MAX3296CHJ-T [MAXIM]
Interface Circuit, BIPolar, PQFP28, 5 X 5 MM, 1 MM HEIGHT, MS-026AAA-HD, TQFP-32;
| 型号： | MAX3296CHJ-T |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Interface Circuit, BIPolar, PQFP28, 5 X 5 MM, 1 MM HEIGHT, MS-026AAA-HD, TQFP-32 接口集成电路 |
| 文件： | 总28页 (文件大小：727K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-1550; Rev 0; 12/99
to
3.0V 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
General Description
Features
The MAX3286/MAX3296 series of products are high-
speed 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 con-
trol (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 vertical-
cavity surface-emitting lasers (VCSELs).
ꢀ 7ps Deterministic Jitter (MAX3296)
22ps Deterministic Jitter (MAX3286)
ꢀ +3.0V to +5.5V Supply Voltage
ꢀ 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
The MAX3286 series (MAX3286/MAX3287/MAX3288/
MAX3289) is optimized for operation at 1.25Gbps, and
the MAX3296 series (MAX3296/MAX3297/MAX3298/
MAX3299) is optimized for 2.5Gbps operation. Each
device can switch 30mA of laser modulation current at
the specified data rate. Adjustable temperature com-
pensation is provided to keep the optical extinction
ratio within specifications over the operating tempera-
ture range. This series of devices is optimized to drive
lasers packaged in low-cost TO-46 headers. Deter-
ministic jitter (DJ) for the MAX3286 is typically 22ps,
allowing a 72% margin to Gigabit Ethernet DJ specifi-
cations.
ꢀ Integrated Safety Circuits
ꢀ Power-On Reset Signal
ꢀ 16-Pin TSSOP-EP Package Available
Ordering Information
TEMP. RANGE
0°C to +70°C
0°C to +70°C
PART
PIN-PACKAGE
32 TQFP (5mm x 5mm)
Dice*
MAX3286CHJ
MAX3286C/D
Ordering Information continued at end of data sheet.
*Dice are designed to operate from T = 0°C to +110°C, but are
J
tested and guaranteed only at T = +25°C.
A
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 start-up.
Pin Configurations
TOP VIEW
The MAX3286/MAX3296 are available in a compact,
5mm x 5mm, 32-pin TQFP package or in die form. The
MAX3287/MAX3288/MAX3289 and MAX3297/MAX3298/
MAX3299 are available in smaller 16-pin TSSOP-EP
packages, which are ideal for small form-factor optical
modules.
GND
1
2
3
4
5
6
7
8
16 TC
FLTDLY
15 MODSET
V
14 V
CC
CC
IN+
IN-
MAX3287
MAX3289
MAX3297
MAX3299
13 OUT-
12 OUT+
Applications
GND
REF
MD
11
10 BIASDRV
SHDNDRV
V
CC
Gigabit Ethernet Optical Transmitter
Fibre Channel Optical Transmitter
ATM LAN Optical Transmitter
9
TSSOP-EP*
*Exposed paddle is connected to GND.
Pin Configurations continued at end of data sheet.
Typical Application Circuits and Selector Guide appear at
end of data sheet.
________________________________________________________________ Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
ABSOLUTE MAXIMUM RATINGS
Supply Voltage at V
..........................................-0.5V to +7.0V
Continuous Power Dissipation (T = +70°C)
A
CC
Voltage at EN, EN, PORDLY, FLTDLY, LV, IN+, IN-,
REF, POL, POL, MD, MON, BIASDRV,
MODSET, TC..........................................................-0.5V to (V + 0.5V)
32-Pin TQFP (derate 14.3mW/°C) ...............................1100mW
16-Pin TSSOP (derate 27mW/°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
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
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 and T = +25°C, R = open;
CC
A
CC
A
TC
see Figure 1a.)
