MAXIM MAX3905/D

19-3242; Rev 0; 4/04
150Mbps Automotive VCSEL Driver
Features
The MAX3905 150Mbps automotive VCSEL driver
implements low-cost transmitters operating from 8Mbps
to 150Mbps at junction temperatures up to +140°C. The
device accepts single-ended TTL, differential PECL or
LVDS input data, and provides bias and modulation
currents for driving a VCSEL. The output is DC-coupled
to the VCSEL to minimize component count.
♦ -40°C to +140°C Operating Junction Temperature
Range
♦ +3.0V to +5.25V Supply Voltage
♦ TTL/CMOS-, LVDS-, or PECL-Compatible Data
Input
♦ Compatible with SP1 Automotive Network
Interface
The driver provides temperature compensation to
VCSEL high and low currents. Adjustments of the bias
current, modulation current, bias-current temperature
coefficient, and center of the temperature-stable bias
current region are all programmable by wirebond
options. The power-reduction feature decreases output
modulation by approximately 50%. The data squelch
feature disables the VCSEL current when no data is
present.
The MAX3905 is available in die form and operates
from -40°C to +140°C junction temperature, over a +3.0V
to +5.25V supply range.
♦ Wirebond-Adjustable VCSEL Low and High
Currents
♦ Optical Power-Reduction Feature
♦ Output Squelch
Ordering Information
PART
MAX3905E/D
TEMP RANGE
-40°C to +140°C
PIN-PACKAGE
Dice*
*Dice are designed to operate from TJ = -40°C to +140°C, but
are tested and guaranteed at TA = +49°C only.
Applications
Optical Transmitters for Automotive Networks
Polymer-Clad Silica Fiber-Based Networks
Typical Application Circuits
+5V AUTOMOTIVE TRANSMITTER (TTL NETWORK CHIP INTERFACE, DATA RATE < 50Mbps)
VCC = +5V
MODULATION
CONTROL
VCC
TRANSMIT OPTICAL SUBASSEMBLY (TOSA)
DRIVER TO SET
SUPPLY FILTER
RGAIN
GAIN
TX
TTL OUTPUT
DATA
(SP1 AUTOMOTIVE
NETWORK INTERFACE)
3DB
MOD1
MOD2
DT01
DT02
VCC
IN_TTL
OUT
IN+
VCSEL
MAX3905
IN-
OUT
SQEN
DIFF LOW1
LOW2
TC1
TC2
TC3
VEE
GND
BIAS SET
BIAS
TEMPERATURE
COEFFICIENT
INDICATES OPTIONAL
WIREBOND CONNECTION
Typical Application Circuits continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MAX3905
General Description
MAX3905
150Mbps Automotive VCSEL Driver
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, (VCC - VEE) ..................................-0.5V to +6.0V
Voltage at 3DB, IN+, IN-, IN_TTL, DIFF, OUT, OUT,
MOD1, MOD2, DT01, DT02, SQEN,
TEMPSENS ..............................................-0.5V to (VCC + 0.5V)
Voltage at LOW1, LOW2, TC1, TC2, TC3.................-0.5V to +2V
Differential Input Voltage |IN+ - IN-|.......................................VCC
Current into OUT...............................................................+12mA
Storage Ambient Temperature Range...............-65°C to +150°C
Operating Junction Temperature Range ...........-40°C to +150°C
Electrostatic Discharge (ESD)
(Human Body Model, tested per JES D22-A114) ...............2kV
(Machine Model, tested per JES D22-A115) ..................+400V
Die Attach Temperature...................................................+400°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(VCC = +3.0V to +5.25V, TJ = -40°C to +140°C. Typical values are at VCC = +5.0V and TA = +25°C, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
