《电路》（英文版）3-1 The OP-amp

s3-1 The OP-AMP The operational amplifier hereafter OP-AMP) is developed in the 1940s primarily for use in analog computers, made cheaply and readily available in the late 1960s through integrated-circuit technology. The actual construction of a modern oP-AMP is indeed very complex, involving many transistors, diodes, resistors and capacitors

The operational amplifier (hereafter OP-AMP) is developed in the 1940s primarily for use in analog computers, made cheaply and readily available in the late 1960s through integrated-circuit technology. §3-1 The OP-AMP The actual construction of a modern OP-AMP is indeed very complex, involving many transistors, diodes, resistors and capacitors

B Bt. B--batteries 十 N,P input-voltages 十 P output-voltage B A--gain (Some of the connected terminals to the op-amp N R R; --input-resistor 2 Ro--output-resistor P A(U PO C P N a controlled source (a simple model of the op-amp)

input voltages  N , P − − − B B − −batteries + − , − −output − voltage 2 R input resistor i − − − R output resistor o − − − A− −gain − − a controlled source ( )  C = A  P − N  P Ri Ro ( )  C = A  P − N (a simple model of the op-amp) − + − +  2  N (Some of the connected terminals to the op-amp) + B − B  N  P − +  2  A + + − •

The bt and b are usually suppressed in the symbol. R R A (UP-UN) P (some of the connected (a simple model of the op-amp) terminals to the op-amp) In the ideal model,A→0,R2→>o,Rn=0. J 十 G AO-D)U2U2>10007 A→

???? : V If P N V 100000 1 2  = =    In the ideal model, → , → , = 0. A Ri Ro ( ) A  P − N A→ + i − i − +  2 P  N  − + (a simple model of the op-amp)  + i − i •  N  P − +  2 + + − (some of the connected terminals to the op-amp) •  N  P − +  2  A + + − The B+ and B- are usually suppressed in the symbol.  P Ri Ro A( )  P − N − + − +  2  N