3.3V, 2.7Gbps SDH/SONET LASER DRIVER WITH AUTOMATIC POWER CONTROL FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTION Single 3.3V power supply Up to 2.7Gbps operation Rise/Fall times: < 75ps Independent programmable laser modulation and bias currents Bias current to 100mA and modulation current to 90mA Automatic average laser power control Bias and modulation current monitors Operating temperature range of –40°C to +85°C Complies with ANSI, ITU, and Bellcore SDH/SONET specifications Available in DIE form and 32-pin (5mm × 5mm) EPAD-MLF™ package SY88952L is a highly integrated and programmable laser driver for SONET/SDH application up to 2.7Gbps. The device accepts differential PECL or LVDS data and clock inputs. It provides programmable bias and modulation currents for driving a laser. The modulation output of SY88952L can be DC-coupled to drive the laser diode, providing a significant power saving over ACcoupled operation. A synchronizing TTL input latch can be used to reduce jitter if a clock signal is available. A TTL enable is also incorporated in the device. EN only enables/disables IMOD. It does not enable/disable IBIAS. An automatic power controller (APC) is integrated into SY88952L to maintain a constant average optical output power over temperature and lifetime. The modulation current can be externally temperature compensated to minimize the variation of extinction ratio of the optical output. Several safety features will enable an alarm function when the output signal is too high, or bias current is too high. There are two alarm conditions: 1. /FAIL asserts when bias current loop goes to maximum of it's range. IBIAS and IMOD still flow under this condition. 2. /FAIL asserts when IBIASMAX or IMODSET are too high (implying IBIAS or IMOD will be too high). All currents will shut off under this condition. APPLICATIONS ■ ■ ■ ■ ■ ■ ADVANCE SY88952L OC-48 transceivers and transponders SONET/SDH transmission system Add drop mux Metro area network 2.5Gbps optical transmitter Fiber optical module MLF and MicroLeadFrame are trademarks of Amkor Technology, Inc. Rev.: A 1 Amendment: /0 Issue Date: November 2002 SY88952L Micrel PACKAGE/ORDERING INFORMATION VCC BIASMAX MODSET VEE VEE VEE SLOW MD Ordering Information(Note 1) 1 2 3 4 5 6 7 8 32 3130 29 28 27 26 25 24 23 22 21 20 19 18 17 9 10 11 12 13 14 15 16 VCC /Q /Q VCC Q Q VCC VEE Package Type Operating Range Package Marking SY88952LMI MLF-32 Industrial SY88952L SY88952LMITR* MLF-32 Industrial SY88952L *Tape and Reel Note 1. Dice are designed to operate from –40°C to +85°C, but are tested and guaranteed to TA = +25°C only. EN VEE BIASMON MODMON /FAIL VEE VEE BIAS VCC D /D VCC CLK /CLK VCC LATCH Part Number 32-Pin MLF™ (MLF-32) PIN DESCRIPTION Pin Number Pin Name Pin Function 16 BIAS 11 BIASMON Bias Current Monitor: Sinks current that is proportional to IBIAS, (IBIAS /40). An external current path must exist to VCC. 31 BIASMAX A resistor (RBIASMAX) connected to ground sets the maximum bias current. See “Typical Operating Characteristics” (IBIAS vs. RBIASMAX). 26 SLOW 5, 6 CLK,/CLK 2, 3 D, /D 9 EN 8 LATCH 25 MD 19, 20, 22, 23 Q, /Q 12 MODMON Modulation Current Monitor: Sinks current that is proportional to IMOD, (IMOD /45). An external current path must exist to VCC. 30 MODSET A resistor (RMODSET) connected to ground sets the modulation current. See “Typical Operating Characteristics” (IMOD vs. RMODSET). 