MAXIM MAX3287

19-1550; Rev 3; 7/02
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
♦ Selectable Laser Pinning (Common Cathode or
Common Anode) (MAX3286/MAX3296)
♦ 30mA Laser Modulation Current
♦ Temperature Compensation of Modulation
Current
♦ Automatic Laser Power Control or Constant Bias
Current
♦ Integrated Safety Circuits
♦ Power-On Reset Signal
♦ QFN Package Available
Ordering Information
PART
PIN-PACKAGE
0°C to +70°C
28 QFN (5mm x 5mm)**
MAX3286CHJ
0°C to +70°C
32 TQFP (5mm x 5mm)
MAX3286C/D
0°C to +70°C
Dice*
Ordering Information continued at end of data sheet.
*Dice are designed to operate from TJ = 0°C to +110°C, but are
tested and guaranteed only at TA = +25°C.
**Exposed pad.
VCC
VCC
GND
22
23
OUT-
OUT+
24
25
VCC
26
28
GND
27
TC
TOP VIEW
MODSET
Pin Configurations
FAULT
1
21
BIASDRV
FAULT
2
20
SHDNDRV
19
GND
18
MON
POR
3
GND
4
EN
5
17
MD
EN
6
16
POL
PORDLY
7
15
POL
9
10
11
12
13
14
IN+
IN-
GND
REF
MAX3286
MAX3296
LV
GND
Typical Application Circuits and Selector Guide appear at
end of data sheet.
TEMP RANGE
MAX3286CGI
VCC
Gigabit Ethernet Optical Transmitter
Fibre Channel Optical Transmitter
ATM LAN Optical Transmitter
♦ +3.0V to +5.5V Supply Voltage
8
Applications
♦ 7ps Deterministic Jitter (MAX3296)
22ps Deterministic Jitter (MAX3286)
FLTDLY
The MAX3286/MAX3296 are available in a compact, 5mm
✕ 5mm, 28-pin QFN package; a 5mm ✕ 5mm, 32-pin
TQFP package; or in die form. The MAX3287/MAX3288/
MAX3289 and MAX3297/MAX3298/MAX3299 are available in a 16-pin TSSOP-EP package.
Features
GND
QFN*
*Exposed pad is connected to GND.
Pin Configurations continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products
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.
1
MAX3286–MAX3289/MAX3296–MAX3299
General Description
The MAX3286/MAX3296 series of products are highspeed laser drivers for fiber optic LAN transmitters,
optimized for Gigabit Ethernet applications. Each
device contains a bias generator, laser modulator, and
comprehensive safety features. Automatic power control (APC) adjusts the laser bias current to maintain
average optical power at a constant level, regardless of
changes in temperature or laser properties. For lasers
without a monitor photodiode, these products offer a
constant-current mode. The circuit can be configured
for use with conventional shortwave (780nm to 850nm)
or longwave (1300nm) laser diodes, as well as verticalcavity surface-emitting lasers (VCSELs).
The MAX3286 series (MAX3286–MAX3289) is optimized for operation at 1.25Gbps, and the MAX3296
series (MAX3296–MAX3299) is optimized for 2.5Gbps
operation. Each device can switch 30mA of laser modulation current at the specified data rate. Adjustable
temperature compensation is provided to keep the optical extinction ratio within specifications over the operating temperature range. This series of devices is
optimized to drive lasers packaged in low-cost TO-46
headers. Deterministic jitter (DJ) for the MAX3286 is
typically 22ps, allowing a 72% margin to Gigabit
Ethernet DJ specifications.
These laser drivers provide extensive safety features to
guarantee single-point fault tolerance. Safety features
include dual enable inputs, dual shutdown circuits, and
a laser-power monitor. The safety circuit detects faults
that could cause dangerous light output levels. A programmable power-on reset pulse initializes the laser
driver at startup.
MAX3286–MAX3289/MAX3296–MAX3299
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
ABSOLUTE MAXIMUM RATINGS
Supply Voltage at VCC ..........................................-0.5V to +7.0V
Voltage at EN, EN, PORDLY, FLTDLY, LV, IN+, IN-,
REF, POL, POL, MD, MON, BIASDRV,
MODSET, TC.......................................................-0.5V to (VCC + 0.5V)
Voltage at OUT+, OUT- .........................(VCC - 2V) to (VCC + 2V)
Current into FAULT, FAULT, POR, SHDNDRV....-1mA to +25mA
Current into OUT+, OUT- ....................................................60mA
Continuous Power Dissipation (TA = +70°C)
32-Pin TQFP (derate 14.3mW/°C above +70°C).........1100mW
28-Pin QFN (derate 28.7mW/°C above +70°C) ..........2300mW
16-Pin TSSOP (derate 27mW/°C above +70°C) .........2162mW
Operating Temperature Range...............................0°C to +70°C
Operating Junction Temperature Range ..............0°C to +150°C
Processing Temperature (die) .........................................+400°C
Storage Temperature Range .............................-55°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°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.
ELECTRICAL CHARACTERISTICS
(VCC = +3.0V to +5.5V, TA = 0°C to +70°C, unless otherwise noted. Typical values are at VCC = +3.3V, RTC = open and TA = +25°C;
see Figure 1a.)
