Revision Information This document contains information that is subject to change without notice. Contact Technical Publications for latest revision information. CX02068 3.3 Volt Laser Driver IC for 155/622 Mbps The CX02068 is a highly integrated, programmable laser driver intended for Telecom applications up to 622 Mbps. Using differential PECL data, the CX02068 supplies the bias and modulation current for driving an edge-emitting laser. The modulation output can be DC-coupled to the laser diode, giving a significant power saving over ACcoupled operation. The CX02068 includes automatic power control (APC) to maintain a constant average laser output power over temperature and life. In addition, the modulation current is temperature compensated to minimize variation in extinction ratio over temperature. Output flags indicate laser end of life as well as failure of the APC circuitry to maintain average output power. Features Applications * * * * * * * * * * * * * Rise and fall times <180 ps Operates with +3.3 volt supply DC or AC-coupled modulation drive. Independently programmable laser bias (to 100 mA) and modulation currents (to 85 mA). Automatic laser power control, with programmable temperature compensation and `Slow-Start'. Bias and modulation current monitors Failure monitor Available in BCC+24 , TQFP32 and DIE packages Available in RoHS compliant packages OC-3/STM1, SONET/SDH OC-12/STM4, SONET/SDH ATM FTTH Functional Block Diagram V DD OUTOUT+ RD R SHUNT C SHUNT DIN DIN GNDA X100 DIS ENA BIAS MON X1 55 MOD MON IBIAS X55 I BIAS PD IMOD PP Failure Detect 55 FAIL R MPCSET OCA SET OCA R OCA R TCSTART R MODSET 02068-DSH-001-C R TCSLOPE V REF C MPC V DD Mindspeed Technologies(R) Mindspeed Proprietary and Confidential April 2006 Ordering Information Part Number Package CX02068B24 BCC+24L CX02068TQ32 TQFP32 CX02068G-09-T* BCC+24L, RoHS CX02068G-TQ32* TQFP32, RoHS CX02068DIEWP Waffle pack CX02068WAFER Whole 8" wafer on a 10" grip ring CX02068EVM Evaluation board with a CX02068B24 * The letter "G" designator after the part number indicates that the device is RoHS-compliant. Refer to www.mindspeed.com for additional information. Revision History Revision Level Date ASIC Revision Description C Preliminary April 2006 x Added RoHS package information, updated format, no specification changes. B Preliminary May 2005 x Updated to new data sheet format. A Advance October 2003 x Advance. 23 22 21 20 DIS 2 18 BIASMON 3 17 OCA SET MODSET TCSTART V 25 MPC C 26 CC NC 27 SLOPE GND TC 28 OCA 29 V 31 CC 19 32 VCC DIN DIN SET 24 V CC D IN 1 24 PD 2 23 GND D IN 3 22 GND V CC 4 21 V CC OUT- 7 18 V CC N/C 8 17 BIAS 4mm 02068-DSH-001-C CC V PD A MOD 13 12 MON 11 BIAS 10 GNDA 9 OUT- 8 OUT+ 7 VCC GND A 16 V CC 15 CMPC GND 14 14 6 OCA OUT+ OCA 13 19 12 6 FAIL 20 N/C MON 5 GND 11 N/C FAIL 9 TCSLOPE 15 2068 10 16 5 DIS 4 5mm ENA MODMON BIAS 4mm 1 VCC GND ENA MOD SET TQFP32 Top View 30 BCC+24L Top View 5mm Mindspeed Technologies(R) Mindspeed Proprietary and Confidential ii 1.0 Product Specification 1.1 Absolute Maximum Ratings These are the absolute maximum ratings at or beyond which the IC can be expected to fail or be damaged. Functional operation at these levels is not implied. Table 1-1. Absolute Maximum Ratings Parameter Rating Units Power supply (VCC-GND) -0.5 to +6.0 V Operating ambient -40 to +85 C Storage temperature -65 to +150 C Maximum bias current 120 mA Maximum laser modulation current (through OUT+/OUT2+, OUT-/OUT2-) 100 mA 1.2 Table 