MAX3296EVKIT-SW [MAXIM]
MAX3296 Shortwave or VCSEL (Common Cathode) Evaluation Kit; MAX3296短波或VCSEL （共阴极）评估套件
| 型号： | MAX3296EVKIT-SW |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | MAX3296 Shortwave or VCSEL (Common Cathode) Evaluation Kit |
| 文件： | 总28页 (文件大小：1442K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-1550; Rev 6; 11/04
to
3.0V 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
General Description
Features
♦ 7ps Deterministic Jitter (MAX3296)
22ps Deterministic Jitter (MAX3286)
♦ +3.0V to +5.5V Supply Voltage
The MAX3286/MAX3296 series of products are high-
speed laser drivers for fiber optic LAN transmitters opti-
mized for Gigabit Ethernet applications. Each device
contains a bias generator, laser modulator, and com-
prehensive safety features. Automatic power control
(APC) adjusts the laser bias current to maintain aver-
age 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 vertical-
cavity surface-emitting lasers (VCSELs).
♦ 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 and Thin QFN Packages Available
The MAX3286 series (MAX3286–MAX3289) is opti-
mized for operation at 1.25Gbps, and the MAX3296
series (MAX3296–MAX3299) is optimized for 2.5Gbps
operation. Each device can switch 30mA of laser mod-
ulation current at the specified data rate. Adjustable
temperature compensation is provided to keep the opti-
cal extinction ratio within specifications over the operat-
ing 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.
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
28 Thin QFN
(5mm x 5mm)****
MAX3286CTI+
0°C to +70°C
28 QFN
(5mm x 5mm)***
MAX3286CGI
MAX3286CHJ
0°C to +70°C
0°C to +70°C
32 TQFP
(5mm x 5mm)
Ordering Information continued at end of data sheet.
*Dice are designed to operate from T = 0°C to +110°C, but
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 pro-
grammable power-on reset pulse initializes the laser
driver at startup.
J
are tested and guaranteed only at T = +25°C.
A
**Exposed pad.
***Package Code: G2855-1
****Package Code: T2855-7
+Denotes Lead-Free Package.
Pin Configurations
The MAX3286/MAX3296 are available in a compact, 5mm
TOP VIEW
✕
✕
5mm, 28-pin QFN or thin 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.
+
FAULT
FAULT
POR
1
2
3
4
5
6
7
21 BIASDRV
20 SHDNDRV
19 GND
Applications
Gigabit Ethernet Optical Transmitter
Fibre Channel Optical Transmitter
ATM LAN Optical Transmitter
MAX3286
MAX3296
GND
18 MON
17 MD
EN
EN
16 POL
PORDLY
15 POL
Typical Application Circuits and Selector Guide appear at
end of data sheet.
THIN QFN*
*Exposed pad is connected to GND.
Pin Configurations continued at end of data sheet.
________________________________________________________________ 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.
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
ABSOLUTE MAXIMUM RATINGS
Supply Voltage at V
..........................................-0.5V to +7.0V
28-Pin QFN and 28-Pin Thin QFN
CC
Voltage at EN, EN, PORDLY, FLTDLY, LV, IN+, IN-,
(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
REF, POL, POL, MD, MON, BIASDRV,
MODSET, TC.......................................................-0.5V to (V + 0.5V)
CC
CC
Voltage at OUT+, OUT-.........................(V
- 2V) to (V
+ 2V)
CC
Current into FAULT, FAULT, POR, SHDNDRV....-1mA to +25mA
Current into OUT+, OUT-....................................................60mA
Continuous Power Dissipation (T = +70°C)
A
32-Pin TQFP (derate 14.3mW/°C above +70°C).........1100mW
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 = 0°C to +70°C, unless otherwise noted. Typical values are at V
= +3.3V, R = open and T = +25°C;
CC TC A
CC
A
see Figure 1a.)
PARAMETER
Supply Current
SYMBOL
CONDITIONS
= 1.82kΩ
MOD
MIN
TYP
52
MAX
75
UNITS
mA
mV
µA
I
Figure 1a, R
CC
Data Input Voltage Swing
TTL Input Current
V
ID
Total differential signal, peak-to-peak, Figure 1a
0 ≤ V ≤ V
200
-100
2
1660
+100
PIN
CC
TTL Input High Voltage
TTL Input Low Voltage
V
IH
V
V
0.8
V
IL
FAULT, FAULT Output High
Voltage
V
I
I
= -100µA
= 1mA
2.4
V
V
OH
OH
FAULT, FAULT Output Low
Voltage
V
0.4
+1
OL
OL
BIAS GENERATOR (Note 1)
BIASDRV Current, Shutdown
BIASDRV Current Sink
BIASDRV Current Source
REF Voltage
EN = GND
-1
µA
mA
mA
V
FAULT = low, V
FAULT = low, V
≥ 0.6V
0.8
BIASDRV
≤ V
- 1V
0.8
BIASDRV
CC
I
≤ 2mA, MON = V
2.45
1.55
2.65
1.7
2.85
1.85
1.2
REF
CC
MD Nominal Voltage
V
MD
APC loop is closed
V
Common-cathode configuration
Common-anode configuration
Normal operation (FAULT = low)
0.4
MD Voltage During Fault
V
2
V
- 0.8
CC
MD Input Current
MON Input Current
POWER-ON RESET
-2
+0.16
0.44
+2
6
µA
µA
V
= V
CC
MON
LV = GND
LV = open
3.9
4.5
POR Threshold
V
2.65
3.00
POR Hysteresis
150
mV
FAULT DETECTION
REF Fault Threshold
MD High Fault Threshold
MD Low Fault Threshold
2.95
V
V
V
+ 5%
- 20%
V
+ 20%
MD
MD
MD
V
- 5%
CC -
MD
V
-
V
CC
MON Fault Threshold
MAX3286/MAX3288/MAX3296/MAX3298
mV
V
600
480
MODSET, TC Fault Threshold
0.9
2
_______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
ELECTRICAL CHARACTERISTICS (continued)
(V
= +3.0V to +5.5V, T = 0°C to +70°C, unless otherwise noted. Typical values are at V
= +3.3V, R = open and T = +25°C;
CC TC A
CC
A
see Figure 1a.)