PARAMETER
SYMBOL
CONDITIONS
Supply Current
ICC
Figure 1a, RMOD = 1.82kΩ
Data Input Voltage Swing
VID
Total differential signal, peak-to-peak, Figure 1a
0 ≤ VPIN ≤ VCC
TTL Input Current
TTL Input High Voltage
VIH
TTL Input Low Voltage
VIL
FAULT, FAULT Output High
Voltage
VOH
IOH = -100µA
FAULT, FAULT Output Low
Voltage
VOL
IOL = 1mA
MIN
TYP
MAX
UNITS
52
75
mA
200
1660
mV
-100
+100
µA
2
V
0.8
2.4
V
V
0.4
V
+1
µA
BIAS GENERATOR (Note 1)
BIASDRV Current, Shutdown
EN = GND
-1
BIASDRV Current Sink
FAULT = low, VBIASDRV ≥ 0.6V
0.8
BIASDRV Current Source
FAULT = low, VBIASDRV ≤ VCC - 1V
0.8
REF Voltage
IREF ≤ 2mA, MON = VCC
2.45
2.65
2.85
V
APC loop is closed
1.55
1.7
1.85
V
0.4
1.2
MD Nominal Voltage
MD Voltage During Fault
VMD
mA
Common-cathode configuration
V
Common-anode configuration
2
VCC - 0.8
MD Input Current
Normal operation (FAULT = low)
-2
+0.16
+2
µA
MON Input Current
VMON = VCC
0.44
6
µA
POWER-ON RESET
POR Threshold
LV = GND
3.9
4.5
LV = open
2.65
3.00
POR Hysteresis
150
V
mV
FAULT DETECTION
REF Fault Threshold
2.95
MD High Fault Threshold
VMD + 5%
VMD + 20%
MD Low Fault Threshold
VMD - 20%
VMD - 5%
MON Fault Threshold
MAX3286/MAX3288/MAX3296/MAX3298
VCC 600
MODSET, TC Fault Threshold
2
_______________________________________________________________________________________
V
VCC 480
mV
0.9
V
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
(VCC = +3.0V to +5.5V, TA = 0°C to +70°C, unless otherwise noted. Typical values are at VCC = +3.3V, RTC = open and TA = +25°C;
see Figure 1a.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
SHUTDOWN
ISHDNDRV = 10µA, FAULT asserted
Voltage at SHDNDRV
VCC - 0.4
ISHDNDRV = 15mA, FAULT not asserted
0
VCC - 1.2
ISHDNDRV = 1mA, FAULT not asserted
0
VCC - 2.4
V
LASER MODULATOR
Data Rate
MAX3286 series
1.25
MAX3296 series
2.5
Minimum Laser Modulation
Current
Gbps
2
Maximum Laser Modulation
Current
Tolerance of Modulation Current
Modulation-Current Edge
Speed
RL ≤ 25Ω
30
RMOD = 1.9kΩ (iMOD = 30mA)
-10
+10
RMOD = 13kΩ (iMOD = 5mA)
-15
+15
130
220
MAX3296 series
90
150
RMOD = 13kΩ
(iMOD = 5mA)
46
65
RMOD = 4.1kΩ
(iMOD = 15mA)
29
45
RMOD = 1.9kΩ
(iMOD = 30mA)
22
35
RMOD = 13kΩ
(iMOD = 5mA)
14
35
RMOD = 4.1kΩ
(iMOD = 15mA)
8
22
RMOD = 1.9kΩ
(iMOD = 30mA)
7
20
MAX3286 series
2
8
MAX3296 series
2
4
15
200
MAX3286 series
Deterministic Jitter (Note 2)
MAX3296 series
Random Jitter, RMS (Note 3)
Tempco = max, RMOD = open; Figure 5
4000
Tempco = min, RTC = open; Figure 5
Differential Input Resistance
Single ended
ps
42
ps
µA
ppm/°C
50
620
Output Resistance
%
ps
Shutdown Modulation Current
Modulation-Current
Temperature Coefficient
mA
MAX3286 series
20% to 80%
mA
800
980
Ω
50
58
Ω
VCC - 0.3
V
0.3
1.25
µs
3
5.5
ms
22
µs
20
µs
Input Bias Voltage
LASER SAFETY CIRCUIT
PORDLY = open
POR Delay
tPORDLY
Fault Time
tFAULT
Glitch Rejection at MD
CPORDLY = 0.01µF,
MAX3286/MAX3296 only
(Note 4)
10
_______________________________________________________________________________________
3
MAX3286–MAX3289/MAX3296–MAX3299
ELECTRICAL CHARACTERISTICS (continued)
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +3.0V to +5.5V, TA = 0°C to +70°C, unless otherwise noted. Typical values are at VCC = +3.3V, RTC = open and TA = +25°C;
see Figure 1a.)
PARAMETER
SYMBOL
FLTDLY Duration
tFLTDLY
FAULT Reset After EN, EN, or
POR Transition
SHDNDRV Asserted After EN =
Low or EN = High
CONDITIONS
MIN
TYP
CFLTDLY = 0
0.2
1
CFLTDLY = 270pF
100
140
MAX
UNITS
µs
MAX3286/MAX3296 only, Figure 1b,
CFLTDLY = open
6
MAX3286/MAX3296 only, Figure 1b,
CFLTDLY = 0.01µF
6
tRESET
MAX3286/MAX3296 only, Figure 1b
1
2
µs
tSHUTDN
MAX3286/MAX3296 only, Figure 1b
3.5
5.5
µs
EN or EN Minimum Pulse Width
tEN_RESET
Required to Reset a Latched
Fault
10
ns
µs
Note 1: Common-anode configuration refers to a configuration where POL = GND, POL = VCC, and an NPN device is used to set
the laser bias current. Common-cathode configuration refers to a configuration where POL = VCC, POL = GND, and a PNP
device is used to set the laser bias current.
Note 2: Deterministic jitter measured with a repeating K28.5 bit pattern 00111110101100000101. Deterministic jitter is the peak-topeak deviation from the ideal time crossings per ANSI X3.230, Annex A.
Note 3: For Fibre Channel and Gigabit Ethernet applications, the peak-to-peak random jitter is 14.1 times the RMS jitter.
Note 4: Delay from a fault on MD until FAULT is asserted high.
Typical Operating Characteristics
(TA = +25°C, unless otherwise noted.)
MAX3286 toc02
MAX3286 toc01
10,000
EYE DIAGRAM
FLTDLY DURATION vs. CFLTDLY
10,000
MAX3286 toc03
POR DELAY vs. CPORDLY
100,000
1000
1000
DELAY (µs)
DELAY (µs)
MAX3286–MAX3289/MAX3296–MAX3299
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
100
10
10
1
1
10
100
1000
10,000
CAPACITANCE (pF)
4
100
100,000
1
10
100
CAPACITANCE (pF)
1000
10,000
50ps/div
2.5Gbps, 1310nm LASER, 27 - 1 PRBS, iMOD = 15mA
_______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
EN STARTUP
(COMMON-ANODE CONFIGURATION)
EYE DIAGRAM
MD
EN
MAX3286 toc06
MAX3286 toc05
MAX3286 toc04
MD SHUTDOWN
FAULT
FAULT
BIASDRV
SHDNDRV
OPTICAL
OUTPUT
OPTICAL
OUTPUT
5µs/div
10µs/div
100ps/div
1.25Gbps, 1310nm LASER, 27 - 1 PRBS, imod = 15mA
Pin Description
PIN
QFN
MAX3286
MAX3296
TQFP
MAX3286
MAX3296
TSSOP-EP
MAX3287
MAX3297
MAX3289
MAX3299
TSSOP-EP
MAX3288
MAX3298
NAME
FUNCTION
1
1
—
—
FAULT
—
2, 16, 19
—
—
N.C.
2
3
—
—
FAULT
Noninverting Fault Indicator. See Table 1.
3
4
—
—
POR
Power-On Reset. POR is a TTL-compatible
output. See Figure 14.
4, 13, 19
5, 14, 22, 30
1, 6
1, 6
GND
Ground
5
6
—
—
EN
Enable TTL Input. Laser output is enabled
only when EN is high and EN is low. If EN is
left unconnected, the laser is disabled.
EN
Inverting Enable TTL Input. Laser output is
enabled only when EN is low or grounded
and EN is high. If EN is left unconnected, the
laser is disabled.
PORDLY
Power-On Reset Delay. To extend the delay
for the power-on reset circuit, connect a
capacitor to PORDLY. See the Design
Procedure section.
6
7
7
8
—
—
—
—
Inverting Fault Indicator. See Table 1.
No Connect
_______________________________________________________________________________________
5
MAX3286–MAX3289/MAX3296–MAX3299
Typical Operating Characteristics (continued)
(TA = +25°C, unless otherwise noted.)
