MAX3669EHJ+T ,+3.3V, 622Mbps SDH/SONET Laser Driver with Current Monitors and APCApplicationsMAX3669EHJ -40°C to +85°C 32 TQFP 622Mbps SDH/SONET Access NodesMAX3669EHJ+ -40°C to +8 ..
MAX3669ETG , 3.3V, 622Mbps SDH/SONET Laser Driver with Current Monitors and APC
MAX3669ETG , 3.3V, 622Mbps SDH/SONET Laser Driver with Current Monitors and APC
MAX3669ETG+ ,+3.3V, 622Mbps SDH/SONET Laser Driver with Current Monitors and APCELECTRICAL CHARACTERISTICS(V = +3.14V to +5.5V, T = -40°C to +85°C, unless otherwise noted. Typical ..
MAX3669ETG+T ,+3.3V, 622Mbps SDH/SONET Laser Driver with Current Monitors and APCapplications. Two pins are provided to♦♦ Complies with ANSI, ITU, and Bellcoremonitor the current l ..
MAX366CPA ,Signal-Line Circuit ProtectorsMAX366/MAX36719-0326; Rev 0; 12/94Signal-Line Circuit Protectors_______________
MAX7312AUG ,2-Wire-Interfaced 16-Bit I/O Port Expander with Interrupt and Hot-Insertion Protectionapplications. The MAX7312 consists of input port 5V Overvoltage Tolerant I/Osregisters, output por ..
MAX7312AUG+ ,2-Wire-Interfaced 16-Bit I/O Port Expander with Interrupt and Hot-Insertion ProtectionELECTRICAL CHARACTERISTICS (continued)+ +(V = 2V to 5.5V, T = -40°C to +125°C, unless otherwise not ..
MAX7313AEG ,16-Port I/O Expander with LED Intensity Control, Interrupt, and Hot-Insertion ProtectionMAX731319-3059; Rev 5; 6/1116-Port I/O Expander with LED IntensityControl, Interrupt, and Hot-Inser ..
MAX7313AEG+ ,16-Port I/O Expander with LED Intensity Control, Interrupt, and Hot-Insertion ProtectionMAX731319-3059; Rev 5; 6/1116-Port I/O Expander with LED IntensityControl, Interrupt, and Hot-Inser ..
MAX7313AEG+T ,16-Port I/O Expander with LED Intensity Control, Interrupt, and Hot-Insertion ProtectionApplicationsSCL 19 12 P10LCD BacklightsSDA 20 11 P9LED Status IndicationV+ 21 10 P8Portable Equipme ..
MAX7313ATG , 16-Port I/O Expander with LED Intensity Control, Interrupt, and Hot-Insertion Protection
MAX3669EHJ+-MAX3669EHJ+T-MAX3669ETG+-MAX3669ETG+T
+3.3V, 622Mbps SDH/SONET Laser Driver with Current Monitors and APC
General DescriptionThe 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.
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.
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.
Applications622Mbps SDH/SONET Access Nodes
Laser Driver Transmitters
Section Regenerators
Features♦
+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♦
Enable Control
+3.3V, 622Mbps SDH/SONET
Laser Driver with Current Monitors and APC
MAX3669EVALUATION KIT AVAILABLE
DATA+
BIASMAXMODSETAPCSETCAPC
FAIL
ENABLE
GNDMD
BIASBIASMON
MODMON
OUT+
0.1μF
LASER
OUT-
CMD
100pF
RFILT
20Ω
CFILT
5pF
1μF
20Ω
6.3Ω
FERRITE
BEAD
VCC
DATA-
PECL
+3.3V
+3.3V
+3.3V
84.5Ω84.5Ω
124Ω124Ω
4:1
SERIALIZER
WITH
CLOCK GEN
MAX3693
MAX3669
Typical Application Circuit
Ordering Information
Pin Configurations appear at end of data sheet.
PART TEMP RANGE PIN-PACKAGE MAX3669ETG -40°C to +85°C 24 TQFN-EP*
MAX3669ETG+ -40°C to +85°C 24 TQFN-EP*
MAX3669EHJ -40°C to +85°C 32 TQFP
MAX3669EHJ+ -40°C to +85°C 32 TQFP
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
+3.3V, 622Mbps SDH/SONET
Laser Driver with Current Monitors and APC
MAX3669
ABSOLUTE MAXIMUM RATINGS
DC ELECTRICAL CHARACTERISTICS(VCC= +3.14V to +5.5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at VCC= +3.3V, TA= +25°C.)
