10
LTC1060
1060fb
3. Highpass function: available only in mode 3 at the
ouput Pins 3 (18). (Figure 3.)
G(s) = H
OHP
H
OHP
= gain of the HP output for f→
s
2
s
2
+ s(ω
o
/Q) + ω
o
f
CLK
2
2
4. Notch function: available at Pins 3 (18) for several
modes of operation.
G(s) = (H
ON2
)
H
ON2
= gain of the notch output for f→
s
2 +
ω
2
o
s
2
+ (sω
o
/Q) + ω
o
f
CLK
2
2
H
ON1
= gain of the notch output for f→0
f
n
= ω
n
/2π; f
n
is the frequency of the notch occurrence.
5. Allpass function: available at Pins 3(18) for mode 4, 4a.
G(s) = H
OAP
H
OAP
= gain of the allpass output for 0 <f<
[s
2
– s(ω
o
/Q) + ω
o
]
s
2
+ s(ω
o
/Q) + ω
o
f
CLK
2
2
2
For allpass functions, the center frequency and the Q of
the numerator complex zero pair is the same as the
denominator. Under these conditions, the magnitude
response is a straight line. In mode 5, the center frequency
f
z
, of the numerator complex zero pair, is different than f
0
.
For high numerator Q’s, the magnitude response will have
a notch at f
z
.
Table 3. Modes of Operation: 1st Order Functions
MODE PIN 2 (19) PIN 3 (18) f
C
f
Z
6a LP HP
•
f
CLK
100(50)
R2
R3
6b LP LP
•
f
CLK
100(50)
R2
R3
7LPAP
•
f
CLK
100(50)
R2
R3
•
f
CLK
100(50)
R2
R3
Figure 1 Figure 2 Figure 3
f
0
; f
0
=
f
H
–
f
L
f
L
f
H
H
OBP
0.707 H
OBP
f
0
f
L
f
H
Q =
–1
20
1
2
2Q
f
L
= f
0
++ 1
(
(
(
)
1
2Q
1
2
2Q
f
H
= f
0
++ 1
(
(
(
)
BANDPASS OUTPUT
f(LOG SCALE)
GAIN (V/V)
TLC1060 • DFF01
H
OP
H
OLP
f
P
f
C
0.707 H
OLP
1
2
2Q
f
C
= f
0
•1 – + + 1
(
(
1
2
2
2Q
1 –
(
(
LOWPASS OUTPUT
f(LOG SCALE)
GAIN (V/V)
TLC1060 • DFF02
1
2
2Q
1
1
Q
f
P
= f
0
H
OP
= H
OLP
•
1 –
1
2
4Q
1 –
f
C
1
2
2Q
f
C
= f
0
•1 – ++ 1
– 1
– 1
1
(
(
1
2
2
2Q
1 –
(
(
f(LOG SCALE)
TLC1060 • DFF03
H
OP
H
OHP
f
P
0.707 H
OHP
HIGHPASS OUTPUT
GAIN (V/V)
1
2
2Q
1
Q
f
P
= f
0
•
H
OP
= H
OHP
•
1 –
1
2
4Q
1 –
DEFINITION OF FILTER FUNCTIONS
UU UU
ODES OF OPERATIO
UW