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
MAX3286–MAX3289/MAX3296–MAX3299
Pin Description (continued)
PIN
QFN
MAX3286
MAX3296
6
TQFP
MAX3286
MAX3296
TSSOP-EP
MAX3287
MAX3297
MAX3289
MAX3299
TSSOP-EP
MAX3288
MAX3298
NAME
FUNCTION
8
9
2
2
FLTDLY
Fault Delay Input. Determines the delay of
the FAULT and FAULT outputs. A capacitor
attached to FLTDLY ensures proper startup.
(See Typical Operating Characteristics.)
FLTDLY = GND: holds FAULT low and
FAULT high. When FLTDLY = GND, EN =
high, EN = low, and VCC is within the
operational range, the safety circuitry is
inactive.
9
10
—
—
LV
Low-Voltage Operation. Connect to GND for
4.5V to 5.5V operation. Leave open for 3.0V
to 5.5V operation (Table 2).
10, 22, 23,
26
11, 25, 26,
29
3, 11, 14
3, 11, 14
VCC
Supply Voltage
11
12
4
4
IN+
Noninverting Data Input
12
13
5
5
IN-
Inverting Data Input
14
15
7
7
REF
Reference Voltage. A resistor connected at
REF to MD determines the laser power when
APC is used with common-cathode lasers.
15
17
—
—
POL
Polarity Input. POL is used for programming
the laser-pinning polarity (Table 4).
16
18
—
—
POL
Inverting Polarity Input. POL is used for
programming the laser-pinning polarity
(Table 4).
17
20
8
8
MD
Monitor Diode Connection. MD is used for
automatic power control.
18
21
—
9
MON
Laser Bias Current Monitor. Used for
programming laser bias current in VCSEL
applications.
20
23
9
—
SHDNDRV
Shutdown Driver Output. Provides a
redundant laser shutdown.
21
24
10
10
BIASDRV
Bias-Controlling Transistor Driver. Connects
to the base of an external PNP or NPN
transistor.
_______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
PIN
QFN
MAX3286
MAX3296
TQFP
MAX3286
MAX3296
TSSOP-EP
MAX3287
MAX3297
MAX3289
MAX3299
TSSOP-EP
MAX3288
MAX3298
NAME
24
27
12
12
OUT+
Modulation-Current Output. See Typical
Application Circuits.
25
28
13
13
OUT-
Modulation-Current Output. See Typical
Application Circuits.
27
31
15
15
MODSET
28
32
16
16
TC
Temperature-Compensation Set. The resistor
at TC programs the temperature-increasing
component of the laser modulation current.
EP
—
EP
EP
Exposed
Pad
Ground. This must be soldered to the circuit
board ground for proper thermal
performance. See Layout Considerations.
Table 1. Typical Fault Conditions
PIN
FAULT CONDITION
VCC
LV = GND and VCC < 4.5V
REF
VREF > 2.95V
POL and POL
MON
MD
EN and EN
MODSET
and TC
POL = POL
FUNCTION
Modulation-Current Set. The resistor at
MODSET programs the temperature-stable
component of the laser modulation current.
Table 2. LV Operating Range
LV
OPERATING VOLTAGE
RANGE (V)
Open
>3.0
Grounded
>4.5
VMON < VCC - 540mV
VMD > 1.15 ✕ VMD(nom),
VMD < 0.85 ✕ VMD(nom)
EN = low or open, EN = high or open
VMODSET and VTC ≤ 0.8V
_______________________________________________________________________________________
7
MAX3286–MAX3289/MAX3296–MAX3299
Pin Description (continued)
MAX3286–MAX3289/MAX3296–MAX3299
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
VCC
ICC
IOUT
FERRITE BEAD*
VOLTS
0.01µF
VIN+
DIFFERENTIAL INPUT
100mVp-p MIN
830mVp-p MAX
0.01µF
VCC
OUT-
OUT+
MAX3286 VCC
MAX3296
VCC
50Ω
VIN-
50Ω
iMOD
RL
25Ω
BIASDRV
(OPEN)
INMODSET
*MURATA
BLM11HA102
MODULATION
CONTROL
RMOD
200mVp-p MIN
1660mVp-p MAX
VID = VIN+ - VIN-
CURRENT
L = 3.9nH
IN+
VID
RESULTING SIGNAL
L = 3.9nH
iMOD
TIME
RL = 25Ω
iMOD3/2
LASER
EQUIVALENT
LOAD
TC
Figure 1a. Output Load for AC Specification
_______________Detailed Description
VCC
The MAX3286/MAX3296 series of laser drivers contain a
bias generator with APC, laser modulator, power-on reset
(POR) circuit, and safety circuitry (Figures 2a and 2b).
tPORDLY
POR
tFAULT
tRESET
Bias Generator
FAULT
tSHUTDN
SHDNDRV
OPTICAL
OUT
tEN_RESET
EN
FAULT ON MD
NOTE: TIMING IS
NOT TO SCALE.
RESET BY EN SHUTDOWN
BY EN
Figure 3 shows the bias generator circuitry containing a
power-control amplifier, controlled reference voltage,
smooth-start circuit, and window comparator. The bias
generator combined with an external PNP or NPN transistor provides DC laser current to bias the laser in a lightemitting state. When there is a monitor diode (MD) in the
laser package, the APC circuitry adjusts the laser-bias
current to maintain average power over temperature and
changing laser properties. The MD input is connected to
Figure 1b. Fault Timing
8
_______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
POR CIRCUIT
PORDLY
the anode or cathode of a monitor photodiode or to a
resistor-divider, depending on the specific application
circuit. Three application circuits are supported:
common-cathode laser with photodiode, commoncathode laser without photodiode, and common- anode
laser with photodiode (as shown in the Design Procedure
section). The POL and POL inputs determine the laser
pinning (common cathode, common anode) (Table 4).
The smooth-start circuitry prevents current spikes to the
laser during power-up or enable; this ensures compliance
with safety requirements and extends the life of the laser.
The power-control amplifier drives an external transistor
to control the laser bias current. In a fault condition, the
power-control amplifier’s output is disabled (high
POR
FAULT
EN
EN
FAULT
SAFETY
SHDNDRV
FLTDLY
POL
MD
POL
BIASDRV
BIAS GENERATOR
MON
REF
MD
OUT+
IN+
LASER
MODULATOR
IN-
TC
OUT-
MODSET
Figure 2a. Simplified Laser Driver Functional Diagram
LV
PORDLY
POR
FAULT
REF
POR CIRCUIT
MAX3286
MAX3296
1.7V
REF
CONTROLLED
REFERENCE
GENERATOR
FAULT
MON
VCC - 0.54V
SAFETY
CIRCUITRY
FLTDLY
SHDNDRV
1.97V
EN
EN
MD
BIASDRV
1.53V
POL
POL
SMOOTHSTART
BIAS GENERATOR
+1.7V
OUTOUT+
IN+
ININPUT BUFFER
50Ω
50Ω
LASER
MODULATOR
VCC
MODULATION CURRENT
GENERATOR
TC
MODSET
RTC
RMOD
Figure 2b. Laser Driver Functional Diagram
_______________________________________________________________________________________
9
MAX3286–MAX3289/MAX3296–MAX3299
LV
MAX3286–MAX3289/MAX3296–MAX3299
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
impedance). This ensures that the PNP or NPN transistor
is turned off, removing the laser-bias current. (See the
Applications Information section.)