PARAMETER
SYMBOL
CONDITIONS
= 1.82kΩ
MOD
MIN
TYP
MAX
75
UNITS
mA
mV
µA
Supply Current
I
Figure 1a, R
52
CC
Data Input Voltage Swing
TTL Input Current
V
ID
Total differential signal, peak-peak, Figure 1a
0 ≤ V ≤ V
200
-100
2.0
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
FAULT = low, V
FAULT = low, V
≥ 0.6V
0.8
BIASDRV
mA
≤ V
- 1V
0.8
BIASDRV
CC
I
≤ 2mA, MON = V
2.45
1.55
2.65
1.7
2.85
1.85
1.2
V
V
REF
CC
MD Nominal Voltage
V
MD
APC loop is closed
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
3.0
POR Threshold
V
2.65
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
0.8
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 and T = +25°C, R = open;
CC
A
CC
A
TC
see Figure 1a.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
SHUTDOWN
I
= 10µA, FAULT asserted
= 15mA, FAULT not asserted
= 1mA, FAULT not asserted
V
- 0.4
SHDNDRV
CC
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
MOD
MOD
MOD
Tolerance of Modulation Current
= 13kΩ (i
MOD
MAX3286 series
MAX3296 series
130
90
220
150
Modulation-Current Edge
Speed
20% to 80%
ps
R
(i
= 13kΩ
MOD
MOD
46
29
22
14
8
65
45
35
35
22
20
= 5mA)
R
= 4.1kΩ
= 15mA)
MOD
MOD
MAX3286 series
MAX3296 series
(i
R
= 1.9kΩ
= 30mA)
MOD
MOD
(i
Deterministic Jitter (Note 2)
ps
R
= 13kΩ
= 5mA)
MOD
MOD
(i
R
= 4.1kΩ
= 15mA)
MOD
MOD
(i
R
= 1.9kΩ
= 30mA)
MOD
MOD
7
(i
MAX3286 series
MAX3296 series
2
2
8
4
Random Jitter, RMS (Note 3)
Shutdown Modulation Current
ps
15
200
µA
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 and T = +25°C, R = open;
CC
A
CC
A
TC
see Figure 1a.)
PARAMETER
SYMBOL
CONDITIONS
MIN
0.2
TYP
1
MAX
UNITS
C
C
= 0
FLTDLY
FLTDLY Duration
t
µs
FLTDLY
= 270pF
100
140
FLTDLY
EN or EN Minimum Pulse Width
Required to Reset a Latched
Fault
MAX3286/MAX3296 only,
Figure 1b
t
6
10
ns
EN_RESET
MAX3286/MAX3296 only,
Figure 1b
FAULT Reset After EN, EN, or
POR Transition
t
1
2
µs
µs
RESET
SHDNDRV Asserted After EN =
low or EN = high
MAX3286/MAX3296 only,
Figure 1b
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
POR DELAY vs. C
PORDLY
EYE DIAGRAM
FLTDLY DURATION vs. C
FLTDLY
100k
10k
1k
10k
1k
100
100
10
1
10
1
10
100
1k
10k
100k
1
10
100
1k
10k
50ps/div
CAPACITANCE (pF)
7
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
50ps/div
10µs/div
5µs/div
7
2.5Gbps, 1310nm LASER, 2 - 1 PRBS, i
= 15mA
mod
Pin Description
PIN
MAX3287
NAME
FUNCTION
MAX3286
MAX3296
MAX3297
MAX3289
MAX3299
MAX3288
MAX3298
1
—
—
—
—
Inverting Fault Indicator. See Table 1.
No Connect
FAULT
N.C.
2, 16
3
—
—
FAULT
POR
Noninverting Fault Indicator. See Table 1.
4
—
—
Power-On Reset. POR is a TTL-compatible output. See Figure 14.
Ground
5, 14, 22, 30
1, 6
1, 6
GND
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.
6
7
8
—
—
—
—
—
—
EN
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.
Power-On Reset Delay. To extend the delay for the power-on reset circuit,
connect a capacitor to PORDLY. See Design Procedure.
PORDLY
Fault Delay Input. Determines the delay of the FAULT and FAULT outputs.
A capacitor attached to FLTDLY ensures proper start-up. (See Typical
Operating Characteristics.) FLTDLY = GND: holds FAULT low and FAULT
9
2
2
FLTDLY
LV
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.
