270Mbps Driver MAX3967A programmable driver fiber optic transmitt
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19-3629; 3/05
270Mbps Driver
MAX3967A programmable driver fiber optic transmitters operating data rates 270Mbps. circuit contains high-speed current driver with programmable temperature coefficient (tempco), adjustments prebias voltage, disable feature. circuit accepts PECL data inputs, operates from single +2.97V +5.5V power supply. driver switch 100mA into typical high-speed light-emitting diodes. temperature increases, device's modulation current increases with tempco that programmable from 2500ppm/°C 12,000ppm/°C. modulation current programmed with single external resistor. MAX3967A's prebias voltage programmable from 400mV 925mV. prebias circuit produces peaking current, which improves switching speed. Complementary current outputs help maintain constant supply current, reducing supply noise generated transmitter module. MAX3967A available form, 4mm, 24-pin thin package. TX_DISABLE Compatibility Single +2.97V +5.5V Power Supply Adjustable Temperature Compensation Adjustable Modulation Current Complementary Output Reduces Supply Noise Programmable Prebias Voltage Available 24-Pin Thin
Features
MAX3967A
Ordering Information
PART MAX3967AETG MAX3967AE/D TEMP RANGE -40°C +85°C -40°C +85°C PIN-PACKAGE Thin Dice*
*Dice tested guaranteed only +25°C.
Applications
Multimode Transmitters
MODSET
Configuration
VCCOUT VCCOUT N.C. OUTOUTOUT+ OUT+ VEEOUT TCNOM VEEOUT VIEW
Fast Ethernet/FDDI 155Mbps ATransceivers ESCON Receivers Transceivers
N.C.
ININ+ TX_DISABLE
MAX3967A
Typical Operating Circuits appear data sheet.
TCMIN
THIN (4mm 4mm)
EXPOSED MUST CONNECTED GROUND PROPER THERMAL ELECTRICAL PERFORMANCE
Maxim Integrated Products
pricing, delivery, ordering information, please contact Maxim/Dallas Direct! 1-888-629-4642, visit Maxim's website www.maxim-ic.com.
270Mbps Driver MAX3967A
ABSOLUTE MAXIMUM RATINGS
Supply Voltage VCC, VCCOUT (VEE, VEEOUT .-0.5V Current into OUT+, OUT- .-40mA +160mA Differential Output Voltage (OUT+ OUT-) .-3.3V +3.3V Voltage PB1, PB2, PB3, IN+, IN-, OUT+, OUT-, TX_DISABLE.-0.5V (VCC 0.5V) Voltage TCMIN, TCNOM, MODSET, .-0.5V Continuous Power Dissipation +85°C) 24-Lead Thin (derate 20.8mW/C° above +85°C).1354mW Operating Junction Temperature Range .-40°C +150°C Attach Temperature.+375°C Storage Temperature Range .-50°C +150°C Lead Temperature (soldering, 10s) .+300°C
Stresses beyond those listed under "Absolute Maximum Ratings" cause permanent damage device. These stress ratings only, functional operation device these other conditions beyond those indicated operational sections specifications implied. Exposure absolute maximum rating conditions extended periods affect device reliability.
ELECTRICAL CHARACTERISTICS
(Load specified Figure +2.97V +5.5V pins); VEE, VEEOUT -40°C +85°C, unless otherwise noted. Temperature coefficients referenced +25°C. Typical values +3.3V, +25°C, unless otherwise noted. Dice tested +25°C only.)