The REF pin provides a controlled reference voltage
dependent upon the voltage at MON. The voltage at
REF is VREF = 2.65 - 2.25(VCC - VMON). A resistor connected at REF determines the laser power when APC is
used with common-cathode lasers. See the Design
Procedure section for setting the laser power.
POLARITY_FAULT
POL
SMOOTHSTART
POL
Safety Circuitry
ENABLE
POWERCONTROL
AMPLIFIER
iMOD = 15mA
REF
RTC
(kΩ)
RMOD
(kΩ)
RTC
(kΩ)
REF_FAULT
2.95V
MON
VCC - 540mV
MONITOR_FAULT
Figure 3. Bias Generator Circuitry
VCC
MAX3286
MAX3296
50Ω
50Ω
OUT+
IN+
400Ω
CURRENT
SWITCH
INPUT
BUFFER
OUT-
VCC - 0.3V
400Ω
IN-
ENABLE
CURRENT AMPLIFIER
MODULATION CURRENT
GENERATOR
4000ppm/°C
REFERENCE
1.2V
REFERENCE
MOD_FAULT
TC_FAULT
0.8V
0.8V
3500
26.7
1.69
53.6
3.65
162
11.5
3000
9.53
2.0
18.7
4.32
57.6
13.3
2500
5.76
2.49
11.3
5.23
34.8
16.2
TC
2000
4.12
3.16
8.06
6.49
24.9
20.0
RTC
1500
3.24
4.32
6.19
8.87
19.1
26.7
1000
2.67
6.49
5.11
13.3
15.8
40.2
500
2.26
13.3
4.22
26.7
13.3
80.6
10
BIASDRV
CONTROLLED REFERENCE VOLTAGE
VREF = 2.65 - 2.25 (VCC - VMON)
iMOD = 5mA
RMOD
(kΩ)
ENABLE
+1.7V
Table 3. RTC and RMOD Selection Table
iMOD = 30mA
TEMPCO
(ppm/°C) RMOD RTC
(kΩ)
(kΩ)
WINDOW
COMPARATOR
+1.97V
Modulation Circuitry
The laser driver can be used with two popular safety
systems. APC maintains laser safety using local feedback. Safety features monitor laser driver operation and
MD
FAULT
GLITCH
REJECT
MD
The modulator circuitry consists of an input buffer, current
generator, and high-speed current switch (Figure 4). The
modulator drives up to 30mA of modulation current into
a 25Ω load.
Many of the modulator performance specifications
depend on the total modulator current (IOUT) (Figure 1a).
To ensure good driver performance, the voltage at
OUT+ and OUT- must not be less than VCC - 1V.
The amplitude of the modulation current is set with
resistors at the MODSET and temperature coefficient (TC)
pins. The resistor at MODSET (RMOD) programs the
temperature-stable portion of modulation current, while
the resistor at TC (R TC) programs the temperatureincreasing portion of the modulation current. Figure 5
shows modulation current as a function of temperature
for two extremes: RTC is open (the modulation current
has zero temperature coefficient) and RMOD is open
(the modulation temperature coefficient is 4000ppm).
Intermediate tempco values of modulation current can
be obtained as described in the Design Procedure section. Table 3 is the RTC and RMOD selection table.
+1.53V
MODSET
RMOD
Figure 4. Laser Modulator Circuitry
______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Another safety system, Open Fiber Control (OFC), uses
safety interlocks to prevent eye hazards. To accommodate the OFC standard, the MAX3286/MAX3296 series
provide dual enable inputs and dual fault outputs.
The safety circuitry contains fault detection, dual enable
inputs, latched fault outputs, and a pulse generator
(Figure 6).
Safety circuitry monitors the APC circuit to detect unsafe
levels of laser emission during single-point failures. A
single-point failure can be a short to VCC or GND, or
between any two IC pins.
1.3
iMOD/(iMOD AT+ 52°C)
1.2
1.1
RTC ≥ 1.9kΩ
RMOD = OPEN
TEMPCO = 4000ppm/°C
RTC = OPEN
TEMPCO = 50ppm/°C
0.8
0.7
0.6
0 10 20 30 40 50 60 70 80 90 100 110
JUNCTION TEMPERATURE (°C)
Figure 5. Modulation Current vs. Temperature for Maximum
and Minimum Temperature Coefficient
(FROM POR CIRCUIT)
EN
Fault Detection
The MAX3286/MAX3296 series has extensive and comprehensive fault-detection features. All critical nodes
are monitored for safety faults, and any node voltage
that differs significantly from its expected value results
in a fault (Table 1). When a fault condition is detected,
the laser is shut down. See the Applications Information
section for more information on laser safety.
Shutdown
The laser drivers offer dual redundant bias shutdown
mechanisms. The SHDNDRV output drives an optional
external MOSFET semiconductor. The bias and modulation drivers have separate, internal disable signals.
1.0
0.9
Pulse Generator
During startup, the laser is not emitting light and the
APC loop is not closed, triggering a fault signal. To
allow startup, an internal fault-delay pulse disables the
safety system for a programmable period of time, allowing
the driver to begin operation. The length of the pulse is
determined by the capacitor connected at FLTDLY and
should be set 5 to 10 times longer than the APC time
constant. The internal safety features can be disabled
by connecting FLTDLY to GND. Note that EN must be
high, EN must be low, and VCC must be in the operational range for laser operation.
Latched Fault Output
Two complementary FAULT outputs are provided with
the MAX3286/MAX3296 series. In the event of a fault,
these outputs latch until one of three events occurs:
1) The power is switched off, then on.
PULSE GENERATOR
FLTDLY
tFLTDLY
R
VCC
Q
RESET
DOMINANT
FAULT
LATCH
FAULT
DETECTION
REF_FAULT
MONITOR_FAULT
MD_FAULT
POLARITY_FAULT
TC_FAULT
MOD_FAULT
FAULT
S
FAULT
EN
SHDNDRV
ENABLE
MAX3286
MAX3296
Figure 6. Simplified Safety Circuit Schematic
______________________________________________________________________________________
11
MAX3286–MAX3289/MAX3296–MAX3299
force a shutdown if a fault is detected. The shutdown
condition is latched until reset by a toggle of EN, EN, or
power.
MAX3286–MAX3289/MAX3296–MAX3299
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
rent while the resistor R TC sets the temperatureincreasing portion of the modulation current.
To determine the appropriate temperature coefficient
from the slope efficiency (α) of the laser, use the following
equation:
PORDLY
VCC
MAX3286
MAX3296
28k
25k
Laser tempco =
LV
VARIABLE
DELAY
POR
1.2V
10 +6 [ppm / °C]
where α is the slope of the laser output power to the
laser current.
