Abstract: Method and circuits for sensing a bidirectional current without requiring an external sense resistor are disclosed. In a preferred embodiment the invention is applied for fuel gauging of one or more batteries and comprises a charger/active diode, which can source current into the battery and sink current from the battery to supply a mobile electronic device. The invention can be applied to any other application requiring sensing of bidirectional currents. A regulated cascode forces a voltage drop over a power transistor and a sense transistor to be the same. A feedback current is measured by an ADC. The integration of these current measurements over time is equal to the actual charge of the battery.

Abstract: Circuits and methods to maintain a resistive voltage divider ratio during start-up of an electronic circuit comprising a feed-forward capacitor across a feedback resistor using a dynamic start-up circuit are disclosed as e.g. a LDO or an amplifier. In a preferred embodiment of the disclosure is applied to an LDO. Modification of the resistive voltage divider ratio caused by the feed-forward capacitor during start-up is prevented while the voltage level of a voltage access point of the voltage divider on the feed-forward capacitor is maintained. Embodiments of the disclosure presented comprise using a start-up buffer or a start-up capacitor during the start-up phase.

Abstract: Power converters, such as switched-mode power converters comprise a reduced number of sensing pins. A power converter is configured to convert electrical energy at an input voltage into electrical energy at an output voltage. The power converter comprises a power switch configured to be switched between on- and off-states; and a controller configured to generate a control signal for putting the power switch into the on-state and off-state, respectively; wherein the control signal is generated based on a first and second measurement signal from the power converter external to the controller. The controller comprises a sensing pin configured to sense the first measurement signal, when the power switch is in on-state, and configured to sense the second measurement signal, when the power switch is in off-state.

Abstract: Circuits and methods to achieve a clean start-up process and power saving of pulsed enabled electronic devices having an output capacitor and components requiring biasing during normal operating conditions are disclosed. These electronic devices could be e.g. LDOs, amplifiers or buffers. A set of switches are enabling bias currents from the output capacitor to internal nodes requiring biasing under normal operational conditions as e.g. output nodes of amplifying means.

Abstract: An apparatus for synchronizing an incoming signal with a clock signal comprises two or more synchronizer circuits, wherein each synchronizer circuit receives the incoming signal and the clock signal. Each synchronizer circuit generates a synchronized signal, wherein the state of each synchronized signal changes on a different phase of said clock signal in response to a change of the state of said incoming signal. A decision mechanism circuit receives the synchronized signals generated by each synchronizer circuit, wherein the decision mechanism circuit determines the output signal in response to the change of the state of the incoming signal. The decision mechanism circuit further comprises a memory element having a state which is set according to a previously detected state of said signal, wherein the output signal is determined according to the state of the memory element.

Abstract: Power switches operate with reduced power consumption. A circuit controls a power switch via its gate having a gate capacitor. The circuit comprises an on-control switch coupling the gate of the power switch with a charge supply to provide a gate charge to the gate capacitor of the power switch, thereby putting the power switch to the on-state; a transformer and an off-control switch coupling the gate of the power switch with ground via a primary winding of the transformer to discharge the gate capacitor of the power switch, thereby causing a discharge current through the primary winding and thereby putting the power switch to the off-state; wherein a secondary winding is coupled to the charge supply, such that a current, which is induced in the secondary winding, recharges the charge supply.

Abstract: A current mode buck converter has a power stage and a feedback stage. The power stage converts a higher power supply voltage level to a lower output voltage level. The feedback stage is connected with the power stage for controlling the levels of repetitive switching of an output current by phase and frequency locking a switching frequency of the output current to an external clocking signal. The feedback stage controls two levels of output current bounds by transforming a current error to a phase error to prevent error amplification such that an average output current remains constant at any duty cycle.

Abstract: This invention relates to driver circuits used within high voltage power supplies, e.g. for light bulb assemblies. A driver circuit providing electrical energy at an output derived from electrical energy at an input is described. The driver circuit comprises a power converter, a controller, a supply voltage capacitor, and is configured to provide a supply voltage to the controller. A start-up resistor is coupled to the input of the driver circuit, charges the supply voltage capacitor, and is coupled to the supply voltage capacitor during start-up of the driver circuit. A back-up capacitor is coupled to the output of the driver circuit and with the supply voltage capacitor if a voltage at the back-up capacitor exceeds the supply voltage by a forward voltage threshold, and is decoupled from the supply voltage capacitor if the supply voltage exceeds the voltage at the back-up capacitor by a reverse voltage threshold.

Abstract: A differential audio amplifier system and a related system to generate an output signal free or with only very limited clipping are disclosed. It provides a solution to solve the problem of limited electrical speaker amplifier output power available (e.g. inside battery driver applications). A differential speaker amplifier has positive and negative supply rails. In a first embodiment of the disclosure the negative supply rail is connected to the output of an inverting buck-boost converter and the positive supply rail is directly connected to VSS voltage. In a second embodiment of the disclosure the positive supply rail is connected to the output of a buck-boost converter and the negative supply rail is directly connected to a positive battery voltage.

Abstract: A power supply or driver circuit configured to provide electrical energy at a drive voltage. The driver circuit converts electrical energy at an input voltage to the electrical energy at the drive voltage. A controller is configured to control the power converter to provide electrical energy at the drive voltage. The controller stops operation at an interruption of electrical energy to the driver circuit. The controller is configured to resume operation subsequent restoration of electrical energy to the driver circuit. The controller is configured to maintain the timing voltage above a first voltage level when the controller is in operation and to determine the duration of an interruption of electrical energy to the driver circuit.

