Abstract: A single-ended operational amplifier includes an output stage, a first transconductance amplifier and a second transconductance amplifier. In an offset cancellation mode, two inputs of the first transconductance amplifier are supplied with a reference voltage to sink two currents from two inputs of the output stage respectively, the output stage generates a third current according to the difference between the two currents to charge a capacitor, and the second transconductance amplifier generates two currents according to the voltage in the capacitor to make currents in the two inputs of the output stage equal to each other, thereby canceling the offset of the single-ended operational amplifier.

Abstract: For efficiency improvement of a LED display system including a charge pump and a LED connected to either the voltage input terminal or the voltage output terminal of the charge pump, either one or both of two current regulators are enabled according to a voltage detected from the LED, for establishing a driving current for the LED. When the detected voltage is higher than a threshold, the first one of the current sources is enabled sole. When the detected voltage is lower than the threshold, the second one of the current sources is enabled sole, or both the current sources are enabled, or the current sources are alternatively enabled.

Abstract: The present invention discloses a single-wire transmission interface, and a method of transmission through single-wire. The method comprises: providing a single-wire signal through a single-wire; and transmitting information only in a transmission period defined by a fixed first time period starting from one of a rising or a falling edge of the single-wire signal.

Abstract: The present invention discloses a charge pump down circuit which comprises three capacitors operating in three time phases. In the first time phase, the total of the voltages across the three capacitors is equal to an input voltage; in the second time phase, the voltage across the second capacitor is equal to the voltage across the third capacitor; in the third time phase, the difference between the voltages across the first and the second capacitors is equal to the voltage across the third capacitor, wherein the voltage across the third capacitor is the output voltage of the charge pump down circuit.

Abstract: A non-synchronous boost converter includes a low-voltage device connected between the input voltage terminal and the output voltage terminal of the converter. When the converter is shutdown, the low-voltage device disconnects the output voltage terminal and the input voltage terminal. Since it is a low-voltage device used in the converter for load disconnection, the efficiency of the converter is improved with lower cost.

Abstract: The present invention discloses a charge pump down circuit which comprises three capacitors operating in three time phases. In the first time phase, the total of the voltages across the three capacitors is equal to an input voltage; in the second time phase, the voltage across the second capacitor is equal to the voltage across the third capacitor; in the third time phase, the difference between the voltages across the first and the second capacitors is equal to the voltage across the third capacitor, wherein the voltage across the third capacitor is the output voltage of the charge pump down circuit.

Abstract: A current regulator includes a first current source to provide a reference current varying with a dimming step, and a second current source to generate a drive current for a white LED according to the reference current. The reference current and the dimming step have a relationship identical to or approximating a relationship between luminance and lightness perceived by human eyes. Thus, the white LED is controlled to have a linear variation of the luminance perceived by human eyes when the dimming step is changed.

Abstract: A single-ended operational amplifier includes an output stage, a first transconductance amplifier and a second transconductance amplifier. In an offset cancellation mode, two inputs of the first transconductance amplifier are supplied with a reference voltage to sink two currents from two inputs of the output stage respectively, the output stage generates a third current according to the difference between the two currents to charge a capacitor, and the second transconductance amplifier generates two currents according to the voltage in the capacitor to make currents in the two inputs of the output stage equal to each other, thereby canceling the offset of the single-ended operational amplifier.

Abstract: A low noise multiphase charge pump comprises a plurality of capacitors and a plurality of switches configured as a network, the switches are so switched that the charge pump operates in at least three phases by turns, and the operational durations and the operational currents of the phases are preferably balanced, so as to reduce the noise of the charge pump.

Abstract: Fluid injection devices comprise M sets of fluid injection units. Each fluid injection unit comprises N injectors separately connecting to a driver. A controller separately transmits a signal to the driver, thereby simultaneously driving a selected injector of each of the M sets of fluid injection units. A non-selected injector of each of the M sets of fluid injection units does not trigger bipolar junction transistors (BJTs).