For example, suppose a laser has a slope efficiency
α 25 of 0.021mW/mA at +25°C, which reduces to
0.018mW/mA at +70°C. Using the above equation will
produce a laser tempco of -3175ppm/°C.
To obtain the desired modulation current and tempco
for the device, the following two equations can be used
to determine the required values of RMOD and RTC:
= 0.7s/µF CPORDLY
36k
α 70 − α 25
×
α 25 (70°C − 25°C)
BANDGAP
Figure 7. Power-On Reset Circuit
2) EN is switched low, then high.
3) EN is switched to high, then low.
Power-On Reset (POR)
Figure 7 shows the POR circuit for the MAX3286/
MAX3296 series devices. A POR signal asserts low
when VCC is in the operating range. The voltage operating range is determined by the LV pin, as shown in
Table 2. POR contains an internal delay to reject noise
on VCC during power-on or hot-plugging. The delay can
be extended by adding capacitance to the PORDLY
pin. The POR comparator includes hysteresis to improve
noise rejection. The laser driver is shut down while VCC
is out of the operating range.
Design Procedure
Select Laser
Select a communications-grade laser with a rise time of
260ps or better for 1.25Gbps, or 130ps or better for
2.5Gbps applications. To obtain the MAX3286/
MAX3296s’ AC specifications, the instantaneous output
voltage at OUT+ must remain above VCC - 1V at all
times. Select a high-efficiency laser that requires low
modulation current and generates low-voltage swing at
OUT+. Laser package inductance can be reduced by
trimming the leads. Typical package leads have inductance of 25nH/in (1nH/mm); this inductance causes a
larger voltage swing across the laser. A compensation filter network can also be used to reduce ringing, edge
speed, and voltage swing.
R TC =
RMOD =
0.21
− 250Ω
tempco (iMOD )
(R TC + 250Ω)52 × tempco
− 250Ω
(0.19 − 48 × tempco)
where tempco = -laser tempco.
Figure 8a shows a family of curves derived from these
equations. The straight diagonal lines depict constant
tempcos. The curved lines represent constant modulation currents. If no temperature compensation is
desired, Figure 8b displays a series of curves that
show laser modulation current with respect to RMOD for
different loads.
The following useful equations were used to derive
Figure 8a and the equations at the beginning of this
section. The first assumes RL = 25Ω.
1.15
1.06


+
×
R
+ 250Ω RTC + 250Ω 
iMOD = 51 ×  MOD
[A ]


−3
1
+
4
.
0
×
10
T
–
25
°
C
(
)


(
)
iMOD(70°C) = iMOD(25°C) + iMOD(25°C)
(tempco)(70°C – 25°C)[ A]
Programming the Modulation Current
Programming the Bias Current/APC
Resistors at the MODSET and TC pins set the amplitude of the modulation current. The resistor RMOD sets
the temperature-stable portion of the modulation cur-
Three application circuits are described below: common-cathode laser with photodiode, common-cathode
laser without photodiode, and common-anode laser
12
______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
500ppm
2000ppm
with photodiode. The POL and POL inputs determine
the laser pinning (common cathode, common anode)
and affect the smooth-start circuits (Table 4).
2500ppm
1000ppm
3000ppm
1500ppm
Common Cathode with Photodiode
(Optical Feedback)
In the common cathode with photodiode configuration,
a servo control loop is formed by external PNP Q1, the
laser diode, the monitor diode, RSET, and the powercontrol amplifier (Figure 9). The voltage at MD is stabilized to 1.7V. The monitor photodiode current (ID) is set
by (VREF - VMD) / RSET = 0.95 / RSET. Determine the
desired monitor current (ID), then select RSET = 0.95 / ID.
The APC loop is compensated by CBIASDRV. A capacitor
must be placed from BIASDRV to VCC to ensure lownoise operation and to reject power-supply noise. The
time constant governs how quickly the laser bias current
reacts to a change in the average total laser current
(IBIASDRV + iMOD). A capacitance of 0.1µF is sufficient
to obtain a loop time constant in excess of 1µs, provided that RDEG is chosen appropriately. Resistor RDEG
may be necessary to ensure the APC loop’s stability
when low bias currents are desired.
RTC (kΩ)
3500ppm
5mA
10
10mA
15mA
20mA
25mA
RL = 25Ω
30mA
1
1
100
10
1000
RMOD (kΩ)
Figure 8a. RTC vs. RMOD for Various Conditions
LASER MODULATION CURRENT (iMOD) (mA)
40
35
30
10Ω
LOAD NOTE: RTC = OPEN
25
20
The voltage across RDEG should not be any larger than
250mV at maximum bias current.
The discrete components used with the common cathode with photodiode configuration are as follows:
RSET = 0.95 / ID
25Ω
LOAD
15
50Ω
LOAD
10
5
0
0
2
4
6
8
RMOD (kΩ)
10
12
CBIASDRV = 0.1µF (typ)
RDEG = 0.25 / IBIAS(MAX)
14
Figure 8b. Laser-Modulation Current vs. RMOD
Table 4. POL Pin Setup for Each Laser Configuration Type
POL
POL
MAX3286/MAX3296
VCC
GND
MAX3287/MAX3297
—
—
MAX3286/MAX3296
VCC
GND
MAX3288/MAX3298
—
—
MAX3286/MAX3296
GND
VCC
DEVICE
DESCRIPTION
LASER PINNING
Common cathode with
photodiode
Common cathode without
photodiode
VCC
Common anode with
photodiode
MAX3289/MAX3299
—
—
MAX3286/MAX3296
VCC
VCC
Not allowed; fault occurs
—
MAX3286/MAX3296
GND
GND
Not allowed; fault occurs
—
______________________________________________________________________________________
13
MAX3286–MAX3289/MAX3296–MAX3299
1000
MAX3286–MAX3289/MAX3296–MAX3299
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Q1 = general-purpose PNP, β >100, ft > 5MHz
B1 = ferrite bead (see Bias Filter section)
M1 = general-purpose PMOS device (optional)
Common Cathode with Current Feedback
In the common-cathode configuration with current feedback, a servo control loop is formed by an external PNP
transistor (Q1), RMON, the controlled-reference voltage
block, R SET , R MD , and the power-control amplifier
(Figure 10). The voltage at MD is stabilized to 1.7V. The
voltage at MON is set by the resistors RSET and RMD.
As in the short-wavelength configuration, a 0.1µF
CBIASDRV connected between BIASDRV and VCC is
sufficient to obtain approximately a 1µs APC loop time
constant. This improves power-supply noise rejection.
To select the external components:
1) Determine the required laser bias current:
IBIAS = ITH + iMOD / 2
2) Select RMD and RSET.
Maxim recommends RSET = 1kΩ, RMD = 5kΩ, which
results in VCC - VMON ≈ 250mV.
3) Select RMON where RMON = 250mV / IBIAS, assuming
RSET = 1kΩ and RMD = 5kΩ.
