Ece 511 analog integrated circuits fall 2016

Question

Analog Integrated Circuits Assignment

For the transistors used in the Operational Trans conductance Amplifier (OTA) below,

V_ton = 0.4V, V_top = -0.4V, µ_nC_ox = 0.3mA/V², µ_pC_ox = 0.1mA/V², and λ=0.2. Neglect body effect.

1. Complete the table on the following page related to the operating point for all transistors. This should help in computing the rest of the homework questions. I recommend a spreadsheet for this exercise.

2. Calculate the differential-mode gain (in dB).

3. Calculate the output swing of the circuit (min and max values).

4. Calculate the common-mode input range (min and max values).

5. If the OTA were placed in unity-gain feedback as a voltage-follower buffer (below), what is the maximum signal swing which can be buffered with no error incurred in closed loop gain?

6. What is the percent error in the closed loop gain due to T being finite?

7. If a 5pF capacitor were placed on the output node to ground, estimate the 3dB bandwidth of the circuit and the gain-bandwidth product (express in units of hertz, meaning you must remember the factor of 2*pi)

V_ton = 0.4V, V_top = -0.4V, µ_nC_ox = 0.3mA/V², µ_pC_ox = 0.1mA/V², and λ=0.2

Transistor	Type	W/L	Beta	Current	VDSAT	gm	gds	ro
M1, M2	PMOS	120
M3, M4	NMOS	50
M5, M6	NMOS	50
M7, M8	PMOS	120
M9, M10	PMOS	120
M11, M12	PMOS	30
M13, M14	PMOS	120
M15, M16	NMOS	10