MAX3934 MAX3934AE/D MAX3934BE/D MAX3952 MAX3934A OC-192 80CIDS MAX3934B MAX4281 - Datasheet Archive
10.7Gbps Compact Laser Diode Driver The MAX3934 is a compact +5V or -5.2V laser driver designed to directly modulate a laser
19-2605; Rev 0; 10/02 10.7Gbps Compact Laser Diode Driver The MAX3934 MAX3934 is a compact +5V or -5.2V laser driver designed to directly modulate a laser diode at data rates up to 10.7Gbps. The driver provides externally programmable laser biasing and modulation currents. DC-coupling with an integrated compensation network, consisting of a series-damping resistor and a shunt RC, makes the MAX3934 MAX3934 ideal for compact subassemblies. The MAX3934 MAX3934 accepts a differential CML or PECL data signal and includes 50 on-chip termination resistors. It delivers a 1mA to 60mA laser bias current and a 20mA to 80mA laser modulation current with a typical edge speed of 25ps (20% to 80%). A high-bandwidth, fully differential signal path is internally implemented to minimize jitter accumulation. Additional features include a data polarity control, bias current, and modulation current monitors. Features o o o o o o o o o o o 1.30mm × 1.35mm Die Size Integrated Compensation Network Single +5V or -5.2V Power Supply 73mA Supply Current Up to 10.7Gbps (NRZ) Operation Programmable Laser Bias Current Up to 60mA Programmable Modulation Current Up to 80mA Polarity Control 25ps Output Edge Speed CML-/PECL-Compatible Signal Inputs Integrated Input Termination Resistors Ordering Information Applications Compact Optical Transmitters XFP Modules PART TEMP RANGE PINPACKAGE RD/CCOMP* MAX3934AE/D MAX3934AE/D XENPAK/XPAK Modules Add/Drop Multiplexer -40°C to +85°C Dice* 12/580fF MAX3934BE/D MAX3934BE/D -40°C to +85°C Dice* 15/464fF *Dice are designed to operate over a -40°C to +120°C junction temperature (TJ) range, but are tested and guaranteed only at TA = +25°C. *See Figure 3. Typical Application Circuit VCC VCC VBIAS VEE VEE VEE BIASMON VCC BIASSET VCC VCC SDO+ SDO- IN+ 50 50 OUT1+ MAX3934 MAX3934 INVCC 10Gbps SERIALIZER OUT2+ VCC OUT2PLRT VEE MAX3952 MAX3952 VEE OUT1- BIAS MODMON MODSET LB VCC VEE VMOD VEE VEE REPRESENTS A CONTROLLED IMPEDANCE TRANSMISSION LINE VEE Covered by U.S. Patent number 5,883,910 _ 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 MAX3934 MAX3934 General Description MAX3934 MAX3934 10.7Gbps Compact Laser Diode Driver ABSOLUTE MAXIMUM RATINGS Supply Voltage (VCC - VEE) .-0.5V to +6.0V Voltage at IN+, IN- .(VCC - 1.2V) to (VCC + 0.5V) PLRT, BIASMON, MODMON .(VEE - 0.5V) to (VCC + 0.5V) BIASSET .(VEE - 0.5V) to (VEE + 2.6V) MODSET .(VEE - 0.5V) to (VEE + 1.4V) Current into IN+, IN-.-24mA to +30.5mA Current into OUT1+, OUT2+,OUT1-, OUT2-.-20mA to +200mA Current into BIAS .-20mA to +100mA Storage Temperature Range .-55°C to +150°C Operating Junction Temperature Range .-55°C to +150°C Processing Temperature (die) .