A supply voltage sensitivity of an output current of a bias current generator circuit is reduced. The bias current generator includes a plurality of transistors and a plurality of resistors coupled to the plurality of transistors. The supply voltage sensitivity of the output current of the bias current generator circuit is reduced by applying a second bias current generated by the bias current generator circuit to a first bias current generated by the bias current generator circuit.

A voltage reference circuit includes a first circuit block configured to generate a proportional to absolute temperature current, the first circuit block comprising a current mirror amplifier, a second circuit block coupled to the first circuit block and configured to generated a complimentary to absolute temperature current, and a third circuit block coupled to both the first circuit block and the second circuit block. The second circuit block includes a multi-stage common-source amplifier. The third circuit block is configured to combine the proportional to absolute temperature current and the complimentary to absolute temperature current to generate a reference voltage at an output of the voltage reference circuit.

A controllable temperature coefficient bias (CTCB) circuit is disclosed. The CTCB circuit can provide a bias to an amplifier. The CTCB circuit includes a variable with temperature (VWT) circuit having a reference circuit and a control circuit. The control circuit has a control output, a first current control element and a second current control element. Each current control element has a “controllable” resistance. One of the two current control elements may have a relatively high temperature coefficient and another a relatively low temperature coefficient. A controllable resistance of one of the current control elements increases when the controllable resistance of the other current control element decreases. However, the “total resistance” of the current control circuit remains constant with a constant temperature. The VWT circuit has an output with a temperature coefficient that is determined by the relative amount of current that flows through each current control element of the control circuit. A Current Digital to Analog Converter (IDAC) scales the output of the VWT and provides the scaled output to an amplifier bias input.

Provided is a reference voltage circuit including a first MOS transistor to a sixth MOS transistor, a first resistor and a second resistor, a current source circuit, and an output terminal. Five of the transistors form a differential transconductance amplifier, and an input transistor of the differential transconductance amplifier operates in the manner of weak inversion operation.

This document describes a start-up circuit for a self-biasing generator providing a reference voltage or a reference current, the start-up circuit comprising: an impedance circuit; means for coupling, in response to a start-up signal input to the start-up circuit, the impedance circuit to a bias voltage line of a current mirror circuit of the self-biasing generator, thereby inducing current to flow in the self-biasing generator and starting the self-biasing generator; a bypass current source coupled to the current mirror circuit and to the impedance, wherein the bypass current source is configured to be driven by a current in the current mirror circuit and to supply current to the impedance in proportion to the current in the current mirror circuit, thereby limiting the current induced to the self-biasing generator by the start-up circuit.

An apparatus is provided which generates a reverse bandgap reference using capacitive bias, which is applied to a single n-well diode. The capacitive bias allows for determining the current density precisely by pure timing control. An apparatus is also described for sensing temperature in which a forward-bias diode voltage can be sampled with a capacitor, and large current ratios are possible (e.g., ratio N greater than 1000). Duty cycle of a digital output of the sensor is used to determine the temperature sensed by the sensor.

In an example, an integrated circuit includes a junction-gate field effect transistor (JFET), a current generator, a dynamic filter, and an output transistor. The JFET has a JFET gate, a JFET source, and a JFET drain, the JFET drain adapted to be coupled to a power supply. The current generator has a current generator input and current generator outputs, the current generator input coupled to the JFET source and a first of the current generator outputs coupled to the JFET gate. The dynamic filter has a dynamic filter input and a dynamic filter output, the dynamic filter input coupled to a second of the current generator outputs. The output transistor has an output transistor gate coupled to the dynamic filter output.

The present invention discloses a reference circuit with temperature compensation, which is characterized in that a current output circuit is designed to receive a reference voltage from a bias voltage generation circuit, generate two reference currents with opposite temperature variation characteristics, and then merge them into a compensated current with temperature compensation. In addition, a voltage output circuit is designed to receive a reference voltage from a bias voltage generation circuit, which includes several field-effect transistors operating in saturation regions, and a precision voltage increases with threshold voltages of the field-effect transistors to compensate for the temperature variation. Resistors can be incorporated or sizes of the field effect transistors can be changed to adjust the output current, output voltage or the temperature variation characteristics.

A current reference which includes a tracking voltage generator including a flipped gate transistor, a first transistor connected with the flipped gate transistor in a Vgs subtractive arrangement, an output node providing a tracking voltage which has a positive or negative temperature dependency based on the flipped gate transistor and the first transistor, and a second transistor connected to the output node; an amplifier to receive the tracking voltage and output an amplified signal; a control transistor to receive the amplified signal; a control resistor connected in series with the control transistor; and a current mirror to receive and mirror a reference current to at least one external device, the current mirror including mirroring pairs having a corresponding mirroring resistor coupled in series with a corresponding mirroring transistor, the mirroring resistor of at least one of the mirroring pairs having a serpentine structure.

A semiconductor device according to the present embodiment includes a plurality of switching elements and a plurality of variable capacitance elements. The switching elements are switching elements connected in series between a first control terminal and a second control terminal and plural types of capacitance control signals can be supplied to the first control terminal and the second control terminal. The variable capacitance elements have capacitance control terminals connected to corresponding one ends of the switching elements, respectively.