LT10647FB_15 Datasheet, PDF (4/16 Pages) Linear Technology – Linear Phase, 8th Order Lowpass Filter

LTC1064-7
ELECTRICAL CHARACTERISTICS
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_C; f_C = cutoff frequency.
Figure 1 curve shows the typical phase response of an LTC1064-7
operating at f_CLK = 1MHz, ratio = 50:1, f_C = 20kHz and it closely matches
an ideal straight line. The phase shift is described by: phase shift =
180° – F (f/f_C); f ≤ f_C.
F is arbitrarily called the “phase factor” expressed in degrees. The phase
factor allows the calculation of the phase at a given frequency.
Example: The phase shift at 14kHz of the LTC1064-7 shown in Figure 1 is:
phase shift = 180° – 430° (14kHz/20kHz) ± nonlinearity = –121° ± 1% or
–121° ± 1.20°.
Note 3: Group delay and group delay deviation are calculated from the
measured phase factor and phase deviation specifications.
Note 4: Phase deviation and group delay deviation for LTC1064-7MJ is
±4%.
Note 5: The AC swing is typically 11V_P-P, 7V_P-P, 2.8V_P-P, with ±7.5V, ±5V,
±2.5V Supply respectively. For more information refer to the THD + Noise
vs Input graphs.
180
f_CLK = 1MHz
RATIO = 50:1
90
0
– 90
–180
–270
–360
02 4
6 8 10 12 14 16 18 20
FREQUENCY (kHz)
1164-7 F01
Figure 1. Phase Response in the Passband (Note 2)
10647fb
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