Consider a CG amplifier shown in figure. Assume that μnCox = 400 μA/V2, (WIL) = 20, Vt = 1 V I = 1 mA, RD = 5 kohm, and ro = ∞. RS = 2kohm, Cgs = 1.5pF, Cgd = 0 pF, CL = 0.5 pF Find the frequency response of the voltage gain Av(s) and draw the frequency response.
Consider a CG amplifier as shown below. Assume the following parameters: Vdd = 3V, kn = 2mA/V2, Vt = 0.4V, and Rd = 10kΩ. Ignore channel length modulation and body effect, VB is a dc bias and equal to 1.1 V. The input signal applied to the amplifier is given by Vin = 0.25V + 0.01sin(2π × 10kHz × t). a. Calculate the de voltage at the output b. Calculate small signal gain of the amplifier
Consider the amplifier shown below. Transconductance of M1 is gm and there is no channel-length modulation. Assume the following parameters: RL = 5kΩ, gm = 2mS, RS = 1kΩ, C1 = 100fF, CL = 1pF. Calculate bandwidth (in MHz) of the amplifier using OCT. 24.1 MHz 12 MHz 32 MHz
Consider the current mirror depicted in Fig. P3.6 where Iin = 100 µA, R = 2 kΩ, and each transistor has W/L = 10 µm/0.4 µm. Given the 0.35-μm CMOS device parameters in Table 1.5, what drain voltage at Q2 will ensure that Iin is precisely equal to Iout?
The circuit shown in Fig. P4.1-3 illustrates a single-channel MOS resistor with a W/L of 4 mm/1 mm. Using Table 3.1-2 model parameters, calculate the small-signal ON resistance of the MOS transistor at various values for VS and fill in the table below. Note that the most positive supply voltage is 5 V. VS (volts) R (ohms) 1.0 3.0 5.0
(a) The current mirror shown below is designed to generate Io = 10 µA. Assume all the MOSFETs are identical with µnCox = 400 µA/V2 and overdrive voltage of 200mV. Neglect channel length modulation effects. Find the error in the mirror ratio if for all MOSFETs threshold voltage is 0.5V and the channel length modulation coefficient is 0.5V-1. (b) Find the output resistance of the current mirror.
Figure P4.1-12 illustrates a circuit that contains a charge-cancellation scheme. Design the size of M2 to minimize the effects of charge feedthrough. Assume a slow rise and fall time of the clock.
The following circuit shows a MOS Wilson mirror in which Q1 and Q3 are matched, and they have the same (W/L)1 ratio that is 2 times of the (W/L)2 of Q2. All MOSFETs have the same Vt. 1) Derive the relationship between lout and IREF 2) Using small-signal model of the MOSFETs, derive and appreciate the output resistance of the current source, Ro.
The three-transistor circuit shown in Fig. P3.7 is lo be used as a current source. For this circuit, the. 0.18-µm CMOS device parameters in Table 1.5 are used, (W/L)1 = 4 µm/0.25 µm and (W/L)2 = 12 µm/0.25 µm. a) Determine the size of transistor so that I1 = 200 µA. b. What is the maximum voltage that can appear at Vo while still keeping in saturation? c. Keeping the device sizes the same, calculate a new value for the resistor so that I1 = 250 µA.
A simple MOSFET current mirror is shown in figure Q.6. The supply voltages are ±5 V. The two transistors are identical and have kn = 1 mA/V2, Vtn = 0.5 V and λ = 0.04 V−1. The reference current is 200 µA. The load resistor is 8 kΩ. (a) Determine the value of the reference resistor, Rref. (b) Calculate the output current Iout and voltage Vout using the MOSFET current-voltage relation in saturation, including the channel length modulation effect. (c) Calculate the output current Iout and voltage Vout using the MOSFET’s large-signal equivalent circuit (i.e. IDS0, Vov & ro ).
Consider the common-source amplifier shown in Fig. P3.11. The transistors are sized (W/L)1 = 6 µm/0.3 µm and (W/L)2 = 4 µm/0.3 µm. Transistor Q1 is biased so that Veff1 = 200 mV. Using the 0.18−µm CMOS device parameters in Table 1.5, and assuming a supply voltage of 1.8 V, estimate: a. the power consumption of the amplifier b. the small-signal output resistance of the amplifier c. the small-signal gain of the amplifier, vout /vin
Consider the current mirror circuit shown in Figure 4 on page 6 where an additional resistor R is connected between the gates of the MOSFETS and ground. Assume all transistors are in saturation and you can ignore Early effect. (a) Given that IREF = 250 µA, Kn’ for the MOSFET is 10 µA/V2, VTN = 1 V, (W/L)1 = 5, (W/L)2 = 10 and R = 20 kΩ, find the values of the DC voltage VGS1 and DC currents ID1 and ID2. (10 Marks) (b) Perform an AC small-signal analysis to find an algebraic expression of the input resistance Rin in terms of the transconductance gm of the MOSFETS and the resistor R. Indicate clearly the gm of the i-th transistor as gmi. For example, the gm of transistor M1 should be written as gm1. (5 Marks) (c) Using the transistor parameters and resistor values given in part (a), find out the magnitude of the input resistance Rin found in part (b). (5 Marks)