PARAMETER
SHUTDOWN
SYMBOL
CONDITIONS
MIN
- 0.4
TYP
MAX
UNITS
I
= 10µA, FAULT asserted
= 15mA, FAULT not asserted
= 1mA, FAULT not asserted
V
CC
SHDNDRV
Voltage at SHDNDRV
I
0
V
- 1.2
- 2.4
V
SHDNDRV
CC
I
0
V
CC
SHDNDRV
LASER MODULATOR
MAX3286 series
MAX3296 series
1.25
2.5
Data Rate
Gbps
mA
mA
%
Minimum Laser Modulation
Current
2
Maximum Laser Modulation
Current
R
≤ 25Ω
30
L
R
R
= 1.9kΩ (I
= 30mA)
= 5mA)
-10
-15
+10
+15
220
150
MOD
MOD
MOD
Tolerance of Modulation Current
= 13kΩ (I
MOD
MAX3286 series
MAX3296 series
130
90
Modulation-Current Edge
Speed
20% to 80%
ps
R
(I
= 13kΩ
= 5mA)
MOD
MOD
46
29
22
14
8
65
45
35
35
22
20
R
(I
= 4.1kΩ
= 15mA)
MOD
MOD
MAX3286 series
MAX3296 series
R
(I
= 1.9kΩ
= 30mA)
MOD
MOD
Deterministic Jitter (Note 2)
ps
R
(I
= 13kΩ
= 5mA)
MOD
MOD
R
(I
= 4.1kΩ
= 15mA)
MOD
MOD
R
(I
= 1.9kΩ
= 30mA)
MOD
MOD
7
MAX3286 series
MAX3296 series
2
2
8
4
Random Jitter (Note 3)
RMS
ps
µA
Shutdown Modulation Current
15
200
Tempco = max, R
= open; Figure 5
4000
50
MOD
Modulation-Current
Temperature Coefficient
ppm/°C
Tempco = min, R = open; Figure 5
TC
Differential Input Resistance
Output Resistance
620
42
800
50
980
58
Ω
Ω
V
Single ended
Input Bias Voltage
V
- 0.3
CC
LASER SAFETY CIRCUIT
PORDLY = open
0.3
3
1.25
µs
POR Delay
t
PORDLY
C
= 0.01µF,
PORDLY
5.5
ms
MAX3286/MAX3296 only
Fault Time
t
(Note 4)
22
20
µs
µs
FAULT
Glitch Rejection at MD
10
_______________________________________________________________________________________
3
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
ELECTRICAL CHARACTERISTICS (continued)
(V
= +3.0V to +5.5V, T = 0°C to +70°C, unless otherwise noted. Typical values are at V
= +3.3V, R = open and T = +25°C;
CC TC A
CC
A
see Figure 1a.)
PARAMETER
SYMBOL
CONDITIONS
= 270pF
MIN
0.2
TYP
1
MAX
UNITS
C
C
= 0
FLTDLY
FLTDLY Duration
t
µs
FLTDLY
100
140
FLTDLY
MAX3286/MAX3296 only, Figure 1b,
= open
6
6
10
ns
µs
µs
µs
EN or EN Minimum Pulse Width
Required to Reset a Latched
Fault
C
FLTDLY
t
EN_RESET
MAX3286/MAX3296 only, Figure 1b,
= 0.01µF
C
FLTDLY
FAULT Reset after EN, EN, or
POR Transition
t
MAX3286/MAX3296 only, Figure 1b
MAX3286/MAX3296 only, Figure 1b
1
2
RESET
SHDNDRV Asserted after EN =
Low or EN = High
t
3.5
5.5
SHUTDN
Note 1: Common-anode configuration refers to a configuration where POL = GND, POL = V , and an NPN device is used to set
CC
the laser bias current. Common-cathode configuration refers to a configuration where POL = V , POL = GND, and a PNP
CC
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-to-
peak 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
(T = +25°C, unless otherwise noted.)
A
EYE DIAGRAM
POR DELAY vs. C
PORDLY
FLTDLY DURATION vs. C
FLTDLY
100,000
10,000
1000
10,000
1000
100
100
10
1
10
1
10
100
1000
10,000
100,000
1
10
100
1000
10,000
50ps/div
7
CAPACITANCE (pF)
CAPACITANCE (pF)
2.5Gbps, 1310nm LASER, 2 - 1 PRBS, I
= 15mA
MOD
4
_______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Typical Operating Characteristics (continued)
(T = +25°C, unless otherwise noted.)
A
EN STARTUP
(COMMON-ANODE CONFIGURATION)
EYE DIAGRAM
MD SHUTDOWN
MD
EN
FAULT
FAULT
BIASDRV
SHDNDRV
OPTICAL
OUTPUT
OPTICAL
OUTPUT
10µs/div
5µs/div
100ps/div
7
1.25Gbps, 1310nm LASER, 2 - 1 PRBS, I
= 15mA
mod
Pin Description
PIN
TSSOP-EP
MAX3287
MAX3297
MAX3289
MAX3299
QFN/
TQFP
MAX3286
MAX3296
TSSOP-EP
MAX3288
MAX3298
NAME
FUNCTION
THIN QFN
MAX3286
MAX3296
1
—
2
1
2, 16, 19
3
—
—
—
—
—
—
FAULT
N.C.
Inverting Fault Indicator. See Table 1.
No Connect
FAULT
Noninverting Fault Indicator. See Table 1.
Power-On Reset. POR is a TTL-compatible
output. See Figure 14.
3
4
—
—
POR
GND
4, 13, 19
5, 14, 22, 30
1, 6
1, 6
Ground
Enable TTL Input. The laser output is enabled
only when EN is high and EN is low. If EN is
left unconnected, the laser is disabled.
5
6
6
7
—
—
—
—
EN
Inverting Enable TTL Input. The laser output
is enabled only when EN is low or grounded
and EN is high. If EN is left unconnected, the
laser is disabled.
EN
Power-On Reset Delay. To extend the delay
for the power-on reset circuit, connect a
capacitor to PORDLY. See the Design
Procedure section.
7
8
—
—
PORDLY
_______________________________________________________________________________________
5
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Pin Description (continued)
PIN
TSSOP-EP
MAX3287
MAX3297
MAX3289
MAX3299
QFN/
TQFP
MAX3286
MAX3296
TSSOP-EP
MAX3288
MAX3298
NAME
FUNCTION
THIN QFN
MAX3286
MAX3296
Fault Delay Input. Determines the delay of
the FAULT and FAULT outputs. A capacitor
attached to FLTDLY ensures proper startup
(see the Typical Operating Characteristics) .
FLTDLY = GND: holds FAULT low and
8
9
2
2
FLTDLY
FAULT high. When FLTDLY = GND, EN =
high, EN = low, and V
is within the
CC
operational range, the safety circuitry is
inactive.
Low-Voltage Operation. Connect to GND for
4.5V to 5.5V operation. Leave open for 3.0V
to 5.5V operation (Table 2).
9
10
—
—
LV
10, 22, 23,
26
11, 25, 26,
29
3, 11, 14
3, 11, 14
V
Supply Voltage
CC
11
12
12
13
4
5
4
5
IN+
IN-
Noninverting Data Input
Inverting Data Input
Reference Voltage. A resistor connected at
REF to MD determines the laser power when
APC is used with common-cathode lasers.
14
15
16
17
18
20
21
15
17
18
20
21
23
24
7
—
—
8
7
—
—
8
REF
POL
Polarity Input. POL is used for programming
the laser-pinning polarity (Table 4).