OPERATING CONDITIONS
Voltage at OUT
VOUT
Data Rate
TTL Data Input-Edge Transition
Time
0.9
V
With TTL input
8
50
With differential input
40
150
One-pole response, 10% to 90%
Mbps
0.23
UI
25
mA
POWER SUPPLY
Supply Current
Supply Current While Data is
Squelched
ICC
Excludes IOUT and IOUT
14
ISTDBY
Excludes IOUT and IOUT
14
mA
CURRENT GENERATOR
Low Current (TJ = DT0)
Low-Current Positive
Temperature Coefficient
(TJ > DT0)
Low-Current Negative
Temperature Coefficient
(TJ < DT0)
Width of Temperature-Stable
Low-Current Region
IDT0
TCLOW+
TCLOW-
LOW1 open, LOW2 open
1.69
1.8
1.91
LOW1 GND, LOW2 open
2.02
2.17
2.28
LOW1 open, LOW2 GND
2.35
2.53
2.65
LOW1 GND, LOW2 GND
2.68
2.90
3.02
TC1 open, TC2 open, TC3 open
12
16
18
TC1 GND, TC2 open, TC3 open
16
21
24
TC1 GND, TC2 GND, TC3 open
24
32
36
TC1 GND, TC2 GND, TC3 GND
36
48
54
TC1 open, TC2 open, TC3 open
-18
-16
-12
TC1 GND, TC2 open, TC3 open
-24
-21
-16
TC1 GND, TC2 GND, TC3 open
-36
-32
-24
TC1 GND, TC2 GND, TC3 GND
-54
-47
-36
38
45
52
31.5
36
41.5
TW
DT01 open, DT02 open
Center of Temperature-Stable
Low-Current Region
Modulation-Current Temperature
Coefficient
2
DT0
TCMOD
DT01 VCC, DT02 open
44
49
54
DT01 open, DT02 VCC
56
61
66
DT01 VCC, DT02 VCC
68.5
74
78.5
Relative to IMOD at TJ = +25°C
0.311
0.38
0.471
_______________________________________________________________________________________
mA
µA/°C
µA/°C
°C
°C
%/°C
150Mbps Automotive VCSEL Driver
MAX3905
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +3.0V to +5.25V, TJ = -40°C to +140°C. Typical values are at VCC = +5.0V and TA = +25°C, unless otherwise noted.)
PARAMETER
Modulation Current at TJ = +25°C
Modulation Current in Low-Power
Mode
SYMBOL
IMOD
CONDITIONS
MIN
TYP
MAX
UNITS
MOD1 open, MOD2 open
2.84
3.01
3.22
MOD1 VCC, MOD2 open
3.44
3.65
3.88
MOD1 open, MOD2 VCC
4.03
4.28
4.55
MOD1 VCC, MOD2 VCC
4.62
4.91
5.22
40
50
60
%
0.5
ns
mA
ILP
Relative to programmed nominal, TJ = +25°C
Modulation Switching Time
tr, tf
20% to 80% (Note 1)
Pulse-Width Variation
PWV
(Notes 1, 2)
0.97
1.03
UI
Pulse-Width Distortion
PWD
(Notes 1, 2)
-0.02
+0.02
UI
Data-Dependent Jitter
DDJ
(Notes 1, 2)
Uncorrelated Jitter
UJ
(Notes 1, 2)
Deterministic Jitter
DJ
K28.5 pattern at 125Mbps (Notes 1, 3)
Random Jitter
RJ
1-0 pattern differential input (Note 1)
0.2
0.004
0.01
UI
0.001
UI
85
200
psP-P
3
11
psRMS
+0.80
V
IN_TTL DATA INPUT
Input Low
VINL
-0.03
Input High
VINH
2.0
Input Resistance
4
Input Capacitance
(Note 1)
VCC + 0.3
5.75
V
kΩ
0.3
2
pF
25
200
mVP-P
DIFFERENTIAL DATA INPUT
Differential-Input Sensitivity
Differential-Input Overload
1860
Differential-Input Resistance
mVP-P
8
kΩ
1.5
V
3DB INPUT
Input Threshold Voltage
Normal mode
3DB Input Voltage
2.0
Low-power mode
Diagnostic Resistor
RGAINN
VCC > 4.75V, normal mode
RGAINL
VCC > 4.75V, low-power mode
0.8
16
29
V
kΩ
DATA SQUELCH
Output Current While Squelched
IOFF
No input data
Time to Squelch
tSQ
(Note 1)
Time to Resume from Squelch
State
tRS
(Note 1)
1
3
50
µA
8
25
µs
0.1
5
µs
ESD PROTECTION
IN+, IN-, TTL_IN, 3DB
Human Body Model
Machine Model
±4
kV
±400
V
Note 1: These specifications are guaranteed by design and characterization.
