ATA06211
1.2
900
800
700
600
500
400
300
B(3dB) A/2π Rf(Cin +Ct)
1.1
VDD = 5.5 V
VDD = 5.5 V
1.0
0.9
V
DD = 5.0 V
0.8
V
DD = 4.5 V
VDD = 4.5 V
0.7
0.6
IIN
50
0
0.2
0.4 0.6 0 .8 1.0 1.2 1.4 1.6
0.5
CT(pF)
2.1
- 1.6
- 1.1
- 0.6
- 0.1
Figure 5: Bandwidth vs. CT
IIN (mA DC)
IIN Connection
Figure 7: Bandwidth vs. IIN
(Refer to the equivalent circuit diagram.) Bonding the
detector cathode to IIN (and thus drawing current from
theATA06211) improves the dynamic range. Although
the detector may be used in the reverse direction for
input currents not exceeding 25 mA, the specifications
for optical overload will not be met.
VOUT Connection
The output pad should be connected via a coupling
capacitor to the next stage of the receiver channel
(filter or decision circuits), as the output buffers are
not designed to drive a DC coupled 50 ohm load
(this would require an output bias current of
approximately 36 mA to maintain a quiescent 1.8
Volts across the output load). If VOUT is connected to a
high input impedance decision circuit (>500 ohms),
then a coupling capacitor may not be required,
although caution should be exercised since DC
offsets of the photo detector/TIA combination may
cause clipping of subsequent gain or decision
circuits.
5
Rf
4
3
2
IIN
50
I
3.4
3.2
heavy AGC
3.0
VDD = 5.5 V
2.9
Output Collapse
1
2.7
2.5
2.4
2.2
2.0
1.9
1.7
VDD = 4.5 V
VDD =5.5 V
Linear Region
-2.1
- 1.6
-1.1
- 0.6 - 0.1
1.5
Rf
1.4
1.2
1.0
0.8
0.7
0.5
0.3
0.2
0.0
IIN (mA DC)
Figure 6: Transimpedance vs. IIN
IIN
VOUT
VDD=4.5 V
- 4
- 3
- 2
- 1
IIN(mA DC)
Figure 8: VOUT vs. IIN
5
PRELIMINARY DATA SHEET - Rev 4
08/2001
ANADIGICS [ ANADIGICS, INC ]
