EVALUATION KIT AVAILABLE
MAX3643
155Mbps to 2.5Gbps Burst-Mode Laser Driver
General Description
The MAX3643 burst-mode laser driver provides bias and
modulation current drive for PON burst-mode ONT appli-
cations. It is specifically designed for use with a low-cost
external controller for the APC (and if desired, AMC) loop.
A high-speed differential burst-enable input enables the
driver to switch the laser from a dark (output off) condition
to full on-condition in less than 2ns. When BEN is inac-
tive, typical modulation and bias currents are 5µA each.
Laser modulation current can be set from 10mA to
85mA and bias current can be set from 1mA to 70mA
using the MODSET and BIASSET inputs. A sample-and-
hold circuit is provided to capture the monitor diode
output during short PON bursts, if needed, and the BEN
high-speed signal is mirrored on an LVCMOS output to
be used by the controller operating the APC/AMC loop.
The MAX3643 burst-mode laser driver is packaged in a
4mm x 4mm, 24-pin thin QFN package. It operates from
-40°C to +85°C.
♦
10mA to 85mA Modulation Current
♦
1mA to 70mA Bias Current
♦
Monitor Diode Sample and Hold
♦
45ps Output Transition Time
♦
2ns Turn-On/-Off Time
♦
Reference Voltage Generator
♦
LVPECL High-Speed Inputs (Data, Burst Enable)
Features
Ordering Information
PART
MAX3643ETG
MAX3643ETG+
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
24 TQFN-EP*
24 TQFN-EP*
+Denotes
a lead(Pb)-free/RoHS-compliant package.
*EP
= Exposed paddle.
Applications
A/B/G/XGPON ONT Modules Up to 2.5Gbps
1.25Gbps IEEE EPON ONT Modules
Pin Configuration appears at end of data sheet.
Typical Application Circuit
3.3V
15Ω
3.3V
+3.3V
130Ω
SERIAL
DATA
SOURCE
Z
0
= 50Ω
Z
0
= 50Ω
82Ω
82Ω
5.6Ω
BIAS+
130Ω
V
CC
IN+
IN-
OUT+
OUT-
5.6Ω
15Ω
FILTER
10nH
10pF
75Ω
27pF
1kΩ
MAX3643
3.3V
BIAS-
130Ω
BURST
CONTROL
Z
0
= 50Ω
Z
0
= 50Ω
82Ω
82Ω
MON1
3kΩ
1kΩ
1kΩ
130Ω
BEN+
MODSET
BIASSET
BENOUT
VBSET
IMAX
VREF
GND
BEN-
EN
BCMON
VMSET
MDOUT
MDIN
10Ω
+3.3V
BMD
DS1875
PON TRIPLEXER AND SFP
CONTROLLER
BEN
BIAS
MOD
For pricing, delivery, and ordering information, please contact Maxim Direct at
1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
19-3848; Rev 4; 12/12
MAX3643
155Mbps to 2.5Gbps Burst-Mode Laser Driver
ABSOLUTE MAXIMUM RATINGS
Supply Voltage V
CC
..............................................-0.5V to +4.0V
Current into BIAS-, BIAS+, OUT-, OUT+ .......-20mA to +150mA
Voltage at VMSET, VBSET, IN+, IN-, BEN+, BEN-,
EN,
MDIN,
MDOUT, BENOUT, BCMON ...................-0.5V to (V
CC
+ 0.5V)
Voltage at MODSET, BIASSET, VREF, IMAX ........-0.5V to +3.0V
Voltage at OUT-, OUT+, BIAS-, BIAS+ .....+0.3V to (V
CC
+ 0.5V)
Continuous Power Dissipation (T
A
= +85°C)
24-Pin TQFN, Multilayer Board
(derate 27.8mW/°C above +85°C) ............................1807mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range ............................-55°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow)
Lead(Pb)-free..............................................................+260°C
Containing lead(Pb) ....................................................+240°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.
