| 摘要 |
A DESCRIPTION IS GIVEN OF A CIRCUIT ARRANGEMENT COMPRISING A LOGARITHMIC TRANSFER FUNCTION BETWEEN AN INPUT SIGNAL (UE) AND AN OUTPUT SIGNAL (UA) IN A PREDEFINED LEVEL RANGE (UE1 TO UE2) OF THE INPUT SIGNAL (UE), COMPRISING - A PAIR OF AMPLIFIER ELEMENTS (11, 12) FORMING A FIRST DIFFERENTIAL AMPLIFIER -- THE MAIN CURRENT PATHS OF WHICH AMPLIFIER ELEMENTS (11, 12) ARE CONNECTED,--- ON THE ONE HAND, TO EACH OTHER AND TO A FIRST CURRENT SOURCE (131) AND --- ON THE OTHER HAND, TO WORKING IMPEDANCES (141, 142; 151, 152) SUBDIVIDED BY RESPECTIVE TAPS (104; 105), AND -- THE CONTROL TERMINALS OF WHICH AMPLIFIER ELEMENTS (11, 12) ARE SUPPLIED WITH THE INPUT SIGNAL (UE), - A PAIR OF AMPLIFIER ELEMENTS (111, 112) FORMING A SECOND DIFFERENTIAL AMPLIFIER,-- THE MAIN CURRENT PATHS OF WHICH AMPLIFIER ELEMENTS (11L, 112) ARE CONNECTED, --- ON THE ONE HAND, TO EACH OTHER AND TO A SECOND CURRENT SOURCE (132) AND -- ON THE OTHER HAND, TO THE CONNECTIONS (102; 103) OF THE MAIN CURRENT PATHS OF THE FIRST DIFFERENTIAL AMPLIFIER (11, 12) AND THE WORKING IMPEDANCES (141, 142; 151, 152), AND -- WHOSE CONTROL TERMINALS ARE CROSS-CONNECTED TO THE TAPS (104; 105) OF THE WORKING IMPEDANCES (141, 142; 151, 152), AND - A RECTIFIER STAGE (16) WHOSE INPUT IS CONNECTED TO THE CONNECTIONS (102; 103) OF THE MAIN CURRENT PATHS OF THE DIFFERENTIAL AMPLIFIERS (11, 12; 1LL, 112) AND THE WORKING IMPEDANCES (141, 142; 151, 152) AND WHOSE OUTPUT SIGNAL (UA) IS TAPPED FROM ITS OUTPUT.THIS CIRCUIT ARRANGEMENT HAS A VERY LOW POWER CONSUMPTION AND LOW CIRCUIT COMPLEXITY.(FIG 3)
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