reference and an output connected to selected transistors for driving selected transistors and setting a PWM duty cycle for the selected arrays of light emitting diodes to determine the brightness of selected light emitting diodes. An oscillator is connected to the PWM controller for driving the PWM controller.

Abstract: A comparator circuit for positive and negative signals having zero consumption and suitable for devices with a single positive power supply includes a first and second comparator connected in parallel and receiving a common input signal and, respectively, a first positive threshold voltage and a second negative threshold voltage. The comparator circuit further includes a first logic circuit cascade-connected to the first and second comparators. The first and second comparators are respectively suitable to detect the crossing on the part of the input signal of the first and second threshold voltages. The second comparator is provided by n-channel and p-channel MOS transistors of the enhancement type. The comparator circuit also includes a second logic circuit cascade-connected to the first logic circuit, and a monostable circuit connected to the second logic circuit.

Abstract: Presented is a low-voltage automatic lock-up biasing circuit with input terminals that accept input voltages, and with an internal node coupled to both input terminals an which takes take the highest of the voltage values applied to the input terminals. This circuit uses a comparator having respective inputs connected to the input terminals and with an output connected to a level shifter. Outputs of the level shifter are coupled to respective enable elements connected between each input terminal and the internal node. The enable elements are driven each by a respective output of the level shifter.

Abstract: Presented is a DC/DC converting circuit adapted to convert a DC input voltage to a DC output voltage. The converting circuit uses, as its synchronous rectifier member, a PMOS bipolar power transistor of the PMOS type, and allows it to be turned on by a control logic circuit capable of quickly sensing automatically the difference in electric potential between a conduction terminal and the body terminal of the transistor.

Abstract: A step-up continuous-mode DC-to-DC converter with integrated current control, comprising a comparator for comparing a voltage signal output from the converter and a reference signal for generating an error signal and circuitry for generating a compensation ramp which generates a ramp signal which is added to a signal which is proportional to a current ramp that flows across the converter. The signal output from the comparator and the signal obtained from the sum are sent to an additional comparator, the output whereof, together with an oscillator signal, is used for driving a power transistor of the converter.

Abstract: A DC/DC conversion circuit, adapted to convert a DC input voltage to a DC output voltage, employs a PNP type of bipolar power transistor as a synchronous rectifier element, to allow power-on through a simplified control circuitry capable of sensing, automatically and at a high speed, the difference of potential across the switch. This approach allows power to be transferred from the input to the output unilaterally, while automatically controlling the depth of saturation of the power transistor and regulating its base current.

Abstract: A voltage booster circuit including a pull-up capacitor connected to the supply line via a PMOS switching transistor. The other terminal of the pull-up capacitor is supplied with a pull-up voltage switching between a first value determining charging of the capacitor, and a second value higher than the first and determining pull-up of the capacitor. A negative voltage source presents an output connected to the control terminal of a switch transistor, and generates a negative voltage of a value lower than the first pull-up voltage value when charging the capacitor, so as to saturate the switch transistor and charge the capacitor to a voltage close to the supply voltage.