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.
Supply Voltage, VCC.............................................-0.5V to +7.0V
Current into BIAS............................................-20mA to +150mA
Current into OUT+, OUT-...............................-20mA to +100mA
Current into MD....................................................-5mA to +5mA
Voltage at DATA+, DATA-, ENABLE,
FAIL,BIASMON, MODMON..................-0.5V to (VCC+ 0.5V)
Voltage at OUT+, OUT-.............................+1.5V to (VCC + 1.5V)
Voltage at MODSET, APCSET, BIASMAX, CAPC...-0.5V to +3.0V
Voltage at BIAS.........................................+1.0V to (VCC + 0.5V)
Continuous Power Dissipation (TA= +85°C)
TQFN (derate 20.8mW/°C above +85°C).................1354mW
TQFP (derate 14.3mW/°C above +85°C)....................929mW
Operating Junction Temperature Range...........-55°C to +150°C
Storage Temperature Range............................-65°C to +165°C
Lead Temperature (soldering, 10s).................................+300°C
MODMON to IMODGainAMOD29mA/mAIMOD/IMODMON
BIASMON to IBIASGainABIAS38mA/mAIBIAS/IBIASMONIMD= 18µA (Note 4)
IMD= 1mA
815IBIAS= 1mA
IBIAS= 80mA
PARAMETERSYMBOLMINTYPMAXUNITSCommon-Mode Input VoltageVICMVCC -VCC -VCC -
1.491.32VID/4V
Differential Input VoltageVID2001600mVP-P
Bias Current Absolute Accuracy-15+15%
Bias Current Stability255ppm/°C
DATA+, DATA- Input CurrentIIN-1+10µA
Monitor Diode Current Stability-480-50+480ppm/°C
Monitor Diode Current
Absolute Accuracy-15+15%
DC Monitor Diode CurrentIMD181000µA
Bias Current Range
Supply Current4060mA
IBIAS180mA
Bias Off Current100µA
Monitor Diode Input Voltage
(MDPin)VMD0.8V
TTL Input High VoltageVIH2V
TTL Input Low VoltageVIL0.8V
TTL Output High Voltage (FAIL)VOH2.4VCC - 0.3VCCV
TTL Output Low Voltage (FAIL)VOL0.10.44V
CONDITIONSPECL compatible
Figure 1
APC open loop
APC open loop
(Note 3)
Sourcing 50µA
Sinking 100µA
(Note 1)
VBIAS= VCC - 1.6V
ENABLE = low (Note 2)
+3.3V, 622Mbps SDH/SONET
Laser Driver with Current Monitors and APC
AC ELECTRICAL CHARACTERISTICS(VCC= +3.14V to +5.5V, load as shown in Figure 2, TA= -40°C to +85°C, unless otherwise noted. Typical values are at VCC= +3.3V,= +25°C.) (Note 5)
MAX3669
Note 1:Tested with RMODSET= 5.11kΩ(IMOD≈38mA), RBIASMAX= 4.56kΩ(IBIAS≈52mA), excluding IBIASand IMOD.
Note 2:Both the bias and modulation currents will be disabled if any of the current set pins are shorted to ground.
Note 3:Guaranteed by design and characterization. This assumes that the laser to monitor diode transfer function does not change
with temperature.
Note 4:See the Typical Operating Characteristicsfor worst-case distributions.
Note 5:ACcharacteristics are guaranteed by design and characterization.
Note 6:Total IMODout of OUT+. See the Design Procedure section for information regarding current delivered to the laser.
Note 7:Input signal is a 622Mbps, 213 - 1 PRBS with eighty inserted 0s.
Note 8:Input signal is a 622Mbps, 11110000 pattern.
Note 9:PWD = (wider pulse – narrower pulse) / 2.
