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LTC1067/LTC1067-50

Rail-to-Rail, Very Low Noise

Universal Dual Filter Building Block

FEATURES

DESCRIPTION

The LTC

®1067/LTC1067-50 consist of two identical rail-

to-rail, high accuracy and very wide dynamic range 2nd

order switched-capacitor building blocks. Each building

block, together with three to five resistors, provides 2nd

order filter functions such as bandpass, highpass, lowpass,

notch and allpass. High precision 4th order filters are

easily designed.

The center frequency of each 2nd order section is tuned by

the external clock frequency. The internal clock-to-center

frequency ratio (100:1 for the LTC1067 and 50:1 for the

LTC1067-50) can be modified by the external resistors.

These devices have a double sampled architecture which

places aliasing and imaging components at twice the clock

frequency. The LTC1067-50 is a low power device con-

suming about one half the current of the LTC1067. The

LTC1067-50’s typical supply current is about 1mA from a

3.3V supply.

The LTC1067 and LTC1067-50 are available in 16-pin

narrow SSOP and SO packages.

Mask programmable versions of the LTC1067 and

LTC1067-50, with thin film resistors on-chip and custom

clock-to-cutoff frequency ratios, can be designed in an

SO-8 package to realize application specific monolithic

filters. Please contact LTC Marketing for more details.

, LTC and LT are registered trademarks of Linear Technology Corporation.

TYPICAL APPLICATION

Frequency Response

FREQUENCY (kHz)

8

12

1067 • TA02

9

10

11

0

–10

–20

–30

–40

0.1

µF

1067 TA01

LTC1067-50

V+

NC

V+

SA

LPA

BPA

HPA/NA

INV A

CLK

AGND

V–

SB

LPB

BPB

HPB/NB

INV B

3.3V

R32, 200k

R22, 10k

R31, 200k

R21, 10k

R11

200k

IN

RB1, 200k

OUT

1

µF

fCLK = 500kHz

TOTAL OUTPUT NOISE: 90

µVRMS

S/N RATIO: 80dB

1

2

3

4

5

6

7

8

16

15

14

13

12

11

10

9

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Rail-to-Rail Input and Output Operation

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Operates from a Single 3V to

±5V Supply

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Dual 2nd Order Filter in a 16-Lead SSOP Package

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> 80dB Dynamic Range on Single 3.3V Supply

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Clock-to-Center Frequency Ratio of 100:1 for the

LTC1067 and 50:1 for the LTC1067-50

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Internal Sampling-to-Center Frequency Ratio of

200:1 for the LTC1067 and 100:1 for the LTC1067-50

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Center Frequency Error <

±0.2% Typ

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Low Noise: < 40

µVRMS, Q ≤ 5

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Customizable with Internal Resistors

APPLICATIONS

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Notch Filters

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Narrowband Bandpass Filters

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Tone Detection

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Noise Reduction Systems

Single 3.3V Supply Rail-to-Rail,

4th Order, 10kHz Bandpass Filter