The circuit below, Figure 1, shows an amplifier with a diode in the feedback. The amplifier can be considered to be ideal. The diode has a threshold voltage of 0.6 V. The values for the components are R1 is 1 k0, R2 = R3 = 9 KQ. Determine the transfer function of this circuit.

Problem C It is desired to have a gain of 20 for frequencies up to 180 kHz. Determine the minimum unity gain frequency specification for the op amp. The gain should be within at least 98% Vsig Rin + Rf Vcc/-Vcc +12v/ -12V Vout

Figure 6 (a) shows the circuit diagram for a differential amphfier. You may assume that M and M, have identical parameters. Referring to Figure 6 (a): (a) What kind of amplifier is it? What is its role in a three-stage op amp? Draw the small signal equivalent eircuit and derive the differential voltage gain Aag. For the analysis consider RDI RD2 >>Rp State any assumption. (b) RD. gml gm gm, and r re=r What is the new Adr in the circuit of Figure 6 (b), where a PMOS current source has replaced the two drain resistors Ror R Rp and a NMOS current sink has replaced the source resistor Rs? (c) What are the advantages in using the circuit of Figure 6 (b) instead of Figure 6 (a) to realize an op amp? (d) Ven Ms Mg Rp1 Rpa Vo HM, My M Ma M3 Vss 0 V Vss 0 V Figure 6(b) Figure 6 (a)

Assuming an ideal· op-amp's saturation voltage- UsSAT = +15V. For the- circuit in Figure · if u = 3V, the output voltage of op-amp is (404) i 10