J111-E3 Vishay, J111-E3 Datasheet - Page 4

• Manufacturer Part Number: J111-E3
• Description: 51K2069
• Manufacturer: Vishay

Specifications of J111-E3

• Breakdown Voltage Vbr: -55V
• Zero Gate Voltage Drain Current Idss: 20mA
• Gate-source Cutoff Voltage Vgs(off) Max: -10V
• Power Dissipation Pd: 360mW
• Operating Temperature Range: -55°C To +150°C
• No. Of Pins: 3
• Rohs Compliant: Yes

Experimental Results
Figures 8 and 9 show low voltage output characteristic
curves for a typical Siliconix n-channel voltage-controlled
resistor, VCR7N. Bias conditions are shown both with and
without feedback. Figure 8 shows a two-volt peak-to-peak
signal on the V
in the first and third quadrants. The VCR is operated without
feedback.
The forward-biased gate-drain PN junction may be seen
at approximately –0.6 V, and bending of the bias curve is
apparent in the third quadrant. The photo also demon-
strates the comparison between a fixed resistor (the linear
line superimposed on the bias curve) and the distortion
apparent in the VCR without feedback compensation; the
VCR signal is unusable with the indicated amount of dis-
tortion at 2 V peak-to-peak.
AN105
4
–100
–200
200
100
0
–1.0
V
Figure 8. VCR7N Without Feedback
GS
GS
Temperature
Temperature
= V
= 0 V bias curve, with the VCR operating
V
DS
CONTROL
( C)
+125
+25
–55
–0.4
– Drain-Source Voltage (V)
0
V
GS
r
DS
= 0 V
>13%
>10%
= r
3.9%
0.4
V
DS(on)
Without Feedback
GS
Table 1: Distortion vs. Temperature
= –2.5 V
r
1.0
DS
= 10 r
3.2%
>6%
>5%
DS(on)
In Figure 9, the same VCR7N FET is shown operating
with the addition of the feedback resistors. Distortion has
been reduced to less than 0.5%, and the characteristics of
the VCR are now closely comparable to those of a fixed
resistor.
In Figures 8 and 9, the same VCR FET characteristics are
shown, with V
network is employed in Figure 8, and measured distortion
is greater than 8%. In Figure 9, the feedback resistors
have been added and distortion has been reduced to less
than 0.5%.
Some degree of non-linearity will be experienced in both
the first and third quadrants as V
cut-off voltage. For this reason, it is important that the
feedback resistors be of equal value so that the non-linear-
ities likewise will be equal in both quadrants.
–100
–200
r
200
100
DS
0
–1.0
<0.5%
<0.5%
<0.5%
= r
GS
DS(on)
With Feedback
adjusted for higher r
Figure 9. VCR7N With Feedback.
V
DS
–0.4
r
– Drain-Source Voltage (V)
DS
V
= 10 r
GS
<0.5%
<0.5%
<0.5%
= V
GS
0
DS(on)
CONTROL
approaches the FET
V
CONTROL
DS
0.4
. No feedback
V
= 0 V
GS
10-Mar-97
= –3 V
= –6 V
Siliconix
1.0