Abstract:
Fault tolerant switches are provided herein. In certain embodiments, a fault tolerant switch includes a switch, a gate driver, and a clamp. The switch includes a switch p-type field effect transistor (PFET) and a switch n-type field effect transistor (NFET) electrically connected in series and controlled by the gate driver. Additionally, the clamp is electrically connected in parallel with the switch, and includes a forward protection circuit including a first diode and a first clamp FET in series, and a reverse protection circuit including a second diode and a second clamp FET in series. The clamp further includes a first gate bias circuit configured to bias a gate of the first clamp FET and a second gate bias circuit configured to bias a gate of the second clamp FET.
Abstract:
A control circuit for use with a four terminal sensor, the sensor having first and second drive terminals and first and second measurement terminals, the control circuit arranged to drive at least one of the first and second drive terminals with an excitation signal, to sense a voltage difference between the first and second measurement terminals, and control the excitation signal such that the voltage difference between the first and second measurement terminals is within a target range of voltages, and wherein the control circuit includes N poles in its transfer characteristic and N−1 zeros in its transfer characteristic such that when a loop gain falls to unity the phase shift around a closed loop is not substantially 2π radians or a multiple thereof, where N is greater than 1.
Abstract:
Subject matter herein can include identifying a biochemical test strip assembly electrically, such as using the same test circuitry as can be used to perform an electrochemical measurement, without requiring use of optical techniques. The identification can include using information about a measured susceptance of an identification feature included as a portion of the test strip assembly. The identification can be used by test circuitry to select test parameters or calibration values, or to select an appropriate test protocol for the type of test strip coupled to the test circuitry. The identification can be used by the test circuitry to validate or reject a test strip assembly, such as to inhibit use of test strips that fail meet one or more specified criteria.
Abstract:
A control apparatus is provided that can provide high dynamic resolution and is suitable for inclusion within an integrated circuit. The control apparatus receives a demand signal representing a desired value of a measurand, and a feedback signal representing a present value or a recently acquired value of the measurand. The processing circuit forms a further signal a further signal which is a function of the demand and feedback signals. The further signal is then subjected to at least an integrating function. The demand signal, feedback signal or the further signal is processed or acquired in a sampled manner. The use of such sampled, i.e. discontinuous, processing allows integration time constants to be synthesized which would otherwise require the use of unfeasibly large components within an integrated circuit, or the use of off-chop components. Both of these other options are expensive.
Abstract:
Fault tolerant switches are provided herein. In certain embodiments, a fault tolerant switch includes a switch, a gate driver, and a clamp. The switch includes a switch p-type field effect transistor (PFET) and a switch n-type field effect transistor (NFET) electrically connected in series and controlled by the gate driver. Additionally, the clamp is electrically connected in parallel with the switch, and includes a forward protection circuit including a first diode and a first clamp FET in series, and a reverse protection circuit including a second diode and a second clamp FET in series. The clamp further includes a first gate bias circuit configured to bias a gate of the first clamp FET and a second gate bias circuit configured to bias a gate of the second clamp FET.
Abstract:
Subject matter herein can include identifying a biochemical test strip assembly electrically, such as using the same test circuitry as can be used to perform an electrochemical measurement, without requiring use of optical techniques. The identification can include using information about a measured susceptance of an identification feature included as a portion of the test strip assembly. The identification can be used by test circuitry to select test parameters or calibration values, or to select an appropriate test protocol for the type of test strip coupled to the test circuitry. The identification can be used by the test circuitry to validate or reject a test strip assembly, such as to inhibit use of test strips that fail meet one or more specified criteria.
Abstract:
A control circuit for use with a four terminal sensor, such as a glucose sensor. The Glucose sensor is a volume product and typically its manufacture will want to make it as inexpensively as possible. This may give rise to variable impedances surrounding the active cell of the sensor. Typically the sensor has first and second drive terminals and first and second measurement terminals, so as to help overcome the impedance problem. The control circuit is arranged to drive at least one of the first and second drive terminals with an excitation signal, and control the excitation signal such that a voltage difference between the first and second measurement terminals is within a target range of voltages. To allow the control circuit to work with a variety of measurement cell types the control circuit further comprises voltage level shifters for adjusting a voltage at one or both of the drive terminals, or for adjusting a voltage received from one or both of the measurement terminals.