An integrated circuit can comprise an output terminal, a power transistor having a first current electrode coupled to the output terminal and a second current electrode coupled to a power supply terminal, a driver having an output coupled to a control electrode of the power switch, a capacitor having a first terminal coupled to the output terminal and a second terminal coupled to a circuit node, a first low pass filter coupled between the circuit node and an input of the driver, the first low pass filter having a first cut off frequency, a set of current sources, and a second low pass filter coupled between the circuit node and an output of the set of current sources. The second low pass filter can have a second cut off frequency that is higher than the first cut off frequency.

Embodiments of an SMPS controller and a method for operating a switched-mode power supply (SMPS) controller are described. In an embodiment, an SMPS controller includes a gate driver circuit configured to generate a drive signal for a switch of an SMPS and a current sense electrical terminal configured to receive sensed current corresponding to the switch and to conduct driver discharge current from the gate driver circuit.

The present invention provides a transmitter including a first variable resistor, a first transistor, a second transistor, a third transistor and a fourth transistor is disclosed. The first variable resistor is coupled between a supply voltage and a first node. A first electrode of the first transistor is coupled to the first node, and a second electrode of the first transistor is coupled to a first output terminal of the transmitter. A first electrode of the second transistor is coupled to the first output terminal of the transmitter, and a second electrode of the second transistor is coupled to a second node. A first electrode of the third/fourth transistor is coupled to the first node, and a second electrode of the third/fourth transistor is coupled to a second output terminal of the transmitter.

A compact RF switch with improved isolation is presented. According to one aspect, the RF switch includes a basic single-pole single-throw (SPST) switch element that includes an inductor in parallel with a series FET transistor. An inductance of the inductor is selected to provide in combination with an off capacitance of the series FET transistor a resonance at a specific frequency of interest. The frequency of interest can be in-band or out-of-band, including the band’s fundamental frequency or a harmonic thereof. According to another aspect, the inductor is conditionally coupled to the series FET transistor via a reduced size FET transistor. Complex RF switches can include a plurality of the SPST switch elements, each tuned to a same or different frequency of interest. According to yet another aspect, SPST switch elements in their OFF states can provide matching to an SPST element in the ON state.

A driver circuit drives an output terminal with an input/output voltage using an NMOS transistor and a PMOS transistor. A pre-driver for the NMOS transistor supplied with a drive voltage and receives a data signal referenced to the drive voltage. A pre-driver for the PMOS transistor has a positive supply input connected to the positive supply rail, a negative supply input receiving a second drive voltage equal to the supply voltage minus the drive voltage. A level shifter circuit, shifts the data signal to be referenced between the supply voltage and the second drive voltage. A charge pump circuit for providing second drive voltage, the charge pump circuit driven with a variable switching frequency proportional to a current of the PMOS transistor.

A slew rate adjusting circuit includes an adjustment transistor configured to provide an adjustment current into an output port of an arithmetic amplifier, a first transistor connected between a power line of the arithmetic amplifier and the adjustment transistor, and a second transistor connected between the first transistor and an output node of the output port, wherein the adjustment transistor is turned on by the second transistor in response to a difference between an input voltage and an output voltage being equal to or greater than a reference voltage, and the adjustment current is provided to the output port in response to the adjustment transistor being turned on.

A circuit and method for controlling charge injection in a circuit are disclosed. In one embodiment, the circuit and method are employed in a semiconductor-on-insulator (SOI) Radio Frequency (RF) switch. In one embodiment, an SOI RF switch comprises a plurality of switching transistors coupled in series, referred to as “stacked” transistors, and implemented as a monolithic integrated circuit on an SOI substrate. Charge injection control elements are coupled to receive injected charge from resistively-isolated nodes located between the switching transistors, and to convey the injected charge to at least one node that is not resistively-isolated. In one embodiment, the charge injection control elements comprise resistors. In another embodiment, the charge injection control elements comprise transistors. A method for controlling charge injection in a switch circuit is disclosed whereby injected charge is generated at resistively-isolated nodes between series coupled switching transistors, and the injected charge is conveyed to at least one node of the switch circuit that is not resistively-isolated.

A voltage tracking circuit is provided and includes first and second P-type transistors and a voltage reducing circuit. The drain of the first P-type transistor is coupled to a first voltage terminal. The voltage reducing circuit is coupled between the first voltage terminal and the gate of the first P-type transistor. The voltage reducing circuit reduces a first voltage at the first voltage terminal by a modulation voltage to generate a control voltage and provides the control voltage to the gate of the first P-type transistor. The gate of the second P-type transistor is coupled to the first voltage terminal, and the drain thereof is coupled to a second voltage terminal. The source of the first P-type transistor and the source of the second P-type transistor are coupled to the output terminal of the voltage tracking circuit. The output voltage is generated at the output terminal.

A radio frequency (RF) switch includes a first terminal, a second terminal, a series switch circuit, a shunt switch circuit, an inductor and a reference voltage terminal. An RF signal at the first terminal. The series switch circuit is coupled to the first terminal, the second terminal, and the shunt switch circuit. The shunt switch circuit includes a sub-switch circuit, a transistor coupled to the sub-switch circuit, and a compensation capacitor parallel-coupled to the transistor. The inductor is coupled to the shunt switch circuit and the reference voltage terminal. When the RF signal is operated in a first frequency band, the first transistor is turned on for the shunt switch circuit and the inductor to provide a first impedance. When the RF signal is operated in a second frequency band, the first transistor is turned off for the shunt switch circuit and the inductor to provide a second impedance.

A selection circuit architecture makes it possible to perform upward and/or downward transitions in sets of sequences of slow and fast phases so as at the same time to solve the problems of inductive switching noise and the problems of currents in the supply rails. This solution has multiple advantages linked to the ease of implementation and flexibility of configurations that are possible for adapting to the specific constraints when designing the circuit.