+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 - VEE = 4.75V to 5.5V, TA = -40°C to +85°C. Typical values are at VCC - VEE = 5V, IBIAS = 35mA, IMOD = 65mA, and TA = +25°C, unless otherwise noted.) PARAMETER SYMBOL Power-Supply Voltage Power-Supply Current ICC CONDITIONS MIN TYP MAX UNITS 4.75 5 5.50 V Excluding IMOD and IBIAS, data inputs AC-coupled 73 110 mA (Notes 1, 2) 20 VCC - VEE Power-Supply Noise Rejection PSNR dB SIGNAL INPUT Input Data Rates NRZ Single-Ended Input Resistance To VCC 10.7 Single-Ended Input Return Loss (Note 1) f < 10GHz 14 10GHz f 15GHz 8 42.5 50 Gbps 58.5 dB Single-Ended Input Voltage (DC-Coupled) VIS Figure 2a VCC - 1 VCC V Single-Ended Input Voltage (AC-Coupled) VIS Figure 2b VCC 0.4 VCC + 0.4 V Differential Input Voltage (DC-Coupled) VID Figure 4 0.2 2.0 VP-P Differential Input Voltage (AC-Coupled) VID Figure 4 0.2 1.6 VP-P Bias Current-Setting Range IBIAS (Note 3) Bias Sensing Resistor RBIAS LASER BIAS Bias Current Temperature Stability 1 5.4 60 6 mA 6.6 ppm/°C (Note 1) -480 +480 Bias Current-Setting Error (Note 3) IBIAS 10mA, VBIAS < VCC - 1.2V -10 +10 IBIAS = 1mA, VBIAS < VCC - 1.2V -20 +20 Bias Off-Current BIASSET VEE + 0.4V % 0.1 mA LASER MODULATION Modulation Current-Setting Range IMOD Modulation Sensing Resistor RMOD Modulation Current Temperature Stability 2 (Note 5) 20 2.7 (Note 1) 80 3 -480 _ mA 3.3 +480 ppm/°C 10.7Gbps Compact Laser Diode Driver (VCC - VEE = 4.75V to 5.5V, TA = -40°C to +85°C. Typical values are at VCC - VEE = 5V, IBIAS = 35mA, IMOD = 65mA, and TA = +25°C, unless otherwise noted.) PARAMETER CONDITIONS MIN Modulation Current-Setting Error VOUT_+ < VCC - 1.2V (Note 5) -10 Modulation Off-Current MODSET VEE + 0.4V Output Edge Speed SYMBOL tR , tF Output Overshoot/Undershoot MAX UNITS +10 25 -15 % 0.2 20% to 80% (Notes 1, 4, 6) (Notes 1, 4, 6) TYP mA 35 ps +15 % Driver Random Jitter RJ REXT + RD = 20 (Note 1) 0.3 psRMS Driver Deterministic Jitter DJ (Notes 1, 7) 9.7 psP-P TTL INPUT Input High Voltage VEE + 2.0 VEE + 0.8 Input Low Voltage Input Current V -70 V +70 µA Note 1: Guaranteed by design and characterization using the circuit shown in Figure 1. Note 2: PSNR = 20 × log[VCC / (IMOD × 20)]. Measured with VCC = 100mVP-P and f 10MHz. Excludes the effect of the external op amp. Note 3: The minimum voltage at the BIAS pad is VEE + 1.85V + (IBIAS × 8). Note 4: The combined driver AC load (on-chip load and off-chip laser load) is 20. Measured using a 10.7Gbps repeating 0000 0000 1111 1111 pattern. Note 5: The minimum voltage at the OUT_+ pad is VEE + 1.65V + (IMOD × RD) (Figure 3). Note 6: The maximum allowed inductance per bond wire is 0.4nH for OUT1±, OUT2±, VCC, VEE, and 0.5nH for IN±. Note 7: Deterministic jitter is defined as the arithmetic sum of PWD (pulse-width distortion) and PDJ (pattern-dependent jitter). Measured using a 10.7Gbps 27 - 1 PRBS with eighty 0s and eighty 1s inserted in the data pattern. _ 3 MAX3934 MAX3934 ELECTRICAL CHARACTERISTICS (continued) MAX3934 MAX3934 10.7Gbps Compact Laser Diode Driver VCC BIAS VCC OUT1PATTERN GENERATOR IN+ 50 MAX3934A MAX3934A OUT1+ 39 39 50 IN- 50 OUT2+ VCC VEE 39 39 50 OUT2- -5V OSCILLOSCOPE EQUIVALENT CIRCUIT RD REXT 12 IMOD 8 IBIAS Figure 1. AC Characterization Circuit VCC 100mV 1.0V VCC - 0.5V VCC - 1.0V (a) DC-COUPLED SINGLE-ENDED CML INPUT VCC + 0.4V 800mV VCC 100mV VCC - 0.4V (b) AC-COUPLED SINGLE-ENDED (CML OR PECL) INPUT Figure 2. Definition of Input Voltage Swing 4 _ 10.7Gbps Compact Laser Diode Driver OC-192 OC-192 OPTICAL EYE DIAGRAM (IMOD = 55mA, IBIAS = 30mA, 223 - 1 PRBS) OC-192 OC-192 ELECTRICAL