19-0432; Rev 2; 5/01
Single +5V, Fully Integrated,
155Mbps Laser Diode Driver
________________General Description
The MAX3263 is a complete, easy-to-program, single
+5V-powered, 155Mbps laser diode driver with com-
plementary enable inputs and automatic power control
(APC). The MAX3263 accepts differential PECL inputs
and provides complementary output currents. A tem-
perature-stabilized reference voltage is provided to
simplify laser current programming. This allows modu-
lation current to be programmed up to 30mA and bias
current to be programmed from up to 60mA with two
external resistors.
An APC circuit is provided to maintain constant laser
power in transmitters that use a monitor photodiode.
Only two external resistors are required to implement
the APC function.
The MAX3263’s fully integrated feature set includes a
TTL-compatible laser failure indicator and a program-
mable slow-start circuit to prevent laser damage. The
slow-start is preset to 50ns and can be extended by
adding an external capacitor.
____________________________Features
o
Rise Times Less than 1ns
o
Differential PECL Inputs
o
Single +5V Supply
o
Automatic Power Control
o
Temperature-Compensated Reference Voltage
o
Complementary Enable Inputs
MAX3263
_______________Ordering Information
PART
MAX3263CAG
TEMP. RANGE
0°C to +70°C
PIN-PACKAGE
24 SSOP
________________________Applications
Laser Diode Transmitters
155Mbps SDH/SONET
155Mbps ATM
_____________Typical Operating Circuit
+5V
0.01µF
VCCA VCCB
+5V
0.01µF
+5V
OUT+
PHOTO-
DIODE
IPIN
___________________Pin Configuration
TOP VIEW
VREF2 1
IPINSET 2
FAILOUT 3
GNDB 4
VIN+ 5
VIN- 6
GNDB 7
VCCB
8
24 SLWSTRT
23 IPIN
22 VCCA
21 GNDA
PECL
INPUTS
VIN+
VIN-
GNDA
GNDB
LASER
MAX3263
ENB+
IBIASOUT
FERRITE BEAD
+5V
MAX3263
20 OUT+
19 GNDA
18 OUT-
17 GNDA
16 IBIASOUT
15 IMODSET
14 IBIASSET
13 IBIASFB
VREF1
ENB-
SLWSTRT
OUT-
FAILOUT
IBIASFB
2.7k
ENB- 9
ENB+ 10
VREF1 11
OSADJ 12
VREF2
IBIASSET
IMODSET
OSADJ
IPINSET
SSOP
________________________________________________________________
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.
Single +5V, Fully Integrated,
155Mbps Laser Diode Driver
MAX3263
ABSOLUTE MAXIMUM RATINGS
Terminal Voltage (with respect to GND)
Supply Voltages (V
CC
A, V
CC
B).............................-0.3V to +6V
VIN+, VIN-, FAILOUT ................................................0V to V
CC
OUT+, OUT-, IBIASOUT ......................................+1.5V to V
CC
ENB+, ENB- ......................V
CC
or +5.5V, whichever is smaller
Differential Input Voltage (
|
VIN+ - VIN-
|
).........................+3.8V
Input Current
IBIASOUT ............................................................0mA to 75mA
OUT+, OUT- ........................................................0mA to 40mA
IBIASSET ........................................................0mA to 1.875mA
IMODSET...............................................................0mA to 2mA
IPIN, IPINSET, OSADJ...........................................0mA to 2mA
FAILOUT..............................................................0mA to 10mA
IBIASFB................................................................-2mA to 2mA
Output Current
VREF1, VREF2.....................................................0mA to 20mA
SLWSTRT ..............................................................0mA to 5mA
Continuous Power Dissipation (T
A
= +70°C)
SSOP (derate 8mW/°C above +70°C) ..........................640mW
Operating Temperature Range...............................0°C to +70°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-55°C to +175°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
DC ELECTRICAL CHARACTERISTICS
(V
CC
= V
CC
A = V
CC
B = +4.75V to +5.25V, T
A
= 0°C to +70°C, unless otherwise noted. Typical values are at V
CC
= +5V and
T
A
= +25°C.)
PARAMETER
Range of Programmable Laser
Bias Current
Reference Voltage
Available Reference Current
Supply Current
PECL Input High
PECL Input Low
TTL High Input
TTL Low Input
FAILOUT Output High
FAILOUT Output Low
SYMBOL
I
BIAS
V
REF
I
REF
I
VCC
V
IH
V
IL
V
IH
V
IL
V
OH
V
OL
Loaded with 2.7kΩ pull-up resistor to V
CC
Loaded with 2.7kΩ pull-up resistor to V
CC
4.5
0.5
2
(Note 1)
V
CC
- 1.165
V
CC
- 1.475
0.8
T
A
= +25°C
3.15
3.3
12
50
CONDITIONS
MIN
TYP
MAX
60
3.55
UNITS
mA
V
mA
mA
V
V
V
V
V
V
Note 1:
I
VCC
= I
VCCA
+ I
VCCB
, I
BIAS
= 60mA, I
MOD
= 30mA, and I
PIN
= 140µA.
