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.

Abstract: A solution is provided for adaptive slope compensation in a DC-DC switching converter. Jitter is reduced for on times less than 50% Tpd by using two or more different slopes for the compensation ramp. Additionally, any discontinuities at the 50% duty cycle point are reduced. Details of the compensation ramp are described, where the ramp rate for the first half of the switching period, for on times greater than 50% Tpd, decreases with increasing on time until, at an on time of 100% Tpd, it is approximately zero. In addition, the ramp rate for the second half of the switching period, for on times greater than 50% Tpd, decreases with decreasing on time until, at a duty of 50%, it is equal to the ramp rate used for the first half of the switching period.

Abstract: The clock input of a buck converter is delayed, preventing sub-harmonic oscillation. The function may be achieved by implementing a clock delay generation circuit, configured to delay a next clock pulse by an amount of time directly proportional to the most recent on time of the high-side switch for peak-mode current control, inversely proportional to the most recent on time of the low-side switch for peak-mode current control, inversely proportional to the most recent on time of the high-side switch for valley-mode current control, or inversely proportional to the clock minus the most recent on time of the high-side switch for valley-mode current control.

Abstract: It is an object of one or more embodiments of the present disclosure to provide a Multiple-Inductor Multiple-Output (MIMO) switching converter to supply several different output voltages. The combination of this MIMO converter with a booster circuit supplies one or more individual cores with current that bypasses the parasitic network. The booster circuit has a wider bandwidth or a faster response when compared to the main MIMO switching converter. The MIMO booster circuit can supply a number of cores with only a single set of shared inductors. The main advantages include a lower component count and a reduced printed circuit board footprint to support multiple cores in a Multiple-Inductor Multiple-Output. The present disclosure makes use of the low duty-cycle of the power peaks and the low statistical likelihood of these peaks occurring for all cores simultaneously.

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.

Abstract: A solution is provided for adaptive slope compensation in a DC-DC switching converter. Jitter is reduced for on times less than 50% Tpd by using two or more different slopes for the compensation ramp. Additionally, any discontinuities at the 50% duty cycle point are reduced. Details of the compensation ramp are described, where the ramp rate for the first half of the switching period, for on times greater than 50% Tpd, decreases with increasing on time until, at an on time of 100% Tpd, it is approximately zero. In addition, the ramp rate for the second half of the switching period, for on times greater than 50% Tpd, decreases with decreasing on time until, at a duty of 50%, it is equal to the ramp rate used for the first half of the switching period.

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.

Abstract: A power supply and a method to provide power to a load via a power delivery network are presented. The power delivery network adds a pole and/or zero to a transfer function of the power supply. The power supply has a feedback unit to sense a load voltage at the load and to provide a feedback voltage which is indicative of the load voltage. The power supply has an input amplifier provides an error voltage based on the feedback voltage. The power supply has a power converter to provide power to the power delivery network depending on the error voltage. The power supply has an equalization unit to add a zero and/or a pole to the transfer function of the power supply, such that the pole and/or zero of the power delivery network is partially compensated. The equalization unit is located between an input amplifier and a power converter.

Abstract: It is an object of one or more embodiments of the present disclosure to provide a Multiple-Inductor Multiple-Output (MIMO) switching converter to supply several different output voltages. The combination of this MIMO converter with a booster circuit supplies one or more individual cores with current that bypasses the parasitic network. The booster circuit has a wider bandwidth or a faster response when compared to the main MIMO switching converter. The MIMO booster circuit can supply a number of cores with only a single set of shared inductors. The main advantages include a lower component count and a reduced printed circuit board footprint to support multiple cores in a Multiple-Inductor Multiple-Output. The present disclosure makes use of the low duty-cycle of the power peaks and the low statistical likelihood of these peaks occurring for all cores simultaneously.

Abstract: The clock input of a buck converter is delayed, preventing sub-harmonic oscillation. The function may be achieved by implementing a clock delay generation circuit, configured to delay a next clock pulse by an amount of time directly proportional to the most recent on time of the high-side switch for peak-mode current control, inversely proportional to the most recent on time of the low-side switch for peak-mode current control, inversely proportional to the most recent on time of the high-side switch for valley-mode current control, or inversely proportional to the clock minus the most recent on time of the high-side switch for valley-mode current control.

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: The clock input of a buck converter is delayed, and the delay is controlled proportionally to the preceding high-side output switch on time. In the steady state, the high-side switch on time is uniform, and the clock is offset by a fixed amount. When sub-harmonic oscillation begins to occur, the high-side switch on time may increase during a cycle. The longer high-side on time causes the clock to be delayed by an increased amount. This has the effect of increasing the following low-side output switch on time. This further increases the subsequent high-side on time, and counteracts the effects of sub-harmonic oscillation. If the system is properly controlled, loop compensation is implemented correctly and sub-harmonic oscillation is prevented. In addition, the scheme may also be configured for the delay to be controlled proportionally to the preceding low-side output switch on time of the buck converter.

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: An 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: 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 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: A DC-DC current-control mode switching converter is disclosed, with peak-mode control circuitry, configured to compare a coil current to a variable current limit, to turn off a high side device when the coil current exceeds the variable current limit. The DC-DC switching converter includes a compensation ramp generator, configured to provide a compensation ramp signal, and an offset circuit, configured to provide an offset current. The DC-DC switching converter further includes an amplifier, configured to generate a control current proportional to the difference between an output voltage and a target voltage, and an adder, to combine the control current, the compensation ramp signal, and the offset current. A DC-DC current-control mode switching converter, with valley-mode control circuitry, configured to compare a coil current to a variable current limit, to turn off a low side device when the coil current falls below the variable current limit, is also disclosed.

Abstract: A power supply and a method to provide power to a load via a power delivery network are presented. The power delivery network adds a pole and/or zero to a transfer function of the power supply. The power supply has a feedback unit to sense a load voltage at the load and to provide a feedback voltage which is indicative of the load voltage. The power supply has an input amplifier provides an error voltage based on the feedback voltage. The power supply has a power converter to provide power to the power delivery network depending on the error voltage. The power supply has an equalization unit to add a zero and/or a pole to the transfer function of the power supply, such that the pole and/or zero of the power delivery network is partially compensated. The equalization unit is located between an input amplifier and a power converter.

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: 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 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.