10
—
—
11, 25,
26, 29
3, 11, 14
3, 11, 14
V
Supply Voltage
CC
_______________________________________________________________________________________
5
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Pin Description (continued)
PIN
MAX3287
MAX3297
MAX3289
MAX3299
NAME
FUNCTION
MAX3286
MAX3296
MAX3288
MAX3298
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.
15
17
18
7
—
—
7
—
—
REF
POL
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)
19
20
—
8
—
8
I.C.
MD
Internally Connected. Do not connect.
Monitor Diode Connection. MD is used for automatic power control.
Laser Bias Current Monitor. Used for programming laser bias current in
VCSEL applications.
21
23
24
—
9
9
—
10
MON
SHDN-DRV
BIASDRV
Shutdown Driver Output. Provides a redundant laser shutdown.
Bias-Controlling Transistor Driver. Connects to the base of an external
PNP or NPN transistor.
10
27
28
12
13
12
13
OUT+
OUT-
Modulation-Current Output. See Typical Application Circuits.
Modulation-Current Output. See Typical Application Circuits.
Modulation-Current Set. The resistor at MODSET programs the tempera-
ture-stable component of the laser modulation current.
31
32
—
15
16
EP
15
16
EP
MODSET
TC
Temperature-Compensation Set. The resistor at TC programs the tem-
perature-increasing component of the laser modulation current.
Exposed
Paddle
Ground. This must be soldered to the circuit board ground for proper
thermal performance. See Layout Considerations.
Table 2. LV Operating Range
Table 1. Typical Fault Conditions
OPERATING VOLTAGE
PIN
FAULT CONDITION
LV
RANGE (V)
LV = open and V
LV = GND and V
< 3V;
< 4.5V
CC
CC
V
CC
Open
>3.0
>4.5
Grounded
REF
POL and POL
MON
V
> 2.95V
REF
POL = POL
V
< V
- 540mV
MON
CC
V
V
> 1.15 · V
< 0.85 · V
,
MD
MD
MD(nom)
MD(nom)
MD
EN and EN
EN = low or open, EN = high or open
and V ≤ 0.8V
MODSET
and TC
V
MODSET
TC
6
_______________________________________________________________________________________
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+
100mVp-p MIN
830mVp-p MAX
0.01µF
V
CC
OUT-
OUT+
V
IN-
V
V
L = 3.9nH
MAX3286
MAX3296
CC
CC
200mVp-p MIN
1660mVp-p MAX
V
= V - V
IN+ IN-
ID
50Ω
50Ω
i
MOD
R
L
25Ω
CURRENT
i
MOD
IN+
IN-
L = 3.9nH
V
ID
BIASDRV
(OPEN)
TIME
MODSET
R
MODULATION
CONTROL
R .= 25Ω
L
i
3/2
MOD
*MURATA
BLM11HA102
LASER
EQUIVALENT
LOAD
MOD
TC
Figure 1a. Output Load for AC Specification
_______________Detailed Description
The MAX3286/MAX3296 series of laser drivers contain
a bias generator with automatic power control (APC),
laser modulator, power-on reset (POR) circuit, and
safety circuitry (Figures 2a and 2b).
V
CC
t
PORDLY
POR
t
t
RESET
FAULT
FAULT
t
SHUTDN
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 tran-
sistor 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 tem-
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
_______________________________________________________________________________________
7
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
perature and changing laser properties. The MD input
LV
POR
is connected to the anode or cathode of a monitor pho-
todiode or to a resistor-divider, depending on the specific
application circuit. Three application circuits are sup-
ported: common-cathode laser with photodiode, com-
mon-cathode laser without photodiode, and common-
anode laser with photodiode (as shown in the Design
Procedure). The POL and POL inputs determine the laser
pinning (common cathode, common anode) (Table 4).
POR CIRCUIT
PORDLY
FAULT
EN
EN
FAULT
SAFETY
SHDNDRV
FLTDLY
POL
MD
POL
BIASDRV
REF
BIAS GENERATOR
MON
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.
