ODHKGA4143-02
Electronic Components
KGA4143
CONTROLLABILITY OF OUTPUT OFFSET ADJUSTMENT (Vth1 and Vth2) (TYP.)
(Ta= 25°C, Optical Input Power = 0dBm, Extinction ratio of optical input signal: 12dB)
OUTP Output Crossing Point [%]
100
Vth2: Open
90
Vd = +3.46V
Vd = +3.30V
80
Vd = +3.14V
70
60
50
40
30
20
10
0
0.3 0.4 0.5 0.6 0.7 0.8 0.9
Applied Vth1 Voltage [V]
Note: By adjusting the output offset control voltage (either Vth1 or Vth2), the output crossing points are
correspondingly changed. These figures show the output crossing point of OUTP (Xp
(OUTP)
)
dependence on the Vth1 or Vth2. The Xp
(OUTN)
is about 100 - Xp
(OUTP)
.
Vth1:
In case that Vth1 is used, apply the adequate bias to Vth1, independent of the supply voltage
(Vd).
Vth2:
In case that Vth2 is used, to prevent the Xp from changing by the variation in Vd, for example, the
external circuit, as following, is recommended. Here, the value of variable resistor (R1+R2) < 2kohm.
The value of R3 and R4, and the ratio of R3 to R4 are dependent on the characteristics of the diode.
As shown in the next figure, by adjusting the variable resistor, the Xp can be controlled, independent of
the Vd.
Vd
R3
OUTP Output Crossing Point [%]
OUTP Output Crossing Point [%]
100
Vth1: Open
90
Vd = +3.46V
Vd = +3.30V
80
Vd = +3.14V
70
60
50
40
30
20
10
0
0.3 0.4 0.5 0.6 0.7 0.8 0.9
Applied Vth2 Voltage [V]
Vth2
R2
Vf = 2.4 ~2.7V
R1
R4
100
90
80
70
60
50
40
30
20
10
0
0
Vth1: Open
Vd = +3.46V
Vd = +3.30V
Vd = +3.14V
0.05 0.10 0.15 0.20 0.25
R1/(R1+R2)
6
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