Note 2: Pulse-width variation, pulse-width distortion, data-dependent jitter, and uncorrelated jitter are measured at 45Mbps per
MOST specification of physical Layer (revision 1.1).
Note 3: Deterministic jitter is measured with a K28.5 pattern (0011 1110 1011 0000 0101). Deterministic jitter is the peak-to-peak
deviation from ideal time crossings, measured at the 50% crossings of the output. Differential data applied to input.
_______________________________________________________________________________________
3
Typical Operating Characteristics
(LOW[1, 2] = [GND, open], MOD[1, 2] = [open, VCC], DT0[1, 2] = [open, open], TC[1, 2, 3] = [GND, GND, open], TA = +25°C, unless
otherwise noted.)
SUPPLY CURRENT vs. JUNCTION
TEMPERATURE
ELECTRICAL EYE DIAGRAM
(45.1Mbps TTL INPUT)
ELECTRICAL EYE DIAGRAM
(150Mbps DIFFERENTIAL INPUT)
MAX3905 toc02
MAX3905 toc01
30
EXCLUDES IOUT AND IOUT
25
SUPPLY CURRETNT (mA)
MAX3905 toc03
K28.5 PATTERN
VCC = +3.3V
K28.5 PATTERN
VCC = 5.0V
20
15
10
VCC = 3.3V
5
0
-40 -20
0
20
40
60
80 100 120 140
3.7ns/div
1.12ns/div
OPTICAL EYE DIAGRAM
(150Mbps DIFFERENTIAL INPUT)
BIAS CURRENT vs. JUNCTION
TEMPERATURE
OPTICAL EYE DIAGRAM
(45.1Mbps TTL INPUT)
MAX3905 toc04
MAX3905 toc05
6
TC[1, 2, 3] = [GND, GND, OPEN]
DT0[1, 2] = [OPEN, OPEN]
BIAS CURRETNT (mA)
5
VIN = 5.0V
850nm VCSEL
467MHz LOWPASS FILTER
VCC = 3.3V
850nm VCSEL
467MHz LOWPASS FILTER
3.7ns/div
LOW[1, 2] = [GND, GND]
LOW[1, 2] = [OPEN, GND]
4
3
2
LOW[1, 2] = [GND, OPEN]
LOW[1, 2] = [OPEN, OPEN]
1
0
-40 -20
1.12ns/div
0
20
40
60
80 100 120 140
JUNCTION TEMPERATURE (°C)
4
3
DT0 = +36°C
2
TC[1, 2, 3] = [GND, OPEN, OPEN]
TC[1, 2, 3] = [OPEN, OPEN, OPEN]
1
MOD[1, 2] = [VCC, VCC]
MOD[1, 2] = [OPEN, VCC]
7
6
5
4
3
2
MOD[1, 2] = [VCC, OPEN]
MOD[1, 2] = [OPEN, OPEN]
1
0
0
-40 -20
4
8
MODULATION CURRENT (mA)
TC[1, 2, 3] = [GND, GND, GND]
TC[1, 2, 3] = [GND, GND, OPEN]
5
MAX3905 toc07
6
LOW[1, 2] = [GND, OPEN]
DT0[1, 2] = [OPEN, OPEN]
MAX3905 toc08
MODULATION CURRENT
vs. JUNCTION TEMPERATURE
BIAS CURRENT vs. JUNCTION
TEMPERATURE
7
0
20
40
60
80 100 120 140
JUNCTION TEMPERATURE (°C)
MAX3905 toc06
JUNCTION TEMPERATURE (°C)
BIAS CURRETNT (mA)
MAX3905
150Mbps Automotive VCSEL Driver
-40 -20
0 20 40 60 80 100 120 140
JUNCTION TEMPERATURE (°C)
_______________________________________________________________________________________
150Mbps Automotive VCSEL Driver
DETERMINISTIC JITTER vs. JUNCTION
TEMPERATURE
OUTPUT RESUME FROM SQUELCH
MAX3905 toc10
VIN
VIN
OPTICAL
POWER
OUTPUT
OPTICAL
POWER
OUTPUT
tSQ
120