MD
IN+
OUT+
OUT-
LASER
MODULATOR
IN-
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
MODSET
TC
Figure 2a. Simplified Laser Driver Functional Diagram
LV
PORDLY
REF
MAX3286
MAX3296
CONTROLLED
POR
1.7V
POR CIRCUIT
REFERENCE
REF
FAULT
GENERATOR
FAULT
MON
V
- 0.54V
CC
SHDNDRV
1.97V
SAFETY
CIRCUITRY
FLTDLY
EN
EN
MD
BIASDRV
1.53V
POL
POL
SMOOTH
START
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
_______________________________________________________________________________________
8
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
Applications Information.)
POLARITY _FAULT
+1.53V
The REF pin provides a controlled reference voltage
dependent upon the voltage at MON. The voltage at
MD
FAULT
GLITCH
REJECT
POL
POL
SMOOTH
START
REF is V
= 2.65 - 2.25(V
- V
). A resistor con-
MON
REF
CC
WINDOW
+1.97V
nected at REF determines the laser power when APC is
used with common-cathode lasers. See the Design
Procedure for setting the laser power.
COMPARATOR
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
CC
- 540mV
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
The amplitude of the modulation current is set with
resistors at the MODSET and TC (temperature coefficient)
Figure 3. Bias Generator Circuitry
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.
400Ω
V
- 0.3V
CC
400Ω
Safety Circuitry
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
force a shutdown if a fault is detected. The shutdown
condition is latched until reset by a toggle of EN, EN, or
power.
IN-
ENABLE
CURRENT AMPLIFIER
96X
MODULATION CURRENT
GENERATOR
4000ppm/°C
REFERENCE
1.2V
REFERENCE
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.
MOD_FAULT
TC_FAULT
The safety circuitry contains fault detection, dual enable
inputs, latched fault outputs, and a pulse generator
(Figure 6).
0.8V
0.8V
Safety circuitry monitors the APC circuit to detect unsafe
levels of laser emission during single-point failures. A
TC
MODSET
R
R
MOD
TC
single-point failure can be a short to V
between any two IC pins.
or GND, or
CC
Figure 4. Laser Modulator Circuitry
_______________________________________________________________________________________
9
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Pulse Generator
During start-up, the laser is not emitting light and the
APC loop is not closed, triggering a fault signal. To
allow start-up, 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
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 Applications
Information 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 modu-
lation drivers have separate, internal disable signals.
high, EN must be low, and V
must be in the opera-
CC
tional 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:
Fault Detection
The MAX3286/MAX3296 series have extensive and
comprehensive fault-detection features. All critical
1) The power is switched off, then on.
2) EN is switched low, then high.
3) EN is switched to high, then low.
1.3
R
R
≥ 1.9kΩ
MOD
TEMPCO = 4000ppm/°C
TC
1.2
1.1
1.0
0.9
0.8
0.7
0.6
= OPEN
Power-On Reset (POR)
Figure 7 shows the power-on reset (POR) circuit for the
MAX3286/MAX3296 series devices. A POR signal
R
= OPEN
asserts low when V
is in the operating range. The
TC
CC
TEMPCO = 50ppm/°C
voltage operating range is determined by the LV pin, as
shown in Table 2. POR contains an internal delay to
reject noise on V
during power-on or hot-plugging.
CC
The delay can be extended by adding capacitance to
the PORDLY pin. The POR comparator includes hys-
teresis to improve noise rejection. The laser driver is
0
10 20 30 40 50 60 70 80 90 100 110
JUNCTION TEMPERATURE (°C)
shut down while V
is out of the operating range.
CC
Figure 5. Modulation Current vs. Temperature for Maximum
and Minimum Temperature Coefficient
PULSE GENERATOR
(FROM POR CIRCUIT)
EN
FLTDLY
FAULT
t
FLTDLY
R
Q
RESET
DOMINANT
FAULT
FAULT
DETECTION
REF_FAULT
LATCH
S
V
MONITOR_FAULT
MD_FAULT
CC
FAULT
200ns
DELAY
POLARITY_FAULT
TC_FAULT
MOD_FAULT
EN
SHDNDRV
MAX3286
MAX3296
ENABLE
Figure 6. Simplified Safety Circuit Schematic
10 ______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
0.018mW/mA at +70°C. Using the above equation will
produce a laser tempco of -3175ppm/°C.