DATA+
DATA-
(DATA+) - (DATA-)
IOUT+
100mV MIN
800mV MAX
200mVP-P
MIN
1600mVP-P
MAX
IMOD
VCC
15Ω
10Ω
1μF
1μF
12.4Ω
20Ω
OUT-
OUT+
BIAS
20Ω
50Ω
OSCILLOSCOPE
MAX3669
VCC
IOUT+135IMOD= 75mA
Maximum ConsecutiveIdentical
Digits at 622MbpsCID80Bits
IMOD= 5mA
IMOD= 75mA
Jitter Generation (Peak-to-Peak)100ps(Note 7)
205IMOD= 5mA (Note 4)
IMOD= 5mA(Notes 8, 9)
PARAMETERSYMBOLMINTYPMAXUNITS230375psOutput Rise/Fall TimetR, tF100200
Modulation Current Absolute
Accuracy-15+15%
Pulse-Width Distortion
(Peak-to-Peak)155ps
Enable/Start-Up Delay 250ns
Modulation Current Stability-620-165+620ppm/°C
CONDITIONS20% to 80%, = 10Ω||20Ωload
Open loop
IMOD= 75mA
Modulation Current RangeIMOD575mA(Note 6)
Modulation Off-Current200µAENABLE = low (Note 2)
ELECTRICAL EYE DIAGRAM
(IMOD = 35mA)MAX3669 TOC02
200ps/div
PATTERN = 213 - 1 + 80 CID
IMOD = 35mA
622Mbps DATA RATE
ELECTRICAL EYE DIAGRAM
(IMOD = 75mA)MAX3669 TOC03
200ps/div
PATTERN = 213 - 1 + 80 CID
IMOD = 75mA
622Mbps DATA RATE
EYE DIAGRAM
(622Mbps, 1300nm LASER
WITH 467MHz FILTER)MAX3669 TOC01
200ps/div
223 – 1 PRBS
MONITOR DIODE CURRENT
vs. APC SET RESISTOR
MAX3669 TOC04
RAPCSET (kΩ)
IMD
(mA)
BIAS CURRENT
vs. MAXIMUM BIAS SET RESISTOR
MAX3669 TOC05
RBIASMAX (kΩ)
IBIAS
(mA)
MODULATION CURRENT
vs. MODULATION SET RESISTOR
MAX3669 TOC06
RMODSET (kΩ)
IMOD
(mA)1
RANDOM JITTER
vs. MODULATON CURRENT
MAX3669 TOC07
RANDOM JITTER (ps
P-P
INCLUDES RANDOM JITTER
DUE TO MEASUREMENT
EQUIPMENT
PULSE-WIDTH DISTORTION
vs. MODULATION CURRENT
MAX3669 TOC08
IMOD (mA)
PWD (ps)
MAX3669 TOC09
SUPPLY CURRENT (mA)
SUPPLY CURRENT
vs. TEMPERATUREIBIAS = 48mA
IMOD = 27mA
VCC = 5.0V
VCC = 3.3V
+3.3V, 622Mbps SDH/SONET
Laser Driver with Current Monitors and APC
MAX3669
Typical Operating Characteristics (VCC= +3.3V, TA= +25°C, unless otherwise noted.)
+3.3V, 622Mbps SDH/SONET
Laser Driver with Current Monitors and APCTA = -40°C TO +85°C
IMOD = 5mA
DISTRIBUTION OF MODULATION CURRENT
STABILITY (WORST CASE)MAX3669-11
MODULATION CURRENT STABILITY (ppm/°C)
UNITS (%)
DISTRIBUTION OF MONITOR DIODE CURRENT
STABILITY (WORST CASE)
MAX3669-12
MONITOR DIODE CURRENT STABILITY (ppm/°C)
PERCENT OF UNITS (%)
TA = -40°C TO +85°C
IMD = 18μA
MAX3669
Typical Operating Characteristics (continued)
(VCC= +3.3V, TA= +25°C, unless otherwise noted.)
RATIO OF IMOD vs. IMODMONMAX3669 toc13
IMOD (mA)
IMOD
MODMON
(mA/mA)20406080
TA = -40°C
TA = +85°C
TA = +25°C20406080
RATIO OF IBIAS vs. IBIASMONMAX3669 toc14
IBIAS (mA)
IBIAS
BIASMON
(mA/mA)
TA = -40°CTA = +25°C
TA = +85°C
+3.3V, 622Mbps SDH/SONET
Laser Driver with Current Monitors and APC
MAX3669
PIN
TQFN-EP TQFP
NAME FUNCTION 1, 13, 16,
1, 2, 6, 15,
17, 20, 24 VCC Positive Supply Voltage 3 DATA+ Positive PECL Data Input 4 DATA- Negative PECL Data Input
4, 8, 11,
17, 22
5, 10, 14,
21, 22, 30 GND Ground 7 BIASMON Sink Current Source. Proportional to the laser bias current. 8 MODMON Sink Current Source. Proportional to the laser modulation current.
