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LTC1064-7

Linear Phase, 8th Order

Lowpass Filter

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FEATURE

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Steeper Roll-Off Than 8th Order Bessel Filters

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Phase Equalized Filter in 14-Pin Package

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Phase and Group Delay Response Fully Tested

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Transient Response Exhibits 5% Overshoot and

No Ringing

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Wide Dynamic Range

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72dB THD or Better Throughout a 50kHz Passband

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No External Components Needed

DESCRIPTIO

The LTC1064-7 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 whilte it exhibits steeper roll-off than an

equivalent 8th order Bessel filter. For instance, at twice the

cutoff frequency the filter attains 34dB attenuation (vs

12dB for Bessel), while at three times the cutoff frequency

the filter attains 68dB attenuation (vs 30dB for Bessel).

The cutoff frequency of the LTC1064-7 is tuned via an

external TTL or CMOS clock.

The LTC1064-7 features wide dynamic range. With single

5V supply, the S/N + THD is 76dB. Optimum 92dB S/N is

obtained with

±7.5V supplies.

The clock-to-cutoff frequency ratio of the LTC1064-7 can

When the filter operates at clock-to-cutoff frequency ratio

of 50:1, the input is double-sampled to lower the risk of

aliasing.

The LTC1064-7 is pin-compatible with the LTC1064-X

series, LTC1164-7 and LTC1264-7.

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APPLICATI

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Data Communication Filters

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Time Delay Networks

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Phase-Matched Filters

APPLICATI

TYPICAL

80kHz Linear Phase Lowpass Filter

Eye Diagram

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2

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4

5

6

7

14

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12

11

10

9

8

LTC1064-7

7.5V

–7.5V

CLK = 4MHz

7.5V

NOTE: THE POWER SUPPLIES SHOULD BE BYPASSED BY A

0.1

µF 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

1064-7 TA01

1064-7 TA02

1

µs/DIV

RATIO = 50:1