Manual

MAX3738
1Gbps to 2.7Gbps SFF/SFP Laser Driver with
Extinction Ratio Control
_______________________________________________________________________________________ 3
Note 1: AC characterization is performed using the circuit in Figure 2 using a PRBS 2
23
- 1 or equivalent 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).
PARAMETER
SYMBOL
CONDITIONS MIN TYP
MAX
UNITS
APC Loop Time Constant
C
APC_FILT
= 0.01µF, ∆I
MD
/ ∆I
BIAS
= 1/70
3.3 µs
APC Setting Stability (Note 6)
±100 ±480
ppm/°C
APC Setting Accuracy T
A
= +25°C
±15
%
I
MOD
Compensation-Setting
Range by Bias
KK = ∆I
MOD
/ ∆I
BIAS
0 1.5
mA/mA
I
MOD
Compensation-Setting
Range by Temperature
TC TC = ∆I
MOD
/ ∆T (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
= 45kΩ (typ) 0.8 V
V
HI
= V
CC
15
TX_DISABLE Input Current
V
LO
= GND -70
-140
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
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)