7 9 ENABLE TTL/CMOS Enable Input. High for normal operation, low to disable laser bias and
modulation currents. Internally pulled high.
9 11 FAIL TTL Output. Indicates APC failure when low. Internally pulled high through a 6k12, 13, 26,
27, 28 N.C. No Connection. Leave unconnected.
12 16 BIAS Laser Bias Current Output. Isolate from laser with a ferrite bead.
14 18 OUT+ Positive Modulation Current Output. IMOD flows into this pad when the input signal is
high. Connect this pad to AC-coupling network.
15 19 OUT- Negative Modulation Current Output. IMOD flows into this pad when the input signal is
low. Connect this pad to VCC through a 6.3 resistor.
18 23 MD Monitor Photodiode Connection. Connect this pad to the monitor photodiode anode.
A capacitor to ground is required to filter high-speed AC monitor photocurrent.
20 25 CAPC APC Compensation Capacitor. A 0.1μF capacitor connected from this pad to ground
controls the dominant pole of the APC feedback loop.
21 29 APCSET
APC Set Resistor. A resistor connected from this pad to ground sets the desired average
optical power. The resulting current is equal to the desired DC monitor diode current.
Connect a 100k resistor from this pad to ground if APC is not used.
23 31 MODSET Modulation Set Resistor. A resistor from this pad to ground sets the laser modulation
current.
24 32 BIASMAX
Maximum Bias Set Resistor. A resistor from this pad to ground sets the maximum laser
bias current. The APC function can subtract from this maximum value but cannot add to
it. This resistor controls the bias-current level when the APC loop is not used. — EP Exposed Pad (TQFN only). The exposed paddle must be soldered to ground.
Pin Description
+3.3V, 622Mbps SDH/SONET
Laser Driver with Current Monitors and APC
MAX3669MAX3669
DATA+
OUT+
OUT-DATA-
100kΩ
ENABLE
IMOD
VCC
IMD
RAPCSETRBIASMAX
RBIASMON
RMODMON
RMODSET
APCSETCAPC
CAPC
BIASMAX
MODSET
FAIL
BIASIBIAS
165X
VCC
FAILURE
DETECTOR
40XVCC
IBIAS
IMOD
Figure 3. Functional Diagram
Detailed DescriptionThe MAX3669 laser driver consists of three main parts:
a high-speed modulation driver, a laser-biasing block
with automatic power control (APC), and bias current
and modulation current monitors. The circuit is opti-
mized for low-voltage (+3.3V) operation.
The output stage is composed of a high-speed differential
pair and a programmable modulation current source.
Since the modulation output drives a maximum current
of 75mA into the laser with a 230ps edge speed, large
transient voltage spikes can be generated due to the
parasitic inductance. These transients and the laser for-
ward voltage leave insufficient headroom for the proper
operation of the laser driver if the modulation output is
DC-coupled to the laser diode. To solve this problem,
the MAX3669’s modulation output is designed to be
AC-coupled to the cathode of a laser diode. A simpli-
fied functional diagram is shown in Figure 3.
The MAX3669 modulation output is optimized for driv-
ing a 20Ω⎥⎥ 10Ωload; the minimum required voltage at
OUT+ is 2.0V. Modulation current swings of 75mA are
possible. To interface with the laser diode, a damping
resistor (RD) is required for impedance matching. An
RC shunt network may be used to compensate for the
laser-diode parasitic inductance, thereby improving the
optical output aberrations and duty-cycle distortion.
At a 622Mbps data rate, any capacitive load at the cath-
ode of a laser diode degrades the optical output perfor-
mance. Since the BIAS output is directly connected to the
laser cathode, minimize the parasitic capacitance associ-
ated with this pin by using an inductor to isolate the BIAS
pin from the laser diode.