Inverting Polarity Input. POL is used for
programming the laser-pinning polarity
(Table 4).
POL
Monitor Diode Connection. MD is used for
automatic power control.
MD
Laser Bias Current Monitor. Used for
programming laser bias current in VCSEL
applications.
—
9
9
MON
Shutdown Driver Output. Provides a
redundant laser shutdown.
—
10
SHDNDRV
BIASDRV
Bias-Controlling Transistor Driver. Connects
to the base of an external PNP or NPN
transistor.
10
6
_______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Pin Description (continued)
PIN
TSSOP-EP
QFN/
TQFP
MAX3286
MAX3296
TSSOP-EP
MAX3288
MAX3298
MAX3287
MAX3297
MAX3289
MAX3299
NAME
FUNCTION
THIN QFN
MAX3286
MAX3296
Modulation-Current Output. See the Typical
Application Circuits.
24
25
27
28
12
13
12
13
OUT+
OUT-
Modulation-Current Output. See the Typical
Application Circuits.
Modulation-Current Set. The resistor at
MODSET programs the temperature-stable
component of the laser modulation current.
27
28
EP
31
32
—
15
16
EP
15
16
EP
MODSET
TC
Temperature-Compensation Set. The resistor
at TC programs the temperature-increasing
component of the laser modulation current.
Ground. This must be soldered to the circuit
board ground for proper thermal
performance. See Layout Considerations.
Exposed
Pad
Table 2. LV Operating Range
Table 1. Typical Fault Conditions
PIN
FAULT CONDITION
OPERATING VOLTAGE
LV
RANGE (V)
>3.0
V
CC
LV = GND and V < 4.5V
CC
Open
REF
POL and POL
MON
V
> 2.95V
REF
Grounded
>4.5
POL = POL
V
MON
< V
- 540mV
CC
✕
✕
V
V
> 1.15
< 0.85
V
V
,
MD
MD(nom)
MD
MD
MD(nom)
EN and EN
EN = low or open, EN = high or open
and V ≤ 0.8V
MODSET
and TC
V
MODSET
TC
_______________________________________________________________________________________
7
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
V
CC
I
I
OUT
CC
FERRITE BEAD*
VOLTS
0.01µF
DIFFERENTIAL INPUT
RESULTING SIGNAL
V
IN+
100mV MIN
P-P
0.01µF
830mV MAX
P-P
V
CC
OUT-
OUT+
V
IN-
V
CC
V
CC
L = 3.9nH
MAX3286
MAX3296
200mV MIN
P-P
V
ID
= V - V
IN+ IN-
1660mV MAX
P-P
50Ω
50Ω
i
MOD
R
L
25Ω
CURRENT
I
MOD
IN+
IN-
L = 3.9nH
V
ID
BIASDRV
(OPEN)
TIME
MODSET
MODULATION
CONTROL
R = 25Ω
L
I 3/2
MOD
*MURATA
LASER
BLM11HA102
R
MOD
EQUIVALENT
LOAD
TC
Figure 1a. Output Load for AC Specification
_______________Detailed Description
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).
V
CC
t
PORDLY
POR
t
t
RESET
FAULT
Bias Generator
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 transis-
tor provides DC laser current to bias the laser in a light-
emitting 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
FAULT
t
SHUTDN
SHDNDRV
OPTICAL
OUT
t
EN_RESET
EN
FAULT ON MD
RESET BY EN SHUTDOWN
BY EN
NOTE: TIMING IS NOT TO SCALE.
Figure 1b. Fault Timing
8
_______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
the anode or cathode of a monitor photodiode or to a
LV
POR
resistor-divider, depending on the specific application
circuit. Three application circuits are supported:
common-cathode laser with photodiode, common-
cathode 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).
POR CIRCUIT
SAFETY
PORDLY
FAULT
EN
EN
FAULT
SHDNDRV
FLTDLY
POL
MD
POL
BIASDRV
REF
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.
BIAS GENERATOR
MON
MD
IN+
OUT+
OUT-
LASER
MODULATOR
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
IN-
MODSET
TC
Figure 2a. Simplified Laser Driver Functional Diagram
LV
PORDLY
REF
MAX3286
MAX3296
CONTROLLED
REFERENCE
GENERATOR
POR
1.7V
REF
POR CIRCUIT
FAULT
FAULT
MON
V
CC
- 0.54V
SHDNDRV
1.97V
SAFETY
CIRCUITRY
FLTDLY
EN
EN
MD
1.53V
POL
BIASDRV
SMOOTH-
START
POL
BIAS GENERATOR
+1.7V
OUT-
OUT+
IN+
IN-
INPUT BUFFER
50Ω
50Ω
LASER
MODULATOR
V
CC
MODULATION CURRENT
GENERATOR
TC
MODSET
R
TC
R
MOD
Figure 2b. Laser Driver Functional Diagram
_______________________________________________________________________________________
9
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.)
POLARITY_FAULT
+1.53V
The REF pin provides a controlled reference voltage
MD
FAULT
GLITCH
REJECT
dependent upon the voltage at MON. The voltage at REF
POL
SMOOTH-
START
is V
= 2.65 - 2.25(V
- V ). A resistor connected
MON
REF
CC
POL
WINDOW
COMPARATOR
+1.97V
at REF determines the laser power when APC is used
with common-cathode lasers. See the Design Procedure
section for information about setting the laser power.
ENABLE
POWER-
CONTROL
AMPLIFIER
ENABLE
MD
REF
BIASDRV
MON
Modulation Circuitry
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.
+1.7V
CONTROLLED REFERENCE VOLTAGE
= 2.65 - 2.25 (V - V
V
)
MON
REF
CC
Many of the modulator performance specifications
V
- 540mV
CC
REF_FAULT
MONITOR_FAULT
depend on the total modulator current (I
) (Figure 1a).
OUT
2.95V
To ensure good driver performance, the voltage at
OUT+ and OUT- must not be less than V - 1V.
CC
Figure 3. Bias Generator Circuitry
The amplitude of the modulation current is set with
resistors at the MODSET and temperature coefficient (TC)
pins. The resistor at MODSET (R
) programs the
MOD
temperature-stable portion of modulation current, while
the resistor at TC (R ) programs the temperature-
TC
V
CC
increasing portion of the modulation current. Figure 5
shows modulation current as a function of temperature
MAX3286
MAX3296
50Ω
50Ω
OUT+
OUT-
for two extremes: R
is open (the modulation current
TC
IN+
CURRENT
SWITCH
has zero temperature coefficient) and R
is open
MOD
INPUT
BUFFER
(the modulation temperature coefficient is 4000ppm).
Intermediate tempco values of modulation current can
be obtained as described in the Design Procedure sec-
400Ω
V
- 0.3V
CC
tion. Table 3 is the R and R
selection table.