DETERMINISTIC JITTER (psP-P)
MAX3905 toc09
MOD[1, 2] = [OPEN, OPEN]
MOD[1, 2] = [VCC, OPEN]
100
MAX3905 toc11
OUTPUT SQUELCH
80
60
MOD[1, 2] = [OPEN, VCC]
MOD[1, 2] = [VCC, VCC]
40
20
tRS
150Mbps K28.5 PATTERN
0
2µs/div
40ns/div
RANDOM JITTER (psRMS)
MAX3905 toc13
MAX3905 toc12
5.5
0 20 40 60 80 100 120 140
JUNCTION TEMPERATURE (°C)
PULSE-WIDTH VARIATION AND AVERAGE
PULSE-WIDTH DISTORTION
RANDOM JITTER
vs. JUNCTION TEMPERATURE
6.0
-40 -20
45.1Mbps TTL
BIPHASE-CODED DATA
5.0
4.5
4.0
3.5
3.0
2.5
10ns/div
2.0
-40 -20
0
20
40
60
80 100 120 140
JUNCTION TEMPERATURE (°C)
_______________________________________________________________________________________
5
MAX3905
Typical Operating Characteristics (continued)
(LOW[1, 2] = [GND, open], MOD[1, 2] = [open, VCC], DT0[1, 2] = [open, open], TC[1, 2, 3] = [GND, GND, open], TA = +25°C, unless
otherwise noted.)
MAX3905
150Mbps Automotive VCSEL Driver
Pad Description
PAD
NAME
1, 20, 26
VEE
Circuit Ground
2
DIFF
Differential-Input Data Enable. Leave open to enable the TTL data input, or connect to ground to enable
the differential data input.
3
IN_TTL
4, 5, 6
N.C.
No Connection
7
IN+
Positive Differential-Data Input, PECL- or LVDS-Compatible. This high-impedance input is internally
biased to approximately 1.4V and requires an external termination resistor and an AC-coupling
capacitor. It is active when DIFF is connected to ground.
8
TEMPSENS
Junction Temperature Sensor. Analog output corresponding to the junction temperature of the die.
Leave open for normal use.
9
IN-
Negative Differential-Data Input, PECL- or LVDS-Compatible. This high-impedance input is internally
biased to approximately 1.4V and requires an external termination resistor and an AC-coupling
capacitor. It is active when DIFF is connected to ground.
10, 15
VCC
Power Supply
11
DT01
Driver T0 Programming Input. Sets the center temperature of lowest bias current. Connect to VCC or
leave open.
12
DT02
Driver T0 Programming Input. Sets the center temperature of lowest bias current. Connect to VCC or
leave open.
13
MOD2
Modulation-Current Programming Input. Sets the modulation-current amplitude. Connect to VCC or leave open.
14
MOD1
Modulation-Current Programming Input. Sets the modulation-current amplitude. Connect to VCC or leave open.
6
FUNCTION
Single-Ended Data Input, TTL. Compatible with SP1 automotive network interface. This input is active
when DIFF is left open.
16
OUT
Complementary Data Output. Connect to VCC or VCSEL anode.
17
OUT
Data Output. Connect to VCSEL cathode.
