Abstract: A buck switching regulator implements a fixed frequency feedback control circuit including a voltage control loop and a frequency control loop to regulate the switching frequency of the buck switching regulator to a fixed or nearly fixed frequency. The voltage control loop, implementing ripple mode control, is configured to control the power switches in response to the switching regulator output voltage or a signal related to the switching regulator output voltage. The frequency control loop, implementing a phase-locked loop control scheme, is configured to adjust the on-time of the high-side switch so as to regulate the switching frequency to be equal to or be proportional to the reference frequency.

Abstract: A buck switching regulator includes a feedback control circuit using a four-input comparator to regulate the output voltage to a substantially constant level with reduced voltage offset and with fast transient response. In some embodiments, the buck switching regulator uses the four-input comparator to compare a first feedback signal without ripple and a second feedback signal with injected ripple components to a reference level. The four-input comparator generates an output signal to control the switching of the power switches. The buck switching regulator generates an output voltage with increased accuracy and fast transient response. Furthermore, the buck switching regulator can be used with output capacitor having any value of ESR.

Abstract: A buck switching regulator includes a feedback control circuit including a first gain circuit generating a first feedback signal indicative of the regulated output voltage; a ripple generation circuit generating a ripple signal that is injected to the first feedback signal; and a comparator receiving a first reference signal and the first feedback signal to generate a comparator output signal. The switching regulator further includes an offset compensation circuit including a second gain circuit generating a second feedback signal indicative of the regulated output voltage; and an operational transconductance amplifier (OTA) configured to receive the second feedback signal and the first reference signal and to generate an output signal. The output signal of the OTA is coupled to the comparator to adjust an offset to the comparator so as to cancel the offset at the regulated output voltage due to the injected ripple signal.

Abstract: A buck switching regulator implements a fixed frequency feedback control circuit including a voltage control loop and a frequency control loop to regulate the switching frequency of the buck switching regulator to a fixed or nearly fixed frequency. The voltage control loop, implementing ripple mode control, is configured to control the power switches in response to the switching regulator output voltage or a signal related to the switching regulator output voltage. The frequency control loop, implementing a phase-locked loop control scheme, is configured to adjust the on-time of the high-side switch so as to regulate the switching frequency to be equal to or be proportional to the reference frequency.

Abstract: A buck switching regulator includes a feedback control circuit using a four-input comparator to regulate the output voltage to a substantially constant level with reduced voltage offset and with fast transient response. In some embodiments, the buck switching regulator uses the four-input comparator to compare a first feedback signal without ripple and a second feedback signal with injected ripple components to a reference level. The four-input comparator generates an output signal to control the switching of the power switches. The buck switching regulator generates an output voltage with increased accuracy and fast transient response. Furthermore, the buck switching regulator can be used with output capacitor having any value of ESR.

Abstract: A buck switching regulator includes a feedback control circuit including a feedback network including first and second gain circuits configured to generate first and second feedback signals, respectively, indicative of the regulated output voltage; a ripple generation circuit configured to inject a ripple signal to the first gain circuit; an operational transconductance amplifier (OTA) configured to receive the second feedback signal and a reference signal and to generate an output signal being coupled to the first gain circuit to adjust the first feedback signal; and a comparator configured to receive the first feedback signal and the reference signal and to generate a comparator output signal. The output signal of the OTA is applied to the first feedback signal to cancel a voltage offset in the regulated output voltage due to the injected ripple signal to the first gain circuit.

Abstract: A buck switching regulator includes a feedback control circuit including a feedback network including first and second gain circuits configured to generate first and second feedback signals, respectively, indicative of the regulated output voltage; a ripple generation circuit configured to inject a ripple signal to the first gain circuit; an operational transconductance amplifier (OTA) configured to receive the second feedback signal and a reference signal and to generate an output signal being coupled to the first gain circuit to adjust the first feedback signal; and a comparator configured to receive the first feedback signal and the reference signal and to generate a comparator output signal. The output signal of the OTA is applied to the first feedback signal to cancel a voltage offset in the regulated output voltage due to the injected ripple signal to the first gain circuit.

Abstract: A buck switching regulator includes a feedback control circuit including a first gain circuit generating a first feedback signal indicative of the regulated output voltage; a ripple generation circuit generating a ripple signal that is injected to the first feedback signal; and a comparator receiving a first reference signal and the first feedback signal to generate a comparator output signal. The switching regulator further includes an offset compensation circuit including a second gain circuit generating a second feedback signal indicative of the regulated output voltage; and an operational transconductance amplifier (OTA) configured to receive the second feedback signal and the first reference signal and to generate an output signal. The output signal of the OTA is coupled to the comparator to adjust an offset to the comparator so as to cancel the offset at the regulated output voltage due to the injected ripple signal.

Abstract: A container assembly for storing, treating, transporting and stabilizing a biological sample includes a container, a cap and a sample holder removably received in the container. The sample holder can be a platform-like device dimensioned to be supported on a ledge formed in the side wall of the container. The sample holder includes a central cavity for receiving the sample and immersing the sample in the stabilizing agent in the container. In another embodiment, the sample holder has a closure member for closing the open top end of the cavity. The container includes a liquid reagent in an amount sufficient to treat the biological sample. The biological sample is retained in a predetermined containment area of the container to maintain the biological sample immersed in the reagent without regard to the orientation of the container.