1-2. Recommended Operating Conditions Recommended Operating Conditions Parameter Rating Units Power supply (VCC-GND) 3.3 10% V Junction temperature (die) -40 to +120 C Operating ambient -40 to +85 C 02068-DSH-001-C Mindspeed Technologies(R) Mindspeed Proprietary and Confidential 1 Product Specification 1.3 DC Characteristics VCC=+3.3V 10%, TA=-40 C to +85 C, unless otherwise noted. Table 1-3. DC Characteristics Parameter Conditions Min Typ Max Units Supply current Excluding IBIAS and IMOD, but with IBIAS and IMOD set to 50 mA - 42 47 mA Bias current adjust range Limited by IREF across temperature range 4 - 100 mA Bias current with output disabled Tx_Dis = HIGH - - 10 A Bias current limit adjustment region TA = +85 C 20 - 100 mA 100 - 130 A/C Monitor diode reverse bias voltage 2 - - V Monitor diode current adjustment range 10 - 1000 A TTL/CMOS input HIGH voltage (enable, disable) 2.0 - - V TTL/CMOS input LOW voltage (enable, disable) - - 0.8 V CMOS output HIGH voltage (FAIL, OCA) 2.4 - - V CMOS output LOW voltage (FAIL, OCA) - - 0.4 V 2.5 - - k VCC-1.7 - VCC - VIN (Diff) 4 V VCC-1.7 - VCC-0.47 V Change in bias current limit over temperature Differential input impedance Data and clock inputs Common-mode input voltage Self-biased common mode input voltage 02068-DSH-001-C Data and clock inputs Mindspeed Technologies(R) Mindspeed Proprietary and Confidential 2 Product Specification 1.4 AC Characteristics VCC = +3.3V 10%, TA = -40 C to +85 C, unless otherwise noted. Table 1-4. AC Characteristics Parameter Conditions Differential input voltage =2 x (DIN+HIGH-DIN+LOW) (clock inputs follow same relationship) Modulation current range Modulation current with output disabled DIS-HIGH Min. Typ. Max. Units. 300 - 1860 mV 5 - 85 mA - - 300 A 4 ppm/C Programmable range for modulation current temperature coefficient Adjustable 500 - 10 Programmable temperature at which modulation current TC compensation enables Programmed by choice of RTCSLOPE 20 - 60 C Modulation output rise/fall times 20% to 80% into 25, with matching network - - 180 ps -10 - +10 % - - 1 120 ps - - 140 ps Overshoot of modulation output current Modulation output pulse width distortion Modulation output deterministic jitter Into 25 load, with matching network 1 Measured using alternating 1-0 pattern 23 peak-to-peak. Measured into 25 load using: 2 -1 PRBS at 622 Mbps includes pulse width distortion NOTE: 1. Contact your Mindspeed sales representative concerning availability of parts with a maximum modulation output pulse width distortion of 80 ps or less 02068-DSH-001-C Mindspeed Technologies(R) Mindspeed Proprietary and Confidential 3 2.0 Pin Description 2.1 Pin Descriptions Table 2-1. Pin Descriptions Pin No BCC+24 Pin No TQFP32 Name - 18 VCC - 22 GNDA - 32 VCC Power supply. Connect to VCC, do not leave open. - 5, 6, 8, 27 NC Not connected - 7 VCC Power supply. Connect to VCC, do not leave open. - 25 VCC Power supply. Connect to VCC, do not leave open. 1 9 ENA Bias and modulation output enable (TTL/CMOS). HIGH for normal operation 2 10 DIS Bias and modulation output disable (TTL/CMOS). LOW for normal operation 3 11 BIASMON Bias monitor. Connect a resistor between this pin and VCC to monitor. Connect to VCCif not in use. 4 12 MODMON Modulation monitor. Connect a resistor between this pin and VCC to monitor. Connect to VCC if not in use. 5 13 FAIL Mean power control failure indicator (TTL/CMOS). Goes low when control loop is no longer able to maintain constant current at PD 6 14 OCA Over-Current Alarm (TTL/CMOS). Goes low when IBIAS exceeds the preset bias current limit 7 - GND Ground. Connect to VCC, do not leave open. 8 17 BIAS Laser bias current output 9 1 VCC Power supply. Connect to VCC, do not leave open. 10 19 OUT+ Positive modulation current output. Sinks current when DIN is HIGH. 11 20 OUT- Negative modulation current output. Sinks current when DIN is HIGH. 12 23 GNDA Ground to output stage.