VCC
VCC
RDEG
MAX3286
MAX3287
MAX3296
MAX3297
REF
RSET
VCC
MAX3286/96
ONLY
POL
POL
CONTROLLED REFERENCE VOLTAGE
VREF = 2.65V
MON
VCC
CBIASDRV
SHDNDRV
SMOOTHSTART
M1
1.7V
Q1
BIASDRV
MD
ID
POWER-CONTROL
AMPLIFIER
PHOTO
DIODE
IBIAS
FERRITE
BEAD
B1
LASER
Figure 9. Common-Cathode Laser with Photodiode
VCC
VCC
RMON
MAX3286
MAX3288
MAX3296
MAX3298
REF
RSET
VCC
MAX3286/96
POL ONLY
POL
CONTROLLED REFERENCE VOLTAGE
VREF = 2.65V - 2.25V (VCC - VMON)
MON
SHDNDRV
SMOOTHSTART
M1
1.7V
BIASDRV
MD
ID
CBIASDRV
RMD
POWER-CONTROL
AMPLIFIER
FERRITE
BEAD
B1
Q1
IBIAS
LASER
Figure 10. Common Cathode with Current Feedback (PNP Configuration)
14
______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Common Anode with Photodiode
In the common-anode configuration with photodiode, a
servo control loop is formed by an external NPN transistor (Q1), the laser diode, the monitor diode, RSET, and
the power-control amplifier. The voltage at MD is stabilized to 1.7V. The monitor photodiode current is set by
ID = VMD / RSET (Figure 12). Determine the desired monitor current (ID), then select RSET = 1.7V / ID.
M1 = general-purpose PMOS (optional)
Programming POR Delay
A capacitor may be added to PORDLY to increase the
delay for which POR will be asserted low (meaning that
VCC is within the operational range) when powering up
the part.
100
LASER BIAS CURRENT (mA)
RSET = 1kΩ
RMD = 5kΩ
10
The delay will be approximately:
t =
1
CPORDLY
(1.4)10−6
[s]
See Typical Operating Characteristics.
0.1
10
1k
100
10k
RMON (Ω)
Figure 11. Common Cathode without Photodiode Laser
VCC
MAX3286
MAX3289
MAX3296
MAX3299
VCC
LASER
VCC
MAX3286/96
POL ONLY
MONITOR
DIODE
VCC
POL
MD
RSET
MON
ID
FERRITE
BEAD
B1
SHDNDRV
SMOOTHSTART
1.7V
Q1
BIASDRV
CBIASDRV
POWER-CONTROL
AMPLIFIER
IBIAS
RDEG
Figure 12. Common Anode with Photodiode
______________________________________________________________________________________
15
MAX3286–MAX3289/MAX3296–MAX3299
CBIASDRV and a degeneration resistor (RDEG) must be
connected to the bias transistor (in this case NPN) to
obtain the desired APC loop time constant. This
improves power-supply (and ground) noise rejection. A
capacitance of 0.1µF is sufficient to obtain time constants of up to 5µs in most cases. The voltage across
RDEG should not be larger than 250mV at maximum bias
current.
The discrete components used with the common anode
with photodiode configuration are summarized as follows:
RSET = 1.7 / ID
CBIASDRV = 0.1µF (typ)
RDEG = 0.25 / IBIAS(MAX)
Q1 = general-purpose NPN, β > 100, ft > 5MHz
B1 = ferrite bead (see Bias Filter section)
The relationship between laser bias current and RMON
is shown in Figure 11. The remaining discrete components used with the common cathode without photodiode configuration are as follows:
Q1 = general-purpose PNP, β >100, ft > 5MHz
B1 = ferrite bead (see Bias Filter section)
M1 = general-purpose PMOS device (optional)
CBIASDRV = 0.1µF (typ)
Designing the Bias Filter and
Output Pullup Beads
To reduce deterministic jitter, add a ferrite-bead inductor between the collector of the biasing transistor and
either the anode or cathode of the laser, depending on
type (see Typical Operating Characteristics). Use a ferrite-bead inductor with an impedance >100Ω between ƒ =
10MHz and ƒ = 2GHz, and a DC resistance < 3Ω.
Maxim recommends the Murata BLM11HA102SG.
These inductors are also desirable for tying the OUT+
and OUT- pins to VCC.
Designing the Laser-Compensation
Filter Network
Laser package inductance causes the laser impedance
to increase at high frequencies, leading to ringing, overshoot, and degradation of the output eye pattern. A lasercompensation filter network can be used to reduce the
output load seen by the laser driver at high frequencies,
thereby reducing output ringing and overshoot.
The compensation components (RCOMP and CCOMP)
are most easily determined by experimentation. Begin
with RCOMP = 25Ω and CCOMP = 2pF. Increase CCOMP
until the desired transmitter eye is obtained (Figure 13).
Quick Shutdown
To reduce laser shutdown time, a FET device can be
attached to SHDNDRV as shown in Figure 10. This will
provide a typical laser power shutdown time of less
than 10µs.
Applications Information
Laser Safety and IEC 825
The International Electrotechnical Commission (IEC)
determines standards for hazardous light emissions
from fiber optic transmitters. IEC 825 defines the maximum light output for various hazard levels. The MAX3286/
MAX3296 series provides features that facilitate compliance with IEC 825.
A common safety requirement is single-point fault tolerance, whereby one unplanned short, open, or resistive
connection does not cause excess light output. When
these laser drivers are used, as shown in the Typical
Operating Circuits, the circuits respond to faults as listed in Table 5.
Using these laser drivers alone does not ensure that a
transmitter design is compliant with IEC 825. The entire
transmitter circuit and component selections must be
considered. Customers must determine the level of fault
tolerance required by their applications, recognizing that
Maxim products are not designed or authorized for use
as components in systems intended for surgical implant
16
UNCOMPENSATED
CORRECTLY COMPENSATED
POWER
MAX3286–MAX3289/MAX3296–MAX3299
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
OVERCOMPENSATED
TIME
Figure 13. Laser Compensation
into the body, for applications intended to support or sustain life, or for any other application where the failure of
a Maxim product could create a situation where personal injury or death may occur.
Layout Considerations
The MAX3286/MAX3296 series comprises high-frequency products. Their performance largely depends
upon the circuit board layout.
Use a multilayer circuit board with a dedicated ground
plane. Use short laser package leads placed close to
the modulator outputs. Power supplies must be capacitively bypassed to the ground plane with surface-mount
capacitors placed near the power-supply pins.
The dominant pole of the APC circuit is normally located at BIASDRV. To prevent a second pole in the APC
(that can lead to oscillations), ensure that parasitic
capacitance at MD is minimized.
Common Questions
Laser output is ringing or contains overshoot. This is often
caused by inductive laser packaging. Try reducing the
length of the laser leads. Modify the compensation components to reduce the driver’s output edge speed (see
Design Procedure). Extreme ringing can be caused by
low voltage at the OUT± pins. This may indicate that pullup beads or a lower modulation current are needed.