EYE DIAGRAM (IMOD = 20mA, 223 - 1 PRBS) MAX3934 MAX3934 toc03 MAX3934 MAX3934 toc02 MAX3934 MAX3934 toc01 OC-192 OC-192 ELECTRICAL EYE DIAGRAM (IMOD = 80mA, 223 - 1 PRBS) 15ps/div 15ps/div 10.31Gbps OPTICAL EYE DIAGRAM (IMOD = 55mA, IBIAS = 30mA, 223 - 1 PRBS) 10.31Gbps ELECTRICAL EYE DIAGRAM (IMOD = 80mA, 223 - 1 PRBS) 10.31Gbps ELECTRICAL EYE DIAGRAM (IMOD = 20mA, 223 - 1 PRBS) MAX3934 MAX3934 toc06 MAX3934 MAX3934 toc05 MAX3934 MAX3934 toc04 15ps/div 14ps/div 14ps/div SUPPLY CURRENT vs. MODULATION CURRENT (EXCLUDES BIAS AND MODULATION CURRENTS) DETERMINISTIC JITTER vs. MODULATION CURRENT (10.7Gbps, 27 - 1 PRBS + 80CIDS 80CIDS) TA = +85°C 90 80 70 60 50 TA = -40°C TA = +25°C 40 16 60 12 10 8 TA = +85°C TA = +25°C 4 10 0 20 30 40 50 60 MODULATION CURRENT (mA) 70 80 40 20 2 20 50 30 6 30 70 TA = -40°C 14 MAX3934 MAX3934 toc09 18 IMOD (mA) SUPPLY CURRENT (mA) 100 IMOD vs. VMOD 80 MAX3934 MAX3934 toc08 110 20 DETERMINISTIC JITTER (psP-P) MAX3934 MAX3934 toc07 120 14ps/div 0 20 30 40 50 60 MODULATION CURRENT (mA) 70 80 0 50 100 150 200 250 VMOD (mV) _ 5 MAX3934 MAX3934 Typical Operating Characteristics (Typical values at VCC - VEE = 5V, IBIAS = 35mA, IMOD = 65mA, TA= +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (Typical values at VCC - VEE = 5V, IBIAS = 35mA, IMOD = 65mA, TA= +25°C, unless otherwise noted.) POWER-SUPPLY NOISE REJECTION vs. FREQUENCY 50 DIFFERENTIAL S11 vs. FREQUENCY 0 MAX3934 MAX3934 toc11 40 MAX3934 MAX3934 toc10 60 35 -5 -10 30 30 -15 25 |S11| (dB) PSNR (dB) 40 20 15 20 MAX3934 MAX3934 toc12 IBIAS vs. VBIAS IBIAS (mA) MAX3934 MAX3934 10.7Gbps Compact Laser Diode Driver -20 -25 -30 -35 10 10 -40 5 100 0 200 300 VBIAS (mV) 400 -45 0 0 -50 0.1 1 10 100 1000 10,000 0 2 4 6 8 10 12 14 16 18 20 FREQUENCY (GHz) FREQUENCY (kHz) Pad Description PAD VEE 6 BIASSET Bias Current Set. Connected to the output of an external op amp (see the Design Procedure section). 7 BIASMON Bias Current Monitor (VBIASMON - VEE) / RBIAS = IBIAS 8, 9, 11, 13, 21, 22, 27 VCC Positive Supply Voltage. All pads must be connected to VCC. 10 IN+ Positive Data Input. CML/PECL with 50 integrated termination resistor. 12 IN- Negative Data Input. CML/PECL with 50 integrated termination resistor. 14 PLRT 15 MODMON Modulation Current Monitor (VMODMON - VEE) / RMOD = IMOD 16 MODSET Modulation Current Set. Connected to the output of an external op amp (see the Design Procedure section). 23, 26 OUT2-, OUT1- Complementary Laser Modulation Current Outputs. Include 20 equivalent on-chip output resistor. Connect both to VCC. 24, 25 OUT2+, OUT1+ Laser Modulation Current Outputs. Include integrated damping resistor and provide laser modulation current (sinking). Connect both to laser diode cathode. 28 6 NAME 15, 1720 FUNCTION BIAS Negative Supply Voltage. All pads must be connected to VEE. Differential Data Polarity Swap Input. TTL. Set high or floating for normal operation. Set low to invert the differential signal polarity. Laser Bias Current Output (Sinking) _ 10.7Gbps Compact Laser Diode Driver MAX3934 MAX3934 VCC PLRT VCC OUT- MAX3934 MAX3934 20 VCC VEE RD ILD OUT+ 50 IN+ RCOMP 50 50 BIAS CCOMP IN- 50 LB 8 VCC 50 IBIAS IMOD PART MAX3934A MAX3934A VCC MAX3934B MAX3934B RMOD 3 645 MODSET RBIAS 6 645 