MAX3996
19-2194; Rev 3; 5/04
3.0V to 5.5V, 2.5Gbps VCSEL
and Laser Driver
General Description Features
The MAX3996 is a high-speed laser driver for small-
9ps Deterministic Jitter
P-P
form-factor (SFF) fiber optic LAN transmitters. It con-
20-Pin QFN 4mm 4mm Package
tains a bias generator, a laser modulator, and
comprehensive safety features. Automatic power con-
3.0V to 5.5V Supply Voltage
trol (APC) adjusts the laser bias current to maintain
Automatic Power Control
average optical power, regardless of changes in tem-
perature or laser properties. The driver accommodates
Integrated Safety Circuits
common anode or differential laser configurations. The
30mA Laser Modulation Current
output current range of the MAX3996 is appropriate for
VCSELs and high-efficiency edge-emitting lasers.
Temperature Compensation of Modulation
The MAX3996 operates up to 3.2Gbps. It can switch up
Current
to 30mA of laser modulation current and sink up to
Compliant with SFF and SFP MSA
60mA bias current. Adjustable temperature compensa-
tion is provided to keep the optical extinction ratio with-
in specifications over the operating temperature range.
The MAX3996 accommodates various laser packages,
including low-cost TO-46 headers. Low deterministic jit-
Ordering Information
ter (9ps ), combined with fast edge transitions,
P-P
(65ps) provides excellent margins compared to indus-
TEMP PIN- PACKAGE
try-standard transmitter eye masks.
PART
RANGE PACKAGE CODE
This laser driver provides extensive safety features to
MAX3996CGP 0C to +70C 20 QFN G2044-3
guarantee single-point fault tolerance. Safety features
include a transmit disable, redundant shutdown, and
MAX3996CTP+ 0C to +70C 20 Thin QFN T2044-3
laser-bias monitoring. The safety circuit detects faults
+
Denotes Lead-Free Package
that could cause hazardous light levels and immediate-
ly disables the laser output. The MAX3996 safety cir-
cuits are compliant with SFF and small-form-factor
Typical Application Circuit
pluggable (SFP) multisource agreements (MSA).
The MAX3996 is available in a compact 4mm 4mm,
V
CC
20-pin QFN package and a 20-pin thin QFN package. It
OPTIONAL SHUTDOWN
operates over a temperature range of 0C to +70C. CIRCUITRY
V
CC 1.8k
Applications
Fibre Channel Optical Transmitters
0.01 F
V
CC SHDNDRV
TX_DISABLE
VCSEL Transmitters
0.01 F
Gigabit Ethernet Optical Transmitters
FAULT
OUT-
ATM LAN Optical Transmitters
0.01 F
0.01 F
10 Gigabit Ethernet WWDM
IN+ OUT+
MAX3996
L1*
0.01 F 25
IN-
BIAS
PORDLY
Pin Configuration appears at end of data sheet.
MD
TC MODSET MON1 MON2 COMP GND
C
PORDLY
R
SET
N.C.
R R
TC MOD
C
COMP
*FERRITE BEAD
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxims website at www.maxim-ic.com.3.0V to 5.5V, 2.5Gbps VCSEL
and Laser Driver
ABSOLUTE MAXIMUM RATINGS
Supply Voltage at V ...........................................-0.5V to +7.0V Current into FAULT, SHDNDRV ..........................-1mA to +25mA
CC
Voltage at TX_DISABLE, PORDLY, MON1, COMP, Current into OUT+, OUT-....................................................60mA
IN+, IN-, MD, BIAS, MODSET, TC..........-0.5V to (V + 0.5V) Current into BIAS ..............................................................120mA
CC
Voltage between COMP and MON2 .....................................2.3V Continuous Power Dissipation (T = +70C)
A
Voltage between IN+ and IN- ..................................................5V 20-Pin QFN (derate 20mW/C)...................................1600mW
Voltage at OUT+, OUT-.........................(V - 2V) to (V + 2V) Operating Ambient Temperature Range .............-40C to +85C
CC CC
Voltage between MON1 and MON2 .....................................1.5V Operating Junction Temperature Range...........-40C to +150C
Voltage between BIAS and MON2...........................................4V Storage Temperature Range.... .........................-55C to +150C
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V = 3.0V to 5.5V, T = 0C to +70C, unless otherwise noted. Typical values are at V = 3.3V, TC pin not connected, T =
CC A CC A
+25C.) (Figure 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
V = 3.3V, I = 15mA 47
CC MOD
I
CC
Supply Current (Figure1) mA
V = 5.5V, I = 30mA,
CC MOD
52 75
(Note 1)
R = 2.37k
MODSET
Data Input Voltage Swing V Total differential signal (Figure 2) 200 2200 mV
ID P-P
TX_DISABLE Input Current 0 < V < V -100 +100 A
PIN CC
TX_DISABLE Input High Voltage V 2.0 V
IH
TX_DISABLE Input Low Voltage V 0.8 V
IL
FAULT Output High Voltage V I = -100A, 4.7k < R < 10k 2.4 V
OH OH FAULT
FAULT Output Low Voltage V I = 1mA 0.4 V
OL OL
BIAS GENERATOR
Minimum Bias Current I Current into BIAS pin 1 mA
BIAS
Maximum Bias Current I Current into BIAS pin 60 mA
BIAS
APC loop is closed 1.04 1.12
MD Quiescent Voltage V FAULT = high V - 0.73 V
MD CC
TX_DISABLE = high V - 0.73
CC
Monitor Resistance R (Figure 4) 9.3 11 12.7
MON
MD Input Current FAULT = low, TX_DISABLE = low -3 +0.8 +3 A
BIAS Current During Fault I 10 A
BIAS_OFF
APC Time Constant C = 0.1F 35 s
COMP
POWER-ON RESET (POR)
POR Threshold Measured at V 2.65 2.7 3.0 V
CC
PORDLY = open (Note 3) 30 55 s
POR Delay t
PORDLY
C = 0.001F (Note 3) 1.7 2.4 ms
PORDLY
POR Hysteresis 20 mV
SHUTDOWN
I = 10A, FAULT = high V - 0.4
SHDNDRV CC
Voltage at SHDNDRV I = 1mA, FAULT = low V - 2.4 V
SHDNDRV CC
I = 15mA, FAULT = low 0 V - 1.2
SHDNDRV CC
LASER MODULATOR
Data Rate < 3.2 Gbps
2 _______________________________________________________________________________________
MAX3996