PARAMETER Data Input High Voltage Data Input Voltage Supply Current Input Current INRMODSET (Note -40°C +25°C +85°C Modulation Current RMODSET 3.0k (Note -40°C +25°C +85°C RMODSET 1.0k (Note -40°C +25°C 3.3V 17.5 21.9 0.368 0.575 0.848 SYMBOL CONDITIONS Referenced VCC, DC-coupled input Referenced VCC, DC-coupled input (Note 15.3 19.8 0.400 0.625 0.925 12,000 3600 2500 Resistance (Note IMON IMODSET, VMON 1.1V, RMODSET TCMIN 0.92 1.08 ppm/°C 28.7 0.451 0.696 1.026 -1.165 -1.810 -0.880 -1.475 UNITS
+85°C PB1, PB2, (open, open, open) Prebias Voltage PB1, PB2, (VEE, VEE, open) PB1, PB2, (VEE, VEE, VEE) Maximum tempco open) Temperature Coefficient Modulation Current Prebias Resistor TX_DISABLE Resistance TX_DISABLE High TX_DISABLE Monitor Gain RPREBIAS Nominal tempco shorted TCNOM) Minimum tempco shorted TCMIN)
Note RMODSET Excludes IOUT+ IOUT-, TX_DISABLE high low. Note connected TCMIN, VEE, open. Note TX_DISABLE internally pulled low. driver enabled when TX_DISABLE left open.
270Mbps Driver
ELECTRICAL CHARACTERISTICS
(Load specified Figure unless otherwise noted. +2.97V +5.5V pins), RMODSET -40°C +85°C. Input data shaped 470MHz 4-pole filter, VEE, open. Typical values +3.3V, connected TCMIN, +25°C.) (Note
PARAMETER Data Input Range Output-Current Edge Speed Output-Current Pulse-Width Correction (PWC) Output-Current Data-Dependent Jitter Random Jitter TX_DISABLE Assert Time TX_DISABLE Negate Time Power-On Time t_off t_on t_init Time from rising edge TX_DISABLE output steady state Time from rising edge TX_DISABLE output steady state Time from 2.97V output steady state SYMBOL CONDITIONS Differential input 80%, input 12.5MHz square wave (Note 266Mbps (Note 155Mbps (Note 0.01 0.01 2400 1230 UNITS mVP-P psP-P psRMS
MAX3967A
Note Note Note Note
characteristics guaranteed design characterization. (widthCURRENT widthCURRENT OFF) Test pattern K28.5 (0011 1110 1011 0000 0101) transmitted 266Mbps. Test pattern equivalent PRBS containing consecutive zeros consecutive ones.
VLED 1.55V VPREBIAS
OUTOUT+ OUTL1 FERRITE BEAD
OSCILLOSCOPE
0.22µF
OUTOUT+
MAX3967A
MAX3967A
MAX3967A
0.22µF
SWITCHING DIODE OUT+
ELECTRICAL LOAD (EXCEPT PREBIAS VOLTAGE)
ELECTRICAL LOAD PREBIAS VOLTAGE
ELECTRICAL LOAD
Figure MAX3967A Output Test Loads
270Mbps Driver MAX3967A
Typical Operating Characteristics
(MAX3967AETG Maxim evaluation board, +3.3V, VEE, open, connected TCNOM, RMODSET +25°C, unless otherwise noted.)
