a sample and hold (s/h) circuit, having a holding capacitor of 0.1nf, is used at the input of an adc (analog - to - digital converter). the conversion time of the adc is 1 microsec. and during this time, the capacitor should not loose more than 0.5% of the charge put across it during the sampling time.the maximum value of the input signal to the s/h circuit is 5v. the leakage current of the s?h circuits should be less than (a)2.5ma(b)0.25ma(c)25µa(d)2.5µa

Which of the followings are TRUE about ADC?Hold – the action of holding the voltage for a brief amount of time by use of a capacitor.n represents the number of bits in the digital value of the conversion. The smaller the n, the closer the digital value is to the actual analog voltage.Analog-to-Digital Converter (ADC or A2D) – a circuit that takes in an analog voltage and produces a digital representation of its value.Sample – the action of duplicating the voltage value of the input signal.The number of bits n is called the ADC’s accuracy.Digitizing, quantizing, or discretizing is to convert the analog voltage into a digital number.

A capacitor (with capacitance C) is placed in series in a circuit with a power supply and a resistor. The power supply has some internal resistance R1 = 0.2 kΩ and the resistor has value R2 = 0.7 kΩ.A square wave voltage input is supplied, with the voltage switching between constant positive and negative levels. The behaviour of the current through the circuit is observed on an oscilloscope. It is seen to drop exponentially with time after each voltage switch. The half time is measured to be t1/2= 30 µs.Calculate the value of the capacitor C. Give your answer to 3 significant figures.Note you need to use the total resistance in the circuit R = R1 + R2 in your calculation.Entering numbers in scientific notation: Example: 1.45 x 10-9 should be entered as 1.45E-9

A capacitor (with capacitance C) is placed in series in a circuit with a power supply and a resistor. The power supply has some internal resistance R1 = 0.4 kΩ and the resistor has value R2 = 0.7 kΩ.A square wave voltage input is supplied, with the voltage switching between constant positive and negative levels. The behaviour of the current through the circuit is observed on an oscilloscope. It is seen to drop exponentially with time after each voltage switch. The half time is measured to be t1/2= 36 µs.Calculate the value of the capacitor C. Give your answer to 3 significant figures.Note you need to use the total resistance in the circuit R = R1 + R2 in your calculation.Entering numbers in scientific notation: Example: 1.45 x 10-9 should be entered as 1.45E-9

Figure shows the capacitors in steady state, with S open. When S is closed :-

A capacitor in an RC circuit with R = 2 ohms and C = 4 uF is being charged. The time required for the capacitor voltage to reach 63.2 percent of its steady-state value is:a.8 sb.8 usc.2 sd.2 us