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

no-image

LTC1264-7C

Manufacturer Part Number
LTC1264-7C
Description
Linear Phase/ Group Delay Equalized/ 8th Order Lowpass Filter
Manufacturer
Linear Technology
Datasheet
FEATURE
A
TYPICAL
PPLICATI
Steeper Roll-Off Than Bessel Filters
High Speed: f
Phase Equalized Filter in a 14-Pin Package
Phase and Group Delay Response Fully Tested
Transient Response Exhibits 5% Overshoot and
No Ringing
65dB THD or Better Throughout a 100kHz Passband
No External Components Needed
Data Communication Filters
Time Delay Networks
Phase Matched Filters
V
8V
IN
NOTE: THE POWER SUPPLIES SHOULD BE BYPASSED BY A
0.1 F CAPACITOR CLOSE TO THE PACKAGE AND ANY PRINTED
CIRCUIT BOARD ASSEMBLY SHOULD MAINTAIN A DISTANCE
OF AT LEAST 0.2 INCHES BETWEEN ANY OUTPUT OR INPUT
PIN AND THE f
200kHz Linear Phase Lowpass Filter
A
S
C
O
PPLICATI
1
2
3
4
5
6
7
CLK
U
200kHz
LINE.
S
LTC1264-7
O
14
13
12
11
10
9
8
U
1264-7 TA01
V
–8V
f
8V
CLK
OUT
= 5MHz
Linear Phase, Group Delay
D
The LTC1264-7 is a clock-tunable monolithic 8th order
lowpass filter with linear passband phase and flat group
delay. The amplitude response approximates a maximally
flat passband and exhibits steeper roll-off than an equiva-
lent 8th order Bessel filter. For instance, at twice the cutoff
frequency the filter attains 28dB attenuation (vs 12dB for
Bessel), while at three times the cutoff frequency the filter
attains 55dB attenuation (vs 30dB for Bessel). The cutoff
frequency of the LTC1264-7 is tuned via an external TTL or
CMOS clock.
The clock-to-cutoff frequency ratio of the LTC1264-7 can
be set to 25:1 (pin 10 to V
When the filter operates at clock-to-cutoff frequency ratio
of 25:1, the input is double-sampled to lower the risk of
aliasing.
The LTC1264-7 is optimized for speed. Depending on the
operating conditions, cutoff frequencies between 200kHz
and 250kHz can be obtained. (Please refer to the Passband
vs Clock Frequency graphs.)
The LTC1264-7 is pin-compatible with the LTC1064-X
series.
ESCRIPTIO
f
f
CLK
C
= 200kHz
= 5MHz
Equalized, 8th Order
4-Level PAM Eye Diagram
U
500ns/DIV
+
Lowpass Filter
) or 50:1 (pin 10 to V
LTC1264-7
1264-7 TA02
).
1

Related parts for LTC1264-7C

LTC1264-7C Summary of contents

Page 1

... Bessel), while at three times the cutoff frequency the filter attains 55dB attenuation (vs 30dB for Bessel). The cutoff frequency of the LTC1264-7 is tuned via an external TTL or CMOS clock. The clock-to-cutoff frequency ratio of the LTC1264-7 can ...

Page 2

... CLK Phase Factor ( F ) Phase = 180 – (Note 1) Phase Nonlinearity (Note (Note 1) Operating Temperature Range LTC1264-7C ...................................... – LTC1264-7M ................................... – 125 C + Lead Temperature (Soldering, 10 sec)................. 300 0.3V ORDER PART NUMBER GND 3 ...

Page 3

... Note 1: Input frequencies, f, are linearly phase shifted through the filter as long cutoff frequency. C Figure 1 curve (A) shows the typical phase response of an LTC1264-7 operating 2.5MHz 100kHz. An endpoint straight line, curve (B), depicts the ideal linear CLK C phase response of the filter described by: phase shift = 180 – ...

Page 4

... LTC1264 TYPICAL PERFOR A Gain vs Frequency ±7. 1MHz CLK T = 25°C A –10 –20 –30 –40 50:1 25:1 –50 –60 –70 –80 –90 –100 1 10 100 1000 FREQUENCY (kHz) 1264-7 G01 Phase Factor vs f Max Representative Units) 450 V = ±7.5V S 445 ( 25:1 CLK ...

Page 5

... 1.5MHz 3 CLK T = 25° 2.0MHz CLK –1 – –3 –4 –5 10 100 FREQUENCY (kHz) LTC1264-7 Passband Gain vs f CLK ±7. 25 CLK –1 – 2 – 3 –4 –5 1000 ...

Page 6

... LTC1264 TYPICAL PERFOR A Gain vs f CLK 0.5MHz CLK 1MHz CLK 2MHz –10 CLK – –30 –40 –50 – SINGLE 5V S – 50:1 CLK C AGND = 2V – 25°C A –90 10 100 200 FREQUENCY (kHz) 1264-7 G17 Delay vs f CLK ...

Page 7

... Unit) CLK 0.000 180.00 25.000 71.77 50.000 – 37.11 75.000 – 146.19 100.000 – 255.85 LTC1264-7 Power Supply Current vs Power Supply Voltage 1MHz 44 CLK ...

Page 8

... LTC1264 TYPICAL PERFOR A Table 3. Passband Gain and Phase 25: CLK C A FREQUENCY (kHz) GAIN (dB 1MHz (Typical Unit) CLK 0.000 0.081 10.000 0.081 20.000 0.071 30.000 – 0.631 40.000 – 2.732 f = 2MHz (Typical Unit) CLK 0.000 – 0.016 20.000 – ...

Page 9

... CLK – gives a 50:1 ratio. For – 0 200 11 CLOCK SOURCE GND 8 DIGITAL SUPPLY V 1264-7 F02 OUT /f = 25:1 CLK CUTOFF 200 4 11 LTC1264-7 CLOCK SOURCE GND 7 8 DIGITAL SUPPLY OUT 1264-7 F03 /f = 25:1 CLK CUTOFF + 9 ...

Page 10

... Most of its frequency contents lie within the filter passband and it cannot be reduced with post filtering. For instance, the 50:1 LTC1264-7 wideband noise at 5V supply is 160 V 100 V RMS 145 V RMS ...

Page 11

... RMS IN CLK 0.7V (f 500kHz) If, for instance, an LTC1264-7 operating with a 100kHz RMS IN 0.5V (f 400kHz) RMS IN clock and 2kHz cutoff frequency receives a 95kHz 10mV input signal, a 5kHz 56 V output. When the LTC1264-7 operates with a clock-to- cutoff frequency of 25:1, aliasing occurs at twice the clock frequency ...

Page 12

... LTC1264-7 PACKAGE DESCRIPTIO 0.290 – 0.320 (7.366 – 8.128) 0.008 – 0.018 0° – 15° (0.203 – 0.460) 0.385 ± 0.025 0.038 – 0.068 (9.779 ± 0.635) (0.965 – 1.727) 0.300 – 0.325 (7.620 – 8.255) 0.015 (0.380) MIN 0.130 ± 0.005 (3.302 ± ...

Related keywords