EVAL-ADN2531-NPZ AD [Analog Devices], EVAL-ADN2531-NPZ Datasheet - Page 15

• Manufacturer Part Number: EVAL-ADN2531-NPZ
• Description: 11.3 Gbps, Active Back-Termination, Differential Laser Diode Driver
• Manufacturer: AD [Analog Devices]

APPLICATIONS INFORMATION
TYPICAL APPLICATION CIRCUIT
Figure 40 shows a typical application circuit for the ADN2531.
The dc voltages applied to the BSET and MSET pins control the
bias and modulation currents. The bias current can be monitored
as a voltage drop across the 750 Ω resistor connected between
the IBMON pin and GND. The dc voltage applied to the CPA
pin controls the crosspoint in the output eye diagram. By tying
the CPA pin to V
allows the user to turn the bias and modulation currents on and
off, depending on the logic level applied to the pin. The data
signal source must be connected to the DATAP and DATAN
pins of the ADN2531 using 50 Ω transmission lines. The
modulation current outputs, IMODP and IMODN, must be
connected to the load (TOSA) using 100 Ω differential (50 Ω
single-ended) transmission lines.
Table 6 provides a list of recommended components for the ac
coupling interface between the ADN2531 and the TOSA. The
reference circuit can support up to 11.3 Gbps applications, and
CC
, the CPA function is disabled. The ALS pin
DATAN
DATAP
MSET
BSET
+3.3V
Z
Z
0
0
= 50Ω
= 50Ω
V
V
CC
CC
C1
C2
GND
C7
20µF
VCC
DATAP
DATAN
VCC
V
CC
MSET
GND
BSET IBMON IBIAS GND
Figure 40. Typical ADN2531 Application Circuit
TP1
ADN2531
CPA
CPA
R5
750Ω
ALS
ALS
Rev. 0 | Page 15 of 20
GND
IMODN
IMODP
VCC
VCC
10nF
10nF
GND
C5
C6
GND
V
V
CC
CC
Z
Z
the low frequency cutoff performance is dependent on the dc
blocking capacitance and the transmission line impedance. For
additional applications information and optical eye diagram
performance data, consult the relevant application notes on the
ADN2531 product page at www.analog.com.
Table 6. Recommended Components
Component
R1, R2
R3, R4
R13, R14
C3, C4
L6, L7
L2, L3
L1, L4, L5, L8
0
0
V
V
= 50Ω
= 50Ω
CC
CC
GND
GND
L4
L1
L2
L3
V
V
CC
CC
R1
R14
R13
R2
C4
C3
L5
Value
110 Ω
300 Ω
Varies
100 nF
160 nH
10 μH
L8
V
CC
Z
Z
0
0
= 50Ω
= 50Ω
L7
L6
Description
0603 size resistor
0603 size resistor
The resistor value and size are TOSA
load impedance dependent
0402 size capacitor,
Phycomp 223878719849
0603 size inductor,
Murata LQW18ANR16
0603 size chip ferrite bead, Murata
BLM18HG601
0805 size inductor,
Murata LQM21FN100M70L
100nF
C8
R4
R3
TOSA
V
CC
ADN2531