Various technologies pertaining to a high-impedance current source are described herein. The current source outputs a substantially constant current by way of a first transistor that draws current from a supply. The current source is configured to feed back noise from the supply to a feedback resistor at an input of an operational amplifier (op-amp) by way of a second transistor. The feedback resistor and the op-amp are configured such that responsive to receiving the supply noise feedback, the op-amp drives a gate voltage of the first transistor to cause the first transistor to reject the supply noise and cause the output of the current source to remain substantially constant.

A dynamic current sink includes the following elements. A voltage comparator compares a reference voltage with a second control signal from an LDO (Low Dropout Linear Regulator) to generate a first control signal. A first transistor selectively pulls down a voltage at a first node according to the first control signal. The inverter is coupled between the first node and a second node. An NAND gate has a first input terminal coupled to a second transistor and a third node, a second input terminal coupled to the second node, and an output terminal coupled to a fourth node. A capacitor is coupled between the fourth node and a fifth node. A resistor is coupled between the fifth node and a ground voltage. A third transistor has a control terminal coupled to the fifth node, and selectively draws a discharge current from an output node of the LDO.

Disclosed is a voltage regulator. The voltage regulator includes a reference voltage circuit, a noise cancellation circuit, an error amplifier, a pass transistor and a voltage divider. The voltage regulator can cancel the noise generated by the reference voltage circuit and the error amplifier, and also can improve its Power Supply Rejection Ratio (PSRR).

A low drop-out voltage regulator includes an error amplifier that generates an amplified error voltage, the error amplifier including a first input for receiving a reference voltage, a second input for receiving a feedback voltage, a bias terminal for receiving an adaptive bias current, and an output. A pass gate providing an output voltage includes a first input connected to a supply voltage and a second input connected to the error amplifier output. A feedback network generating the feedback voltage includes a first terminal connected to the output of the pass gate and a second terminal connected to the second input of the error amplifier. An adaptive bias network providing the adaptive bias current includes a first transistor connected to the bias terminal of the error amplifier, a second transistor connected to the first transistor as a current mirror, and a third transistor connected in parallel with the pass gate.

A measurement apparatus includes a linear regulator, a switching regulator, an acquisition unit configured to acquire measurement data by sensing a signal as a measurement target, and a control unit configured to selectively drive the linear regulator or the switching regulator, wherein the control unit is configured to select and drive the linear regulator in a first period in which the measurement data is acquired by the acquisition unit, and select and drive the switching regulator in a second period that is different from the first period.

A dynamic current sink includes the following elements. A voltage comparator compares a reference voltage with a second control signal from an LDO (Low Dropout Linear Regulator) to generate a first control signal. A first transistor selectively pulls down a voltage at a first node according to the first control signal. The inverter is coupled between the first node and a second node. An NAND gate has a first input terminal coupled to a second transistor and a third node, a second input terminal coupled to the second node, and an output terminal coupled to a fourth node. A capacitor is coupled between the fourth node and a fifth node. A resistor is coupled between the fifth node and a ground voltage. A third transistor has a control terminal coupled to the fifth node, and selectively draws a discharge current from an output node of the LDO.

Regulator circuitry configured to manage power supply ripple using an adaptive loop gain that offers ripple rejection performance related to the ripple magnitude for a negative closed loop of the regulator circuitry. The power supply regulator circuitry of this disclosure includes an error amplifier in the closed loop and an adaptive loop gain circuitry. The adaptive loop gain circuit removes a DC component of the sensed output and feeds the sensed output, including the output ripple, to peak detector circuitry to obtain a Vpeak signal. The Vpeak signal output from the peak detector circuitry is a continuous signal that tracks the wave peak. The circuit arrangement multiplies the output of the error amplifier by the signal Vpeak resulting in improved power supply ripple rejection as the ripple amplitude increases. To avoid control signal with zero value during times that the peak-to-peak value of the sensed voltage.

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.

A dynamic current sink includes the following elements. A voltage comparator compares a reference voltage with a second control signal from an LDO (Low Dropout Linear Regulator) to generate a first control signal. A first transistor selectively pulls down a voltage at a first node according to the first control signal. The inverter is coupled between the first node and a second node. An NAND gate has a first input terminal coupled to a second transistor and a third node, a second input terminal coupled to the second node, and an output terminal coupled to a fourth node. A capacitor is coupled between the fourth node and a fifth node. A resistor is coupled between the fifth node and a ground voltage. A third transistor has a control terminal coupled to the fifth node, and selectively draws a discharge current from an output node of the LDO.

A circuit layout for improving the power supply rejection ratio includes a radio frequency (RF) choke and an inductor. The RF choke receives a supply voltage and includes: a first choke coil positioned in an ultra-thick metal (UTM) layer, the coil including a first choke electrode; and a second choke coil positioned in a redistribution layer (RDL), the coil including a second choke electrode. The inductor belongs to a main circuit and includes: a primary-side coil surrounding the first choke coil in the UTM layer, and being coupled to the first/second chock electrode and the main circuit's signal input circuit; and a secondary-side coil surrounding the first choke coil in the UTM layer and surrounding the second choke coil in the RDL, and being used for signal output. The inductor and the RF choke jointly form mutual induction to suppress the noise of the supply voltage.