(inductor to ground to optimize output stage performance) 13 24 PD 14 26 CMPC Mean power control dominant pole capacitor 15 15 GND Ground. Connect to VCC, do not leave open. 16 28 TCSLOPE 02068-DSH-001-C Function Power supply. Connect to VCC, do not leave open. Ground to output stage.(inductor to ground to optimize output stage performance) Monitor photodiode input. This input is connected to the monitor photodiode anode for automatic power control. Connecting a resistor between this pin and ground sets the temperature coefficient of IMODSET (using the internal IC temperature). Mindspeed Technologies(R) Mindspeed Proprietary and Confidential 4 Pin Description Table 2-1. Pin Descriptions (Continued) Pin No BCC+24 Pin No TQFP32 Name 17 - TCSTART Secondary temperature coefficient of IMOD. A resistor on this pin to ground sets the threshold temperature at which the temperature compensation starts. 18 30 MODSET Modulation current set. Connect a resistor between this pin and ground 19 31 OCASET Over current alarm set. Connect a resistor between this pin and ground 20 4 VCC Power supply. Connect to VCC, do not leave open. 21 2 DIN Positive Data Input (PECL). Self biased. 22 3 DIN Negative Data Input (PECL). Self biased 23 16 VCC Power supply. Connect to VCC, do not leave open. 24 29 GND Ground. Connect to VCC, do not leave open. 02068-DSH-001-C Function Mindspeed Technologies(R) Mindspeed Proprietary and Confidential 5 3.0 Functional Description 3.1 Overview The CX02068 laser driver consists of a high-speed modulation driver and a laser bias generator with mean power control (MPC). It is optimized for high speed, low power operation at 3.3 V supply. Figure 3-1. CX02068 Block Diagram V DD OUTOUT+ RD R SHUNT C SHUNT DIN DIN GNDA X100 DIS ENA BIAS MON X1 55 MOD MON IBIAS X55 I BIAS PD IMOD PP Failure Detect 55 FAIL R MPCSET 02068-DSH-001-C OCA SET OCA R OCA R TCSTART R TCSLOPE R MODSET V REF C MPC V DD Mindspeed Technologies(R) Mindspeed Proprietary and Confidential 6 Functional Description 3.2 Features * Rise and fall times <180 ps * Operates with +3.3 volt supply * DC or AC-coupled modulation drive * Independently programmable laser bias (to 100 mA) and modulation currents (to 85 mA) * Automatic laser power control, with programmable temperature compensation and `Slow-Start' * Bias and modulation current monitors * Failure monitor * Available in BCC+24 , TQFP32 and DIE packages * Available in RoHS compliant packages 3.3 Modulator The modulator output stage is designed to drive up to coupled performance depends on the laser used. 85 mA in either AC-coupled or DC-coupled mode. DC- The CX02068 modulation output is optimized for driving a 25 dynamic load; the minimum required voltage at OUT+ and OUT- is 0.6 V. To interface with the laser diode, a matching resistor (RD) is required for impedance matching. An RC shunt network is necessary to compensate for the laser diode parasitic inductance, thereby improving the optical eye. Typical values are RSHUNT = 51, CSHUNT = 3.3 pF Any capacitive loading at the cathode of a laser diode