AC ELECTRICAL CHARACTERISTICS
(V
CC
= V
CC
A = V
CC
B = +4.75V to +5.25V, R
LOAD
(at OUT+ and OUT-) = 25Ω connected to V
CC
, T
A
= 0°C to +70°C, unless other-
wise noted. Typical values are at V
CC
= +5V and T
A
= +25°C.) (Note 2)
PARAMETER
Range of Programmable
Modulation Current
Modulation-Current Rise and
Fall Time
Aberrations, Rising and Falling
Edge
Modulation-Current Pulse-
Width Distortion
SYMBOL
I
MOD
t
R
, t
F
OS
PWD
CONDITIONS
Minimum differential input swing is 1100mVp-p
(Note 3)
I
BIAS
= 25mA, I
MOD
= 12mA, 4ns unit interval;
measured from 10% to 90%
I
MOD
= 12mA, T
A
= +25°C
I
BIAS
= 25mA, I
MOD
= 12mA, 8ns period
±15
100
MIN
TYP
MAX
30
1
UNITS
mA
ns
%
ps
Note 2:
AC characteristics are guaranteed by design and characterization.
Note 3:
An 1100mVp-p differential is equivalent to complementary 550mVp-p signals on VIN+ and VIN-.
2
_______________________________________________________________________________________
Single +5V, Fully Integrated,
155Mbps Laser Diode Driver
__________________________________________Typical Operating Characteristics
(MAX3263CAG loads at OUT+ and OUT- = 25Ω, V
CC
= V
CC
A = V
CC
B = +5V, T
A
= +25°C, unless otherwise noted.)
R
BIASSET
vs. BIAS CURRENT
MAX3263-01
MAX3263
R
MODSET
vs. MODULATION CURRENT
MAX3263-02
R
PINSET
vs. MONITOR CURRENT
MAX3263-03
8
7
6
12
10
8
6
4
DIFFERENTIAL INPUT
SWING = 1100 mVp-p
1,000,000
100,000
R
MODSET
(kΩ)
R
PINSET
(Ω)
0
5
10
15
20
25
R
BIASSET
(kΩ)
5
4
3
2
1
0
0
20
I
BIAS
(mA)
40
60
10,000
1000
2
0
30
MODULATION CURRENT (mAp-p)
100
0
500
MONITOR CURRENT (µA)
1000
PERCENT CHANGE IN MODULATION
CURRENT vs. TEMPERATURE
MAX3263-04
PERCENT CHANGE IN BIAS
CURRENT vs. TEMPERATURE
MAX3263-05
SUPPLY CURRENT
vs. TEMPERATURE
48
SUPPLY CURRENT (mA)
46
44
42
40
38
36
MAX3263-06
10
8
6
% CHANGE (w.r.t. +25°C)
4
2
0
-2
-4
-6
-8
-10
0
20
40
TEMPERATURE (°C)
60
3
APC DISABLED
2
% CHANGE (w.r.t. +25°C)
50
1
0
-1
-2
80
0
10
20
30
40
50
60
70
80
TEMPERATURE (°C)
34
0
20
40
TEMPERATURE (°C)
60
80
ALLOWABLE R
OSADJ
RANGE
vs. MODULATION CURRENT
MAX3263-07
MAXIMUM MODULATION CURRENT
vs. MINIMUM DIFFERENTIAL
INPUT SIGNAL AMPLITUDE
MAXIMUM MODULATION CURRENT (mAp-p)
35
30
25
20
15
10
5
0
R
MODSET
= 1.2kΩ
R
OSADJ
= 2kΩ
MAX3263-08
12
10
ALLOWABLE R
OSADJ
(kΩ)
8
6
4
2
0
0
5
10
15
20
25
ALLOWABLE
RANGE
40
30
0
400
800
1200
1600
2000
MODULATION CURRENT (mAp-p)
MINIMUM DIFFERENTIAL
INPUT SIGNAL AMPLITUDE (mVp-p)
_______________________________________________________________________________________
3
Single +5V, Fully Integrated,
155Mbps Laser Diode Driver
MAX3263
______________________________________________________________Pin Description
PIN
1
2
NAME
VREF2
IPINSET
FUNCTION
Temperature-Compensated Reference Output. VREF2 is internally connected to VREF1.
Monitor Photodiode Programming Input. Connect INPINSET to VREF1 or VREF2 through a
resistor to set the monitor current when using automatic power control (see
Typical Operating
Characteristics).