MODMON BIASSET VEE RD CCOMP 12 580fF 15 464fF BIASMON VEE Figure 3. Functional Diagram VID = 0.2VP-P TO 2.0VP-P (DC-COUPLED) VID = 0.2VP-P TO 1.6VP-P (AC-COUPLED) (IN+) - (IN-) ILD PLRT = HIGH PLRT = LOW IMOD = 20mA TO 80mA IBIAS = 1mA TO 60mA Figure 4. Required Input Signal and Output Polarity Detailed Description The MAX3934 MAX3934 laser driver consists of two main parts, a high-speed modulation driver and a laser-biasing block (see Figure 3). The circuit operates from a single +5V or -5.2V supply. When operating from a +5V supply, connect all V CC pads to +5V and all V EE pads to ground. If operating from a -5.2V supply, connect all VEE pads to -5.2V and all VCC pads to ground. The modulation output stage is composed of a highspeed differential pair and a programmable modulation current source with a maximum modulation current of 80mA. The rise and fall times are typically 25ps. The MAX3934 MAX3934 contains an integrated damping resistor (RD) with the value of 12 or 15 depending on part version. The modulation output is optimized for driving a 20 load; therefore, the total series load of RD and RLD (where RLD represents the laser diode resistance) should equal 20. At the data rate of 10.7Gbps, capacitive loads at the cathode of a laser diode degrade the optical output performance. Because the BIAS output is directly connected to the laser cathode, use a ferrite bead (LB) with low shunt capacitance to isolate the BIAS pad from the laser cathode. Polarity Switch The MAX3934 MAX3934 includes a TTL controlled polarity switch. When the PLRT pad is high or floating, the output maintains the polarity of the input data. When the PLRT pad is low, the output is inverted relative to the input data (see Figure 4). _ 7 MAX3934 MAX3934 10.7Gbps Compact Laser Diode Driver Table 1. Optical Power Relations PARAMETER SYMBOL RELATION Average Power PAVG Extinction Ratio re r e = P1 / P 0 Optical Power of a "1" P1 P1 = 2PAVG re / (re + 1) Optical Power of a "0" P0 P0 = 2PAVG / (re + 1) Optical Amplitude Laser Slope Efficiency Modulation Current PP-P PAVG = (P0 + P1) / 2 OPTICAL POWER PP-P = P1 - P0 = 2PAVG(re - 1) / (re + 1) = PP-P / IMOD IMOD PP-P PAVG P0 IMOD = PP-P / Note: Assuming a 50% average duty cycle and mark density. Current Monitors The MAX3934 MAX3934 features a bias current monitor output (BIASMON) and a modulation current monitor output (MODMON). The voltage at BIASMON is equal to (IBIAS × RBIAS) + VEE, and the voltage at MODMON is equal to (IMOD × RMOD) + VEE, where IBIAS represents the laser bias current, IMOD represents the modulation current, and RBIAS and RMOD are internal 6 and 3 (±10%) resistors, respectively. BIASMON and MODMON should be connected to the inverting input of an operational amplifier to program the bias and modulation current (see the Design Procedure section). Design Procedure When designing a laser transmitter, the optical output usually is expressed in terms of average power and extinction ratio. Table 1 gives relationships helpful in converting between the optical average power and the modulation current. These relationships are valid if the mark density and duty cycle of the optical waveform are 50%. Programming the Modulation Current For a desired laser