Abstract: A asymmetric two-stage DC-DC switching converter, using multi-stage phases, in parallel to single-stage phases, to supply an output voltage, is described. An intermediate voltage supply is used to provide supply to some second-stage phases. Several different silicon dies are used to implement a multi-phase DC-DC switching converter, where different phases are located on different dies, and different silicon processes are used to implement the different dies. The silicon die containing the faster phases, and the fast-response control circuitry, is placed closer to the load, than the silicon die containing the slower phases, and the larger value inductors. A single control signal is used to control all the single-stage and second-stage phases. A way of implementing a control scheme for the second-stage phases that allows them to operate independently from the first-stage phases, but still regulate correctly in the DC-DC switching converter system, is described.

Abstract: The proposed disclosure combines peak-mode monitoring with valley-mode control, in a Buck switching converter, by means of a peak-current sampling circuit, not to turn the high side device off, but to control a slow loop, which in turn controls a variable offset incorporated into the loop control current. This helps the loop control current define the exact peak current, regardless of what other offsets, compensation ramp or peak-to-peak current ripple, are applied to the loop control current. The peak current is determined by an operational transconductance amplifier (OTA), whose maximum current is clamped to a programmed value. The loop control current is most likely implemented using a digital successive approximation register (SAR) system, but may also be implemented using a slow analog control loop.

Abstract: A system is disclosed which provides a dynamic current limit circuit that accurately defines both the lower and the upper limits for the current limit. The circuit ensures both the lower and upper current limits are well-controlled. The lower current limit is matched to the normal pulse-frequency modulation (PFM) limit, and the upper current limit is matched to the pulse-width modulation (PWM) limit. This implementation has several key benefits, including making the peak current limit accurate in both sync and dynamic sleep modes. If the scheme is carefully designed, the dynamic sleep current limit gives the best load transient response.

Abstract: A variable efficiency and response buck converter is achieved. The device includes a multi-phase switch, the coupled coils, the filter capacitor, and the load. The multi-phase switch includes the phase control inputs, the circuit common reference, at least two pairs of complementary switches with each switch containing one upper switch and one lower switch, at least two phase control outputs from the complementary switches. The coupled inductive coils are coupled to the phase control outputs to enable weak couplings and strong couplings. Based on the working mode, equivalently the coupled coils can provide strong mutual inductances and weak mutual inductances. The filter capacitors connected to the output of the coupled coils provide high efficiency output to the load.

Abstract: An object of this disclosure is to implement a Buck, Boost, or other switching converter, with a circuit to supply a reference voltage and Adaptive Voltage Positioning (AVP), by means of a servo and programmable load regulation. The reference voltage is modified, achieving a high DC gain, using a servo to remove any DC offset at the output of the switching converter. The correction implemented by the servo is measured, and a programmable fraction of the correction is injected back on either the reference voltage or the output feedback voltage. To accomplish at least one of these objects, a Buck, Boost, or other switching converter is implemented, consisting of an output stage driven by switching logic, with a servo configured between the reference voltage and the control loops of the Buck converter. The AVP function is implemented on either the reference voltage or output feedback voltage.

Abstract: A system is disclosed which allows for a multiphase Buck switching converter, where some phases operate in peak-mode current control, and some phases operate in valley-mode current control, simultaneously with the peak-mode phases. The peak-mode phases of the switching converter operate at lower frequency, and with a higher value inductor than the valley mode phases. The peak-mode phases support discontinuous control mode (DCM) operation and continuous control mode (CCM) operation, and the valley-mode phases only support CCM operation. The peak-mode phases of the switching converter are always enabled, and the valley-mode phases are only enabled at high currents. The peak-mode and valley-mode currents are matched with a peak current servo, for better efficiency.

Abstract: An object of the disclosure is to provide a multiphase Buck, Boost, or other switching converter to give high efficiency over the full range of output currents, and to maximize the total output current the switching converter is able to supply, by fully utilizing every phase of the switching converter. Further, another object of this disclosure is to balance the asymmetric transconductance, such that the load share between phases is optimized for different load levels of coil value, coil type, pass-device scaling, and frequency. Still further, another object of this disclosure requires that each of the switching converter operates at a similar point of saturation current at each point along the output load range, and each phase provides a different percentage of the total output current.

Abstract: A switching mode power supply (SMPS) configured for clearing an overvoltage condition. The overvoltage is determined by detecting that the output voltage has exceeded the input voltage by a limited amount. The overvoltage is cleared by repetitively turning on and then off the switches controlling the flow of energy to the SMPS in sequence until the excess charge resulting from the overvoltage is couple to circuit ground, and the output is reduced to within acceptable limits.

Abstract: A multi-phase DC-to-DC converter is configured to achieve fast transient response and to optimize efficiency over the load range. Phase shedding changes the active number of phases according to output currents. Each phase of the converter has an inductor configured to optimize the efficiency for a range of load currents in which that phase is used. A converter may have 3 phases, the first used only in sleep mode and has a large inductance with low AC losses, the second used in sync mode at low currents and having a lower inductance with low AC losses, the third phase is used in sync mode at high currents and has small inductance with low DC losses. The number of phases is ?2.

Abstract: Disclosed are methods and circuits to measure independently of duty cycles a pulsed current of a pass transistor of a switched circuit. Methods and circuits of one embodiment may be applied to precisely operate DC-to-DC converters such as buck converters in the most efficient operation modes. Another embodiment can be used to measure the pulsed current independently of duty cycle over a wide range of current values.