MOD
TC
400Ω
IN-
Safety Circuitry
ENABLE
The laser driver can be used with two popular safety
systems. APC maintains laser safety using local feed-
back. Safety features monitor laser driver operation and
CURRENT AMPLIFIER
MODULATION CURRENT
GENERATOR
4000ppm/°C
REFERENCE
1.2V
REFERENCE
Table 3. R and R
Selection Table
TC
MOD
MOD
MOD
MOD_FAULT
I
= 30mA
I
= 15mA
I
= 5mA
MOD
TC_FAULT
TEMPCO
(ppm/°C)
R
R
R
R
TC
R
(kΩ)
162
R
TC
MOD
TC
MOD
MOD
(kΩ)
26.7
9.53
5.76
4.12
3.24
2.67
2.26
(kΩ)
1.69
2.0
(kΩ)
53.6
18.7
11.3
8.06
6.19
5.11
4.22
(kΩ)
3.65
4.32
5.23
6.49
8.87
13.3
26.7
(kΩ)
11.5
13.3
16.2
20.0
26.7
40.2
80.6
0.8V
0.8V
3500
3000
2500
2000
1500
1000
500
57.6
34.8
24.9
19.1
15.8
13.3
2.49
3.16
4.32
6.49
13.3
TC
MODSET
R
R
MOD
TC
Figure 4. Laser Modulator Circuitry
10 ______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
force a shutdown if a fault is detected. The shutdown
Pulse Generator
During startup, the laser does not emit 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
condition is latched until reset by a toggle of EN, EN, or
power.
Another safety system, open fiber control (OFC), uses
safety interlocks to prevent eye hazards. To accommo-
date 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).
high, EN must be low, and V
must be in the opera-
CC
Safety circuitry monitors the APC circuit to detect unsafe
levels of laser emission during single-point failures. A
tional range for laser operation.
Fault Detection
single-point failure can be a short to V
short between any two IC pins.
or GND or a
CC
The MAX3286/MAX3296 series has extensive and com-
prehensive 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.
1.3
R
R
≥ 1.9kΩ
TC
1.2
1.1
1.0
0.9
0.8
0.7
0.6
= OPEN
MOD
TEMPCO = 4000ppm/°C
Shutdown
The laser drivers offer dual redundant bias shutdown
mechanisms. The SHDNDRV output drives an optional
external MOSFET semiconductor. The bias and modu-
lation drivers have separate internal disable signals.
R
= OPEN
TC
TEMPCO = 50ppm/°C
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:
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
1) The power is switched off, then on.
PULSE GENERATOR
(FROM POR CIRCUIT)
EN
FLTDLY
t
FLTDLY
R
Q
FAULT
RESET
DOMINANT
FAULT
LATCH
FAULT
DETECTION
REF_FAULT
S
V
MONITOR_FAULT
MD_FAULT
CC
FAULT
POLARITY_FAULT
TC_FAULT
MOD_FAULT
EN
SHDNDRV
MAX3286
MAX3296
ENABLE
Figure 6. Simplified Safety Circuit Schematic
______________________________________________________________________________________ 11
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
rent, while the resistor R
sets the temperature-
TC
PORDLY
increasing portion of the modulation current.
To determine the appropriate temperature coefficient
from the slope efficiency (α) of the laser, use the following
equation:
V
CC
MAX3286
MAX3296
28kΩ
α70 − α25
α25 (70°C − 25°C)
6
25kΩ
36kΩ
Laser tempco =
× 10 ppm/ °C
[
]
LV
VARIABLE
DELAY
POR
where α is the slope of the laser output power to the
= 0.7s/µF C
PORDLY
laser current.
1.2V
BANDGAP
For example, suppose a laser has a slope efficiency
α
of 0.021mW/mA at +25°C, which reduces to
25
0.018mW/mA at +70°C. Using the above equation pro-
duces a laser tempco of -3175ppm/°C.
Figure 7. Power-On Reset Circuit
To obtain the desired modulation current and tempco
for the device, the following two equations can be used
2) EN is switched low, then high.
to determine the required values of R
and R
:
MOD
TC
3) EN is switched to high, then low.
0.21
R
=
− 250Ω
TC
Power-On Reset (POR)
Figure 7 shows the POR circuit for the MAX3286/
MAX3296 series devices. A POR signal asserts low
tempco I
MOD
(R + 250Ω)52 × tempco
TC
R
=
− 250Ω
MOD
when V
is in the operating range. The voltage operat-
CC
(0.19 − 48 × tempco)
ing range is determined by the LV pin, as shown in
Table 2. POR contains an internal delay to reject noise
where tempco = -laser tempco.
on V
during power-on or hot-plugging. The delay can
CC
Figure 8a shows a family of curves derived from these
equations. The straight diagonal lines depict constant
tempcos. The curved lines represent constant modula-
tion currents. If no temperature compensation is
desired, Figure 8b displays a series of curves that
show laser modulation current with respect to R
different loads.
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 V
is out of the operating range.
CC
for
MOD
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/
MAX3296’s AC specifications, the instantaneous output
The following useful equations were used to derive
Figure 8a and the equations at the beginning of this
section. The first assumes R = 25Ω.
L
1.15
+ 250Ω
1.06
R + 250Ω
TC
+
×
voltage at OUT+ must remain above V
- 1V at all
CC
R
MOD
I
= 51 ×
A
[ ]
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 induc-
tance of 25nH/in (1nH/mm); this inductance causes a
larger voltage swing across the laser. A compensation fil-
ter network also can be used to reduce ringing, edge
speed, and voltage swing.
MOD
−3
1+ 4.0 × 10
T – 25°C
(
)
I
= I
+ I
MOD(70°C)
MOD(25°C) MOD(25°C)
(tempco)(70°C – 25°C) A
Programming the Bias Current/APC
Programming the Modulation Current
Three application circuits are described below: com-
mon-cathode laser with photodiode, common-cathode
laser without photodiode, and common-anode laser
Resistors at the MODSET and TC pins set the ampli-
tude of the modulation current. The resistor R
sets
MOD
the temperature-stable portion of the modulation cur-
12 ______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
with photodiode. The POL and POL inputs determine
the laser pinning (common cathode, common anode)
and affect the smooth-start circuits (Table 4).
1000
500ppm
1000ppm
1500ppm
2000ppm
2500ppm
3000ppm
3500ppm
Common Cathode with Photodiode
(Optical Feedback)
5mA
10
In the common cathode with photodiode configuration,
a servo control loop is formed by external PNP Q1, the
10mA
15mA
20mA
laser diode, the monitor diode, R
, and the power-
SET
control amplifier (Figure 9). The voltage at MD is stabi-
lized to 1.7V. The monitor photodiode current (I ) is set
25mA
30mA
D
R = 25Ω
L
by (V
- V ) / R
= 0.95 / R
D
. Determine the
REF
MD
SET
SET
1
desired monitor current (I ), then select R
= 0.95 / I .
