LM124-LM224-LM324 TYPICAL SINGLE- SUPPLY APPLICATIONS ACTIVER BANDPASS FILTER IGH INPUTZ DC DIFFERENTIAL AMPLIFIER F (CMRR depends on this resistor ratio match) +V20 F 1kHz R A=100(400B) As shown eo=(e2·e1) USING SYMETRICAL AMPLIFIERS TO REDUCE INPUT CURRENT(GENERAL CONCEPT) LM124 2N929 001μ lB lB 3MS2LM24 ux.amplifier for input current compensation 1.5M 9/13LM124-LM224-LM324 9/13 TYPICAL SINGLE - SUPPLY APPLICATIONS ACTIVER BANDPASS FILTER HIGH INPUTZ,DC DIFFERENTIALAMPLIFIER USING SYMETRICAL AMPLIFIERS TO REDUCE INPUT CURRENT (GENERAL CONCEPT) 1/4 LM124 1/4 LM124 R3 10kΩ 1/4 LM124 e 1 eO R8 100kΩ R7 100kΩ C3 10µF VCC R5 470kΩ C2 330pF R4 10MΩ R6 470kΩ R1 100kΩ C1 330pF Fo = 1kHz Q = 50 Av = 100 (40dB) 1/4 LM124 R1 100kΩ R2 100kΩ R4 100kΩ R3 100kΩ +V2 +V1 Vo 1/4 LM124 For (CMRR depends on this resistor ratio match) R1 R2 ------- R4 R3 = ------- e0 (e2 - e1) As shown e0 = (e2 - e1) 1 R4 R3 + -------     1/4 I LM124 B 2N 929 0.001µF IB 3MΩ IB I eo I e I IB IB Aux. amplifier for input current compensation 1.5MΩ 1/4 LM124