18
SQEN
Squelch Enable Input. Leave open to enable squelch or connect to ground to disable squelch.
19
3DB
Power-Reduction Input. Compatible with TTL. When low, 3DB activates a test mode, which reduces output
power by 50%. When 3DB is high, the modulation output is normal. See the Detailed Description section.
21
TC1
Low-Current Temperature-Coefficient Programming Input. Sets the temperature coefficient of the bias
current. Connect to GND or leave open. Do not connect to VCC.
22
TC2
Low-Current Temperature-Coefficient Programming Input. Sets the temperature coefficient of the bias
current. Connect to GND or leave open. Do not connect to VCC.
23
TC3
Low-Current Temperature-Coefficient Programming Input. Sets the temperature coefficient of the bias
current. Connect to GND or leave open. Do not connect to VCC.
24
LOW1
Low-Current Programming Input. Sets the VCSEL-low (bias) current at the temperature set by the
DT0 pins. Connect to GND or leave open. Do not connect to VCC.
25
LOW2
Low-Current Programming Input. Sets the VCSEL-low (bias) current at the temperature set by the
DT0 pins. Connect to GND or leave open. Do not connect to VCC.
_______________________________________________________________________________________
150Mbps Automotive VCSEL Driver
MAX3905
VCC
INPUT
BUFFERS
OUT
IN+
IN-
MAX3905
GND
OUT
OUTPUT
DRIVER
OPEN
IN_TTL
SIGNAL
DETECT
SQUELCH
MODULATION
CURRENT
GENERATOR
VCC
DIFF
BIAS
CURRENT
GENERATOR
IMOD
IMOD
IBIAS
TEMP
SQEN
DT0
SET
K
VEE
TEMPSENS
IBIAS
TEMP
3DB
MOD[1, 2]
DT0[1, 2]
TC[1, 2, 3]
LOW[1, 2]
Figure 1. Functional Diagram
Detailed Description
The MAX3905 is comprised of a differential LVDS- or
PECL-compatible input buffer, a TTL-compatible input
buffer, signal detection, DT0 set block, modulation-current generator, bias-current generator, and output driver (Figure 1). The device implements temperature
compensation in the bias and modulation that can be
customized to accommodate the variation of VCSEL
properties with process and temperature. See Figure 2
and Table 1 for driver current and temperature coefficient definitions.
Input Buffers
The MAX3905 has two input buffers, one for TTL-compatible DC-coupled input data, and the other for ACcoupled, differential LVDS or PECL input data. The
differential input is relatively high impedance. This
allows external resistors to be configured in several
ways to meet the AC- and DC-termination requirements
of LVDS or PECL.
The active data input buffer is set by the DIFF input. To
select the single-ended TTL input, leave DIFF open. To
select the differential input, connect DIFF to ground.
When using the differential input buffer, input noise can
be sufficient to prevent normal operation of the squelch
function. A small offset on the input ensures proper
functioning of the squelch feature. A 1MΩ resistor from
IN- to ground or VCC creates a 7mV offset.
Signal Detection and Data Squelch
When no data transitions are present at the input, the
signal detection issues a squelch signal to the bias and
modulation current, disabling the VCSEL output. This
ensures that the receiver IC can easily detect the difference between transmitter on and transmitter off. The
squelch function is enabled when SQEN is left unconnected. The squelch function can be disabled by connecting SQEN to ground.
With squelch enabled, the delay of the squelch function is
suitable for use with biphase-encoded data (maximum of
three consecutive identical digits (CIDs)) or 8B-/10Bencoded data (maximum five CIDs). To use the MAX3905
with scrambled data, disable the squelch function.
DT0 Set Block
Inputs DT01 and DT02 are the 2-bit control of the center of the temperature-stable region, DT0. The temperature set by DT0[1, 2] should correspond to the T0 of the
VCSEL. Connect DT01 or DT02 to VCC to set the bit
high, or leave open to set the bit low.
