Techniques and apparatus for output common-mode control of dynamic amplifiers, as well as analog-to-digital converters (ADCs) and other circuits implemented with such dynamic amplifiers. One example amplifier circuit includes a dynamic amplifier and a current source. The dynamic amplifier generally includes differential inputs, differential outputs, transconductance elements coupled to the differential inputs, a first set of capacitive elements coupled to the differential outputs, and a control input for controlling a time length of amplification for the dynamic amplifier. The current source is configured to generate an output current such that portions of the output current are selectively applied to the differential outputs of the dynamic amplifier during at least a portion of the time length of amplification.

Systems and method for improving operation of a radio frequency system are provided. One embodiment includes a switching power amplifier that outputs an amplified analog electrical signal based on an input electrical signal and voltage of an envelope voltage supply rail. The switching power amplifier includes a first transistor with a gate that receives the input electrical signal, a source electrically coupled to the envelope voltage supply rail, and a drain electrically coupled to an output of the switching power amplifier; a second transistor with a gate that receives the input electrical signal, a source electrically coupled to ground, and a drain electrically coupled to the output; and a third transistor with a gate that receives the input electrical signal, a drain electrically coupled to the envelope voltage supply rail, and a source electrically coupled to an output of another switching power amplifier.

Techniques and apparatus for output common-mode control of dynamic amplifiers, as well as analog-to-digital converters (ADCs) and other circuits implemented with such dynamic amplifiers. One example amplifier circuit includes a dynamic amplifier and a current source. The dynamic amplifier generally includes differential inputs, differential outputs, transconductance elements coupled to the differential inputs, a first set of capacitive elements coupled to the differential outputs, and a control input for controlling a time length of amplification for the dynamic amplifier. The current source is configured to generate an output current such that portions of the output current are selectively applied to the differential outputs of the dynamic amplifier during at least a portion of the time length of amplification.

An amplifier circuit includes a resistor divider (R.sub.REF) comprising n resistive elements, two main nodes defined at each end thereof, two readout nodes (d.sub.1, d.sub.2), resistor nodes (q) defined between adjacent resistive elements, and an input current source (I.sub.REF) connected or connectable to the first main node (a). The resistor divider (R.sub.REF) comprises two arrays of addressable switch elements controllable by a feedback signal (s.sub.FB) to be open or closed. The amplifier circuit includes a differential pair of transistors (T.sub.1, T.sub.2), wherein source terminals of each of the transistors (T.sub.1, T.sub.2) are connected to the second node (b), gate terminals of the transistors (T.sub.1, T.sub.2) are connected to input signals (v.sub.1, v.sub.2), drain terminals of the transistors (T.sub.1, T.sub.2) are connected to current sources (I.sub.1, I.sub.2), and bulk terminals of the transistors (T.sub.1, T.sub.2) are connected to the readout nodes (d.sub.1, d.sub.2). The amplifier circuit functions as a difference amplifier, wherein the bulk terminals affect a threshold of the respective transistors (T.sub.1, T.sub.2) so as to add or subtract a differential signal derived from the readout nodes (d.sub.1, d.sub.2) of the resistor divider (R.sub.REF) determined by the feedback signal (s.sub.FB).

An amplifier circuit comprises a multi-stage amplifier having a plurality of amplifiers cascaded between an input port V.sub.in and an output port V.sub.out to form a differential input stage and N subsequent gain stages, a capacitive load C.sub.L coupled to the output port V.sub.out, and a compensation network coupled to the multi-stage amplifier and configured for positioning Pole-Zero pairs of each stage of the multi-stage amplifier below a unity gain frequency ω.sub.t of the multi-stage amplifier when compensated, with Zeros positioned lower than Poles so as to increase the unity gain frequency ω.sub.t.

An analog front-end circuit capable of dynamically adjusting gain includes a programmable gain amplifier (PGA) circuit, a sensor, a calculation circuit, a gain coarse control circuit and a gain fine control circuit. The PGA circuit includes an amplifier, a gain coarse adjustment circuit and a gain fine adjustment circuit. The gain coarse adjustment circuit is controlled by a coarse control signal, and a gain is adjusted in a coarse step according to an initial gain. The gain fine adjustment circuit is controlled by a fine control signal in a data mode, and the gain is adjusted in a fine step. The calculation circuit calculates a primary gain adjustment and a secondary gain adjustment. The gain coarse control circuit generates the coarse control signal according to the primary gain adjustment, and the gain fine control circuit generates the fine control signal according to the secondary gain adjustment.

A distributed power management circuit is provided. In embodiments disclosed herein, the distributed power management circuit can achieve multiple performance enhancing objectives simultaneously. More specifically, the distributed power management circuit can be configured to switch a modulated voltage from one voltage level to another within a very short switching window, reduce in-rush current required for switching the modulated voltage, and minimize a ripple in the modulated voltage, all at same time. As a result, the distributed power management circuit can be provided in a wireless device (e.g., smartphone) to enable very fast voltage switching across a wide modulation bandwidth (e.g., 400 MHz) with reduced power consumption and voltage distortion.

A multi-voltage power generation circuit is disclosed. More specifically, the multi-voltage generation circuit includes multiple voltage modulation circuits that are configured to generate and maintain multiple modulated voltages. In a non-limiting example, the multiple modulated voltages can be used for amplifying multiple radio frequency (RF) signals concurrently. Contrary to using multiple direct-current (DC) to DC (DC-DC) converters for generating the multiple modulated voltages, the voltage modulation circuits are configured to share a single current modulation circuit based on time-division. By sharing a single current modulation circuit among the multiple voltage modulation circuits, it is possible to concurrently support multiple load circuits (e.g., power amplifier circuits) with significantly reduced footprint.

A multi-voltage power generation circuit is disclosed. More specifically, the multi-voltage generation circuit includes multiple voltage modulation circuits that are configured to generate and maintain multiple modulated voltages. In a non-limiting example, the multiple modulated voltages can be used for amplifying multiple radio frequency (RF) signals concurrently. Contrary to using multiple direct-current (DC) to DC (DC-DC) converters for generating the multiple modulated voltages, the voltage modulation circuits are configured to share a single current modulation circuit based on time-division. By sharing a single current modulation circuit among the multiple voltage modulation circuits, it is possible to concurrently support multiple load circuits (e.g., power amplifier circuits) with significantly reduced footprint.

A temperature sensor that is insensitive to process variation and mismatch is disclosed. The temperature sensor includes a PTAT voltage generator, a sampling and gain boosting circuit, a filter and a controller. The PTAT voltage generator utilizes a plurality of current sources, each of which is in electrical communication with the same diode, or diode stack. The output of the PTAT voltage generator is sampled and amplified with the sampling and gain boosting circuit. The output of the sampling and gain boosting circuit is then filtered using a low pass filter. The selection of the current mirrors, the sampling timing and other signals are provided by the controller. In some simulations, the output from the temperature sensor was accurate to within 1.5° C., using a one temperature calibration process.