SUPPLY CURRENT TEMPERATURE
MAX3967 toc01
MODULATION CURRENT TEMPERATURE
MAX3967 toc02
MODULATION CURRENT TEMPERATURE
MAX3967 toc03
SUPPLY CURRENT (mA) 3.3V 5.0V EXCLUDES CURRENT INTO OUT+ OUT-
NOMINAL TEMPCO MODULATION CURRENT (mA) MAXIMUM TEMPCO MINIMUM TEMPCO
MAXIMUM TEMPCO NOMINALTEMPCO MINIMUM TEMPCO
AMBIENT TEMPERATURE (°C)
MODULATION CURRENT (mA)
AMBIENT TEMPERATURE (°C)
JUNCTION TEMPERATURE (°C)
MODULATION CURRENT TEMPCO
MAX3967 toc04
MODULATION CURRENT RMODSET
MAX3967 toc05
MODULATION CURRENT RMODSET
MAX3967 toc06
100,000 MODULATION CURRENT TEMPCO (ppm/°C)
NOMINAL TEMPCO MODULATION CURRENT (mA) MINIMUM TEMPCO
MODULATION CURRENT (mA)
MINIMUM TEMPCO
10,000
MAXIMUM TEMPCO
NOMINAL TEMPCO MAXIMUM TEMPCO
1000
RMODSET
RMODSET
DIAGRAM (ELECTRICAL) 266Mbps
MAX3967 toc07
DIAGRAM (OPTICAL) 155Mbps
MAX3967 toc08
DIAGRAM (OPTICAL) 155Mbps
MAX3967 toc09
500ps/div PATTERN PRBS
1ns/div RECEIVER 200MHz, 2.97V, +85°C, PAVE -17.1dBm, PATTERN PRBS
1ns/div RECEIVER 200MHz, 5.5V, -40°C, PAVE -15.8dBm, PATTERN PRBS
270Mbps Driver
Typical Operating Characteristics (continued)
(MAX3967AETG Maxim evaluation board, +3.3V, VEE, open, connected TCNOM, RMODSET +25°C, unless otherwise noted.)
DIAGRAM (OPTICAL) 155Mbps
MAX3967 toc10
MAX3967A
DIAGRAM (OPTICAL) 155Mbps
MAX3967 toc11
RANDOM JITTER TEMPERATURE
MAX3967 toc12
RANDOM JITTER (psRMS) 3.3V MAXIMUM TEMPCO
5.0V MINIMUM TEMPCO AMBIENT TEMPERATURE (°C)
1ns/div RECEIVER 200MHz, 5.5V, +85°C, PAVE -17.1dBm, PATTERN PRBS
1ns/div RECEIVER 200MHz, 2.97V, -40°C, PAVE -15.8dBm, PATTERN PRBS
TX_DISABLE NEGATE TIME
MAX3967 toc13
TX_DISABLE ASSERT TIME
MAX3967 toc14
OUTPUT
OUTPUT
t_on TX_DISABLE TX_DISABLE
t_off
4ns/div
4ns/div
270Mbps Driver MAX3967A
Description
NAME TCNOM PB1, PB2, VEEOUT OUT+ OUTN.C. VCCOUT MODSET ININ+ TX_DISABLE TCMIN Exposed FUNCTION Shorting TCNOM provides modulation tempco approximately 3600ppm/°C. resistor (RTC) connected between TCMIN pins sets tempco modulation current. Leaving unconnected provides maximum tempco. Programs Prebias Voltage OUT+ (Table Ground Output-Current Drivers Current Output Complementary Current Output Connection. internally connected. Supply Connection Output-Current Drivers Provides Current Internal Amplifiers Current Sourced from Proportional Modulator Current Resistor from MODSET Programs Modulation Current Inverting Data Input Noninverting Data Input Transmit Disable. When high, current OUT+ pins state. transmitter enabled when TX_DISABLE open. Ground internal amplifiers. Shorting TCMIN provides minimum modulation-current tempco. Connect exposed board ground optimal correct electrical thermal performance.
Detailed Description
MAX3967A provides flexible current drive modulation fiber optic light-emitting diodes (LEDs). circuit designed used with +3.3V power supplies. provides 100mA modulation current. adjustable prebias current source sets prebias voltage. integrated resistor provides passive peaking optical pulse-width compensation. Figure shows block diagram MAX3967A, which comprises reference-voltage generator, modulation-current generator, input buffer with disable, prebias-current generator, main output driver, complementary output driver, LED-compensation network.
perature coefficient (tempco) useful compensate temperature characteristics typical fiber optic LEDs. first source temperature-stable output. second source temperature-increasing output with tempco approximately 12,000ppm/°C (relative +25°C). resistor-divider between reference generators programs modulation-current tempco. maximum modulation-current tempco, leave disconnected. tempco approximately 3600ppm/°C, connect TCNOM. obtain minimum tempco, connect TCMIN Intermediate tempco values programmed connecting external resistor (RTC) between TCMIN
Input Buffer
inputs connected PECL-compatible differential input buffer. left unconnected, internally pulled PECL pulled PECL high, causing current OUT+. input impedance approximately 50k.
