Tektronix AFG3000C Series Manual

Tektronix AFG3000 Series Function Generator Guide v1.0 Portland State University
15
Example:
You connect a function generator with output impedance R
O
= 50 Ω to a test circuit which has a load
resistance of R
L
. You configure the generator to output a sinusoid of amplitude V
SET
= 1 V
p-p
at frequency
f
SET
. The voltage V
L
across the load is monitored with an oscilloscope using a 1× probe. The oscilloscope
has an input resistance of R
in
= 1M Ω in parallel with an input capacitance of C
in
= 15 pF.
Figure 11: Example test circuit with oscilloscope
The function generator “sees” the load in parallel with the oscilloscope’s input impedance:
SET
OEQ
EQ
L
LinininL
Lin
in
inL
CinLEQ
V
RZ
Z
V
RRCjRR
RR
Cj
RR
ZRRZ
in








+
=→
++
=








++==
−
2
11
||||
1
ω
ω
Table 3: Calculated load voltage V
L
versus load resistance R
L
at specific signal frequencies f
SET
Given V
SET
= 1 V
p-p
, R
in
= 1M
Ω
, C
in
= 15 pF
R
L
(Ω)
V
L
(volts
)
f
SET
= 0 Hz (DC)
f
SET
= 1 MHz
f
SET
= 50 MHz
f
SET
= 100 MHz
f
SET
= 200 MHz
10
0.333
3
0.333
3
0.3331
0.3323
0.3293
50
1.000
0
1.000
0
0.9931
0.9733
0.9046
100
1.333
3
1.333
3
1.317
1
1.2720
1.1290
500
1.818
1
1.818
1
1.7778
1.671
2
1.3807
1000
1.904
7
1.9047
1.8585
1.737
7
1.4175
10K
1.990
0
1.9
899
1.937
4
1.801
7
1.4516
100K
1.999
8
1.999
8
1.94
65
1.80
90
1.4554
Function
Generator
V
G
V
L
R
O
R
L
S
cope
Function
Generator
Test
Circuit
Test
Circuit
R
in
Probe
Oscillos
cope
C
in
Ground

Tektronix AFG3000C Series Specifications

General

Brand	Tektronix
Model	AFG3000C Series
Category	Inverter
Language	English