Abstract: The present invention is a safety shield assembly having a shield and a collar for connecting the shield to a fluid handling device whereby the shield may be pivoted with respect to the collar. Preferably, the safety shield assembly may be used with a needle assembly, an intravenous infusion set a syringe, a catheter or other fluid handling devices or assemblies that contain piercing elements. The shield includes a cannula channel with a finger lock for preventing re-exposure of the used needle.

Abstract: A container assembly for storing, treating, transporting and stabilizing a biological sample includes a container, a cap and a sample holder removably received in the container. The sample holder can be a platform-like device dimensioned to be supported on a ledge formed in the side wall of the container. The sample holder includes a central cavity for receiving the sample and immersing the sample in the stabilizing agent in the container. In another embodiment, the sample holder has a closure member for closing the open top end of the cavity. The container includes a liquid reagent in an amount sufficient to treat the biological sample. The biological sample is retained in a predetermined containment area of the container to maintain the biological sample immersed in the reagent without regard to the orientation of the container.

Abstract: A container assembly for storing, treating, transporting and stabilizing a biological sample includes a container, a cap and a sample holder removably received in the container. The sample holder can be a platform-like device dimensioned to be supported on a ledge formed in the side wall of the container. The sample holder includes a central cavity for receiving the sample and immersing the sample in the stabilizing agent in the container. In another embodiment, the sample holder has a closure member for closing the open top end of the cavity. The container includes a liquid reagent in an amount sufficient to treat the biological sample. The biological sample is retained in a predetermined containment area of the container to maintain the biological sample immersed in the reagent without regard to the orientation of the container.

Abstract: A blood collection set including a non-patient needle assembly interconnected with an intravenous needle assembly through tubing is provided. The non-patient needle assembly includes a hub assembly adapted for mounting with a blood collection set, and an internal blunting member including a blunted tip. The non-patient needle assembly further includes an external cannula concentric with the internal blunting member and including a non-patient puncture tip adjacent the blunted tip. The external cannula is axially displaceable with respect to the hub assembly between a first retracted position in which the non-patient puncture tip extends beyond the blunted tip and a second activated position in which blunted tip extends beyond the non-patient puncture tip.

Abstract: An adaptive capacitor charge/discharge network tailors the rate-of-change of a capacitor. The network includes two circuit groups with two or more parallel circuit branches, each branch including a current source and a controllable switch connected in series. The parallel circuit branches of one group are connected to Vss, and the parallel circuit branches of the other group are connected to Vdd. All the parallel circuit branches are connected to one plate of a capacitor, the other plate of the capacitor is connected to either Vss or Vdd. A control circuit controls the switch status, and incrementally controls the charge/discharge of the capacitor according to a predetermined order and a predetermined timing sequence to achieve a desired tailored charge/discharge curve.

Abstract: A blood collection set including a non-patient needle assembly interconnected with an intravenous needle assembly through tubing is provided. The non-patient needle assembly includes a hub assembly adapted for mounting with a blood collection set, and an internal blunting member including a blunted tip. The non-patient needle assembly further includes an external cannula concentric with the internal blunting member and including a non-patient puncture tip adjacent the blunted tip. The external cannula is axially displaceable with respect to the hub assembly between a first retracted position in which the non-patient puncture tip extends beyond the blunted tip and a second activated position in which blunted tip extends beyond the non-patient puncture tip.

Abstract: A circuit includes a bandgap core coupled to an input voltage and capable of producing an output voltage. The circuit also includes an amplifier coupled to the bandgap core. In addition, the circuit includes a switch coupling the bandgap core to an output terminal. The switch is capable of being closed to provide the output voltage to the output terminal. The switch is also capable of being opened during auto-zeroing of the amplifier.

Abstract: A container assembly and method for storing, treating, transporting and stabilizing a biological sample includes a container, a closure member and a sample holder removably received in the container. The sample holder can be a platform-like device dimensioned to be supported on a ledge formed in the side wall of the container. The sample holder includes a central cavity for receiving the sample and immersing the sample in the stabilizing agent in the container. The closure member includes a body member to close the top end of the central cavity of the sample holder and to limit movement of the sample holder in the container. In another embodiment, the sample holder has a closure cap for closing the open top end of the cavity. The container includes a liquid reagent in an amount sufficient to treat the biological sample.

Abstract: A circuit and method for enabling a rapid adjustment of a reference voltage during a disable period such as a fault condition, shutdown condition, and the like, of a voltage regulator is described. A soft start circuit that is arranged to couple a reference voltage input of an error amplifier to a portion of an output voltage avoiding high current surges and optimizing start up time is modified to include a low resistance switch that provides a path for a reference node capacitance to rapidly discharge. The faster discharge may allow the reference voltage to match the output voltage even when the switch is activated for a very brief interval. This in return allows the output voltage to start up in a controlled manner after a disable period.

Abstract: Adjustment of the temperature dependence of the output voltage of a band gap circuit is achieved by intentionally mismatching currents flowing through nodes coupled to the inputs of an amplifier. Each node is coupled to a bipolar junction transistor and a resistor, such that an output voltage of the band gap circuit varies due to the temperature dependence of currents through the bipolar junction transistors and the temperature dependence of currents flowing through the resistors. Networks of parallel metal oxide semiconductor transistors are coupled to each node, with one network including transistors that may be selectively switched into or out of the network to adjust the effective channel width for that network, thereby altering the ratio of effective channel widths and adjusting the temperature dependence of the band gap circuit's output voltage.