ATA12001
BANDWIDTH vs. CT
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1.0
1800
1600
1400
1200
1000
800
B(3dB) A/2 π R (CN + CT)
≈
F
VDD=5.5 V
VDD = 5.5 V
VDD = 5.0 V
RF
VDD=4.5 V
I
IIN
5
VDD = 4.5 V
600
- 2.2
- 1.7
- 1.2
- 0.7
- 0.2
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
IIN (mA DC)
CT(pF)
Figure 5: Bandwidth vs. CT
Figure 7: Bandwidth vs. IIN
Note: All performance curves are typical @ T =25°C
A
unless otherwise noted.
IIN Connection
VOUT Connection
(refer to the equivalent circuit diagram) Bonding the
detector cathode to IIN (and thus drawing current from
theATA12001) 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.
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.
2.0
1.8
1.6
1.4
12001
1.2
1.0
0.8
0.6
0.4
I
IN
50
I
3.4
3.2
3.0
2.9
2.7
2.5
2.4
2.2
2.0
heavy AGC
Output Collapse
V
DD = 5.5 V
VDD =5.5 V
Linear Region
1.9
1.7
DD
V
= 4.5 V
-0.2
1.5
1.4
1.2
Rf
-2.2
-1.7
-1.2
-0.7
1.0
0.8
0.7
0.5
0.3
0.2
0.0
IIN
VOUT
12001
I
IN (mA DC)
VDD=4.5 V
Figure 6: Transimpedance vs. IIN
- 4
- 3
- 2
- 1
IIN(mA DC)
Figure 8: VOUT vs. IIN
PRELIMINARY DATA SHEET - Rev 4
5
08/2001
ANADIGICS [ ANADIGICS, INC ]