Low-frequency oscillation on the laser output. This is
more prevalent at low temperatures. The APC may be
oscillating. Try increasing the value of C BIASDRV or
increasing the value of RDEG. Ensure that the parasitic
capacitance at the MD node is kept very small (<10pF).
The APC is not needed. Connect FLTDLY to ground to
disable fault detection. Connect MD to REF and MON to
VCC. BIASDRV and SHDNDRV can be left open.
______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
PIN NAME
CIRCUIT RESPONSE TO OVERVOLTAGE OR
SHORT TO VCC
CIRCUIT RESPONSE TO UNDERVOLTAGE OR
SHORT TO GROUND
FAULT
Does not affect laser power
Does not affect laser power
FAULT
Does not affect laser power
Does not affect laser power
POR
Does not affect laser power
Does not affect laser power
PORDLY
Does not affect laser power
Fault state* occurs
EN
Normal condition for circuit operation
Fault state* occurs
EN
Fault state* occurs
Normal condition for circuit operation
LV
Does not affect laser power
Fault state* occurs if VCC is less than +4.5V
POL
If POL is a TTL HIGH, a fault state* occurs; otherwise, the circuit is in normal operation
If POL is a TTL LOW, a fault state* occurs; otherwise, the circuit is in normal operation
POL
If POL is a TTL HIGH, a fault state* occurs; otherwise, the circuit is in normal operation
If POL is a TTL LOW, a fault state* occurs; otherwise, the circuit is in normal operation
MON
(also MAX3288/98)
In common cathode without photodiode configuration, a fault state* occurs; otherwise, does not affect
laser power
Fault state* occurs
SHDNDRV
(also MAX3287/97/
89/99)
Does not affect laser power. If optional FET is used,
the laser output is shut off.
Does not affect laser power
FLTDLY
Any fault that occurs cannot be reset. Does not
affect laser power.
Does not affect laser power
IN+, IN-
Does not affect laser power
Does not affect laser power
REF
Fault state* occurs
In common-cathode configurations, a fault state*
occurs; otherwise, does not affect laser power
MD
Fault state* occurs
Fault state* occurs
In common-cathode configurations, the laser bias
current is shut off. In common anode, high laser
power triggers a fault state.* Shutdown occurs if a
shutdown FET (M1) is used. If shutdown FET is not
used, other means must be used to prevent high
laser power.
In common-anode configurations, the laser bias
current is shut off. In common cathode, high laser
power triggers a fault state.* Shutdown occurs if a
shutdown FET (M1) is used (Figures 9, 10).
OUT+, OUT-
Does not affect laser power
Does not affect laser power
MODSET
Does not affect laser power
Fault state* occurs
TC
Does not affect laser power
Fault state* occurs
BIASDRV
*A fault state will assert the FAULT pins, disable the modulator outputs, disable the bias output, and assert the SHDNDRV pin.
______________________________________________________________________________________
17
MAX3286–MAX3289/MAX3296–MAX3299
Table 5. Circuit Response to Various Single-Point Faults
MAX3286–MAX3289/MAX3296–MAX3299
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Interface Models
The modulator is not needed. Leave TC and MODSET
open. Connect IN+ to VCC, IN- to REF, and leave OUT+
and OUT– open.
Figures 14–18 show typical input/output models for the
MAX3286/MAX3296 series of laser drivers. If dice are
used, replace the package parasitic elements with
bondwire parasitic elements.
Wirebonding Die
The MAX3286/MAX3296 series uses bondpads with gold
metalization. Make connections to the die with gold wire
only, using ball-bonding techniques. Wedge bonding is
not recommended. Bondpad size is 4mil square. Die
thickness is typically 15mils (0.38mm).
VCC
MAX3286
MAX3296
VCC
MAX3286
MAX3296
10k
4k
550Ω
2.5k
60Ω
SHDNDRV
FAULT, FAULT, POR
Figure 15. SHDNDRV Output
Figure 14. Logic Outputs
VCC
VCC
PACKAGE
1.5nH
0.2pF
PACKAGE
50Ω
OUT1pF
50Ω
1pF
OUT+
1.5nH
0.2pF
Figure 16. Modulator Outputs
18
______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
MAX3286–MAX3289/MAX3296–MAX3299
VCC
MAX3286
MAX3296
PACKAGE
VCC
1.5nH
IN+
Q1
0.2pF
1pF
400Ω
VCC
1.5nH
400Ω
IN-
Q2
0.2pF
1pF
INPUT COMMON-MODE VOLTAGE ≈ VCC - 0.3V
RIN Q1, Q2 > 100kΩ
Figure 17. Data Inputs
VCC
MAX3286
MAX3296
40Ω
BIASDRV
40Ω
Figure 18. BIASDRV Output
______________________________________________________________________________________
19
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
MAX3286–MAX3289/MAX3296–MAX3299
Selector Guide
DATA RATE/DEVICE
1.25Gbps
LASER CONFIGURATION
2.5Gbps
MAX3286
MAX3296
MAX3287
MAX3297
MAX3288
MAX3298
MAX3289
MAX3299
COMMON
ANODE
WITH
PHOTODIODE
COMMON
CATHODE
WITH
PHOTODIODE
COMMON
CATHODE
WITH
PHOTODIODE
Longwave
Shortwave or
VCSEL
VCSEL
✓
✓
✓
PACKAGE
32 TQFP/28 QFN/Dice
✓
16 TSSOP-EP
✓
16 TSSOP-EP
✓
16 TSSOP-EP
TC
MODSET
GND
VCC
OUT-
OUT+
VCC
VCC
Pin Configurations (continued)
32
31
30
29
28
27
26
25
TOP VIEW
FAULT
1
24 BIASDRV
N.C.
2
23 SHDNDRV
FAULT
3
22 GND
VCC 3
POR
4
21 MON
IN+ 4
20 MD
IN- 5
19 N.C.
GND 6
GND
5
EN
6
EN
PORDLY
MAX3286
MAX3296
GND 1
18 POL
7
17 POL
8
16 TC
FLTDLY 2
15 MODSET
MAX3287
MAX3289
MAX3297
MAX3299
15
16
REF
14
N.C.
LV
VCC
13
GND
FLTDLY
12
IN-
11
IN+
10
16 TC
14 VCC
VCC 3
13 OUT-
IN+ 4
12 OUT+
IN- 5
15 MODSET
14 VCC
MAX3288
MAX3298
13 OUT12 OUT+
11 VCC
GND 6
11 VCC
REF 7
10 BIASDRV
REF 7
10 BIASDRV
MD 8
9
MD 8
9
TSSOP-EP*
9
GND 1
FLTDLY 2
TQFP
SHDNDRV
MON
TSSOP-EP*
*EXPOSED PAD IS CONNECTED TO GND.