Temperature Compensation
reference-voltage generator circuit provides voltage sources that create modulation-current temperature compensation. positive modulation-current tem6
270Mbps Driver MAX3967A
TX_DISABLE VCCOUT
OUTINPUT BUFFER INMAX3967A
COMPLEMENTARY OUTPUT
MODULATIONCURRENT GENERATOR
MAIN OUTPUT GAIN
RPREBIAS OUT+
REFERENCE-VOLTAGE GENERATOR
12pF
1.2V
PREBIAS-CURRENT GENERATOR
TEMP
TCMIN
TCNOM
MODSET RMODSET
Figure Functional Diagram
Modulation-Current Generator
modulation-current generator circuit provides control modulation-current amplitude. This amplitude determined voltage MODSET external resistor RMODSET. connect bypass capacitors MODSET pin. Capacitance this increases high-frequency output noise. provides optional modulation-current monitor. current sourced from 1/96 modulation current. used, should connected through resistor. resistance must chosen voltage does exceed 1.1V. used, leave open.
Prebias Current Generator
prebias voltage (VPREBIAS) applied improve switching speed. prebias current generator creates current that flows through prebias resistor output stage, creating prebias voltage. prebias voltage adjusted selectively connecting pins PB1, PB2, VEE. Table describes functions PB1, PB2, PB3.
Output Current Drivers
modulation-current reference switched amplified output stages. package lead inductance causes ringing overshoot, which compensated with filter network. MAX3967A includes 12pF
270Mbps Driver MAX3967A
Table Prebias Voltage
Open Open Open Open Open Open Open Open Open Open Open Open PREBIAS 0.400 0.475 0.550 0.625 0.700 0.775 0.850 0.925
Modulation Current Tempco graph Typical Operating Characteristics program custom tempco. From graph, determine appropriate resistor connect between TCMIN example, requires 5000ppm/°C tempco, choose 8.3k.
Program Modulation Current
Determine required modulation current +25°C. Then select appropriate value RMODSET from Modulation Current RMODSET graph Typical Operating Characteristics. example, program 75mA modulation current, graph indicates RMODSET value maximum tempco (12,000ppm/°C) nominal tempco (3600ppm/°C). interpolation, choose RMODSET tempco 5000ppm/°C.
internal compensation. compensation network optimized adding additional components between VCCOUT OUT+. MAX3967A includes complementary output driver, which switched 180° phase with main output. This configuration helps maintain constant current flow from voltage supply, reducing noise EMI. large diode resistor connected series with negative output (OUT-) emulate load OUT+.
Program Prebias Voltage
Determine prebias voltage that produces acceptable trade-off between peaking current extinction ratio. Table PB1, PB2, settings.
Layout Considerations
optimum performance, total load inductance should exceed 10nH. Load inductance includes inductance, package lead inductance, circuitboard traces. Keep connections between MAX3967A pins short possible minimize inductance. Chip-and-wire (hybrid) technology reduces package inductance significantly, provides best possible performance. good high-frequency layout techniques multilayer board with uninterrupted ground plane. Power supplies should capacitively bypassed ground plane with surface-mount capacitors located near power-supply pins.
Peaking Current
prebias resistor provides peaking current improve switching speed. peaking magnitude given following equation: IPEAK PREBIAS peaking amplitude equal rising falling data transitions.
Design Procedure
Select
best performance, select high-efficiency, lowinductance LED. inductance causes large voltage swings ringing.
Program Modulation-Current Tempco
Select modulation-current tempco that provides nearly constant output power temperature varies. minimum tempco, connect TCMIN pin. tempco approximately 3600ppm/°C, connect TCNOM leave TCMIN unconnected. maximum tempco, leave TCMIN, TCNOM, unconnected.