D
SET
1
10
100
1000
R
(kΩ)
The APC loop is compensated by C
. A capacitor
BIASDRV
MOD
must be placed from BIASDRV to V
to ensure low-
CC
Figure 8a. R vs. R
TC
for Various Conditions
MOD
noise 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
40
35
30
25
20
15
10
5
(I
+ I
). A capacitance of 0.1µF is sufficient
MOD
BIASDRV
to obtain a loop time constant in excess of 1µs, provid-
ed that R is chosen appropriately. Resistor R
might be necessary to ensure the APC loop’s stability
when low bias currents are desired.
DEG
DEG
10Ω
LOAD
NOTE: R = OPEN
TC
The voltage across R
250mV at maximum bias current.
DEG should not be larger than
25Ω
LOAD
50Ω
LOAD
The discrete components used with the common cath-
ode with photodiode configuration are:
R
= 0.95 / I
D
SET
0
0
C
= 0.1µF (typ)
BIASDRV
DEG
2
4
6
8
(kΩ)
10
12
14
R
MOD
R
= 0.25 / I
BIAS(MAX)
Figure 8b. Laser-Modulation Current vs. R
MOD
Table 4. POL Pin Setup for Each Laser Configuration Type
DEVICE
POL
DESCRIPTION
LASER PINNING
POL
MAX3286/MAX3296
V
GND
CC
Common cathode with
photodiode
MAX3287/MAX3297
MAX3286/MAX3296
MAX3288/MAX3298
MAX3286/MAX3296
MAX3289/MAX3299
—
—
GND
—
V
CC
Common cathode without
photodiode
—
V
GND
—
V
CC
CC
Common anode with
photodiode
—
MAX3286/MAX3296
MAX3286/MAX3296
V
V
Not allowed; fault occurs
Not allowed; fault occurs
—
—
CC
CC
GND
GND
______________________________________________________________________________________ 13
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Q1 = general-purpose PNP, β >100, f > 5MHz
sufficient to obtain an approximate 1µs APC loop time
constant. This improves power-supply noise rejection.
t
B1 = ferrite bead (see Bias Filter section)
To select the external components:
M1 = general-purpose PMOS device (optional)
1) Determine the required laser bias current
Common Cathode with Current Feedback
In the common-cathode configuration with current feed-
back, a servo control loop is formed by an external PNP
I
= I + I
TH MOD / 2
BIAS
2) Select R
and R
.
MD
SET
transistor (Q1), R
, the controlled-reference voltage
MON
Maxim recommends R
= 1kΩ, R
= 5kΩ, which
MD
block, R
, R , and the power-control amplifier
SET
≈ 250mV.
SET
MD
results in V
- V
(Figure 10). The voltage at MD is stabilized to 1.7V. The
CC
MON
voltage at MON is set by the resistors R and R
.
MD
SET
3) Select R
where R
= 250mV / I
, assuming
BIAS
MON
= 1kΩ and R
MON
= 5kΩ.
As in the short-wavelength configuration, a 0.1µF
R
SET
MD
C
connected between BIASDRV and V
is
CC
BIASDRV
V
V
CC
CC
R
DEG
MAX3286
V
CC
MAX3287
MAX3296
MAX3297
REF
CONTROLLED REFERENCE VOLTAGE
MON
C
BIASDRV
V
= 2.65V
REF
MAX3286/96
SHDNDRV
V
CC
ONLY
M1
Q1
R
POL
SET
SMOOTH-
START
1.7V
POL
MD
BIASDRV
I
D
POWER-CONTROL
AMPLIFIER
I
BIAS
PHOTO
DIODE
FERRITE
BEAD
B1
LASER
Figure 9. Common-Cathode Laser with Photodiode
V
V
CC
CC
R
MON
MAX3286
MAX3288
MAX3296
MAX3298
REF
CONTROLLED REFERENCE VOLTAGE
= 2.65V - 2.25V (V - V
MON
C
BIASDRV
V
)
MON
REF
CC
MAX3286/96
SHDNDRV
V
CC
ONLY
M1
Q1
R
D
POL
SET
SMOOTH-
START
1.7V
POL
MD
BIASDRV
I
POWER-CONTROL
AMPLIFIER
I
BIAS
R
MD
FERRITE
BEAD
B1
LASER
Figure 10. Common Cathode with Current Feedback (PNP Configuration)
14 ______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
The relationship between laser bias current and R
C
and a degeneration resistor (R
) must be
MON
BIASDRV
DEG
is shown in Figure 11. The remaining discrete compo-
nents used with the common cathode without photodi-
ode configuration are as follows:
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 con-
stants of up to 5µs in most cases. The voltage across
Q1 = general-purpose PNP, β >100, f > 5MHz
t
B1 = ferrite bead (see the Bias Filter section)
R
DEG
should not be larger than 250mV at maximum bias
M1 = general-purpose PMOS device (optional)
current.
C
= 0.1µF (typ)
The discrete components used with the common anode
with photodiode configuration are summarized as follows:
BIASDRV
Common Anode with Photodiode
R
= 1.7 / I
D
SET
In the common-anode configuration with photodiode, a
servo control loop is formed by an external NPN transis-
tor (Q1), the laser diode, the monitor diode, R
C
= 0.1µF (typ)
= 0.25 / I
BIAS(MAX)
BIASDRV
, and
SET
R
DEG
the power-control amplifier. The voltage at MD is stabi-
lized to 1.7V. The monitor photodiode current is set by
Q1 = general-purpose NPN, β > 100, f > 5MHz
t
B1 = ferrite bead (see the Bias Filter section)
I = V
/ R
(Figure 12). Determine the desired mon-
MD
SET
D
itor current (I ), then select R
= 1.7V / I .
D
D
SET
M1 = general-purpose PMOS (optional)
Programming POR Delay
A capacitor can be added to PORDLY to increase the
100
R
R
= 1kΩ
= 5kΩ
delay for which POR is asserted low (meaning that V
CC
is within the operational range) when powering up the
part.
SET
MD
10
1
The delay is approximately:
C
PORDLY
t =
s
[ ]
−6
1.4 10
(
)
See the Typical Operating Characteristics.
0.1
10
100
1k
10k
R
(Ω)
MON
Figure 11. Common Cathode without Photodiode Laser
V
CC
MAX3286
MAX3289
V
CC
MAX3296
MAX3299
V
LASER
CC
MON
MAX3286/96
FERRITE
MONITOR
DIODE
ONLY
SHDNDRV
POL
BEAD
B1
SMOOTH-
START
1.7V
V
CC
POL
MD
Q1
BIASDRV
C
BIASDRV
POWER-CONTROL
AMPLIFIER
I
D
R
SET
I
BIAS
R
DEG
Figure 12. Common Anode with Photodiode
______________________________________________________________________________________ 15
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Designing the Bias Filter and
Output Pullup Beads
UNCOMPENSATED
To reduce deterministic jitter, add a ferrite-bead induc-
tor between the collector of the biasing transistor and
either the anode or the cathode of the laser, depending
on type (see the Typical Operating Characteristics).
