19-1575; Rev 5; 2/05
+3.3V, 622Mbps SDH/SONET
Laser Driver with Current Monitors and APC
General Description
Features
The MAX3669 is a complete, +3.3V laser driver with auto-
matic power control (APC) circuitry for SDH/SONET appli-
cations up to 622Mbps. It accepts differential PECL
inputs, provides bias and modulation currents, and oper-
ates over a temperature range from -40°C to +85°C.
♦ +3.3V or +5.0V Single-Supply Operation
♦ 40mA Supply Current at +3.3V
♦ Programmable Bias Current from 1mA to 80mA
♦ Programmable Modulation Current from
5mA to 75mA
♦ Bias Current and Modulation Current Monitors
♦ 200ps Rise/Fall Time
♦ Automatic Average Power Control with Failure
Monitor
♦ Complies with ANSI, ITU, and Bellcore
SONET/SDH Specifications
An APC feedback loop is incorporated to maintain a
constant average optical power over temperature and
lifetime. The wide modulation current range from 5mA to
75mA and bias current of 1mA to 80mA are easy to
program, making this product ideal for use in various
SDH/SONET applications. Two pins are provided to
monitor the current levels in the laser: BIASMON with
current proportional to laser bias current, and MODMON
with current proportional to laser modulation.
♦ Enable Control
The MAX3669 also provides enable control and a failure-
monitor output to indicate when the APC loop is unable
to maintain the average optical power. The MAX3669
is available in 4mm x 4mm 24-pin thin QFN and
5mm x 5mm 32-pin TQFP packages as well as dice.
Ordering Information
TEMP RANGE PIN-PACKAGE
PART
MAX3669ETG
MAX3669ETG+
MAX3669EHJ
MAX3669EHJ+
MAX3669E/D
-40°C to +85°C 24 Thin QFN* (4mm x 4mm)
-40°C to +85°C 24 Thin QFN* (4mm x 4mm)
-40°C to +85°C 32 TQFP (5mm x 5mm)
-40°C to +85°C 32 TQFP (5mm x 5mm)
Applications
622Mbps SDH/SONET Access Nodes
Laser Driver Transmitters
(Note A)
Dice**
+Denotes lead-free package.
Note A: Dice are designed to operate over a -40°C to +140°C
junction temperature (T ) range, but are tested and guaranteed
Section Regenerators
j
at T = +25°C.
*Package Code: T2444-1.
A
Pin Configurations appear at end of data sheet.
**Contact factory for availability.
Typical Application Circuit
+3.3V
+3.3V
LASER
V
CC
R-
6.3Ω
124Ω
124Ω
R+
20Ω
DATA+
DATA-
R
D
OUT-
5Ω
MAX3693
PECL
OUT+
C
1µF
D
4:1
SERIALIZER
WITH
MAX3669
R
20Ω
FILT
84.5Ω
84.5Ω
FERRITE
BEAD
C
FILT
CLOCK GEN
5pF
BIAS
MD
BIASMON
MODMON
C
MD
100pF
0.1µF
+3.3V
________________________________________________________________ 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.