LTC1264-7C Linear Technology, LTC1264-7C Datasheet - Page 3

• Manufacturer Part Number: LTC1264-7C
• Description: Linear Phase/ Group Delay Equalized/ 8th Order Lowpass Filter
• Manufacturer: Linear Technology

ELECTRICAL C
V
time 1 s) and all gain measurements are referenced to passband gain, unless otherwise specified.
PARAMETER
Group Delay (t
t
(Note 2, 3)
Group Delay Ripple
(Note 2)
Input Frequency Range
(Table 9, 10)
Maximum f
Clock Feedthrough
Wideband Noise
(1Hz f < f
Input Impedance
Output DC Voltage Swing
(Note 4)
Output DC Offset
(f
Output DC Offset TempCo
Power Supply Current
(f
Power Supply Range
The
Note 1: Input frequencies, f, are linearly phase shifted through the filter as long as f f
f
Figure 1 curve (A) shows the typical phase response of an LTC1264-7 operating at
f
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
Figure 1 is: phase shift = 180 – 407 (70kHz/100kHz) nonlinearity
104.9
Note 2: Group delay and group delay deviation are calculated from the measured phase
factor and phase deviation specifications.
Note 3: The filter cutoff frequency is abbreviated as f
Note 4: The AC swing is typically 9V
respectively. For more information refer to the THD + Noise vs Input graphs.
d
C
CLK
S
CLK
CLK
= ( F / 360)(1/f
= cutoff frequency.
= 7.5V, R
= 2.5MHz, f
= 1MHz)
= 1MHz)
denotes specifications which apply over the full operating temperature range.
1% or –104.9
CLK
CLK
C
and = 0.75 f
d
)
)
C
L
C
);
= 10k, T
= 100kHz. An endpoint straight line, curve (B), depicts the ideal linear
C
. Example: The phase shift at 70kHz of the LTC1264-7 shown in
1.05 .
A
= 25 C, f
HARA TERISTICS
P-P
CUTOFF
, 5.6V
C
P-P
= 100kHz or 50kHz, f
, 1.8V
CUTOFF
CONDITIONS
(f
(f
(f
(f
(f
(f
(f
(f
(f
(f
V
V
V
25:1, 7.5V, f = f
V
V
V
V
V
V
25:1, V
50:1, V
25:1, V
50:1, V
V
V
V
P-P
S
S
S
S
S
S
S
S
S
S
S
S
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
CLK
= Single 5V (GND = 2V)
= 5V
= 7.5V
= Single 5V
= 5V
= 7.5V
= 2.375V
= 5V
= 7.5V
= 2.375V
= 5V
= 7.5V
with 7.5V, 5V, 2.5V supply
/ f
/ f
/ f
/ f
/ f
/ f
/ f
/ f
/ f
/ f
or f
C
C
C
C
C
C
C
C
C
C
S
S
S
S
) = 25:1, f f
) = 50:1, f f
) = 25:1, f f
) = 50:1, f f
) = 25:1, f f
) = 50:1, f f
) = 25:1, f f
) = 50:1, f f
) = 25:1
) = 50:1
= 5V
= 5V
= 5V
= 5V
C
.
CLK
CLK
C
); f f
CUTOFF
CUTOFF
CUTOFF
CUTOFF
CUTOFF
CUTOFF
CUTOFF
CUTOFF
= 2.5MHz, TTL or CMOS level (maximum clock rise or fall
C
.
= –
C
;
Figure 1. Phase Response in the Passband (Note 1)
–180
–270
–360
–90
180
90
0
0
10
10.9
20.8
MIN
2.375
30
20
2.0
3.0
30
FREQUENCY (kHz)
40
140 5%
160 5%
175 5%
<f
<f
11.3
21.6
TYP
120
CLK
50
50
11
14
17
100
100
200
200
1.0
1.0
1.0
2.3
3.8
CLK
2
3
5
/2
60
LTC1264-7
A
f
(f
CLK
CLK
70
= 2.5MHz
/f
MAX
80
11.7
22.9
C
75
22
22
23
26
28
32
220
220
) = 25:1
2.0
2.0
LTC1264-7 F01
B
8
90
100
UNITS
V
V
V
V
3
MHz
MHz
MHz
V/ C
V/ C
RMS
RMS
RMS
RMS
kHz
kHz
mV
mV
mA
mA
mA
mA
mA
mA
k
%
%
%
%
V
V
V
V
s
s
s
s