Use a ferrite-bead inductor with an impedance >100Ω
between ƒ = 10MHz and ƒ = 2GHz, and a DC resistance
CORRECTLY COMPENSATED
OVERCOMPENSATED
<
3Ω.
BLM11HA102SG. These inductors are also desirable
for tying the OUT+ and OUT- pins to V
Maxim
recommends
the
Murata
.
CC
Designing the Laser-Compensation
Filter Network
TIME
Laser package inductance causes the laser impedance
to increase at high frequencies, leading to ringing, over-
shoot, and degradation of the output eye pattern. A laser-
compensation filter network can be used to reduce the
output load seen by the laser driver at high frequencies,
thereby reducing output ringing and overshoot.
Figure 13. Laser Compensation
into the body, for applications intended to support or sus-
tain life, or for any other application where the failure of
a Maxim product could create a situation where per-
sonal injury or death may occur.
The compensation components (R
and C
)
COMP
COMP
are most easily determined by experimentation. Begin
Layout Considerations
The MAX3286/MAX3296 series comprises high-fre-
quency products. Their performance depends largely
upon the circuit board layout.
with R
= 25Ω and C = 2pF. Increase C
COMP COMP
COMP
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 pro-
vides a typical laser power shutdown time of less than
10µs.
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 capaci-
tively bypassed to the ground plane with surface-mount
capacitors placed near the power-supply pins.
Applications Information
The dominant pole of the APC circuit is normally locat-
ed at BIASDRV. To prevent a second pole in the APC
(which can lead to oscillations), ensure that parasitic
capacitance at MD is minimized.
Laser Safety and IEC 825
The International Electrotechnical Commission (IEC)
determines standards for hazardous light emissions
from fiber optic transmitters. IEC 825 defines the maxi-
mum light output for various hazard levels. The MAX3286/
MAX3296 series provides features that facilitate compli-
ance with IEC 825.
Common Questions
Laser output is ringing or contains overshoot. This often is
caused by inductive laser packaging. Try reducing the
length of the laser leads. Modify the compensation com-
ponents to reduce the driver’s output edge speed (see
Design Procedure). Extreme ringing can be caused by
low voltage at the OUT pins. This might indicate that
pullup beads or a lower modulation current are needed.
A common safety requirement is single-point fault toler-
ance, 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
Application Circuits, the circuits respond to faults as
listed in Table 5.
Low-frequency oscillation on the laser output. This is
more prevalent at low temperatures. The APC might be
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
oscillating. Try increasing the value of C
or
BIASDRV
. Ensure that the parasitic
increasing the value of R
DEG
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
V . BIASDRV and SHDNDRV can be left open.
CC
16 ______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Table 5. Circuit Response to Various Single-Point Faults
CIRCUIT RESPONSE TO OVERVOLTAGE OR
SHORT TO V
CIRCUIT RESPONSE TO UNDERVOLTAGE OR
SHORT TO GROUND
PIN NAME
CC
Does not affect laser power
Does not affect laser power
Does not affect laser power
Does not affect laser power
Fault state* occurs
FAULT
FAULT
POR
Does not affect laser power
Does not affect laser power
Does not affect laser power
PORDLY
EN
Normal condition for circuit operation
Fault state* occurs
Fault state* occurs
Normal condition for circuit operation
EN
LV
Does not affect laser power
Fault state* occurs if V
is less than +4.5V
CC
If POL is a TTL HIGH, a fault state* occurs; other-
wise, the circuit is in normal operation
If POL is a TTL LOW, a fault state* occurs; other-
wise, the circuit is in normal operation
POL
If POL is a TTL HIGH, a fault state* occurs; other-
wise, the circuit is in normal operation
If POL is a TTL LOW, a fault state* occurs; other-
wise, the circuit is in normal operation
POL
MON
(also MAX3288/
MAX3298)
In common cathode without photodiode configura-
tion, a fault state* occurs; otherwise, does not affect
laser power
Fault state* occurs
SHDNDRV
(also MAX3287/
MAX3297/MAX3289/
MAX3299
Does not affect laser power. If optional FET is used,
the laser output is shut off.
Does not affect laser power
Any fault that occurs cannot be reset. Does not
affect laser power.
FLTDLY
IN+, IN-
REF
Does not affect laser power
Does not affect laser power
Does not affect laser power
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).
BIASDRV
OUT+, OUT-
MODSET
TC
Does not affect laser power
Does not affect laser power
Does not affect laser power
Does not affect laser power
Fault state* occurs
Fault state* occurs
*A fault state asserts the FAULT pins, disables the modulator outputs, disables the bias output, and asserts the SHDNDRV pin.
______________________________________________________________________________________ 17
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
The modulator is not needed. Leave TC and MODSET
open. Connect IN+ to VCC, IN- to REF, and leave OUT+
and OUT– open.
Interface Models
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 4 mil square. Die
thickness is typically 15 mils (0.38mm).
V
CC
V
CC
MAX3286
MAX3296
MAX3286
MAX3296
10kΩ
4kΩ
550Ω
60Ω
2.5kΩ
SHDNDRV
FAULT, FAULT, POR
Figure 15. SHDNDRV Output
Figure 14. Logic Outputs
V
CC
V
CC
PACKAGE
PACKAGE
50Ω
50Ω
OUT-
OUT+
1.5nH
1.5nH
0.2pF
1pF
1pF
0.2pF
Figure 16. Modulator Outputs
18 ______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
V
CC
PACKAGE
1.5nH
MAX3286
MAX3296
V
CC
IN+
IN-
Q1
0.2pF
0.2pF
1pF
400Ω
400Ω
V
CC
1.5nH
Q2
1pF
INPUT COMMON-MODE VOLTAGE ≈ V - 0.3V
CC
R
IN
Q1, Q2 > 100kΩ
Figure 17. Data Inputs
V
CC
MAX3286
MAX3296
40Ω
BIASDRV
40Ω
Figure 18. BIASDRV Output
______________________________________________________________________________________ 19
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Selector Guide
DATA RATE/DEVICE
LASER CONFIGURATION
COMMON
ANODE
WITH
COMMON
CATHODE
WITH
COMMON
CATHODE
WITH
PACKAGE
1.25Gbps
2.5Gbps
PHOTODIODE
PHOTODIODE
PHOTODIODE
Shortwave or
VCSEL
Longwave
VCSEL
32 TQFP/28 QFN/
28 Thin QFN/Dice
MAX3286
MAX3296
✓
✓
✓
✓
MAX3287
MAX3288
MAX3289
MAX3297
MAX3298
MAX3299
16 TSSOP-EP
16 TSSOP-EP
16 TSSOP-EP
✓
✓
Ordering Information (continued)
PART
TEMP RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
PIN-PACKAGE
Dice*
MAX3286C/D
MAX3287CUE
MAX3288CUE
MAX3289CUE
16 TSSOP-EP**
16 TSSOP-EP**
16 TSSOP-EP**
28 Thin QFN
(5mm x 5mm)****
MAX3296CTI+
MAX3296CGI
MAX3296CHJ
0°C to +70°C
0°C to +70°C
0°C to +70°C
28 QFN
(5mm x 5mm)***
32 TQFP
(5mm x 5mm)
MAX3296C/D
MAX3297CUE
MAX3298CUE
MAX3299CUE
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
Dice*
16 TSSOP-EP**
16 TSSOP-EP**
16 TSSOP-EP**
*Dice are designed to operate from T = 0°C to +110°C, but are
J
tested and guaranteed only at T = +25°C.