Abstract: In order to accelerate the response of buck converters to load transients buck converters having asymmetric phase designs having a load step detection are used. When a relatively large and fast load step is detected, the clock frequency of “fast”valley mode phases is reduced, which are populated with fast, low value inductors. The clock frequency is returned to its normal rate when the current in the “slow” phases has reached a suitable level.

Abstract: A highly efficient voltage conversion circuit device with both asymmetric and symmetric gate voltages is disclosed, to obtain high efficiency for low or medium load currents through the asymmetric gate voltage control and high efficiency for high load currents through the symmetric gate voltage control. The device includes an intermediate voltage generation circuit unit, gate voltage driver circuits connected to the intermediate voltage generation circuit unit, and multi-phase switches connected to the asymmetric gate voltage driver circuits, etc. The intermediate voltage generation circuit unit includes a voltage reference circuit unit that provides the reference voltage for the intermediate voltage generation, an active current pull-down circuit unit, a current pull-up that is supplied by a high value resistor, and a charge storage capacitor.

Abstract: A switching mode power supply (SMPS) is capable of clearing an overvoltage condition. The overvoltage is determined by detecting that the output voltage has exceeded the input voltage by a limited amount. The overvoltage is cleared by repetitively turning on and then off the switches controlling the flow of energy to the SMPS in sequence until the excess charge resulting from the overvoltage is couple to circuit ground, and the output is reduced to within acceptable limits.

Abstract: A multiple phase, multiple stage SMPC system includes at least one single stage phase SMPC circuit that converts an input voltage to an output voltage applied to an electronic load circuit and at least one multiple stage phase SMPC circuit. The at least one multiple stage phase SMPC circuit has at least one primary stage phase SMPC circuit generates, monitors, and controls an intermediate voltage and at least one secondary stage phase SMPC circuit converts the intermediate voltage to the output voltage. The at least one secondary stage phase has a voltage conditioner that transforms the intermediate voltage to a reference voltage that is approximately the level of the output voltage. The at least one primary stage phase SMPC circuit monitors and controls the intermediate voltage to force the at least one secondary stage phase to make its output current a correct portion of the total load current.

Abstract: Method and circuits enable measuring output current in DC/DC converters operating in pulse frequency modulation (PFM) mode and in pulse width modulation (PWM) mode. The method is applicable to DC/DC converters using an inductor at the output. Current is sampled on one pass transistor only. The DC/DC converter disclosed turns a PMOS transistor off when the output current reaches its current limit.

Abstract: Method and circuits enable measuring output current in DC/DC converters operating in pulse frequency modulation (PFM) mode and in pulse width modulation (PWM) mode. The method is applicable to DC/DC converters using an inductor at the output. Current is sampled on one pass transistor only. The DC/DC converter disclosed turns a PMOS transistor off when the output current reaches its current limit.

Abstract: A servo block in a Buck, Boost, or switching converter allows a positive offset to be applied to the DAC voltage. In a typical switching converter application, the load will have a positive current, sourced from the switching converter to ground through the load. This will cause the output voltage of the switching converter to fall with the output impedance. The servo block corrects the output voltage by adjusting the DAC voltage upwards. In the case where current is forced back into the switching converter, causing the output voltage to rise, the servo block will have affect. The behavior of the servo block is desirable as it reduces the negative affect the servo block may have on load transients occurring when the switching converter is in over voltage. In particular, the idea of shifting the DAC voltage for several different loops with a single servo block is disclosed.

Abstract: A circuit and method providing switching regulation configured to provide a pulse frequency modulation (PFM) mode of operation with reduced electromagnetic interference (EMI) comprising an output stage configured to provide switching comprising a first and second transistor, a sense circuit configured to provide output current information sensing from an output stage and a current limit reference, a first digital-to-analog converter (DAC) configured to provide signal to the current limit reference, an adder function configured to provide a signal to the first digital-to-analog converter (DAC), and a linear shift feedback register (LSFR) configured to provide a signal to an adder function followed by the first digital-to-analog converter (DAC), and the LSFR receives a clock signal from said output stage.

Abstract: A highly efficient voltage conversion circuit device with both asymmetric and symmetric gate voltages is disclosed, to obtain high efficiency for low or medium load currents through the asymmetric gate voltage control and high efficiency for high load currents through the symmetric gate voltage control. The device includes an intermediate voltage generation circuit unit, gate voltage driver circuits connected to the intermediate voltage generation circuit unit, and multi-phase switches connected to the asymmetric gate voltage driver circuits, etc. The intermediate voltage generation circuit unit includes a voltage reference circuit unit that provides the reference voltage for the intermediate voltage generation, an active current pull-down circuit unit, a current pull-up that is supplied by a high value resistor, and a charge storage capacitor.

Abstract: A method of determining the result of an assay in a microfluidic device includes the steps of: dispensing a sample droplet onto a first portion of an electrode array of the microfluidic device; dispensing a reagent droplet onto a second portion of the electrode array of the microfluidic device; controlling actuation voltages applied to the electrode array to mix the sample droplet and the reagent droplet into a product droplet; sensing a dynamic property of the product droplet; and determining an assay of the sample droplet based on the sensed dynamic property. The dynamic property is a physical property of the product droplet that influences a transport property of the product droplet on the electrode array. Example dynamic properties of the product droplet include the moveable state, split-able state, and viscosity based on droplet properties. The method may be used to perform an amoebocyte lysate (LAL) assay.