PORDLY
To obtain the desired modulation current and tempco
V
CC
for the device, the following two equations can be used
MAX3286
MAX3296
to determine the required values of R
and R
:
MOD
TC
28k
0.21
25k
R
=
− 250Ω
TC
Tempco i
MOD
LV
VARIABLE
DELAY
POR
(R +250Ω)52⋅Tempco
TC
= 0.7s/µF C
PORDLY
R
=
− 250Ω
MOD
36k
(0.19− 48Tempco)
1.2V
BANDGAP
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 modula-
tion currents. If no temperature compensation is
desired, Figure 8b displays a series of curves that
Figure 7. Power-On Reset Circuit
Design Procedure
show laser modulation current with respect to R
different loads.
for
MOD
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
+
⋅
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 can also be used to reduce ringing, edge
speed, and voltage swing.
R
MOD
i
= 51⋅
A
[ ]
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 Modulation Current
Programming the Bias Current/APC
Resistors at the MODSET and TC pins set the ampli-
Three application circuits are described below: com-
mon-cathode laser with photodiode, common-cathode
laser without photodiode, and common-anode laser
with photodiode. The POL and POL inputs determine
the laser pinning (common cathode, common anode)
and affect the smooth-start circuits (Table 4).
tude of the modulation current. The resistor R
sets
MOD
the temperature-stable portion of the modulation cur-
rent while the resistor R
sets the temperature-
TC
increasing portion of the modulation current.
To determine the appropriate temperature coefficient
from the slope efficiency (α) of the laser, use the following
equation:
Common Cathode with Photodiode
(Optical Feedback)
α70 − α25
In the common-cathode with photodiode configuration,
a servo control loop is formed by external PNP Q1, the
+6
Laser Tempco =
(70°C −25°C) ⋅ 10 ppm/°C
[
]
α25
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
where α is the slope of the laser output power to the
D
laser current.
by (V
- V ) / R
= 0.95 / R
. Determine the
REF
MD
SET
SET
For example, suppose a laser has a slope efficiency
desired monitor current (I ), then select R
= 0.95 / I .
D
D
SET
α
of 0.021mW/mA at +25°C, which reduces to
25
______________________________________________________________________________________ 11
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
The APC loop is compensated by C
. A capacitor
BIASDRV
1000
500ppm
1000ppm
1500ppm
must be placed from BIASDRV to V
to ensure low-
2000ppm
CC
2500ppm
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
3000ppm
3500ppm
(I
+ i ). A capacitance of 0.1µF is sufficient
MOD
BIASDRV
5mA
10
to obtain a loop time constant in excess of 1µs, provid-
ed that R is chosen appropriately. Resistor R
10mA
DEG
DEG
may be necessary to ensure the APC loop’s stability
when low bias currents are desired.
15mA
20mA
25mA
30mA
The voltage across R
250mV at maximum bias current.
The discrete components used with the common cath-
ode with photodiode configuration are as follows:
DEG should not be any larger than
R = 25Ω
L
1
1
10
100
1000
R
(kΩ)
MOD
R
SET
= 0.88 / I
D
Figure 8a. R vs. R
TC
for Various Conditions
MOD
C
= 0.1µF (typ)
BIASDRV
40
35
30
25
20
15
10
5
Table 3. R and R
Selection Table
MOD
TC
i
= 30mA
i
= 15mA
i
= 5mA
MOD
MOD
MOD
TEMPCO
(ppm/°C)
R
R
R
MOD
R
R
MOD
R
TC
MOD
TC
TC
10Ω
(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)
162
(kΩ)
11.5
13.3
16.2
20.0
26.7
40.2
80.6
LOAD
NOTE: R = OPEN
TC
3500
3000
2500
2000
1500
1000
500
25Ω
LOAD
57.6
34.8
24.9
19.1
15.8
13.3
50Ω
LOAD
2.49
3.16
4.32
6.49
13.3
0
0
2
4
6
8
10
12
14
R
(kΩ)
MOD
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
12 ______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
R
= 0.25 / I
C
connected between BIASDRV and V
is
CC
DEG
BIASDRV
BIAS(MAX)
sufficient to obtain approximately a 1µs APC loop time
Q1 = general-purpose PNP, β >100, f > 5MHz
B1 = ferrite bead (see Bias Filter section)
t
constant. This improves power-supply noise rejection.