OPERATING CONDITIONS
PARAMETER
Supply Turn-On Time
Ambient Temperature
Data Rate
Voltage at VMSET, VBSET
Voltage at BCMON
Voltage at MDIN
0
0
0
SYMBOL
10% to 90%
CONDITIONS
MIN
0.001
-40
TYP
MAX
1000
+85
2500
1.4
1.4
2.56
UNITS
ms
°C
Mbps
V
V
V
ELECTRICAL CHARACTERISTICS
(V
CC
= 3.0V to 3.6V, T
A
= -40°C to +85°C. Typical values are at V
CC
= 3.3V, T
A
= +25°C, I
BIAS
= 20mA, I
MOD
= 30mA, unless other-
wise noted.) (Note 1)
PARAMETER
Supply Current
I/O SPECIFICATIONS
LVPECL Differential Input
LVPECL Common-Mode Input
Voltage
LVCMOS Output High Voltage
LVCMOS Output Low Voltage
BENOUT Propagation Delay
LVCMOS Input Pullup
LVCMOS Input Current
LVCMOS Input High Voltage
LVCMOS Input Low Voltage
BIAS GENERATOR SPECIFICATIONS
Bias Current Range
Bias Current, Burst Off
BIASSET Current Gain
I
BIAS
I
BIAS, OFF
G
BIAS
V
BIAS+
, V
BIAS-
1mA
2mA
10mA
0.6V
1
5
88
70
82.5
88
88
110
94.5
mA/mA
70
50
mA
μA
BEN = low or
EN
= high
I
BIAS
<
2mA, VBSET = VREF
I
BIAS
<
10mA, VBSET = VREF
I
BIAS
<
70mA, VBSET = VREF
V
IN
= 0V or V
IN
= V
CC
2.0
0.2
T
d
SYMBOL
I
CC
CONDITIONS
Excluding laser bias and mode currents,
max at I
MOD
= 85mA, I
BIAS
= 70mA
V
IN
= (V
IN+
) - (V
IN-
)
200
V
CC
-
1.49
I
OH
= -100μA
I
OL
= 100μA
C
L
= 20pF, from BEN zero crossing to 67%
CMOS level
75
50
V
CC
0.8
30
V
CC
-
0.2
0.2
V
CC
-
1.32
MIN
TYP
32
MAX
51
UNITS
mA
V
IN
V
CM
1600
V
CC
-
V
IN
/ 4
mV
P-P
V
V
V
ns
k
μA
V
V
2
Maxim Integrated
MAX3643
155Mbps to 2.5Gbps Burst-Mode Laser Driver
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 3.0V to 3.6V, T
A
= -40°C to +85°C. Typical values are at V
CC
= 3.3V, T
A
= +25°C, I
BIAS
= 20mA, I
MOD
= 30mA, unless other-
wise noted.) (Note 1)
PARAMETER
BIASSET Current Gain Stability
BIASSET Current Gain Linearity
Bias Current Overshoot
Bias Current Monitor Gain
Bias Current Monitor Gain
Stability
BIASSET Resistor
MODULATOR SPECIFICATIONS
Modulation Current Range
Modulation Current Off
Instantaneous Voltage at OUT+
MODSET Current Gain
MODSET Current Gain Stability
MODSET Current Gain Linearity
MODSET, BIASSET Gain
Matching (Note 15)
Modulation Current Rise Time
Modulation Current Fall Time
Deterministic Jitter
Random Jitter
MODSET Resistor
MODSET, BIASSET Voltage
Range
Voltage Error
Input Leakage
TURN-OFF/-ON SPECIFICATIONS
Burst-Enable Time
Burst-Disable Time
SAMPLE/HOLD SPECIFICATIONS
MDIN Voltage Range
MDOUT Settling
Sample/Hold Droop
Bias Current Overshoot
Relative to final value at 3μs, C
