摘要:
An electromechanical system (MEMS) voltmeter. An exemplary MEMS voltmeter includes a proof mass mounted to a substrate in a teeter-totter manner. The MEMS voltmeter also includes an input voltage plate located on the substrate under a first end of the proof mass. The first input voltage plate receives a voltage from a device under test. A drive voltage plate is located on the substrate under a second end of the proof mass. A first sense input voltage plate is located on the substrate under the first end of the proof mass. A second sense voltage plate is located on the substrate under the second end of the proof mass. A rebalancing circuit receives signals from the proof mass and the first and second sense voltage plates and generates a voltage value that is equal to the root mean square (RMS) voltage of the device under test.
摘要:
This disclosure is directed to devices and integrated circuits for instrumentation amplifiers. In one example, an instrumentation amplifier device uses two non-inverted outputs of a first multiple-output transconductance amplifier, and a non-inverted output and an inverted output of a second multiple-output transconductance amplifier. Both multiple-output transconductance amplifiers have a non-inverted output connected to an inverting input, and a non-inverting input connected to a respective input voltage terminal. A first resistor is connected between the inverting inputs of both multiple-output transconductance amplifiers. The outputs of both multiple-output transconductance amplifiers are connected together, connected through a second resistor to ground, and connected to an output voltage terminal. In other examples, two pairs of outputs from triple-output transconductance amplifiers are connected to provide two voltage output terminals, and may also be connected to buffers or a differential amplifier. These provide various advantages over traditional instrumentation amplifiers.
摘要:
This disclosure is directed to devices and integrated circuits for instrumentation amplifiers. In one example, an instrumentation amplifier device uses two non-inverted outputs of a first multiple-output transconductance amplifier, and a non-inverted output and an inverted output of a second multiple-output transconductance amplifier. Both multiple-output transconductance amplifiers have a non-inverted output connected to an inverting input, and a non-inverting input connected to a respective input voltage terminal. A first resistor is connected between the inverting inputs of both multiple-output transconductance amplifiers. The outputs of both multiple-output transconductance amplifiers are connected together, connected through a second resistor to ground, and connected to an output voltage terminal. In other examples, two pairs of outputs from triple-output transconductance amplifiers are connected to provide two voltage output terminals, and may also be connected to buffers or a differential amplifier. These provide various advantages over traditional instrumentation amplifiers.
摘要:
Methods and systems are provided for comparing currents. The method includes driving a first current through a first X leg of a first current conveyor circuit and a second current through a second X leg of a second current conveyor circuit. The method further includes draining a third current from a first X terminal of the first current conveyor circuit to produce a first positive transistor current and a first negative transistor current, and draining a fourth current from a second X terminal of the second current conveyor circuit to produce a second positive transistor current and a second negative transistor current. The method further includes summing the first positive transistor current and the second negative transistor current to produce a first current output, the first negative transistor current and the second positive transistor current to produce a second current output, and the first current output and the second current output to produce a summed current output.
摘要:
An improved motor commutation pulse detection circuit for comparing a filtered motor current signal to a threshold value, where the circuit is responsive to the actual or expected amplitude of the commutation pulses for adjusting the motor current signal or the threshold value so that the compared threshold value is substantially equal in amplitude to minimum amplitude commutation pulses in the compared motor current signal. In one circuit, the threshold value is varied in accordance with the average current flowing through the motor at the time of the commutation event. In another circuit, the threshold is effectively switched between a high value and a low value depending on the mode of operation of the motor. A motor run detection threshold is activated during motor running periods, while a motor brake detection threshold is activated during motor braking. The run time detection threshold is set to a relatively high value to detect the relatively high amplitude commutation pulses that occur during motor running, while the brake detection threshold is set to a relatively low value to detect the relatively low amplitude commutation pulses that occur during motor braking. The threshold can effectively be changed by attenuating the commutation signal by a predetermined factor during motor run periods.
摘要:
This invention relates to source-coupled logic (SCL) which is a functional derivative of emitter-coupled logic (ECL). ECL is widely recognized as having the characteristics of high speed (low propagation delay) and low power supply noise generation. The SCL of the prior art succeeds at maintaining and improving the low noise characteristics of this architecture but does not fulfill the promise of high speed that one would expect from a current-mode logic. In addition, it uses a differential form of logic that is not as flexible and easy-to-use as a reference controlled or “single-ended” logic. The SCL disclosed here has the desired high speed properties and maintains the ease of use that is a property of reference controlled ECL. In addition, the reference controlled SCL of this invention provides new capabilities that make it even more flexible than ECL in generating logical switching functions.
摘要:
An electromechanical system (MEMS) voltmeter. An exemplary MEMS voltmeter includes a proof mass mounted to a substrate in a teeter-totter manner. The MEMS voltmeter also includes an input voltage plate located on the substrate under a first end of the proof mass. The first input voltage plate receives a voltage from a device under test. A drive voltage plate is located on the substrate under a second end of the proof mass. A first sense input voltage plate is located on the substrate under the first end of the proof mass. A second sense voltage plate is located on the substrate under the second end of the proof mass. A rebalancing circuit receives signals from the proof mass and the first and second sense voltage plates and generates a voltage value that is equal to the root mean square (RMS) voltage of the device under test.
摘要:
A temperature compensated low voltage reference circuit can be realized with a reduced operating voltage overhead and reduced spatial requirements This is accomplished in several ways including integrating one or more bipolar junction transistors into a current differencing amplifier and reducing the number of components required to implement various voltage reference circuits. All of the reference circuits may be constructed with various types of transistors including DTMOS transistors.
摘要:
A differential current-mode sigma-delta digital-to-analog converter (SD DAC) and a method for generating positive and negative reference voltages in a sigma-delta digital analog converter are described. The SD DAC includes a low pass filter (LPF) having a first and second input. The SD DAC further includes a first resistance and a second resistance coupled together at a common node. The first resistance may be coupled to the first input of the LPF and the second resistance may be coupled to the second input of the LPF. Additionally, the SD DAC includes a current supply and a switching network for supplying current from the current supply to the first and second resistances. The current supply and the resistances operate to generate a first voltage and a second voltage at the first and second inputs of the LPF.
摘要:
A temperature compensated low voltage reference circuit can be realized with a reduced operating voltage overhead. This is accomplished in several ways including minimizing drain voltage variation at the drains of two inter-connected transistors and implementing a current conveyer in order to adjust the temperature coefficient of an output current or voltage. Various combinations of voltage minimization and temperature coefficient adjustments may be used to design a reference circuit to a circuit designer's preference. A temperature compensated current source may also be created. The temperature compensated current source may be used to provide a wide range of output voltages. All of the reference circuits may be constructed with various types of transistors including DTMOS transistors.