1. PROJECT 2 CASCODE
AMPLIFIER
Steven Hackbarth and Yarob Bahabri

2. LT SPICE DIAGRAM 1MA ICQ
• VCEQ≈10V
• ICQ≈1MA
• RC and RE must drop 5V
• Ratio between R2 and R1≈ 2/3

3. COMPONENT SELECTION 1MA ICQ
• RC and RE must drop 5V
• Used 5.1KΩ for both
• Ratio between R2 and R1≈ 2/3
• Tested small R1 and R2, -9dB

4. COMPONENT
SELECTION10UA ICQ
• RC and RE must still drop 5V
• Used 510kΩ for both
• Ratio between R2 and R1≈ 2/3
• No changes needed aside RC
and RE.

5. SIMULATED RESULTS 1MA ICQ
• 100mV p-p input
• 10.5V p-p Vout

6. SIMULATED RESULTS 10UA ICQ
• 1.96V p-p Vout

7. EXPERIMENTAL SET UP
• Problems with noise.
• Switched boards
• Rebuilt circuit
• Changed probes

8. RESULTS 1MA ICQ
• Best results around 100kHz
• Vmax=7.5V
• 37.5dB at 80kHz-100kHz
• -3dB 5.25V
• This happened at 320kHz

9. RESULTS 10UA ICQ
• Best results around 20kHz
• Vmax=0.788V
• 17.9dB at 20kHz
• -3dB 0.56V
• This happened at 50kHz

10. ANALYSIS OF RESULTS 1MA ICQ VS EXPERIMENT
• Simulation max = 40.4dB at 188kHz with -3dB at 7.5MHz
• Actual results 37.5dB at 80kHz-100kHz with -3dB at 320kHz
• -7.18% difference for max vout
• -95.7% difference for upper frequency

11. ANALYSIS OF RESULTS 10UA ICQ VS EXPERIMENT
• Simulation max = 25.8dB at 253kHz with -3dB at 1.12MHz
• Actual results 17.9dB at 20kHz with -3dB at 50kHz
• -30.6% difference for max vout
• -92.1% difference for upper frequency

12. ANALYSIS OF RESULTS 1MA VS 10UA LTSPICE
40.4
25.8
37.5
17.9
0
5
10
15
20
25
30
35
40
45
1mA 10uA
Comparison of dB Results for Vout/Vin
Simulated Experimental
188
253
100
20
0
50
100
150
200
250
300
1mA 10uA
Comparison of Max Vout/Vin kHz
Simulation Experimental
7.5
1.12
0.32
0.05
0
1
2
3
4
5
6
7
8
1mA 10uA
Upper Half-Power Frequency
MHz
Simulation Experimental

13. POSSIBLE USE

14. SERVICEABILITY
• There was no most critical resistor
• Changed all values +/-5% as shown
• 40.4dB dropped to 39dB
• -3.47% difference in operation

15. COST
• $50 Labor is the only item to pay for and once designed, it can be built in less
than an hour by one person.