ltc1264-7 Linear Technology Corporation, ltc1264-7 Datasheet - Page 4

• Manufacturer Part Number: ltc1264-7
• Description: Linear Phase, Group Delay Equalized, 8th Order Lowpass Filter
• Manufacturer: Linear Technology Corporation

LTC1264-7
ELECTRICAL C
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: Input frequencies, f, are linearly phase shifted through the filter as
long as f ≤ f
Figure 1 curve (A) shows the typical phase response of an LTC1264-7
operating at f
(B), depicts the ideal linear phase response of the filter. It is described by:
phase shift = 180° – F (f/f
F is arbitrarily called the “phase factor” expressed in degrees. The phase
factor together with the specified deviation from the ideal straight line
allows the calculation of the phase at a given frequency. Note, the
maximum phase nonlinearity, Figure 1, occurs at the vicinity of f = 0.25 f
and = 0.75 f
in Figure 1 is: phase shift = 180° – 407° (70kHz/100kHz) ± nonlinearity =
–104.9° ± 1% or –104.9° ± 1.05°.
Note 3: Group delay and group delay deviation are calculated from the
measured phase factor and phase deviation specifications.
Note 4: The filter cutoff frequency is abbreviated as f
Note 5: The AC swing is typically 9V
± 2.5V supply respectively. For more information refer to the THD + Noise
vs Input graphs.
4
C
C
; f
CLK
. Example: The phase shift at 70kHz of the LTC1264-7 shown
C
= cutoff frequency.
= 2.5MHz, f
C
); f ≤ f
C
HARA TERISTICS
= 100kHz. An endpoint straight line, curve
C
.
P-P
, 5.6V
C
P-P
, 1.8V
CUTOFF
P-P
with ± 7.5V, ± 5V,
or f
C
.
C
Figure 1. Phase Response in the Passband (Note 2)
–180
–270
–360
–90
180
90
0
0
10
20
30
FREQUENCY (kHz)
40
50
60
A
f
(f
CLK
CLK
70
= 2.5MHz
/f
80
C
) = 25:1
B
LTC1264-7 F01
90
100
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