ADN2847 Analog Devices, Inc., ADN2847 Datasheet - Page 13

• Manufacturer Part Number: ADN2847
• Description: 3.3 V Dual-loop 50 Mbps To 3.3 Gbps Laser Diode Driver
• Manufacturer: Analog Devices, Inc.

Extinction Ratio = 10 dB, PRBS 31 Pattern. Eye Obtained Using a DFB Laser.
Figure 16. 2.5 Gbps Optical Eye at 25°C. Average Power = 0 dBm,
MPD
NOTES
** FOR DIGITAL PROGRAMMING, THE ADN2850 OR THE ADN2860 OPTICAL SUPERVISOR CAN BE USED.
* DESIGNATES COMPONENTS THAT NEED TO BE OPTIMIZED FOR THE TYPE OF LASER USED.
V
CC
LD
*
LD = LASER DIODE
MPD = MONITOR PHOTODIODE
1µH
*
*
*
V
*
*
V
CC
CC
R
*
*
Z
*
*
37
48
Figure 15. AC-Coupled 50 Mbps to 3.3 Gbps Test Circuit, Data Not Clocked
GND2
IMODN
IMODN
GND2
IMODP
IMODP
GND2
GND2
CCBIAS
V
I
I
BIAS
BIAS
CC
2
36
1
V
CC
1.5kΩ
**
**
ADN2847
1.5kΩ
Rev. A | Page 13 of 16
1kΩ
ALS
1.5kΩ
100nF
Extinction Ratio = 10 dB, PRBS 31 Pattern. Eye Obtained Using a DFB Laser.
Figure 17. 2.5 Gbps Optical Eye at 85°C. Average Power = 0 dBm,
100nF
GND
PAVCAP
V
ERCAP
DATAP
DATAN
CC
12
25
CLKN
CLKP
GND1
GND1
V
GND
GND
GND
CC
1
100nF
V
CLOSE AS POSSIBLE TO THE ACTUAL SUPPLY PINS
ON THE ADN2847 AND THE LASER DIODE USED.
CONSERVATIVE DECOUPLING WOULD INCLUDE
100pF CAPACITORS IN PARALLEL WITH 10nF
CAPACITORS.
13
24
1µF
CC
1µF
s SHOULD HAVE BYPASS CAPACITORS AS
100nF
GND
10nF
10nF
10nF
10nF
10µF
FAIL
DEGRADE
CLKN
CLKP
DATAP
DATAN
ADN2847