average optical power (PAVG) and optical extinction ratio (re) the required modulation current can be calculated based on the laser slope efficiency () using the equations in Table 1. To program the desired modulation current, connect the inverting input of an op amp (such as the MAX4281 MAX4281) to MODMON and connect the output to MODSET. Connect the positive op-amp voltage supply to VCC and the negative supply to VEE (for +5V operation, VCC = +5V and VEE = ground; for -5.2V operation VCC = ground and VEE = -5.2V). Connect a reference voltage (VMOD) to the noninverting input of the op amp to set the modulation current. See the IMOD vs. VMOD graph in the Typical Operating Characteristics to select 8 P1 TIME Figure 5. Optical Power Definitions the value of VMOD that corresponds to the required modulation current. Programming the Bias Current To program the desired laser bias current, connect the inverting input of an op amp (such as the MAX4281 MAX4281) to BIASMON and connect the output to BIASSET. Connect the positive op-amp voltage supply to VCC and the negative supply to VEE (for +5V operation, VCC = +5V and VEE = ground; for -5.2V operation, VCC = ground and VEE = -5.2V). Connect a reference voltage (VBIAS) to the noninverting input of the op amp to set the laser bias current. Refer to the IBIAS vs. V BIAS graph in the Typical Operating Characteristics to select the value of V BIAS that corresponds to the required laser bias current. External Op-Amp Selection External op amps are required for regulating the bias and modulation currents. The ability to operate from a single supply with input common-mode range extending to the negative supply rail is critical in op-amp selection. Low bias current and high PSNR are also important. The op-amp gain bandwidth must be high enough to regulate at the power-supply ripple frequency to maintain the PSNR of the laser driver. Filtering the op-amp output is recommended (see the Typical Application Circuit). To maintain stability, the filter capacitor should be smaller than the op-amp capacitive load specification. Interfacing with Laser Diodes Refer to Maxim application note HFAN-2.0: Interfacing Maxim Laser Drivers with Laser Diodes for detailed information. The MAX3934 MAX3934 contains an integrated damping resistor (RD) with values of 12 or 15, depending on part version. The modulation output is optimized for driving a 20 load; therefore, the total series load of RD and RLD _ 10.7Gbps Compact Laser Diode Driver OUT1- 50 OUT1+ OUT2+ MAX3934 MAX3934 VCC OUT2- 50 40 2 RD 2 RD 40 IN+ IN- IMOD VEE VEE Figure 6. Equivalent Input Circuit Figure 7. Equivalent Output Circuit (where R LD represents the laser diode resistance) should equal 20. OUT1±, OUT2±, VCC, and VEE as short as possible. This is crucial for optimal performance. Both modulation outputs (OUT1+, OUT2+) must be bonded to the laser diode cathode for proper operation. In some applications (depending on the laser diode parasitic inductance), an RF matching network at the laser cathode improves the optical output. For best performance, place a bypass capacitor as close as possible to the anode of the laser diode. Applications Information Interfacing to CML and PECL Outputs The MAX3934 