L
< 20pF
After 100μs (Note 9)
V
CC
turn-on/-off < 1s, I
BIAS
I
BIAS
< 20mA
20mA
0.05
2.56
±1
±2.56
10
2
V
mV
mV
%
mA
(Notes 2, 6, 7)
(Notes 2, 6, 8)
2.3
2.0
ns
ns
(Note 5)
VMSET and VBSET pins
0.1
R
MOD
t
R
t
F
G
MOD
I
MOD
I
MOD, OFF
BEN = low or
EN
= high or V
IN
= low
10mA I
MOD
< 60mA
60mA
I
MOD
85mA
10mA < I
MOD
< 85mA, VMSET = VREF
(Note 13)
(Note 14)
I
BIASSET
= 0.15mA, I
MODSET
= 0.7mA
I
MODSET
= I
BIASSET
= 0.15mA
I
MODSET
= I
BIASSET
= 0.4mA
I
MODSET
= I
BIASSET
= 0.55mA
20% to 80%
20% to 80%
(Note 3)
(Note 4)
40
45
45
17
0.8
50
10
5
0.6
0.75
82.5
-4.4
-2.2
0.5
1.7
1
1
85
85
45
1.4
60
ps
ps
ps
P-P
ps
RMS
%
88
94.5
+4.4
+2.2
85
120
mA
μA
V
mA/mA
%
%
R
BIAS
G
BSM
SYMBOL
5mA
5mA
2mA
1mA
5mA
I
BIAS
I
BIAS
I
BIAS
CONDITIONS
70mA (Note 13)
70mA (Note 14)
70mA, VBSET = VREF
MIN
-4.4
-3.75
11
14
±4
-5
40
50
+5
60
TYP
MAX
+4.4
+3.75
10
17
UNITS
%
%
%
mA/A
%
V
CC
turn-on/-off < 1s
I
BIAS
< 5mA
I
BIAS
70mA
MODSET, BIASSET OPERATIONAL AMPLIFIER SPECIFICATIONS
0.005
1.4
±5
1.5
V
mV
μA
Maxim Integrated
3
MAX3643
155Mbps to 2.5Gbps Burst-Mode Laser Driver
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 3.0V to 3.6V, T
A
= -40°C to +85°C. Typical values are at V
CC
= 3.3V, T
A
= +25°C, I
BIAS
= 20mA, I
MOD
= 30mA, unless other-
wise noted.) (Note 1)
PARAMETER
Sampling Error
SYMBOL
CONDITIONS
Final value measured after 10μs
(MDOUT - MDIN), burst width > 576ns
R
L
> 10k , C
L
< 50pF
5mA < I
BIAS
, 10mA < I
MOD
(Note 10)
(Notes 2, 11)
3
R
IMAX
= 3k
I
BIAS
+I
MOD
R
IMAX
= 5k
R
IMAX
= 10k
155.52Mbps
Eye Margin (Note 12)
622.08Mbps
1.24416Gbps
2.48832Gbps
155
100
50
49
45
38
18
%
150
75
mA
1.175
MIN
TYP
3
MAX
±14
UNITS
mV
BANDGAP VOLTAGE REFERENCE SPECIFICATIONS
VREF Output
MODULATION/BIAS CURRENT DISABLE
Enable Time
Disable Time
R
IMAX
Range
Current Limit (Tested with I
BIAS
= I
MOD
)
OPTICAL EVALUATION
5.5
375
15
μs
ns
k
1.235
1.295
V
Note 1:
Electrical specifications are production tested at T
A
= +25°C. Specifications over the entire operating temperature range
are guaranteed by design and characterization. Typical specifications are at T
A
= +25°C, 3.3V.
Note 2:
For 10mA
≤
I
MOD
≤
85mA and 4mA
≤
I
BIAS
≤
70mA.
Note 3:
Deterministic jitter measured with a continuous pattern of 2
7
-1 PRBS, 80 ones, 2
7
-1 PRBS, 80 zeros at 1.25Gbps, and both
LVPECL inputs terminated by the network shown in Figure 3.
Note 4:
Random jitter, rise time, fall time measured with 0000011111 pattern at 1.25Gbps.
