EE6307
HOME ASSIGNMENT 1
1 (a) Design and size a Miller-compensated 2-stage op-amp in the TSMC18 process that
matches the Reid amplifier (2003) specifications with passband gain = 100 (i.e. 40dB), bandwidth = 7kHz and UGBW = 700kHz (all within ±10% margin).
The first stage input Gm required will be based on your Matriculation number.
If the Last digit of your Matriculation Number is Odd, design for Gm = 1 mA/V. If the Last Digit is Even, design for Gm = 0.1 mA/V.
For example:
|
G2212345J
|
Gm = 1 mA/V
|
|
G2212346J
|
Gm = 0.1 mA/V
|
The choice of input transistors will depend on the last Letter of your Matriculation Number. Letters A-F must use NMOS inputs, and Letters G-Z must use PMOS inputs.
For example:
|
U2212345{A-F}
|
Use NMOS inputs
|
|
U2212346{G-Z}
|
Use PMOS inputs
|
(i) A template for the Reid amplifier is given, with only the first stage of the opamp subcircuit provided, that you need to complete with a second stage.
(ii) Use the TSMC18 curves provided to size all NMOS transistors set to have the same Wn, Ln values and all PMOS transistors set to have the same Wp, Lp values as parameters specified in the top-level simulation. All unknown parameter values are initially set to 1u by default as shown below.
Do not modify the following:
• PMOS pseudo-resistors provide the DC biasing on V+ and V- with Lr=4um and Wr=1um to provide very high resistance > 1GΩ .
• Supply voltage VDD = 2V, DC ground reference Vref= 1V (equivalent to a ±1V low-voltage dual-supply)
• Output load capacitance CL = 10pF
• Capacitor divider {C1} = 20pF and {C2} = 0.2pF for {C1}/{C2} = 100
(iii) Show all calculations how you derive the final Ibias parameter value (noteID for each input transistor will be Ibias/2) along with any Miller compensation component values (Rz, Cc) if required.
(iv) Explain all the design requirements you used to achieve closed loop stability.
(v) Show a screenshot or a drawing of your final op-amp configuration, with all the component values labelled clearly.
(b) Simulate your design in LTspice17 to verify if your hand calculations are correct. Note you cannot use LTspice24, as it does not record the AC small signal parameters in the .log file. So you mustinstall LTspice17instead, highlighted below.
For more details about the bug in LTspice24, please visit this link.
Attach screenshots of the following:
(i) .AC simulation of Vo from 0.1 Hz to 100MHz
(ii) .NOISE simulation from 0.1Hz to 50kHz as given, with the total integrated output noise calculated like shown below. (Hold Ctrl- and click on the onoise label at the top of the graph to integrate the curve)
(iii) Your .log file with the .MEAS results and timestamp from the .AC simulation as shown below.
(iv) Finally, attach a screenshot of the input transistors AC small signal parameters from Id to Gmb values (showing anNMOS input pair highlighted below)
And also show the AC small signal parameters from Id to Gmb for the common source second stage amplifier (showing PMOS below)
Explain any significant differences from your hand calculations in part (a).