A constant voltage generator circuit is provided with an operational amplifier including a feedback circuit having a first resistor, and an output transistor. The operational amplifier generates a feedback voltage generated by dividing an output voltage between an output terminal and a substrate voltage potential of the constant voltage generator circuit by the first resistor and a second resistor. Then, the operational amplifier is configured to amplify a voltage potential difference between a predetermined reference voltage and the feedback voltage and to output a control voltage. The output transistor controls an output voltage based on the control voltage from the operational amplifier, and the feedback circuit is further configured to superimpose high-frequency noise components from the substrate voltage potential onto the feedback voltage.

Power supply noise reduction methods and low drop out (LDO) voltage regulators with capacitively coupled supply noise-reducing components are disclosed. One illustrative voltage regulator includes: a pass transistor having an n-type conduction channel that couples a supply voltage to an output node; an operational amplifier that derives a control signal for the pass transistor from a difference between a reference voltage and a scaled or unscaled voltage of the output node, the control signal being supplied to a gate or base of the pass transistor; a buffer that derives a ripple cancellation signal from the supply voltage; and a coupling capacitor that couples the buffer to the base or gate of the pass transistor to impose the ripple cancellation signal on the control signal.

A constant voltage generator circuit is provided with an operational amplifier including a feedback circuit having a first resistor, and an output transistor. The operational amplifier generates a feedback voltage generated by dividing an output voltage between an output terminal and a substrate voltage potential of the constant voltage generator circuit by the first resistor and a second resistor. Then, the operational amplifier is configured to amplify a voltage potential difference between a predetermined reference voltage and the feedback voltage and to output a control voltage. The output transistor controls an output voltage based on the control voltage from the operational amplifier, and the feedback circuit is further configured to superimpose high-frequency noise components from the substrate voltage potential onto the feedback voltage.

A circuit for parameter PSRR measurement includes a filter, a first regulator and a second regulator. The filter may be configured for receiving an AC input signal and a DC input signal, and for outputting a combined output signal according to the AC input signal and the DC input signal. The first regulator may be configured for receiving the combined output signal, and for outputting a first output signal having a first AC component signal and a first DC component signal. The second regulator may be configured for receiving the first output signal, and for outputting a second output signal having a second AC component signal and a second DC component signal. A parameter PSRR of the second regulator may be obtained according to the first AC component signal and the second AC component signal.

Disclosed herein is a voltage regulator having a capacitive feed-forward ripple cancellation circuit, which includes a pass unit configured to transfer, in response to a control signal, an input voltage provided from an input terminal to an output voltage of an output terminal, an error amplification unit configured to output a comparison signal on the basis of a magnitude comparison result between the output voltage and a reference voltage, and a capacitive feed-forward ripple cancellation unit configured to remove a ripple included in the input voltage using the reference voltage and the comparison signal in order to generate the control signal. In accordance with the present invention, a circuit capable of removing power supply noise while consuming a low quiescent current through a capacitive feed-forward ripple cancellation technique can be provided.

A constant voltage generator circuit is provided with an operational amplifier including a feedback circuit having a first resistor, and an output transistor. The operational amplifier generates a feedback voltage generated by dividing an output voltage between an output terminal and a substrate voltage potential of the constant voltage generator circuit by the first resistor and a second resistor. Then, the operational amplifier is configured to amplify a voltage potential difference between a predetermined reference voltage and the feedback voltage and to output a control voltage. The output transistor controls an output voltage based on the control voltage from the operational amplifier, and the feedback circuit is further configured to superimpose high-frequency noise components from the substrate voltage potential onto the feedback voltage.

For example, a linear power supply includes an output transistor connected between an input terminal of an input voltage and an output terminal of an output voltage, an internal power supply configured to step down the input voltage to generate a predetermined internal power supply voltage, a reference voltage generator configured to generate a predetermined reference voltage from the internal power supply voltage, an amplifier configured to generate a drive signal for the output transistor such that a feedback voltage in accordance with the output voltage is equal to the reference voltage, a drive current generator configured to generate a drive current for the amplifier, and a drive current controller configured to detect a variation of the internal power supply voltage to variably control the drive current.

A technique is provided that reduces dullness of a potential provided to a line such as gate line on an active-matrix substrate to enable driving the line at high speed and, at the same time, reduces the size of the picture frame region. On an active-matrix substrate (20a) are provided gate lines (13G) and source lines. On the active-matrix substrate (20a) are further provided: gate drivers (11) each including a plurality of switching elements, at least one of which is located in a pixel region, for supplying a scan signal to a gate line (13G); and lines (15L1) each for supplying a control signal to the associated gate driver (11). A control signal is supplied by a display control circuit (4) located outside the display region to the gate drivers (11) via the lines (15L1). In response to a control signal supplied, each gate driver (11) drives the gate line (13G) to which it is connected.

Embodiments of the present disclosure describe methods, apparatuses, and systems for hybrid low dropout regulator (LDO) architecture and realization to provide high power supply rejection ratio (PSRR) and high conversion efficiency (CE), and other benefits. The hybrid LDO may be coupled with dual rails for its analog LDO branch and digital LDO respectively to achieve high PSRR and high CE by utilizing the hybrid architecture with several feedback loops. Other embodiments may be described and claimed.

A solid-state circuit is presented which may comprise a pass device, a control circuit, and a leakage current compensation circuit. The pass device may have a first terminal, a second terminal and a drive terminal, wherein the first terminal of the pass device is coupled with an input terminal of the solid-state circuit, and wherein the second terminal of the pass device is coupled with an output terminal of the solid-state circuit. The control circuit may be coupled with the drive terminal of the pass device and may be configured to drive the pass device with a driving voltage. The leakage current compensation circuit may be configured to receive a leakage current of the pass device and may be configured to forward said leakage current as a bias current to said control circuit.