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
SET
≈ 250mV.
MD
block, R
, R , and the power-control amplifier
SET
MD
results in V
- V
CC
MON
(Figure 10). The voltage at MD is stabilized to 1.7V. The
3) Select R
where R
= 1kΩ and R
= 250mV / I , assuming
BIAS
voltage at MON is set by the resistors R
and R
.
MON
MON
= 5kΩ.
SET
MD
R
As in the short-wavelength configuration, a 0.1µF
SET
MD
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)
______________________________________________________________________________________ 13
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 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-
C
= 0.1µF (typ)
= 0.25 / I
BIAS(MAX)
BIASDRV
tor (Q1), the laser diode, the monitor diode, R
, and
SET
R
DEG
the power-control amplifier. The voltage at MD is stabi-
Q1 = general-purpose NPN, β > 100, f > 5MHz
t
lized to 1.7V. The monitor photodiode current is set by
B1 = ferrite bead (see 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
100
A capacitor may be added to PORDLY to increase the
delay for which POR will be asserted low (meaning that
CC
R
R
= 1kΩ
= 5kΩ
SET
MD
V
is within the operational range) when powering up
the part.
10
1
The delay will be approximately:
C
PORDLY
t =
s
[ ]
−6
1.4 10
(
)
See Typical Operating Characteristics.
0.1
10
100
1k
10k
R
MON
(Ω)
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
14 ______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Designing the Bias Filter and
UNCOMPENSATED
Output Pull-Up Beads
To reduce deterministic jitter, add a ferrite-bead induc-
tor 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 fer-
rite-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+
CORRECTLY COMPENSATED
OVERCOMPENSATED
and OUT- pins to V
.
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 are high-frequency
products. Their performance largely depends 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 will
provide 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
(that 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 provide features that facilitate compli-
ance with IEC 825.
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 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 may indicate that pull-
up 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
Operating Circuits, the circuits respond to faults as
shown in Table 5.
Low-frequency oscillation on the laser output. This is
more prevalent at low temperatures. The APC may 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
______________________________________________________________________________________ 15
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
MAX3286/MAX3296 ONLY
Does not affect laser power.
Does not affect laser power.
Does not affect laser power.
Does not affect laser power.
Does not affect laser power.
FAULT
FAULT
POR
Does not affect laser power.
Does not affect laser power.
Fault state* occurs.
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
In common-cathode without photodiode configura-
tion, a fault state* occurs; otherwise, does not affect
laser power.
MON
(Also MAX3288/98)
A 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.
ALL DEVICES
FLTDLY
IN+, IN-
REF
Any fault that occurs cannot be reset. Does not
affect laser power.
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.
A 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 will assert the FAULT pins, disable the modulator outputs, disable the bias output, and assert the SHDNDRV pin.
16 ______________________________________________________________________________________
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 use 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).
