: Hank Zumbahlen [hank.zumbahlen@analog.com] 1 180˚ 1. ButterworthBessel Chebyshev “” () 6n dB/20n dB/n ()6 dB/ 20 dB/(2) 12 dB/40 dB/ /2πHz ( f ) 360˚2π fω ( 3 dB —— 30 —— ) 90˚()502 1 (1)45˚ 2. 32 (1) +45˚ 90˚π/2 radians 3. 1 

α Q Butterworthα1.414(Q0.707) α 4. 1 4(α1.414) (1)-90° 2: 5(α1.414) (1) 180˚ (π) ±180˚181˚ +179˚360˚0˚ 6 R-C1/(2πRC) 245˚ 6. 5 kHz50 Hz500 kHz 7 1/(2πRC) 180˚2- () 7. 8 3 () 5. 1 8. 

Sallen-Key (Multiple-FeedbackMFB) ()12 Sallen-KeyQ ()20 dB(10 )QQ H 12. 2(MFB) 180˚4() Sallen-Key (MFB) 13 - 5() 3() 93() 9. Sallen-Key Sallen-Key Sallen-Key(VCVS) MIT(3)R. P. Sallen E.L. Key1955 10Sallen-Key Sallen-Key () 4Q0.707( α1/Q 1.414 ButterworthSallen-Key 10. 2Sallen-Key Sallen-Key Sallan-Key 11 5() 13. 2(MFB) 11. 2Sallen-Key 

14 3 3(Qω0) 1(4 )2(4) (5) 1 14. 2 - 4)(5) (biquad) (15) J. Tow1968 ( 6) L.C. Thomas 1971(5) (1)(2) 1 2 15. 2 ( )16 1 2Sallen-Key 2 2 21 22 2 2 2Sallen-Key 2 2 2 0˚90˚ 180˚90˚ 0˚ 180˚ 180˚ 0˚ 180˚ 0˚ 0˚ 180˚ 180˚ 0˚ 90˚0˚ 90˚180˚ 180˚ 0˚ 0˚180˚ 0˚180˚ 0˚180˚ Q 2 Q 0.70717 Q () Q 0.10.50.7071 2 5 10 20 Q 1 16. 2() 17. Q 

Q 18Q2 QQ QQ SKMFB 20 34 SKMFB (1 × 11)(SKMFB) 180°( 1 × 1 1) 20. 4 2 360˚ vs. 180˚ 180˚ 8() 18. Q2 dB() Q 194 1 1 2 2 19. 4 2043 Sallen-Key (SK) Butterworth (MFB) ButterworthSK MFB 22Butterworth 4Butterworth Butterworth f01Q 0.5412(α1.8477)f01Q1.3065(α0.7654) HTMLPDFhttp://www.analog.com/analogdialogue“archives”