The typical DT0 can be calculated by:
_______________________________________________________________________________________
7
TCLOW + TCMOD
IHIGH
TCMOD
IMOD = IHIGH - ILOW
ILOW
DTO
TCLOW
VCSEL CURRENT
OUTPUT CURRENT AMPLITUDE
MAX3905
150Mbps Automotive VCSEL Driver
IHIGH
ILOW
TW
JUNCTION TEMPERATURE
TIME
Figure 2. Driver Current and Temperature Coefficient Definitions
Table 1. Driver Current and Temperature
Coefficient Definitions
PARAMETER
DESCRIPTION
ILOW
Total VCSEL current when the data input is
logic-low.
IHIGH
Total VCSEL current when the data input is
logic-high.
IMOD
IHIGH - ILOW.
DT0
The center of the temperature-stable lowcurrent region (TW). DT0 roughly
corresponds to T0 of the VCSEL.
IDT0
ILOW at TJ = DT0.
TW
The size (in °C) of the region where no
temperature coefficient is applied to ILOW.
TCMOD
The temperature coefficient applied to IMOD.
TCLOW
The temperature coefficient applied to ILOW.
This coefficient is negative below DT0 - TW/2
and positive above DT0 + TW/2.
IOFF
Total VCSEL current while squelched.
DT0 ≈ [36 + 13(DT01) + 25(DT02)]°C
where DT0[1, 2] = 1 when bonded to VCC; DT0[1, 2] = 0
when left open.
Modulation-Current Generator
The modulation-current generator provides wirebondselectable current amplitude with temperature compensation. The temperature coefficient (TCMOD) compensates for the slope-efficiency change of the VCSEL over
temperature. The modulation current is set with inputs
MOD1 and MOD2. Connect MOD1 or MOD2 to VCC to
set the bit high, and leave open to set the bit low.
The typical modulation current at +25°C can be calculated by:
IMOD ≈ [3.01 + (0.64 x MOD1) + (1.27 x MOD2)]mA
where MOD[1, 2] = 1 when bonded to V CC ; MOD
[1, 2] = 0 when left open.
Power Reduction
The power-reduction feature is useful for in-system test
and diagnostics. When the 3DB input is low, the modulation current is reduced by 50%. When 3DB is high or
VCC, the modulation output is normal.
For compatibility with 5V POF transmitters, the power
mode can be set by connecting a resistor from 3DB to
VCC. A resistor RGAIN < RGAINN sets the normal power
mode, while RGAIN > RGAINL sets the low-power mode.
Bias-Current Generator
The bias-current generator provides a current that
closely tracks the VCSEL properties with temperature.
This current is summed with the modulation current at
the OUT pad. The bias current at T J = DT 0 is
8
_______________________________________________________________________________________
150Mbps Automotive VCSEL Driver
Junction-Temperature Sensing
A temperature sensor is incorporated into the MAX3905
to aid in evaluation of thermal performance. The
TEMPSENS voltage is proportional to the die junction
temperature (approximately -1.39mV per °C). The temperature of the die can be estimated as:
T(°C) ≈ 597°C - VTEMPSENS (mV) x
0.72°C
1mV
Output Driver
The OUT pad connects directly to the VCSEL cathode.
The OUT pad must be connected to the VCSEL anode
or to VCC. The minimum instantaneous voltage on the
OUT pad is 0.9V.
Applications Information
Additional Design Assistance
For more information and design assistance, refer to
Maxim Design Note HFDN-32.0: Output Current
Calculator for the MAX3905.
Layout Considerations
Load inductance on OUT and OUT should be matched
within 1.5nH to minimize both jitter and supply noise
generation.
Wire Bonding
For high-current density and reliable operation, the
MAX3905 uses gold metalization. For best results, use
gold-wire ball-bonding techniques. Exercise caution
when wedge bonding. Die size is 1.52mm x 1.52mm
(60 mils x 60 mils), and die thickness is 300µm
(12 mils). The bond-pad passivation opening is 93µm x
93µm and bond-pad metal thickness is 1.2µm. Refer to
Maxim Application Note HFAN-08.0.1: Understanding
Bonding Coordinates and Physical Die Size for additional information on bondpad coordinates. Do not
attempt to bond to the laser trim target.
