Manual

MAX3737
Multirate Laser Driver with Extinction
Ratio Control
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +2.97V to +3.63V, T
A
= -40°C to +85°C. Typical values are at V
CC
= +3.3V, I
BIAS
= 60mA, I
MOD
= 60mA, T
A
= +25°C, unless
otherwise noted.) (Notes 1, 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
5mA ≤ I
MOD
≤ 10mA ±20
Modulation-Current Setting Error
15Ω load,
T
A
= +25°C
10mA < I
MOD
≤ 85mA ±15
%
Modulation Off Current TX_DISABLE = high 0.1 mA
Modulation-Current Monitor Ratio I
MOD
/I
MC_MON
223 262 302 mA/mA
EXTINCTION RATIO CONTROLS
M oni tor - D i od e Inp ut C ur r ent Rang eI
MD
Average current into the MD pin 18 1500 µA
MD Pin Voltage 1.4 V
MD-Current Monitor Ratio I
MD
/I
PC_MON
0.85 1.0 1.15 mA/mA
APC Loop Time Constant C
APC_FILT
= 0.01µF, ∆I
MD
/∆I
BIAS
= 1/70 3.3 µs
APC Setting Stability ±100 ±480 ppm/°C
APC Setting Accuracy T
A
= +25°C ±15 %
I
MOD
Compensation Setting
Range by Bias
K K = ∆I
MOD
/∆I
BIAS
0 1.5 mA/mA
I
MOD
Compensation Setting
Range by Temperature
TC TC = ∆I
MOD
/∆Τ (Note 6) 0 1.0 mA/°C
Threshold Setting Range for
Temperature Compensation
T
TH
(Note 6) 10 60 °C
LASER SAFETY AND CONTROL
Bias and Modulation Turn-Off
Delay
C
APC_FILT
= 0.01µF, ∆I
MD
/∆I
BIAS
= 1/80
(Note 6)
5µs
Bias and Modulation Turn-On
Delay
C
APC_FILT
= 0.01µF, ∆I
MD
/∆I
BIAS
= 1/80
(Note 6)
600 µs
Threshold Voltage at Monitor Pins V
REF
Figure 5 1.14 1.3 1.39 V
INTERFACE SIGNALS
TX_DISABLE Input High V
HI
2.0 V
TX_DISABLE Input Low V
LO
R
PULL
= 7.5kΩ 0.8 V
V
HI
= V
CC
15
TX_DISABLE Input Current
V
LO
= GND -450 -800
µA
TX_FAULT Output Low Sinking 1mA, open collector 0.4 V
Shutdown Output High Sourcing 100µA
V
CC
-
0.4
V
Shutdown Output Low Sinking 100µA 0.4 V
Note 1: AC characterization is performed using the circuit in Figure 2 using a PRBS 2
23
- 1 or equivalent test pattern.
Note 2: Specifications at -40°C are guaranteed by design and characterization.
Note 3: Excluding I
BIAS
and I
MOD
. Input data is AC-coupled. TX_FAULT open, SHUTDOWN open.
Note 4: Power-supply noise rejection (PSNR) = 20log
10
(V
noise (on VCC)
/∆V
OUT
). V
OUT
is the voltage across the 15Ω load when IN+ is high.
Note 5: The minimum required voltage at the OUT+ and OUT- pins is +0.75V.
Note 6: Guaranteed by design and characterization.
Note 7: Tested with 00001111 pattern at 2.7Gbps.
Note 8: DJ includes pulse-width distortion (PWD).
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