Failout Output. Active-low, open-collector TTL output indicates if automatic power-control
loop is out of regulation due to insufficient monitor-diode current (when VPIN is below the
2.6V threshold). Connect FAILOUT to VCC through a 2.7kΩ pull-up resistor.
Ground for Voltage Reference and Automatic Power-Control Circuitry
Noninverting PECL Data Input
Inverting PECL Data Input
+5V Supply Voltage for Voltage Reference and Automatic Power-Control Circuitry. Connect
VCCB to the same potential as VCCA, but provide separate bypassing for VCCA and VCCB.
Inverting Enable TTL Input. Output currents are enabled only when ENB+ is high and ENB- is low.
Noninverting Enable TTL Input. Output currents are enabled only when ENB+ is high and
ENB- is low.
Temperature-Compensated Reference Output. VREF1 is internally connected to VREF2.
Overshoot-Adjust Input. Connect to internal voltage reference through a resistor to adjust the
overshoot of the modulation output signal (see
Typical Operating Characteristics).
Bias-Feedback Current Output. Output from automatic power-control circuit. Connect to
I
BIASSET
when using APC.
Laser Bias Current-Programming Input. Connect to internal voltage reference through a resis-
tor to set bias current (see
Typical Operating Characteristics).
I
BIASOUT
= 40 x (I
BIASSET
+ I
BIASFB
).
Laser Modulation Current-Programming Input. Connect to internal voltage reference through
a resistor to set modulation current (see
Typical Operating Characteristics).
I
MOD
= 20 x I
MODSET
.
Laser Bias Current Output. Connect to laser cathode through an R-L filter network (see the
Bias Network Compensation
section).
Ground for Bias and Modulation Current Drivers
Modulation Output. When VIN+ is high and VIN- is low, OUT- sinks I
MOD
.
Modulation Output. When VIN+ is low and VIN- is high, OUT+ sinks I
MOD
.
+5V Supply Voltage for Bias and Modulation Current Drivers. Connect VCCA to the same
potential as VCCB, but provide separate bypassing for VCCA and VCCB.
Monitor Photodiode Current Input. Connect IPIN to photodiode’s anode.
Slow-Start Capacitor Input. Connect capacitor to ground or leave unconnected to set start-up
time, t
STARTUP
= 25.4kΩ (C
SLWSTRT
+
2pF).
3
4, 7
5
6
8
9
10
11
12
13
FAILOUT
GNDB
VIN+
VIN-
VCCB
ENB-
ENB+
VREF1
OSADJ
IBIASFB
14
IBIASSET
15
IMODSET
16
17, 19, 21
18
20
22
23
24
IBIASOUT
GNDA
OUT-
OUT+
VCCA
IPIN
SLWSTRT
4
_______________________________________________________________________________________
Single +5V, Fully Integrated,
155Mbps Laser Diode Driver
MAX3263
V
CC
MAX3263
VIN+
OUT+
LASER
VIN-
VCCA
VCCB
20 x I
MODSET
GNDA
GNDB
40 x I
BIASSET
+2.6V
FAILOUT
I
BIASOUT
OUT-
PHOTO-
DIODE
BIAS
COMPEN-
SATION
ENB+
ENB-
MAIN
BIAS
GENERATOR
COMPARATOR
IPIN
LOOP-
STABILITY
CAPACITOR
0.1µF
1 x I
PINSET
SLWSTRT
BANDGAP
REFERENCE
V
CC
x 3/5
TRANSCONDUCTANCE
AMPLIFIER
IMODSET
IBIASSET
VREF1, VREF2
IBIASFB
IOSADJ
IPINSET
R
PINSET
R
MODSET
R
OSADJ
R
BIASSET
Figure 1. Functional Diagram
_______________Detailed Description
The MAX3263 laser driver has three main sections: a
reference generator with temperature compensation, a
laser bias block with automatic power control, and a
modulation driver (Figure 1).
The reference generator provides temperature-com-
pensated biasing and a voltage-reference output. The
voltage reference is used to program the current levels
of the high-speed modulation driver, laser diode, and
PIN (p+, intrinsic, n-) monitor diode.
The laser bias block sets the bias current in the laser
diode and maintains it above the threshold current. A
current-controlled current source (current mirror) pro-
grams the bias, with IBIASSET as the input. The mirror’s
gain is approximately 40 over the MAX3263’s input
range. Keep the output voltage of the bias stage above
2.2V to prevent saturation.
The modulation driver consists of a high-speed input
buffer and a common-emitter differential output stage.
The modulation current mirror sets the laser modulation
current in the output stage. This current is switched
between the OUT+ and OUT- ports of the laser driver.
The modulation current mirror has a gain of approximately
20. Keep the voltages at OUT+ and OUT- above 2.2V to
prevent saturation.
5
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