Note 5:
Voltage difference between VMSET and MODSET or VBSET and BIASSET excluding IR drops. The maximum operating
voltage at VMSET or VBSET must be less than 1.4V for proper operation.
Note 6:
Turn-on/-off time is when the BEN+/BEN- LVPECL inputs are used to control modulation and bias currents.
Note 7:
Burst-enable delay is measured between the time at which the rising edge of the differential burst-enable input reaches the
midpoint, and the time at which the combined output currents (bias plus modulation) reach 90% of their final level.
Note 8:
Burst-disable delay is measured between the time at which the falling edge of the differential burst-enable input reaches the
midpoint, and the time at which the combined output currents (bias plus modulation) fall below 10% of the bias-on current.
Note 9:
Droop measured with sample/hold output load of 10MΩ.
Note 10:
Enable delay is measured between the time at which the falling edge of the
EN
input reaches
≤
0.8V, and the time at which
the combined output currents (bias plus modulation) reach 90% of their final level.
Note 11:
Disable delay is measured between the time at which the rising edge of the
EN
input reaches
≥
2V, and the time at which
the combined output currents (bias plus modulation) fall below 10% of the bias-on current.
Note 12:
Excelight SLT2886-LR laser.
Note 13:
Current gain stability = [(Gain – nominal Gain) / nominal Gain], nominal Gain at V
CC
= 3.3V, T
A
= +25°C.
Note 14:
Gain linearity = (Gainmax – Gainmin), Gainavg = Gainmax + Gainmin
Gainavg
2
Note 15:
Gain matching =
Gain mod / Gainbias
−
Gain mod nom / Gainbiasnom
, nominal at V
CC
= 3.3V, T
A
= +25°C.
Gain mod nom / Gainbiasnom
4
Maxim Integrated
MAX3643
155Mbps to 2.5Gbps Burst-Mode Laser Driver
Typical Operating Characteristics
(Typical values are at V
CC
= 3.3V, T
A
= +25°C, data pattern =
noted.)
OPTICAL EYE DIAGRAM
(155.52Mbps, 117MHz FILTER,
PATTERN = 2
23
- 1 PRBS)
MAX3643 toc01
2
7
-1
PRBS + 80 ones + 2
7
-1 PRBS + 80 zeros, unless otherwise
OPTICAL EYE DIAGRAM
(622.08Mbps, 467MHz FILTER,
PATTERN = 2
23
- 1 PRBS)
MAX3643 toc02
OPTICAL EYE DIAGRAM
(1.24416Gbps, 933MHz FILTER,
PATTERN = 2
23
- 1 PRBS)
MAX3643 toc03
EXCELIGHT SLT2886-LR LASER
AVERAGE OPTICAL POWER = -6dBm
EXTINCTION RATIO = 15dB
MASK MARGIN = 49%
EXCELIGHT SLT2886-LR LASER
AVERAGE OPTICAL POWER = -6dBm
EXTINCTION RATIO = 15dB
MASK MARGIN = 45%
EXCELIGHT SLT2886-LR LASER
AVERAGE OPTICAL POWER = -6dBm
EXTINCTION RATIO = 14dB
MASK MARGIN = 38%
OPTICAL EYE DIAGRAM
(2.48832Gbps, 2.3GHz FILTER,
PATTERN = 2
23
- 1 PRBS)
MAX3643 toc04
ELECTRICAL EYE DIAGRAM
(2.5Gbps, I
MOD
= 30mA,
PATTERN = PRBS 2
7
- 1 +
80
CID)
MAX3643 toc05
SUPPLY CURRENT vs. TEMPERATURE
(I
BIAS
= 20mA, I
MOD
= 30mA)
55
50
45
I
CC
(mA)
40
35
30
25
20
15
10
EXCLUDES BIAS AND
MODULATION CURRENT
MAX3643 toc06
60
EXCELIGHT SLT2886-LR LASER
AVERAGE OPTICAL POWER = -6dBm
EXTINCTION RATIO = 10dB
MASK MARGIN = 18%
100ps/div
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
Maxim Integrated
5