14

LT2078/LT 2079

Single Supply, Micropower, Second Order Lowpass Filter with 60Hz Notch

–

+

+

–

6

5

7

1/2 LT2078

2.64M

0.1%

2.64M

0.1%

1/2 LT2078

3

2

1

OUTPUT

TYPICAL OFFSET

≈ 600µV

LT2078/79 • TA10

5V

8

4

1.35M

0.1%

IN

2000pF

0.5%

1000pF

0.5%

1000pF

0.5%

0.02

µF

5.1M

1%

120k

5%

100pF

0.01

µF

27.6k

0.1%

27.6k

0.1%

Q = 30

Micropower Multiplier/Divider

6

5

13

12

1/4 LT2079

4

11

714

2

3

1/4 LT2079

1

9

10

1/4 LT2079

8

–1.5V TO –9V

9V

505k

0.1%

505k

0.1%

505k

0.1%

220pF

220pF

30k

5%

30k

5%

Q1

220pF

30k

5%

Y INPUT

(5mV TO 50V)

X INPUT

(5mV TO 50V)

Q2

Q4

499k

0.5%

10k

GAIN

Z INPUT

(5mV TO 50V)

OUTPUT

(5mV TO 8V)

1/4 LT2079

Q1,Q2, Q3, Q4 = MAT-04

TYPICAL LINEARITY = 0.01% OF FULL-SCALE OUTPUT

Q3

OUTPUT =

, POSITIVE INPUTS ONLY

(X)(Y)

(Z)

NEGATIVE SUPPLY CURRENT = 165

µA +

X + Y+ Z + OUT

500k

POSITIVE SUPPLY CURRENT = 165

µA +

Z INPUT = 4kHz

OUT

500k

lt2078/79 • TA11

Micropower Dead Zone Generator

2

3

1

1/4 LT2079

510k

1M**

1M**

1M*

Q1

2N4393

6

5

7

1/4 LT2079

9

10

8

1/4 LT2079

13

12

14

1/4 LT2079

1M**

Q4

Q2

Q3

470k

1M*

GAIN

200k

510k

1M**

510k

4

11

9V

1M

1M

680k

1M

1N914

1N914

Q5

–9V

Q6

2N4393

1000pF

DEAD ZONE

CONTROL INPUT

0.4V TO 5V

LT2078/79 • TA12

BIPOLAR SYMMETRY IS EXCELLENT

BECAUSE ONE DEVICE, Q2,

SETS BOTH LIMITS

SUPPLY CURRENT

≈ 240µA

BANDWIDTH = 150kHz

INPUT

*

**

1% FILM

RATIO MATCH 0.05%

Q2, Q3, Q4, Q5 CA3096 TRANSISTOR ARRAY