V
V
CC
CC
MAX3286
MAX3296
MAX3286
MAX3296
10k
4k
550Ω
60Ω
2.5k
SHDNDRV
FAULT, FAULT, POR
Figure 15. SHDNDRV Output
Figure 14. Logic Outputs
V
V
CC
CC
PACKAGE
PACKAGE
50Ω
50Ω
OUT-
OUT+
1.5nH
1.5nH
0.2pF
1pF
1pF
0.2pF
Figure 16. Modulator Outputs
______________________________________________________________________________________ 17
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
Q1, Q2 > 100kΩ
IN
Figure 17. Data Inputs
V
CC
MAX3286
MAX3296
40Ω
BIASDRV
40Ω
Figure 18. BIASDRV Output
18 ______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Selector Guide
DATA RATE/DEVICE
LASER CONFIGURATION
COMMON
CATHODE
WITH
COMMON
CATHODE
WITHOUT
COMMON
ANODE WITH
PHOTODIODE
PACKAGE
1.25Gbps
2.5Gbps
PHOTODIODE
PHOTODIODE
Shortwave or
VCSEL
Longwave
VCSEL
ꢁ
ꢁ
ꢁ
ꢁ
MAX3286
MAX3287
MAX3288
MAX3289
MAX3296
MAX3297
MAX3298
MAX3299
32 TQFP/Dice
16 TSSOP-EP
16 TSSOP-EP
16 TSSOP-EP
ꢁ
ꢁ
Pin Configurations (continued)
TOP VIEW
32 31 30 29 28 27 26 25
FAULT
1
2
3
4
5
6
7
8
24 BIASDRV
SHDNDRV
23
GND
1
2
3
4
5
6
7
8
16 TC
N.C.
FAULT
POR
FLTDLY
15 MODSET
22 GND
21 MON
20 MD
19 I.C.
18 POL
17 POL
V
CC
14 V
CC
IN+
IN-
MAX3288
MAX3298
13 OUT-
12 OUT+
MAX3286
MAX3296
GND
GND
REF
MD
11
10 BIASDRV
MON
V
CC
EN
EN
9
PORDLY
TSSOP-EP*
9
10 11 12 13 14 15 16
*Exposed paddle is connected to GND.
TQFP
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
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
PIN-PACKAGE
16 TSSOP-EP**
16 TSSOP-EP**
16 TSSOP-EP**
32 TQFP (5mm x 5mm)
Dice*
MAX3287CUE
MAX3288CUE
MAX3289CUE
MAX3296CHJ
MAX3296C/D
MAX3297CUE
MAX3298CUE
MAX3299CUE
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 paddle
______________________________________________________________________________________ 19
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 LASER
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
MOD
TC
R
SET
+3.0V TO +5.5V
0.01µF
R
MON
0.01µF
0.01µF
MAX3286/MAX3296
COMMON-CATHODE LASER
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
0.01µF
OUT+
OUT-
IN-
SHDNDRV
0.01µF
C
COMP
POR
FAULT
FAULT
LV
25Ω
R
COMP
V
CC
POL EN
MODSET
R
REF MD
GND
TC
R
MD
5k
R
TC
MOD
R
SET
1k
20 ______________________________________________________________________________________
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
MOD
TC
R
SET
+3.0V TO +5.5V
0.01µF
MAX3287/MAX3297
COMMON-CATHODE LASER
WITH PHOTODIODE
V
CC
R
DEG
C
0.1µF
BIASDRV
PNP
TRANSISTOR
BIASDRV
0.01µF
V
CC
IN+
IN-
FERRITE
BEAD
DATA
INPUT
115Ω
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
TC
MOD
R
SET
______________________________________________________________________________________ 21
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 LASER
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
5k
R
MOD
TC
R
SET
1k
+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
R
COMP
MAX3289
MAX3299
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
22 ______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Chip Topographies
MAX3286
MAX3296
FLTDLY
LV
TC
TC
FLTDLY
LV
MODSET
MODSET
HF34Z-1Z
HF34Z
V
V
V
CC
V
CC
CC
CC
0.072"
0.072"
(1.829mm)
(1.829mm)
IN+
IN-
OUT-
OUT+
IN+
IN-
OUT-
OUT+
GND
REF
V
V
GND
REF
V
V
CC
CC
CC
CC
0.053"
0.053"
(1.346mm)
(1.346mm)
TRANSISTOR COUNT: 1154
TRANSISTOR COUNT: 1154
SUBSTRATE CONNECTED TO GND
SUBSTRATE CONNECTED TO GND
______________________________________________________________________________________ 23
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Package Information
24 ______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
Package Information (continued)
______________________________________________________________________________________ 25
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
NOTES
26 ______________________________________________________________________________________
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
NOTES
______________________________________________________________________________________ 27
3.0V to 5.5V, 1.25Gbps/2.5Gbps
LAN Laser Drivers
NOTES
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.
28 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 1999 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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