Disclosed is a multi-stage charge pump. A first stage is controlled by a first clock signal. A second stage is controlled by a second clock signal, which has high and low states that are shifted relative to the high and low states of the first clock signal. The high and low states of the second clock signal can be higher than the high and low states, respectively, of the first clock signal for a positive charge pump and vice versa for a negative charge pump. Any additional stage is similarly controlled by an additional clock signal that is shifted with respect to the clock signal controlling the immediately preceding stage. By shifting the high and low states of clock signals controlling downstream stages, the need for series-connected or high voltage capacitors in the downstream stages is eliminated and circuit complexity and area consumption are reduced.

In an embodiment, a voltage multiplier comprises an input node, an output node, and first and second control nodes for receiving first and second clock signals defining two commutation states. An ordered sequence of intermediate nodes is coupled between the input and output nodes and includes two ordered sub-sequences. Capacitors are coupled: between each odd intermediate node in the first sub-sequence and the first control node; between each even intermediate node in the first sub-sequence and the second control node; between each odd intermediate node in the second sub-sequence and a corresponding odd intermediate node in the first sub-sequence; and between each even intermediate node in the second sub-sequence and a corresponding even intermediate node in the first sub-sequence. The circuit comprises selectively conductive electronic components coupled to the intermediate nodes.

A drive device for driving a load includes: an inverter unit having an upper arm element and a lower arm element and converting electric power supplied to the load; and a charge pump circuit that supplies a gate voltage to the upper arm element. An output voltage of the charge pump circuit is variable according to an inverter input voltage input from an inverter input wiring to a high potential side of the inverter unit.

Charge pump stages are coupled between flying capacitor pairs and arranged in a cascaded between a bottom voltage line and an output voltage line. Gain stages apply pump phase signals having a certain amplitude to the charge pump stages via the flying capacitors. A feedback signal path from the output voltage line to the bottom voltage line applies a feedback control signal to the bottom voltage line. Power supply for the gain stages is provided by a voltage of the feedback control signal in order to control the amplitude of the pump phase signals. An asynchronous logic circuit generates the switching drive signals for the gain stages with a certain switching frequency which is a function of a logic supply voltage derived from the voltage of the feedback control signal.

A charge pump circuit is provided. The charge pump circuit includes a dual-phase charge pump, a first load switch, a second load switch, and a control circuit. The dual-phase charge pump performs a voltage pumping operation on a power source in response to a first clock and a second clock to generate a first pumping voltage at a first node and a second pumping voltage at a second node. The control circuit controls the first load switch in response to a third clock and controls the second load switch in response to a fourth clock. In a period during which the first load switch is turned off, the second load switch transfers the first pumping voltage to an output terminal of the charge pump circuit. In a period during which the second load switch is turned off, the first load switch transfers the second pumping voltage to the output terminal.

The charge pump circuit includes multiple boosting stages, and each stage includes following units. A first switch circuit is controlled by a first clock signal to couple a second terminal of a first capacitor to a first input terminal or a second input terminal. A third switch circuit is controlled by a second clock signal to couple a second terminal of a second capacitor to the first input terminal or the second input terminal. A second switch circuit is controlled by electric potentials on the second capacitor to couple a first terminal of the first capacitor to the first input terminal or an output terminal. The fourth switch circuit is controlled by electric potentials on the first capacitor to couple a first terminal of the second capacitor to the first input terminal or the output terminal.

A fingerprint sensing system comprising a device connection interface including a device reference potential input, a sensing arrangement, and sensing reference potential providing circuitry. The sensing arrangement includes multiple sensing structures and read-out circuitry connected to each of the sensing structures. The sensing reference potential providing circuitry provides a sensing reference potential to the sensing arrangement in the form of a sensing reference signal alternating between a first sensing reference potential and a second sensing reference potential, and comprises a first capacitor; a second capacitor; charging circuitry; and switching circuitry for alternatingly switching the sensing reference potential providing circuitry between a first state in which the first capacitor and the second capacitor are connected in parallel to the charging circuitry; and a second state in which the first capacitor and the second capacitor, when charged, are connected in series between the device reference potential input and the sensing arrangement.

A circuit includes a current controller oscillator generating a CCO output signal at a CCO output, a charge pump boosting a supply voltage based on the CCO output signal and producing a charge pump output voltage at an output, and a current sensing circuit sensing load current at the output and generating a feedback signal having a magnitude that varies with the sensed load current if a magnitude of the sensed load current is between lower and upper load current thresholds. A frequency of the CCO output signal is constant at a lower frequency threshold where the sensed load current is below the lower load current threshold, asymptomically rises to an upper frequency threshold where the sensed load current is above the upper load current threshold, and is proportional to the feedback signal where the sensed load current is between the lower and upper load current thresholds.

A charge pump includes an intermediate node capacitively coupled to receive a first clock signal oscillating between a ground and positive supply voltage, the intermediate node generating a first signal oscillating between a first and second voltage. A level shifting circuit shifts the first signal in response to a second clock signal to generate a second signal oscillating between first and third voltages. A CMOS switching circuit includes a first transistor having a source coupled to an input, a second transistor having a source coupled to an output and a gate coupled to receive the second signal. A common drain of the CMOS switching circuit is capacitively coupled to receive the first clock signal. When positively pumping, the first voltage is twice the second voltage and the third voltage is ground. When negatively pumping, the first and third voltages are of opposite polarity and the second voltage is ground.

Charge pump stages are coupled between flying capacitor pairs and arranged in a cascaded between a bottom voltage line and an output voltage line. Gain stages apply pump phase signals having a certain amplitude to the charge pump stages via the flying capacitors. A feedback signal path from the output voltage line to the bottom voltage line applies a feedback control signal to the bottom voltage line. Power supply for the gain stages is provided by a voltage of the feedback control signal in order to control the amplitude of the pump phase signals. An asynchronous logic circuit generates the switching drive signals for the gain stages with a certain switching frequency which is a function of a logic supply voltage derived from the voltage of the feedback control signal.