A
**Exposed pad.
***Package Code: G2855-1
****Package Code: T2855-7
+Denotes Lead-Free Package.
20 ______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Pin Configurations (continued)
TOP VIEW
32 31 30 29 28 27 26 25
FAULT
N.C.
1
2
3
4
5
6
7
8
24 BIASDRV
SHDNDRV
FAULT
FAULT
POR
1
2
3
4
5
6
7
21 BIASDRV
20 SHDNDRV
19 GND
23
22 GND
21 MON
20 MD
19 N.C.
18 POL
17 POL
FAULT
POR
MAX3286
MAX3296
GND
18 MON
17 MD
MAX3286
MAX3296
GND
EN
EN
EN
16 POL
EN
PORDLY
15 POL
PORDLY
9
10 11 12 13 14 15 16
QFN*
TQFP
GND
1
2
3
4
5
6
7
8
16 TC
GND
1
2
3
4
5
6
7
8
16 TC
FLTDLY
15 MODSET
FLTDLY
15 MODSET
V
CC
14
V
CC
V
CC
14 V
CC
IN+
IN-
MAX3287
MAX3289
MAX3297
MAX3299
13 OUT-
12 OUT+
IN+
IN-
MAX3288
MAX3298
13 OUT-
12 OUT+
GND
REF
MD
11
10 BIASDRV
SHDNDRV
V
GND
REF
MD
11
10 BIASDRV
MON
V
CC
CC
9
9
TSSOP-EP*
TSSOP-EP*
*EXPOSED PAD IS CONNECTED TO GND.
______________________________________________________________________________________ 21
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Typical Application Circuits
+3.0V TO +5.5V
0.01µF
PMOSFET
MAX3286/MAX3296
COMMON-CATHODE VCSEL
WITH PHOTODIODE
0.01µF
0.01µF
V
CC
SHDNDRV
BIASDRV
(OPTIONAL)
MON
EN
POL
FLTDLY
C
BIASDRV
0.1µF
PNP
TRANSISTOR
PORDLY
IN+
0.01µF
V
CC
FERRITE
BEAD
DATA
115Ω
INPUT
MAX3286
MAX3296
0.01µF
0.01µF
IN-
OUT+
OUT-
0.01µF
C
R
COMP
POR
FAULT
25Ω
COMP
FAULT
LV
V
CC
POL EN
MODSET
R
REF MD
GND
TC
R
TC
MOD
R
SET
+3.0V TO +5.5V
0.01µF
R
MON
0.01µF
0.01µF
MAX3286/MAX3296
COMMON-CATHODE VCSEL
WITHOUT PHOTODIODE
V
CC
EN
POL
FLTDLY
PORDLY
MON
C
0.1µF
BIASDRV
PNP
TRANSISTOR
BIASDRV
0.01µF
V
CC
IN+
FERRITE
BEAD
DATA
115Ω
INPUT
MAX3286
MAX3296
0.01µF
OUT+
OUT-
IN-
SHDNDRV
0.01µF
0.01µF
C
COMP
POR
FAULT
FAULT
LV
25Ω
R
COMP
V
CC
POL EN
MODSET
R
REF MD
GND
TC
R
MD
5kΩ
R
MOD
TC
R
SET
1kΩ
22 ______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Typical Application Circuits (continued)
+3.0V TO +5.5V
0.01µF
0.01µF
0.01µF
MAX3286/MAX3296
COMMON-ANODE LASER
WITH PHOTODIODE
V
CC
MON
EN
POL
FLTDLY
V
CC
PORDLY
IN+
0.01µF
0.01µF
0.01µF
18Ω
OUT-
OUT+
FERRITE
BEAD
DATA
INPUT
115Ω
C
R
COMP
MAX3286
MAX3296
IN-
25Ω
COMP
0.01µF
POR
FAULT
FAULT
LV
V
CC
NPN
TRANSISTOR
BIASDRV
C
BIASDRV
0.1µF
SHDNDRV
POL EN
MD
MODSET
R
REF
GND
TC
R
DEG
R
TC
MOD
R
SET
+3.0V TO +5.5V
0.01µF
MAX3287/MAX3297
COMMON-CATHODE VCSEL
WITH PHOTODIODE
V
CC
R
DEG
C
0.1µF
BIASDRV
PNP
TRANSISTOR
BIASDRV
0.01µF
V
CC
IN+
IN-
FERRITE
BEAD
DATA
115Ω
INPUT
MAX3287
MAX3297
0.01µF
OUT+
OUT-
0.01µF
0.01µF
C
COMP
0.01µF
R
25Ω
COMP
FLTDLY
SHDNDRV
V
CC
MODSET
R
REF MD
GND
TC
R
MOD
TC
R
SET
______________________________________________________________________________________ 23
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Typical Application Circuits (continued)
+3.0V TO +5.5V
0.01µF
R
MON
MAX3288/MAX3298
COMMON-CATHODE VCSEL
WITHOUT PHOTODIODE
V
CC
MON
C
0.1µF
BIASDRV
PNP
TRANSISTOR
BIASDRV
0.01µF
V
CC
IN+
FERRITE
BEAD
DATA
115Ω
INPUT
MAX3288
MAX3298
0.01µF
OUT+
OUT-
IN-
0.01µF
C
R
COMP
0.01µF
0.01µF
FLTDLY
25Ω
COMP
V
CC
MODSET
R
REF MD
GND
TC
R
MD
5kΩ
R
MOD
TC
R
SET
1kΩ
+3.0V to +5.5V
0.01µF
18Ω
MAX3289/MAX3299
COMMON-ANODE LASER
WITH PHOTODIODE
V
CC
V
CC
0.01µF
IN+
IN-
0.01µF
0.01µF
OUT-
OUT+
FERRITE
BEAD
DATA
INPUT
115Ω
C
COMP
MAX3289
MAX3299
R
25Ω
COMP
0.01µF
0.01µF
V
CC
FLTDLY
NPN
TRANSISTOR
BIASDRV
C
BIASDRV
0.1µF
SHDNDRV
MD
MODSET
R
REF
GND
TC
R
DEG
R
MOD
TC
R
SET
24 ______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Chip Topographies
MAX3286
MAX3296
TC
FLTDLY
LV
FLTDLY
LV
TC
MODSET
MODSET
HF34Z
HF34Z-1Z
V
V
V
V
CC
CC
CC
CC
0.072"
0.072"
(1.829mm)
(1.829mm)
IN+
IN-
OUT-
OUT+
IN+
IN-
OUT-
OUT+
GND
REF
V
GND
REF
V
CC
CC
V
V
CC
CC
0.053"
0.053"
(1.346mm)
(1.346mm)
TRANSISTOR COUNT: 1154
TRANSISTOR COUNT: 1154
SUBSTRATE CONNECTED TO GND
SUBSTRATE CONNECTED TO GND
______________________________________________________________________________________ 25
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
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.)
