high pass filter with analog electronic
TRANSCRIPT
Lecture 11
Welcome to our presentation
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Topic: High-pass filter
By Dilouar HossainEmail- [email protected]
Lecture 112
Group members : 1. Md. Saiful Islam- 151-33-2411 2. Shreekanta Sarker- 151-33-24693. S.M. Sabbir Hossain- 151-33-23224. Majbah Uddin Ahmed- 151-33-25055. Rajib Laskar- 151-33-2349
Lecture 113
High-pass filter A high-pass filter is a filter that passes high
frequencies well, but attenuates (or reduces) frequencies lower than the cutoff frequency.
The actual amount of attenuation for each frequency varies from filter to filter.
A high-pass filter is the opposite of a low-pass filter. It is useful as a filter to block any unwanted low
frequency components of a complex signal while passing the higher frequencies.
Lecture 11
High Pass Filter
a) 1st Order
AV (dB)
AV(max)
AV(max) - 3
fc
0.1fc
0.01fc
AV(max) - 20
AV(max) - 40
+20dB/dec
f (Hz)
R1
R2
_
+Vin
+V
-V
RA
CAVo
Lecture 11
Analysis
At 0 < f < fc, high pass filter will attenuate the frequencies at roll-off of +20dB/decade because XCA is decreasing starts from ∞. When XCA=∞,
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At f = fc, the gain is 0.707AV(max) or in dB, AVdB(max)-3 where the magnitude of the capacitive reactance, XCA equals the resistance of the resistor, RA
At f > fc, high pass filter will pass the frequencies because XCA is decreasing to 0. When XCA= 0
Lecture 11
40dB/decade filterDesign procedure :
1.choose a cutoff frequency.2. Let c1=c2=c and choose a convenient value.
3. R1 = 1.414/WcC 4. R1 = 2R2. 5. Rf = R1
Lecture 117
Vo
R1
R2
_
+Vin
+V
-V
RA
CACB RB
AV (dB)
AV(max)
AV(max) - 3
fc0.1fc
0.01fc
AV(max) - 40AV(max) - 80
+40dB/dec
f (Hz)
AV(max) = 1+ R1
R2
1 2 RARBCACB
fc = fAfB 1
2RACA 1
2RBCB
= =
Lecture 118
+60dB/decade filter:
A high-pass filter of +60 db/decade can be constructed by cascading a +40 db/decade filter with a +20 db/decade filter.
Lecture 119
Design procedure of +60 db/decade high pass filter:1. choose cutoff frequency Wc or fc.2.Let C1=C2=C3=C and choose a convenient value between 100 pF to .1 mF3. R3= 1/WcC4. R1=2R35. R2= R3/2
Lecture 1110
Applications of active high pass filters
-These are used in the loud speakers to reduce the low level noise.
-Eliminates rumble distortions in audio applications so these are also called are treble boost filters.
-These are used in audio amplifiers to amplify the higher frequency signals.
-These are also used in equaliser.
Lecture 1111
Thank you….