Ordering Information (continued)
PART
TEMP RANGE
PIN-PACKAGE
MAX3287CUE
0°C to +70°C
16 TSSOP-EP**
MAX3288CUE
0°C to +70°C
16 TSSOP-EP**
MAX3289CUE
0°C to +70°C
16 TSSOP-EP**
MAX3296CGI
0°C to +70°C
28 QFN (5mm x 5mm)**
MAX3296CHJ
0°C to +70°C
32 TQFP (5mm x 5mm)
MAX3296C/D
0°C to +70°C
Dice*
MAX3297CUE
0°C to +70°C
16 TSSOP-EP**
MAX3298CUE
0°C to +70°C
16 TSSOP-EP**
MAX3299CUE
0°C to +70°C
16 TSSOP-EP**
20
*Dice are designed to operate from TJ = 0°C to +110°C, but are
tested and guaranteed only at TA = +25°C.
**Exposed pad.
______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
+3.0V TO +5.5V
MAX3286/MAX3296
COMMON-CATHODE VCSEL
WITH PHOTODIODE
0.01µF
0.01µF
FLTDLY
MON
POL
CBIASDRV
0.1µF
PORDLY
0.01µF
PMOSFET
(OPTIONAL)
SHDNDRV
VCC
EN
PNP
TRANSISTOR
BIASDRV
0.01µF
VCC
IN+
FERRITE
BEAD
DATA
INPUT 115Ω
MAX3286
MAX3296
IN0.01µF
0.01µF
OUT+
POR
0.01µF
OUT-
CCOMP
FAULT
25Ω
RCOMP
FAULT
LV
POL
VCC
EN
GND
MODSET
TC
REF
MD
RMOD
RTC
RSET
+3.0V TO +5.5V
0.01µF
MAX3286/MAX3296
COMMON-CATHODE VCSEL
WITHOUT PHOTODIODE
0.01µF
0.01µF
0.01µF
POL
FLTDLY
VCC
EN
MON
CBIASDRV
0.1µF
PORDLY
PNP
TRANSISTOR
BIASDRV
VCC
IN+
FERRITE
BEAD
DATA
INPUT 115Ω
0.01µF
RMON
MAX3286
MAX3296
INSHDNDRV
0.01µF
OUT+
0.01µF
OUT-
POR
FAULT
CCOMP
25Ω
RCOMP
FAULT
LV
POL
VCC
EN
GND
MODSET
TC
RTC
REF MD
RMD
5k
RMOD
RSET
1k
______________________________________________________________________________________
21
MAX3286–MAX3289/MAX3296–MAX3299
Typical Application Circuits
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
MAX3286–MAX3289/MAX3296–MAX3299
Typical Application Circuits (continued)
+3.0V TO +5.5V
0.01µF
MAX3286/MAX3296
COMMON-ANODE LASER
WITH PHOTODIODE
FLTDLY
MON
POL
0.01µF
VCC
EN
VCC
PORDLY
0.01µF
0.01µF
IN+
0.01µF
MAX3286
MAX3296
IN0.01µF
18Ω
OUT-
DATA
INPUT 115Ω
CCOMP
0.01µF
OUT+
RCOMP
25Ω
POR
FERRITE
BEAD
FAULT
VCC
FAULT
LV
SHDNDRV
POL
NPN
TRANSISTOR
BIASDRV
EN
CBIASDRV
0.1µF
MD
GND
MODSET
TC
REF
RDEG
RMOD
RTC
RSET
+3.0V TO +5.5V
0.01µF
MAX3287/MAX3297
COMMON-CATHODE VCSEL
WITH PHOTODIODE
VCC
RDEG
CBIASDRV
0.1µF
PNP
TRANSISTOR
BIASDRV
0.01µF
VCC
IN+
FERRITE
BEAD
DATA
INPUT 115Ω
MAX3287
MAX3297
IN-
0.01µF
OUT+
0.01µF
0.01µF
OUT0.01µF
CCOMP
25Ω
FLTDLY
SHDNDRV
GND
MODSET
TC
RTC
REF MD
RCOMP
VCC
RMOD
RSET
22
______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
+3.0V TO +5.5V
0.01µF
MAX3288/MAX3298
COMMON-CATHODE VCSEL
WITHOUT PHOTODIODE
VCC
MON
RMON
CBIASDRV
0.1µF
PNP
TRANSISTOR
BIASDRV
0.01µF
VCC
IN+
FERRITE
BEAD
DATA
INPUT 115Ω
MAX3288
MAX3298
IN-
0.01µF
OUT+
0.01µF
CCOMP
OUT-
0.01µF
0.01µF
FLTDLY
25Ω
GND
MODSET
TC
REF MD
RCOMP
VCC
RMD
5k
RMOD
RTC
RSET
1k
+3.0V to +5.5V
MAX3289/MAX3299
COMMON-ANODE LASER
WITH PHOTODIODE
0.01µF
VCC
VCC
0.01µF
IN+
18Ω
0.01µF
OUT-
DATA
INPUT 115Ω
MAX3289
MAX3299
IN-
OUT+
CCOMP
0.01µF
25Ω
0.01µF
0.01µF
FERRITE
BEAD
RCOMP
VCC
FLTDLY
BIASDRV
CBIASDRV
0.1µF
SHDNDRV
GND
MODSET
TC
NPN
TRANSISTOR
REF MD
RDEG
RTC
RMOD
RSET
______________________________________________________________________________________
23
MAX3286–MAX3289/MAX3296–MAX3299
Typical Application Circuits (continued)
Chip Topographies
FLTDLY
TC
LV
FAULT
FAULT
POR
GND
EN
TC
FLTDLY
MODSET
LV
MODSET
HF34Z-1Z
HF34Z
VCC
VCC
IN+
IN-
VCC
VCC
OUT-
IN+
OUT-
OUT+
IN-
OUT+
0.072"
(1.829mm)
TRANSISTOR COUNT: 1154
SUBSTRATE CONNECTED TO GND
0.053"
(1.346mm)
TRANSISTOR COUNT: 1154
SUBSTRATE CONNECTED TO GND
______________________________________________________________________________________
BIASDRV
SHDNDRV
GND
MON
MD
N.C.
POL
POL
VCC
BIASDRV
REF
SHDNDRV
VCC
GND
REF
MON
VCC
MD
GND
N.C.
VCC
POL
GND
0.053"
(1.346mm)
24
EN
FAULT
PORDLY
MAX3296
FAULT
POR
GND
EN
EN
PORDLY
MAX3286
POL
MAX3286–MAX3289/MAX3296–MAX3299
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
0.072"
(1.829mm
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
32L QFN .EPS
______________________________________________________________________________________
25
MAX3286–MAX3289/MAX3296–MAX3299
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
32L,TQFP.EPS
MAX3286–MAX3289/MAX3296–MAX3299
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
26
______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
TSSOP.EPS
Maxim makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Maxim assume any liability arising out of the application or use of any product or circuit and specifically disclaims any and all liability, including without limitation consequential or
incidental damages. “Typical” parameters can and do vary in different applications. All operating parameters, including “typicals” must be validated for
each customer application by customer’s technical experts. Maxim products are not designed, intended or authorized for use as components in systems
intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the
Maxim product could create a situation where personal injury or death may occur.
27 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2002 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
MAX3286–MAX3289/MAX3296–MAX3299
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)