Question

Problems 20 - 21 Op-amp Parameters: -OVO ERROR OVT MO 4 l = 100 dB Vos = 2 mV 18 = 100 nA los = 20 nA fr= 5 MHz SR = 10 V/us 10k - For Problem 21 Nonideal device parameter values for the op amp are listed to the right of the circuit. 20 What is the value of the circuit's maximum output offset voltage, VO ERROR, attributable to nonideal op-amp device parameters? VO ERROR values: A B C 112 mV 202 mV 292 mV D E 302 mV 312 mV 21 If a capacitor is connected in series between the 10-k2 resistor and ground, re-calculate the value of the above circuit's maximum output offset voltage, VO ERROR, attributable to nonideal op-amp device parameters. VO ERROR Values: A B C 112 mV 202 mV 292 mV D E 302 mV 312 mV

Answer 1

VOERROR Aol= loodB IM RiLOK RA Vos = 2 my Is = loona Ias = con A fi = 5 MHZ Note! Here will VOERROR a result - SR = Lov/us voltage of Vos, IB and Ios be tolog Aul = 100 7 I lolo (exabiga gain) error VOERRIR op worset Voltage due to le offset are Internal circuit Vos voltage may be applied tontre I terminach also ] WA to input offset voltage output voltage voltage a due is (VOERROR), = Vos XRF vost. Ri 19 6 11 = 2x10 -3 (it lo 2x109 (+100) = 2x 10-3x101 0,202 V

due to voltage bias current and output - offset current REVO/RF NO ERROR Tos= 1 I - IL/ It I I Bias - 2 corrent to non inverting terminal In inverting terminal. Consider I ZILI 2Tons - Title I = (IBAS - Fos/) > I = I Biast o%) Iz = voxt from the circuid) 12 RE Vo - I₂ RF = REI Bias & Tos ) olex 0.09V Hence etsen Keltage due to the bias current and aftset current is NOERRUR & ory goo

Total offset output voltage = (VOERROR) + (VO ERRER ? 902 voor = 292m (Ans) RA Ri wow VOERROR Due to presence et sapacitor current flow to Сое тел) a bezer Lers Redrew the circuit NORR RR Ridin wy Nos -VOERER it internal crevit Here are have applied aftset voltage to non inverting termina Vo= Vos = 2mv. le output voltage due to i offset altset voltage is same as if offset vetage NON output voltage due to hias coment ana ile offset curent will be same as ahelated previously, le ooon. so total offset voltage = oogt oon my output AS maximum offset vestire is askea. hence the answer according to option me 112 m .