Abstract: Circuits and methods for over-current protection of pulse-width modulation systems such as switch mode class D audio systems, DC-to-DC converters, or switch mode power supplies have been disclosed. Over-current protection has been achieved by introducing supply-scalable pulses to bring the modulation index of PWM pulses to a safe level. Additionally to the over-current protection a recovery circuit and method to be applied right after an over-current situation has been disclosed.

Abstract: A circuit and method provides compensation for disturbance of an output voltage caused by dielectric absorption of a load capacitor of a low dropout voltage regulator after a modification of the output voltage level of the low dropout voltage regulator. A dielectric absorption current compensation circuit generates a profile current that is applied to an output of the low dropout voltage regulator and in parallel with the load capacitor to compensate for the dielectric absorption current. The dielectric absorption current compensation circuit has a programmable profile current generator that generates the profile current. A switchable current mirror transfers a mirror profile compensation current to the load capacitor to compensate for the dielectric absorption current. In some embodiments, the profile current is a continuous profile dielectric absorption compensation current and in other embodiments, the profile current is a digital profile dielectric absorption compensation current.

Abstract: A driver circuit for a switched-mode power converter is configured to perform hysteretic control of a switched-mode power converter. The switched-mode power converter comprises an inductor configured to store energy during a first state of the switch and to release energy towards a load of the switched-mode power converter during a second state of the switch. The driver circuit comprises a filter unit which is configured to determine a command signal based on a gate control signal applied to a gate of the switch. The command signal is indicative of a current through the inductor. The driver circuit comprises hysteretic control circuitry configured to generate the gate control signal based on the command signal; wherein the switch alternates between the first and second state when being subjected to the gate control signal.

Abstract: Circuits and methods to improve dynamic load transient performance of circuits supplying high current and having parasitic resistances are disclosed. These circuits comprise e.g. LDOs, amplifiers or buffers. The circuits and methods are characterized by including parasitic resistances, caused by bond wires, metallization of pass devices, and substrate routings, in a loop for fast transient response. Furthermore the circuits comprise a stabilization circuit within said loop and a separate pad for said loop.

Abstract: Circuits and related methods for energy efficient battery supplied switching DC-to-DC regulators are disclosed. When entering a power-down state the energy in an output capacitor is harvested and charged back to the battery. This is achieved by ramping-down a reference voltage after a power-down sequence is initiated. The output voltage of the regulator is ramped-down accordingly. At the end of the power down sequence the output voltage of the regulator is down to 0V. The disclosure is especially important for regulators, which frequently are started up and switched down.

Abstract: Circuits and related methods for artificial ramp generation for pulse-width modulators (PWM) for current control mode switch mode power supplies (SMPS).are disclosed. The artificial ramp generation is separated from a current sensing part and allows easy trimming of both paths. Artificial ramp is generated as a voltage on a capacitor biased by constant current and placed between a voltage sensing node and an input of a PWM comparator. The circuit disclosed reduces circuit complexity and susceptibility to noise and spikes from the input voltage.

Abstract: A control circuit for a switch, configured to measure the drain-to-source current of the switch is described. The control circuit is configured to control an external transistor and comprises a control pin coupled to the gate of an external transistor. The external transistor and a level shifting unit are coupled to the control pin and configured to isolate an AC current from the control pin; at a time instant subsequent to the first pulse duration, the isolated AC component of the voltage potential is indicative of a drain-to-source current through the external transistor.

Abstract: A method and system avoid ringing at an external power transistor subsequent to switching OFF the external power transistor. A driver circuit generates a drive signal for switching the external power transistor between OFF-state and ON-state. The driver circuit comprises a drive signal generation unit configured to generate a high drive signal triggering the external power transistor to switch to ON-state, wherein an output resistance of the driver circuit is adjustable, an oscillation detection unit to detect a degree of oscillation on the drive signal, and a resistance control unit to adjust the output resistance of the driver circuit based on the degree of oscillation on the drive signal.

Abstract: Methods and circuits for CMOS relaxation oscillators are disclosed. A single capacitive element, a single current source and a switching network are utilized. A switching network of the oscillator allows both nodes of the capacitive element to rise and fall between a positive and a negative voltage with respect to ground supply, without causing leakage to substrate or risk of latch-up, i.e. the inadvertent creation of a low-impedance path. The oscillator requires minimum silicon area, has an improved duty cycle, is particular useful for implementing lower frequency clocks and is enabled for smaller technology nodes, lower than 250 nm, due to lower supply voltage.

Abstract: A transistor device structured such that the bulk, gate, drain, and source are all accessible from all four edges of the device and such that current distribution is uniform over the device is provided. The transistor is created with a four-metal CMOS process. A bulk connection can be made with Metal 1, which is all around the device. A gate connection can be made with Metal 2, which is all around the device. Additionally, a drain/source connection can be made with Metal 3, which is all around the device. A source/drain connection can be made with Metal 4, which is all around the device. Source/drain connections are made with two or more evenly distributed via stripes to connect the source/drain parts of the transistor fingers. The transistor structure may be used to create an array of transistors for a high power output stage, with the transistors arranged in a checkerboard pattern. The connections of each transistor are automatic by abutting edges of the transistors.