Laser Safety and IEC 825
Using the MAX3905 VCSEL driver alone does not
ensure that a transmitter design is compliant with
IEC 825. The entire transmitter circuit and component
selections must be considered. Determine the level of
fault tolerance required by each application, and recognize that Maxim products are not designed or authorized for use as components in systems intended for
surgical implant into the body, for applications intended
to support or sustain life, or for any other application
where the failure of a Maxim product could create a situation where personal injury or death may occur.
_______________________________________________________________________________________
9
MAX3905
programmed by the LOW1 and LOW2 inputs. Connect
LOW1 or LOW2 to ground to set the bit high, and leave
open to set the bit low. Do not connect LOW1 or LOW2
to VCC.
The typical low current at TJ = DT0 can be calculated by:
ILOW ≈ [1.8 + (0.37 x LOW1) + (0.73 x LOW2)]mA
where, LOW[1, 2] = 1 when bonded to ground; LOW[1, 2]
= 0 when left open.
The temperature coefficient of the bias current is programmed by the TC1, TC2, and TC3 inputs. Connect
TC1, TC2, or TC3 to ground to set the bit high, and
leave open to set the bit low. Do not connect TC1, TC2,
or TC3 to VCC.
The typical temperature coefficient of the bias current
can be calculated by:
TCLOW ≈ [16 + (5 x TC1) + (11 x TC2) +
(16 x TC3)]µA/°C
where, TC[1, 2, 3] = 1 when bonded to ground; TC[1, 2,
3] = 0 when left open.
MAX3905
150Mbps Automotive VCSEL Driver
VCC
VCC
MAX3905
MAX3905
OUT
OUT
1.5V
IN_TTL
VEE
VEE
Figure 3. IN_TTL Equivalent Input Structure
Figure 5. OUT/OUT Equivalent Output Structure
Chip Information
VCC
TRANSISTOR COUNT: 985
PROCESS: Silicon Bipolar GST-2
MAX3905
SUBSTRATE: Connected to VEE
DIE SIZE: 1.52mm x 1.52mm (60mils x 60mils)
DIE THICKNESS: 300µm (12mils)
IN+
5kΩ
1.4V
5kΩ
IN-
VEE
Figure 4. IN+/IN- Equivalent Input Structure
10
______________________________________________________________________________________
150Mbps Automotive VCSEL Driver
+3.3V AUTOMOTIVE TRANSMITTER (TTL NETWORK CHIP INTERFACE, DATA RATE < 50Mbps)
VCC = +3.3V
SUPPLY FILTER
TRANSMIT OPTICAL SUBASSEMBLY (TOSA)
MODULATION
CONTROL
VCC
DRIVER TO SET
REDUCE POWER
TX
TTL OUTPUT
DATA
(SP1 AUTOMOTIVE
NETWORK INTERFACE)
3DB
MOD1
MOD2
DT01
DT02
VCC
IN_TTL
OUT
VCSEL
IN+
MAX3905
IN-
OUT
SQEN
DIFF
LOW1
LOW2
TC1
TC2
VEE
TC3
GND
BIAS SET
BIAS
TEMPERATURE
COEFFICIENT
INDICATES OPTIONAL
WIREBOND CONNECTION
TRANSMITTER WITH DIFFERENTIAL LVDS INTERFACE
