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-
form-factor (SFF) fiber optic LAN transmitters. It con-
tains a bias generator, a laser modulator, and
comprehensive safety features. Automatic power con-
trol (APC) adjusts the laser bias current to maintain
average optical power, regardless of changes in tem-
perature or laser properties. The driver accommodates
common anode or differential laser configurations. The
output current range of the MAX3996 is appropriate for
VCSELs and high-efficiency edge-emitting lasers.
ꢀ 9ps
Deterministic Jitter
P-P
ꢀ 20-Pin QFN 4mm ✕ 4mm Package
ꢀ 3.0V to 5.5V Supply Voltage
ꢀ Automatic Power Control
ꢀ Integrated Safety Circuits
ꢀ 30mA Laser Modulation Current
ꢀ Temperature Compensation of Modulation
The MAX3996 operates up to 3.2Gbps. It can switch up
to 30mA of laser modulation current and sink up to
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-
Current
ꢀ Compliant with SFF and SFP MSA
Ordering Information
ter (9ps
), combined with fast edge transitions,
P-P
(65ps) provides excellent margins compared to indus-
try-standard transmitter eye masks.
TEMP
PIN-
PACKAGE
CODE
PART
RANGE
PACKAGE
This laser driver provides extensive safety features to
guarantee single-point fault tolerance. Safety features
include a transmit disable, redundant shutdown, and
laser-bias monitoring. The safety circuit detects faults
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
pluggable (SFP) multisource agreements (MSA).
MAX3996CGP
0°C to +70°C
20 QFN
G2044-3
MAX3996CTP+ 0°C to +70°C
20 Thin QFN T2044-3
+
Denotes Lead-Free Package
Typical Application Circuit
The MAX3996 is available in a compact 4mm ✕ 4mm,
20-pin QFN package and a 20-pin thin QFN package. It
operates over a temperature range of 0°C to +70°C.
V
CC
OPTIONAL SHUTDOWN
CIRCUITRY
V
V
CC
1.8kΩ
Applications
Fibre Channel Optical Transmitters
0.01µF
CC
SHDNDRV
TX_DISABLE
FAULT
VCSEL Transmitters
0.01µF
Gigabit Ethernet Optical Transmitters
ATM LAN Optical Transmitters
10 Gigabit Ethernet WWDM
OUT-
0.01µF
0.01µF
0.01µF
OUT+
IN+
MAX3996
L1*
25Ω
IN-
BIAS
MD
PORDLY
Pin Configuration appears at end of data sheet.
TC MODSET MON1 MON2 COMP
GND
C
PORDLY
R
SET
N.C.
R
TC
R
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 Maxim’s website at www.maxim-ic.com.