will degrade the optical output performance. An inductor is used to isolate the BIAS pin from the laser cathode. Figure 3-2. Typical modulation current vs RMODSET(3.3V) 0.1 0.09 0.08 IMOD (A) 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 0 5000 10000 15000 20000 25000 30000 35000 RMODSET ( ) 02068-DSH-001-C Mindspeed Technologies(R) Mindspeed Proprietary and Confidential 7 Functional Description 3.4 Mean Power Control Loop To maintain constant average optical power, the CX02068 incorporates a control loop to compensate for the changes in laser threshold current over temperature and lifetime. A monitor photodiode mounted in the laser package is used to convert the optical power into a photocurrent. The MPC loop adjusts the laser bias current so that the monitor current is matched to a reference current set by a single external resistor (RMPCSET). The time constant of the loop is then determined by CMPC. Figure 3-3. Typical bias current vs RBIASSET (3.3V) 120 Bias current (mA) 100 80 60 40 20 0 0 10000 20000 30000 40000 RBIASSET ( ) Safety logic is provided in order to limit the maximum bias current. The bias current at which the safety logic trips is set by an external resistor to ground (ROCA) from the OCASET pin. When the bias current limit is reached alarm flag OCA is asserted LOW. A loop failure alarm is also provided to detect when the bias current can no longer be adjusted to achieve the desired average optical power. Figure 3-4. Typical limiting current vs ROCA (at 25 C) 100 90 80 IOCA (mA) 70 60 50 40 30 20 10 0 0 10000 20000 30000 40000 ROCA ( ) 02068-DSH-001-C Mindspeed Technologies(R) Mindspeed Proprietary and Confidential 8 Functional Description Figure 3-5. Temperature coefficient of IOCA at different ROCA settings Change in I OCA over temperature (mA/C) 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 0 5000 10000 15000 20000 25000 30000 35000 ROCA () Figure 3-6. 02068-DSH-001-C Typical Eye Diagram Mindspeed Technologies(R) Mindspeed Proprietary and Confidential 9 Functional Description 3.5 Enable Control The CX02068 incorporates a dual polarity laser driver enable function. When ENA is LOW or DIS is HIGH, both the bias and modulation currents are off. 3.6 Current Monitors The CX02068 features bias and modulation current monitor outputs. The BIASMON output sinks a current equal to nominally 1/55 of the laser bias current (IBIAS). The MODMON output sinks a current equal to nominally 1/55 of the laser modulation current (IMOD). BIASMON and MODMON should be connected through a pull-up resistor to VCC. Choose a pull-up resistor value that ensures a voltage at BIASMON greater than VCC -1.6 V and a voltage at MODMON greater than VCC -1.0 V. These pins should be tied to VCC if not used. 3.7 Slow-Start For laser safety and reliability, the CX02068 incorporates a slow-start circuit that provides a delay of approximately 200 ns before enabling the laser diode. 3.8 Temperature Compensation The CX02068 features built in temperature compensation of the modulation current set using external resistors. Current pulled from TCSLOPE adjusts the slope of the temperature compensation where as current pulled from TCSTART sets the threshold temperature for the coefficient. 