Capacitors and Op Amps

Study Notes

Capacitors store energy in the form of an electric field.
The energy stored in a capacitor is given by: W = (1/2)CV², where C is capacitance and V is voltage.
Capacitance (C) is directly proportional to the plate area (A) and inversely proportional to the plate separation distance (d): C ~ A/d.
Electrical activity in the body results from ionic solution mixing through the cell membrane.
Resting neuron cell membrane potential is approximately -70 mV.
The output voltage of an amplifier cannot exceed its power supply voltage: -Vs < Vout < +Vs.
In an op amp open-loop configuration, the output voltage Vout = A * (V1 - V2), where A is the open-loop gain, and V1 and V2 are the input voltages.
An op amp in a buffer amplifier configuration has a gain of 1; Vout = Vin.
In the inverting amplifier configuration; Vout = -Vin.
The output voltage of an op amp remains between -Vdc < Vout < +Vdc.
In Amplitude Modulation (AM), the amplitude of the carrier signal is modulated by the signal being transmitted.
In Frequency Modulation (FM), the frequency of the carrier signal is modulated by the signal being transmitted.
In an AM receiver circuit, the diode rectifies the signal, and the low pass filter removes the high-frequency carrier wave.
When converting analog signals into digital signals; sampling frequency measures the rate at which the amplitude of an analog signal is measured.
When converting analog signals into digital signals; bit depth is the binary resolution (2^n possible values) that the amplitude of an analog signal is measured.
The Nyquist-Shannon sampling theorem states a signal can be reconstructed perfectly if the sampling rate is at least twice the signal frequency.
Key logic gate functions to memorize: AND, OR, NOT, NAND.
Understand FDMA, TDMA, and CDMA
Understand how resistive and capacitive touchscreens work.
Understand the role of a clock in sequential logic circuits
Logic gates respond when clock signals switch, either rising (low to high) or falling (high to low)
You should know what a shift register is.