6 cl2_D7
47µF
47µF
47µF
cl2_D6
22µF
22µF
22µF
cl2_D5
12µF
12µF
12µF
cl2_D4
5.6µF
5.6µF
5.6µF
cl2_D3
2.7µF
2.7µF
2.7µF
cl2_D2
1.2µF
1.2µF
1.2µF
cl2_D1
0.68µF
0.68µF
0.68µF
cl2_D0
0.33µF
0.33µF
0.33µF
cl1_D7
47µF
47µF
47µF
cl1_D6
22µF
22µF
22µF
cl1_D5
12µF
12µF
12µF
cl1_D4
5.6µF
5.6µF
5.6µF
cl1_D3
2.7µF
2.7µF
2.7µF
cl1_D2
1.2µF
1.2µF
1.2µF
cl1_D1
0.68µF
0.68µF
0.68µF
cl1_D0
0.33µF
0.33µF
0.33µF
TABLE VI PARAMETERS DURING MEASUREMENT BASED ON SCHEMATIC IN FIG. A-1
c1
30µF
30µF
30µF
c2
20µF
20µF
20µF
Measurement
c3
30µF
30µF
30µF
c4
20µF
20µF
20µF
c5
30µF
30µF
30µF
vsin
1mV
1mV
1mV
Fig. 7. Photograph of the LPNF.
Notch Frequency (Hz) Code
60 Hz (Typical)
58 Hz
120 Hz
11111100
11111111
00000000
D27
1
1
0
D26
1
1
0
D25
1
1
0
D24
1
1
0
D23
1
1
0
D22
1
1
0
D21
0
1
0
D20
0
1
0
D17
1
1
0
D16
1
1
0
D15
1
1
0
D14
1
1
0
D13
1
1
0
D12
1
1
0
D11
0
1
0
D10 NMOS Threshold VDC
0
1
0
1V
1V
1V
3.75V
3.75V
3.75V
R_buffer1
10KΩ
10KΩ
10KΩ
R_buffer2
62KΩ
62KΩ
62KΩ
C_buffer
0.001µF
0.001µF
0.001µF
CL_1
40µF
40µF
40µF
CL_2
40µF
40µF
40µF
Fig. 8 shows the measured transfer function of the LPNF in Fig. 7. This transfer function is based on the collected data from measuring output voltage and input voltage at different frequencies with a Tektronix DPO2024B oscilloscope. It shows that the range of notch frequency in the measurements is from 58Hz to 120Hz depending on the digital code setting. The captured signals at points 1, 2 and 3 in Fig. 8 are shown in Figurers 9-14 (point 1, 2, and 3 are all for the transfer function with the code for a notch at 60Hz). In Figures 9-14, the unit of the vertical axis is dBV(RMS) and the unit of the horizontal axis is Hz. Fig. 9 and Fig. 10 show that when the input signal is at point 1 (5Hz) in Fig. 8, the output signal has
Fig. 8. Transfer function of the LPNF circuit.