Abstract: The phase node voltage or the PWM signal in an asynchronous boost converter is monitored to detect a phase node voltage ringing. When a phase node voltage ringing is detected, a detection signal is asserted to establish a bypass path to bypass the inductor of the converter. A charge bypass circuit is shunt to the inductor, and controlled by the detection signal to establish the bypass path. Due to the bypass path, the phase node voltage is maintained at a constant, and the phase node voltage radiation and input/output noise are eliminated.

Abstract: A mode transition control method and circuit switch a charge pump to an operating mode with lower conversion ratio at a regular interval when the input voltage of the charge pump is detected close to a mode transition point, so as to prevent from misjudgment on the mode transition of the charge pump due to external noise, loading change, or inaccurate equivalent resistance of the charge pump.

Abstract: A charge pump regulator has a charge pump to establish a charge path and a discharge path alternately, so as to produce a regulated voltage on an output terminal. The charge pump has at least a current control element on the charge path or the discharge path to control the current flowing therethrough according to an output-dependent feedback signal.

Abstract: A dimming method for LED driving circuit is proposed. By temporary switching a pin that is originally used for the input/output of other electric signals to a high impedance node, the dimming control signal may be inputted to dim LEDs. The dimming method comprises the steps of: floating the pin every a period of time to pull the pin's voltage being equal to the dimming control signal; detecting the pin's voltage; and retrieving the dimming control signal in accordance with the detected pin's voltage and thereafter dimming the LEDs.

Abstract: A mode transition control method and circuit switch a charge pump to an operating mode with lower conversion ratio at a regular interval when the input voltage of the charge pump is detected close to a mode transition point, so as to prevent from misjudgment on the mode transition of the charge pump due to external noise, loading change, or inaccurate equivalent resistance of the charge pump.

Abstract: A low noise multiphase charge pump comprises a plurality of capacitors and a plurality of switches configured as a network, the switches are so switched that the charge pump operates in at least three phases by turns, and the operational durations and the operational currents of the phases are preferably balanced, so as to reduce the noise of the charge pump.

Abstract: A dimming method for LED driving circuit is proposed. By temporary switching a pin that is originally used for the input/output of other electric signals to a high impedance node, the dimming control signal may be inputted to dim LEDs. The dimming method comprises the steps of: floating the pin every a period of time to pull the pin's voltage being equal to the dimming control signal; detecting the pin's voltage; and retrieving the dimming control signal in accordance with the detected pin's voltage and thereafter dimming the LEDs.

Abstract: A dimming method for LED driving circuit is proposed. By temporary switching a pin that is originally used for the input/output of other electric signals to a high impedance node, the dimming control signal may be inputted to dim LEDs. The dimming method comprises the steps of: floating the pin every a period of time to pull the pin's voltage being equal to the dimming control signal; detecting the pin's voltage; and retrieving the dimming control signal in accordance with the detected pin's voltage and thereafter dimming the LEDs.

Abstract: A fluid jet head with driving circuit of a heater set. A first and a second primary transistor are coupled to a first and a second heater. When the first primary transistor is turned on under control of a first control voltage and a first current is generated flowing through the first heater, the first primary transistor, and the first current path, then the first primary transistor has a first primary equivalent resistance corresponding to the first control voltage. When the second primary transistor is turned on under control of a second control voltage, and a second current is generated flowing through the second heater, the second primary transistor, and a second current path, then the second primary transistor has a second primary equivalent resistance corresponding to the second control voltage. Therefore, the thermal energy generated by the first heater is substantially equal to that generated by the second heater.

Abstract: Fluid injection devices comprise M sets of fluid injection units. Each fluid injection unit comprises N injectors separately connecting to a driver. A controller separately transmits a signal to the driver, thereby simultaneously driving a selected injector of each of the M sets of fluid injection units. A non-selected injector of each of the M sets of fluid injection units does not trigger bipolar junction transistors (BJTs).