TRANSMIT OPTICAL SUBASSEMBLY (TOSA)
MODULATION
CONTROL
VCC = +3.0V TO +5.25V
DRIVER TO SET
SUPPLY FILTER
REDUCE POWER
3DB
MOD1
MOD2
DT01
DT02
VCC
IN_TTL
0.1µF
NETWORK
CHIP WITH
LVDS OUTPUT
50Ω
OUT
VCSEL
IN+
100Ω
MAX3905
50Ω
IN-
OUT
0.1µF
SQEN
1MΩ
DIFF
LOW1
LOW2
TC1
TC2
TC3
VEE
GND
BIAS SET
BIAS
TEMPERATURE
COEFFICIENT
INDICATES OPTIONAL
WIREBOND CONNECTION
______________________________________________________________________________________
11
MAX3905
Typical Application Circuits (continued)
150Mbps Automotive VCSEL Driver
MAX3905
Typical Application Circuits (continued)
TRANSMITTER WITH DIFFERENTIAL-PECL INTERFACE
TRANSMIT OPTICAL SUBASSEMBLY (TOSA)
MODULATION
CONTROL
VCC = +3.0V TO +5.25V
DRIVER TO SET
SUPPLY FILTER
REDUCE POWER
3DB
VCCPECL
MOD1
MOD2
DT01
DT02
VCC
IN_TTL
R1
NETWORK CHIP
WITH
PECL OUTPUT
R1
0.1µF
OUT
50Ω
IN+
50Ω
IN-
VCSEL
MAX3905
R2
R2
OUT
0.1µF
SQEN
DIFF
1MΩ
LOW1
LOW2
TC1
TC2
TC3
VEE
VCCPECL= 3.3V VCCPECL = 5V
R1
82Ω
130Ω
R2
130Ω
82Ω
GND
BIAS SET
BIAS
TEMPERATURE
COEFFICIENT
INDICATES OPTIONAL
WIREBOND CONNECTION
Bonding Coordinates
PAD
PAD NAME
1
VEE
COORDINATES (µm)
COORDINATES (µm)
PAD
PAD NAME
X
Y
1285.9
14
MOD1
1285.9
257.2
VCC
1285.9
427.3
594.7
X
Y
46.6
2
DIFF
46.6
1134.7
15
3
IN_TTL
46.6
983.5
16
OUT
1285.9
4
N.C.
46.6
832.3
17
OUT
1285.9
759.4
5
N.C
46.6
511
18
SQEN
1285.9
921.4
6
N.C
46.6
359.8
19
3DB
1285.9
1086.1
7
IN+
46.6
208.6
20
VEE
1285.9
1285.9
8*
TEMPSENS
46.6
46.6
21
TC1
1059.1
1285.9
9
IN-
262.6
46.6
22
TC2
902.5
1285.9
10
VCC
791.8
46.6
23
TC3
745.9
1285.9
11
DT01
956.5
46.6
24
LOW1
589.3
1285.9
12
DT02
1121.2
46.6
25
LOW2
432.7
1285.9
13
MOD2
1285.9
46.6
26
VEE
276.1
1285.9
Coordinates are for the center of the pad.
Coordinate 0,0 is the lower left corner of the passivation opening for pad 8.
*Index pad. Orient the die with this pad in the lower-left corner.
12
______________________________________________________________________________________
150Mbps Automotive VCSEL Driver
VEE
(PAD 26)
LOW2
(PAD 25)
LOW1
(PAD 24)
TC3
(PAD 23)
TC2
(PAD 22)
TC1
(PAD 21)
VEE
(PAD 20)
VEE
(PAD 1)
DIFF
(PAD 2)
3DB
(PAD 19)
IN_TTL
(PAD 3)
SQEN
(PAD 18)
N.C.
(PAD 4)
OUT
(PAD 17)
60mils
1.52mm
OUT
(PAD 16)
N.C.
(PAD 5)
VCC
(PAD 15)
N.C.
(PAD 6)
MOD1
(PAD 14)
IN+
(PAD 7)
MOD2
(PAD 13)
TEMPSENS
(PAD 8)
IN(PAD 9)
VCC
(PAD 10)
LASER
TRIM
TARGET
DT01
(PAD 11)
DT02
(PAD 12)
60mils
1.52mm
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 13
© 2004 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
MAX3905
Chip Topography