02068-DSH-001-C Mindspeed Technologies(R) Mindspeed Proprietary and Confidential 10 Functional Description Figure 3-7. Temperature Compensation Graphs 80mA 0.047 0.045 1 IMOD (A) 0.043 TCSLOP 2 E 0.041 0.039 0.037 0.035 -40 -20 0 20 40 60 80 100 Temperature (C) -40C +80C TCSTART 0mA 5000 10000 20000 32000 RTCSLOPE - Figures shown are in RTCSTART = 0, VCC = 3.3V 0.065 0.08 0.075 0.06 0.07 0.065 IMOD (A) IMOD (A) 0.055 0.05 0.045 0.06 0.055 0.05 0.04 0.045 0.04 0.035 -40 -20 0 20 40 60 80 Temperature (C) 5000 10000 100 0.035 -40 20000 -20 32000 5000 RTCSLOPE - Figures shown are in RTCSTART = 250, VCC = 3.3V 02068-DSH-001-C 0 20 40 60 80 100 Temperature (C) 10000 20000 32000 RTCSLOPE - Figures shown are in RTCSTART = 400, VCC = 3.3V Mindspeed Technologies(R) Mindspeed Proprietary and Confidential 11 4.0 Packaging Specification GND VCC DIN DIN VCC VCC Bare Die Information GND VCC Figure 4-1. Packaging Specification GND 4.1 1 9 10 VCC 41 ENA OCASET DIS MODSET GND GND BIASMON MPCSET MODMON TCSTART FAIL GND GND TCSLOPE OCA GND GND VCC CMPC 32 31 VCC PD GNDA GNDA VCCA OUTN OUTN OUTP OUTP VCCA GNDA BIAS 21 20 Dimensions: Pad opening 84 x 84 m Die size 1790 x 1718 m Die thickness 300 m 10% 02068-DSH-001-C Mindspeed Technologies(R) Mindspeed Proprietary and Confidential 12 Packaging Specification Table 4-1. Pad Centers PIN X Y PIN X Y PIN X Y PIN X Y ENA -727 440 BIAS -550 -711 VCC 727 -550 GND 550 711 DIS -727 330 GNDA -440 -711 CMPC 727 -440 VCC 440 711 GND -727 220 VCCA -330 -711 GND 727 -33- DIN 330 711 BIASMON -727 110 *OUTP -210 -711 TCSLOPE 727 -220 DIN 220 711 MODMON -727 0 *OUTP -210 -711 GND 727 -110 VCC 110 711 FAIL -727 -110 *OUTN 100 -711 TCSTART 727 0 GND 0 711 GND -727 -220 *OUTN 100 -711 MPCSET 727 110 VCC -110 711 OCA -727 -330 VCCA 220 -711 GND 727 220 VCC -440 711 GND -727 -440 GNDA 330 -711 MODSET 727 330 GND -550 711 VCC -727 -550 GNDA 440 -711 OCASET 727 440 PD 550 -711 VCC 727 550 02068-DSH-001-C Mindspeed Technologies(R) Mindspeed Proprietary and Confidential 13 Packaging Specification Figure 4-2. TQFP32 Package Information N F1 1 PIN 1 ID. 0 0.50P.05 Exposed Pad E E1 C0.50P.05X45D / -A- -B- F2 -D- D1 Chamfer .203 (4X) D TOP VIEW BOTTOM VIEW DETAIL X DETAIL A A2 A b SIDE VIEW Table 4-2. Package Dimensions Dimensions Tolerance 5 x 5 x 1.0 mm TQFP, +2.00 mm FP N Lead count 32 A Max. 1.20 A2 0.05 1.00 D 0.15 7.00 D1 0.05 5.00 E 0.15 7.00 E1 0.05 5.00 F1 0.10 2.67 F2 0.10 2.67 02068-DSH-001-C Mindspeed Technologies(R) Mindspeed Proprietary and Confidential 14 Packaging Specification Figure 4-3. BCC+24L Package Information TOP VIEW (PIN 1 CO RNER) BOTTOM VIEW 3.15 0.50 0.10 0.50 0.10 2.20 0.50 TYP. Y Figure 4-4. "A"(PIN 1 CO RNER) 0.15 C.L(PKG .) C.L(PKG .) 2.20 3.15 4.00 0.10 0.50 TYP. 3.20 4.00 0.10 X "B" 3.20 "C" SMT Mounting Guides 0.025 mm 0.35m m P C B land 0.2mm 0.025 mm Pad 1.3mm 0.3m m 0.025 mm 1.0mm 0.1mm 0.4 mm B C C P ad s view ed fro m ab o ve 0.2m m S older R esist M ask P aste S tencil 1.0m m Pad 0.025m m PC B land Lower R ight Pad 0.55mm 0.125m m 0.025mm 1.0mm 0.025m m 0.45m m 0.125m m 0.025m m 0.025m m 0.45mm C o rn er P ad s 0.55m m Solder R esis t M as k P aste S tencil E xp o sed Cen tral Pad (co n n ected to g ro u n d p lan e) 1.26m m 2.1m m Pad 0.1m m P C B land 1.26mm 0.025mm 0.025mm 0.1mm 0.1mm 2.1mm 0.1m m 0.025m m Paste Stencil Solder R esist M ask 0.025mm 0.025m m 0.675m m 0.675m m W indow S tencil 02068-DSH-001-C Mindspeed Technologies(R) Mindspeed Proprietary and Confidential 15 www.mindspeed.com General Information: Telephone: (949) 579-3000 Headquarters - Newport Beach 4000 MacArthur Blvd., East Tower Newport Beach, CA 92660 (c) 2006 Mindspeed Technologies(R), Inc. All rights reserved. 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