TLC04/MF4A-50, TLC14/MF4A-100

BUTTERWORTH FOURTH-ORDER LOW-PASS

SWITCHED-CAPACITOR FILTERS

SLAS021A – NOVEMBER 1986 – REVISED MARCH 1995

9

POST OFFICE BOX 655303

• DALLAS, TEXAS 75265

APPLICATION INFORMATION

5 VOC

FILTER IN

(see Note B)

10 k

Ω

0.1

µF

10 k

Ω

See Note A

–5 V

0 V

TTL

CLKR

OUT

CMOS

CLKIN

0 V

10 V

10 V

4

VCC –

6

AGND

8

FILTER IN

FILTER

5

φ2

φ1

Butterworth

Fourth-Order

Low-Pass Filter

Nonoverlapping

Clock Generator

2

CLKR

1

CLKIN

3LS

VCC+

7

Level Shift

See Note C

NOTES: A. The external clock used must be of CMOS level because the clock is input to a CMOS Schmitt trigger.

B. The filter input signal should be dc-biased to midsupply or ac-coupled to the terminal.

C. AGND must be biased to midsupply.

Figure 6. External-Clock-Driven Single-Supply Operation