LT1568

12

1568f

Table 1. Resistor Values in Ohms, Dual 2nd Order

Butterworth, Gain = 1, R12 = R11, R22 = R21, R32 = R31

R11 = R21 = R31

0.2

6340

Ω

0.5

2550

Ω

1

1270

Ω

2

634

Ω

3

422

Ω

4

324

Ω

5

255

Ω

6

210

Ω

7

182

Ω

8

162

Ω

9

143

Ω

10

127

Ω

FREQUENCY (MHz)

0.1

–50

–40

–30

–20

–10

110

20

1568 TA07

–60

–70

–80

–90

0

10

Amplitude Response

Transient Response

INPUT

500mV/DIV

OUTPUT

200mV/DIV

1

µs/DIV

1568 TA08

Dual 2nd Order Lowpass Filter,

Dual Supply Operation

1

2

3

4

5

6

7

8

16

15

14

13

12

11

10

9

INVA

SA

OUTA

OUTA

GNDA

NC

INVB

SB

OUTB

OUTB

GNDB

EN

0.1

µF

BAT54S

R11

R31

R22

R32

R12

R21

0.1

µF

–5V

1568 TA03

5V

LT1568

Dual 2nd Order Lowpass Filter,

Single Supply Operation

1

2

3

4

5

6

7

8

16

15

14

13

12

11

10

9

INVA

SA

OUTA

OUTA

GNDA

NC

INVB

SB

OUTB

OUTB

GNDB

EN

0.1

µF

R11

R31

R22

R32

R12

R21

0.1

µF

1568 TA04

2.7V

LT1568

R

ff

C

CUTOFF

11 = R21 = R31 = R = 128

•

10MHz

Ω

=

DUAL 2nd ORDER LOWPASS FILTER DESIG S