output_termination - at the output terminal is only half...

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Function Generator Output Termination The function generator can be modeled as a voltage source with a small internal resistance of 50 shown in Figure 1. The internal resistance limits the amount of current that flows through the function generator to prevent excessive current from damaging the device. The presence of the internal resistance, however, causes the voltage at the output of the function generator V out to be different from the voltage generated V G , since , 50 L L G out R R V V + Ω = from voltage division. The function generator allows its user to specify two kinds of output termination settings: 50 and open circuit (High Z). By default, the function generator assumes the load circuit connected to have an input resistance R L that equals 50 (Figure 2). In such circuit, the voltage
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Unformatted text preview: at the output terminal is only half the voltage provided by the generator: . 2 1 50 50 50 G G out V V V = + = The generator compensates for this by doubling the amplitude of the signal it provides. Most circuits used in ECE 210 lab, however, have input resistances much greater than 50 & (Figure 3). The voltage at the output terminal is the same as the voltage provided by the generator: . 50 G L L G L L G out V R R V R R V V = + = Therefore, default setting of the generator produces double the specified output. Instead, the output termination needs to be changed to High Z. Function Generator V G 50 & V out R L & Function Generator R L =50 & V G 50 & V out Function Generator R L V G 50 & V out Figure 1 Figure 2 Figure 3...
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This note was uploaded on 08/25/2010 for the course ECE 210 taught by Professor Staff during the Spring '08 term at University of Illinois, Urbana Champaign.

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