Disclosed herein are amplification systems that are dynamically biased based on a signal indicative of an envelope of an input radio-frequency (RF) signal being amplified. The amplification systems include a power converter with an envelope tracker and an RC circuit. The envelope tracker and the RC circuit are configured to generate an envelope-based biasing signal to bias a power amplifier and an envelope-based supply voltage to power the power amplifier.

A current regulator and a method for regulating a current flowing through a device such as a semiconductor light source is presented. The current regulator has a voltage controller coupled to a current steering circuit. The voltage controller is adapted to operate the current steering circuit in a linear mode.

A voltage regulator and a method are presented. The regulator has a pass device coupled to an input node at an input voltage. Furthermore, the voltage regulator has a regulator circuit to control the pass device to provide a regulated output voltage at an output node based on the input voltage. Components of the regulator circuit are arranged and operated between the input node and the output node. The voltage regulator allows a load of the voltage regulator to be arranged between the output node and a reference node at a reference voltage, wherein the reference voltage differs from the output voltage.

An offset drift compensation circuit for correcting offset drift that changes with temperature. In one example, offset drift compensation circuit includes a low temperature offset compensation circuit and a high temperature offset circuit. The low temperature offset compensation circuit is configured to compensate for drift in offset at a first rate below a selected temperature. The high temperature offset compensation circuit is configured to compensate for drift in offset at a second rate above the selected temperature. The first rate is different from the second rate.

The constant current circuit includes a constant current generation circuit, a start-up detection circuit configured to detect start-up of the constant current generation circuit, and a clamp circuit configured to output a start-up voltage to the constant current generation circuit. The start-up voltage output from the clamp circuit is a voltage close to gate voltages that are higher than gate voltages of transistors that form a current mirror circuit of the constant current generation circuit, in a state where the constant current generation circuit is operating.

The constant current circuit includes a constant current generation circuit, a start-up detection circuit configured to detect start-up of the constant current generation circuit, and a clamp circuit configured to output a start-up voltage to the constant current generation circuit. The start-up voltage output from the clamp circuit is a voltage close to gate voltages that are higher than gate voltages of transistors that form a current mirror circuit of the constant current generation circuit, in a state where the constant current generation circuit is operating.

A compact ADC circuit can include one or more comparators, and a serial DAC (Digital-to-Analog) circuit that provides a signal to the comparator (or comparators). In addition, the ADC circuit can include a serial DAC redistribution sequencer that can provide a plurality of signals as input to the serial DAC circuit and is subject to a redistribution cycle and which receives as input a signal from a data multiplexer whose input connects electronically to an output of the comparator. The circuit can further include an ADC code register that provides an ADC output that connects electronically to the output of the comparator and the input to the data multiplexer. Shared logic circuitry for sharing common logic between pixels can be included, wherein the shared logic circuitry connects electronically to the data multiplexer and the ADC code register, wherein the shared logic circuitry promotes area and power savings for the pixel detector circuit.

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.

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 source follower with an input node and an output node includes a first transistor, a second transistor, and a DC (Direct Current) tracking circuit. The first transistor has a control terminal, a first terminal coupled to a first node, and a second terminal coupled to a second node. The second transistor has a control terminal, a first terminal coupled to a ground voltage, and a second terminal coupled to the first node. The DC tracking circuit sets the second DC voltage at the second node to a specific level. The specific level is determined according to the first DC voltage at the first node. The output node of the source follower is coupled to the first node.