270Mbps Driver
Input Terminations Exposed-Pad Package
exposed 24-pin TQFN provides very thermal resistance path heat removal from
PECL OUTPUT
MAX3967A
MAX3967A
Chip Information
TRANSISTOR COUNT: SUBSTRATE CONNECTED PROCESS: BIPOLAR THICKNESS: mils
NON-PECL OUTPUT
MAX3967A
SINGLE-ENDED TERMINATION SHOWN. SHOULD TERMINATED SIMILARLY.
Figure Input Terminations
Applications Information
Wire-Bonding
MAX3967A utilizes gold metalization, which provides high reliability. Make connections with gold wire only, using ball-bonding techniques. caution attempting wedge-bonding. size mils mils (100µm). thickness typically mils (375µm).
270Mbps Driver MAX3967A
Typical Operating Circuits
TRANSMITTER +3.3V
FERRITE BEAD
DISABLE TX_DISABLE
VCCOUT OUT-
+3.3V
+3.3V OUT+
DIFFERENTIAL DATA
MAX3967A
VEEOUT
TCNOM TCMIN MODSET
RMODSET
TRANSMITTER WITH DIGITAL MONITOR +3.3V
FERRITE BEAD
DISABLE TX_DISABLE
VCCOUT OUT-
+3.3V
+3.3V OUT+
DIFFERENTIAL DATA
MAX3967A
VEEOUT
TCNOM TCMIN MODSET
RMODSET
DIAGNOSTIC
RMON
270Mbps Driver
Typical Operating Circuits (continued)
TRANSMITTER WITH DISABLE
FERRITE BEAD
MAX3967A
DISABLE TX_DISABLE
VCCOUT OUT-
PECL DATA
OUT+
MAX3967A
INMON TCNOM TCMIN
VEEOUT
MODSET
RTC* *OPTIONAL COMPONENT
RMODSET
TRANSMITTER WITHOUT DISABLE
FERRITE BEAD
TX_DISABLE
VCCOUT OUT-
PECL DATA
OUT+
MAX3967A
VEEOUT
TCNOM TCMIN MODSET
RMODSET
270Mbps Driver MAX3967A
Chip Topography
TX_DISABLE
Coordinates
NUMBER NAME TCMIN TCNOM VEEOUT VEEOUT OUT+ OUT+ OUTOUTVCCOUT VCCOUT MODSET ININ+ TX_DISABLE COORDINATES (µm) 1464 1268 1060 1032 1240 1464 1464 1464 1464 1464
TCMIN
1.85mm (73.0 mils)
TCNOM
MODSET
BP10 BP11 BP12 BP13 BP14 BP15 BP16
VEEOUT VEEOUT
VCCOUT VCCOUT
BP17 BP18 BP19 BP20 BP21 BP22
OUT+ OUT+ OUT1.21mm mils)
OUT-
270Mbps Driver
Package Information
(The package drawing(s) this data sheet reflect most current specifications. latest package outline information, www.maxim-ic.com/packages.)
MAX3967A
PACKAGE OUTLINE, THIN QFN, 4x4x0.8mm
21-0139
PART MAX3967AETG
PACKAGE TYPE thin (4mm 0.8mm)
PACKAGE CODE T2444-4
THIN.EPS
270Mbps Driver MAX3967A
Package Information(continued)
(The package drawing(s) this data sheet reflect most current specifications. latest package outline information, www.maxim-ic.com/packages.)
PACKAGE OUTLINE, THIN QFN, 4x4x0.8mm
21-0139
Maxim cannot assume responsibility circuitry other than circuitry entirely embodied Maxim product. circuit patent licenses implied. Maxim reserves right change circuitry specifications without notice time.
_Maxim Integrated Products, Gabriel Drive, Sunnyvale, 94086 408-737-7600 2005 Maxim Integrated Products Printed registered trademark Maxim Integrated Products, Inc.
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