Contents
How is a sample and hold capacitor connected?
A Sample and Hold circuit, of the form shown in Figure 11.3, is connected to a signal of source resistance 2 kΩ; its output is connected in turn to an ADC. The Sample and Hold capacitor is 90 pF. What acquisition time should be allowed if 10-bit resolution is required by the ADC?
What is the transfer function of a switched capacitor?
Introduction to Switched-Capacitor Circuits wideband signals because it exhibits a high-pass transfer function. In fact, the transfer function is given by V out V in (s) R F 1 C 2 s R F + 1 C 2 s 1 C 1 s (12.3) = R F C 1 s R F C 2 s + 1; (12.4) indicating that V out =V in C1 =C 2 only if! (R F 2) 1.
How is the amount of charge held by a capacitor determined?
The amount of charge a capacitor holds depends on the p.d. between its plates and on its capacitance. Let us consider the p.d. first. If a capacitor holds a certain amount of charge when the p.d. is 1 V, it holds double that amount when the p.d. is 2 V.
Can a hold capacitor be used to reduce droop?
Droop can be reduced by increasing the value of the hold capacitor, but this will also increase acquisition time and reduce bandwidth in the track mode. Differential techniques are often used to reduce the effects of droop in modern IC sample-and-hold circuits that are part of the ADC.
How to calculate the size of a smoothing capacitor?
The capacitor size calculator available online helps you to calculate a smoothing capacitor. Simply enter the values using the formula described above to calculate the size you need. When converting capacitor circuits, caution is always required.
How to calculate the hold up capacitor size?
With a line voltage V line = 415 V, load power P load = 70 W, and efficiency η = 97.2%, then: V disch = √2/2 × V in_max = 415 V at f = 50 Hz, ω = 2πf = 314 sec -1, and P in = P load /η = 72 W From this we obtain a value for V C_av:
How is the charge of a capacitor proportional to the P.D.?
Let us consider the p.d. first. If a capacitor holds a certain amount of charge when the p.d. is 1 V, it holds double that amount when the p.d. is 2 V. It holds a hundred times that amount when the p.d. is 100 V. Charge is proportional to the p.d. between the plates.