MAX3934 data input accepts CML or PECL signals, but care must be taken to maintain proper biasing and common-mode voltages. Refer to Figure 6 and the Maxim application note HFAN-01 HFAN-01.0: Introduction to LVDS, PECL, and CML for additional information. Wire-Bonding Die For high-current density and reliable operation, the MAX3934 MAX3934 uses gold metalization. Make connections to the die with gold wire only, using ball-bonding techniques. Minimize bond-wire lengths and ensure that the span between the ends of the bond wire does not come closer to the edge of the die than two times the bond-wire diameter. The minimum length of the bond wires might be constrained by the type of wire bonder used, as well as the dimensions of the die. To minimize inductance, keep the connections from Layout Considerations Use good high-frequency layout techniques and multilayer boards with an uninterrupted ground plane to minimize EMI and crosstalk. Use controlled impedance lines for the data inputs. Power-supply decoupling should be placed as close to the die as possible. Wafer capacitors are required to filter the VEE supplies on both sides of the die. Connect the backside of the die to VCC. Laser Safety and IEC 825 Using the MAX3934 MAX3934 laser driver alone does not ensure that a transmitter design is compliant with IEC 825. The entire transmitter circuit and component selections must be considered. Each customer must determine the level of fault tolerance required by their application, recognizing 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 Chip Topology/ Pad Configuration Table 2. Bondpad Locations PAD NAME 1 2 COORDINATES (µm) X Y VEE 16 711 VEE 16 599 3 VEE 16 487 4 VEE 16 375 5 VEE 16 263 6 BIASSET 16 151 7 BIASMON 16 39 8 VCC 226 -46 9 VCC 338 The origin for pad coordinates is defined as the bottom left corner of the bottom left pad. All pad locations are referenced from the origin and indicate the center of the pad where the bond wire should be connected. Refer to Maxim application note HFAN-08 HFAN-08.0.1: Understanding Bonding Coordinates and Physical Die Size for detailed information. The die size is 51mil × 53mil (1.30mm × 1.35mm) with 3mil (76µm) octagonal pads and 4mil (102µm) square pads. The die thickness is 8 mils (203µm). -46 10 IN+ 450 -46 11 VCC 562 -46 12 IN- 674 -46 13 VCC 786 -46 14 PLRT 898 -46 15 MODMON 946 105 16 MODSET 946 217 17 VEE 946 329 18 VEE 946 441 VEE (1) 19 VEE 946 553 VEE (2) 20 VEE 946 665 21 VCC 954 901 VEE (5) 22 VCC 828 901 BIASSET (6) 23 OUT2- 704 901 BIASMON (7) 24 OUT2+ 576 901 25 OUT1+ 408 901 26 OUT1- 282 901 27 VCC 156 901 28 BIAS 30 901 VCC (21) VCC (22) OUT2- (23) OUT2+ (24) OUT1+ (25) OUT1- (26) VCC (27) Chip Topology BIAS (28) VEE (20) VEE (19) VEE (3) VEE (4) MODSET (16) VCC (13) IN- (12) VCC (11) IN+ (10) VCC (9) MODMON (15) PLRT (14) DIE COORDINATE ORIGIN 51 mils VEE (18) (1.30mm) VEE (17) VCC (8) MAX3934 MAX3934 10.7Gbps Compact Laser Diode Driver 53 mils (1.35mm) Chip Information TRANSISTOR COUNT: 884 SUBSTRATE: SOI PROCESS: SiGe BIPOLAR DIE THICKNESS: 8 mils 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. 10 _Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2002 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.