PACKAGE OUTLINE,
32L TQFP, 5x5x1.0mm, EP OPTION
1
21-0079
F
2
PACKAGE OUTLINE,
32L TQFP, 5x5x1.0mm, EP OPTION
2
21-0079
F
2
26 ______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
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.)
______________________________________________________________________________________ 27
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
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.)
D2
0.15
C A
D
b
0.10 M
C A B
C
L
D2/2
D/2
k
0.15
C
B
MARKING
XXXXX
E/2
E2/2
C
L
(NE-1) X
e
E2
E
k
L
DETAIL A
e
PIN # 1
I.D.
PIN # 1 I.D.
0.35x45∞
(ND-1) X
e
DETAIL B
e
L
C
C
L
L1
L
L
L
e
e
0.10
C
A
0.08
C
C
A3
A1
PACKAGE OUTLINE,
16, 20, 28, 32L THIN QFN, 5x5x0.8mm
1
-DRAWING NOT TO SCALE-
21-0140
F
2
COMMON DIMENSIONS
20L 5x5 28L 5x5
EXPOSED PAD VARIATIONS
D2 E2
MIN. NOM. MAX. MIN. NOM. MAX. ±0.15
DOWN
BONDS
ALLOWED
L
PKG.
SYMBOL MIN. NOM. MAX. MIN. NOM. MAX. MIN. NOM. MAX. MIN. NOM. MAX.
16L 5x5
32L 5x5
PKG.
CODES
T1655-1
T1655-2
3.00 3.10 3.20 3.00 3.10 3.20
3.00 3.10 3.20 3.00 3.10 3.20
NO
YES
NO
A
**
**
**
**
0.70 0.75 0.80 0.70 0.75 0.80 0.70 0.75 0.80 0.70 0.75 0.80
0.02 0.05 0.02 0.05 0.02 0.05 0.02 0.05
0.20 REF. 0.20 REF. 0.20 REF. 0.20 REF.
A1
0
0
0
0
T1655N-1 3.00 3.10 3.20 3.00 3.10 3.20
A3
b
T2055-2
T2055-3
T2055-4
T2055-5
3.00 3.10 3.20 3.00 3.10 3.20
3.00 3.10 3.20 3.00 3.10 3.20
3.00 3.10 3.20 3.00 3.10 3.20
NO
YES
NO
Y
0.25 0.30 0.35 0.25 0.30 0.35 0.20 0.25 0.30 0.20 0.25 0.30
4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10
4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10
**
**
D
E
3.15 3.25 3.35 3.15 3.25 3.35 0.40
e
0.80 BSC.
0.25
0.30 0.40 0.50 0.45 0.55 0.65 0.45 0.55 0.65 0.30 0.40 0.50
0.65 BSC.
0.50 BSC.
0.50 BSC.
T2855-1
T2855-2
3.15 3.25 3.35 3.15 3.25 3.35
2.60 2.70 2.80 2.60 2.70 2.80
NO
NO
**
**
**
**
k
-
-
0.25
-
-
0.25
-
-
0.25
-
-
L
T2855-3
T2855-4
3.15 3.25 3.35 3.15 3.25 3.35
2.60 2.70 2.80 2.60 2.70 2.80
2.60 2.70 2.80 2.60 2.70 2.80
3.15 3.25 3.35 3.15 3.25 3.35
YES
YES
NO
L1
-
-
-
-
-
-
-
-
-
-
-
-
N
ND
16
4
20
5
28
7
32
8
T2855-5
T2855-6
T2855-7
T2855-8
**
**
**
NO
YES
4
5
7
8
NE
2.80
3.35
3.35
3.20
2.60 2.70
3.15 3.25
2.60 2.70 2.80
3.15 3.25 3.35
3.15 3.25 3.35
3.00 3.10 3.20
WHHB
WHHC
WHHD-1
WHHD-2
JEDEC
0.40
Y
N
NO
T2855N-1 3.15 3.25
**
**
**
NOTES:
T3255-2
T3255-3
T3255-4
3.00 3.10
1. DIMENSIONING & TOLERANCING CONFORM TO ASME Y14.5M-1994.
2. ALL DIMENSIONS ARE IN MILLIMETERS. ANGLES ARE IN DEGREES.
3. N IS THE TOTAL NUMBER OF TERMINALS.
3.00 3.10 3.20 3.00 3.10 3.20
3.00 3.10 3.20 3.00 3.10 3.20
YES
NO
**
**
NO
T3255N-1 3.00 3.10 3.20 3.00 3.10 3.20
4. THE TERMINAL #1 IDENTIFIER AND TERMINAL NUMBERING CONVENTION SHALL
CONFORM TO JESD 95-1 SPP-012. DETAILS OF TERMINAL #1 IDENTIFIER ARE
OPTIONAL, BUT MUST BE LOCATED WITHIN THE ZONE INDICATED. THE TERMINAL #1
IDENTIFIER MAY BE EITHER A MOLD OR MARKED FEATURE.
**SEE COMMON DIMENSIONS TABLE
5. DIMENSION b APPLIES TO METALLIZED TERMINAL AND IS MEASURED BETWEEN 0.25 mm AND 0.30 mm
FROM TERMINAL TIP.
6. ND AND NE REFER TO THE NUMBER OF TERMINALS ON EACH D AND E SIDE RESPECTIVELY.
7. DEPOPULATION IS POSSIBLE IN
A SYMMETRICAL FASHION.
8. COPLANARITY APPLIES TO THE EXPOSED HEAT SINK SLUG AS WELL AS THE TERMINALS.
9. DRAWING CONFORMS TO JEDEC MO220, EXCEPT EXPOSED PAD DIMENSION FOR T2855-1,
T2855-3 AND T2855-6.
10. WARPAGE SHALL NOT EXCEED 0.10 mm.
11. MARKING IS FOR PACKAGE ORIENTATION REFERENCE ONLY.
12. NUMBER OF LEADS SHOWN ARE FOR REFERENCE ONLY.
PACKAGE OUTLINE,
16, 20, 28, 32L THIN QFN, 5x5x0.8mm
2
-DRAWING NOT TO SCALE-
21-0140
F
2
Maxim makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Maxim assume any lia-
bility 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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 28
© 2004 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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