13 /FAIL TTL Open-Collector Output: Connect a 5kΩ resistor to VCC. Indicates APC failure when LOW. 1, 4, 7, 18, 21, 24, 32 VCC Positive Power Supply. 10, 14, 15, 17, 27, 28, 29, EP VEE Device Ground: Ensure the exposed pad is also connected to ground. Bias Current Output (IBIAS). Connect a capacitor (CSLOW) to ground to provide a slow-start. Differential Clock Input. 75KΩ pull-down on CLK, 75kΩ pull-up and 75kΩ pull-down on /CLK. Differential Data Input. 75KΩ pull-down on D, 75kΩ pull-up and 75kΩ pull-down on /D. TTL Input with 75kΩ pull-up: Default HIGH for normal operation; LOW to disable modulation current. TTL Input with 75kΩ pull-up: Default HIGH for latched (clocked) data; LOW for direct data. Connect this pin to a monitor photodiode anode, a resistor (RAPCSET) and a capacitor (CAPCSET). This sets the desired average optical power. Differential Output: Modulation current output (IMOD). TRUTH TABLE(Note 1) D /D EN OUT(Note 2) Note 1. Note 2. /OUT L H H H L H L H L H X X L H L 2 L = LOW, H = HIGH, X = don't care. H = IOUT ≤ IMOD_OFF. Micrel SY88952L Absolute Maximum Ratings(Note 1) Operating Ratings(Note 2, 3) Supply Voltage (VCC) ..................................... +0V to +7.0V Input Voltage (VIN) ............................................ +0V to VCC Output Current (IOUT) ............................................... 100mA Lead Temperature (soldering, 10 sec.) ..................... 300°C Storage Temperature (TS) ....................... –65°C to +150°C Supply Voltage (VCC) .................................. +3.0V to +3.6V Ambient Temperature (TA) ......................... –40°C to +85°C Junction Temperature (TJ) ........................................ 120°C Package Thermal Resistance MLF™ (θJA) still-air ..................................................... 34°C/W (ψJB) still-air ..................................................... 19°C/W Note 1. Permanent device damage may occur if ABSOLUTE MAXIMUM RATINGS are exceeded. This is a stress rating only and functional operation is not implied at conditions other than those detailed in the operational sections of this data sheet. Exposure to ABSOLUTE MAXIMUM RATlNG conditions for extended periods may affect device reliability. Note 2. The data sheet limits are not guaranteed if the device is operated beyond the operating ratings. Note 3. Devices are ESD sensitive. Handling precautions recommended. DC ELECTRICAL CHARACTERISTICS VCC = 3.0V to 3.6V; VEE = GND; RLOAD = 5Ω; TA = –40°C to +85°C Symbol Parameter Condition ICC Supply Current Note 1 IBIAS Bias Current Range Note 2 IMOD Modulation Current Range Note 2 IMOD_OFF Modulation Off Current Note 3 VID Differential Input Voltage VICMR Common Mode Range VIH TTL Input HIGH Voltage VIL TTL Input LOW Voltage VOL /FAIL Output LOW Voltage IOH /FAIL Output Leakage Current Note 1. Note 2. Note 3. Note 4. Note 5. Min Typ Max Units 85 mA 1 100 mA 1 90 mA 750 µA 200 1600 mVp-p VCC –1.49 VCC –VID/4 V 2.0 VCC V 0.8 V Note 4 0.5 V Note 5 100 µA Excluding actual IBIAS and IMOD output currents. Voltage at Q, /Q must not drop below VCC –1.5V. Voltage BIAS, MODMON and BIASMON must not drop below VCC –2V. EN = LOW. IOL = +2mA. VOH = 3.6V. 3 SY88952L Micrel AC ELECTRICAL CHARACTERISTICS(NOTE 1) VCC = 3.0V to 3.6V; VEE = GND; TA = –40°C to +85°C; typical values @VCC = 3.3V, TA = 25°C, IMOD = 40mA, IBIAS = 50mA, RLOAD = 5Ω Symbol Parameter CID Maximum Consecutive Identical Digits PWD Pulse Width Distortion tS Latch Set-Up Time 40 ps tH Latch Hold Time 40 ps t r, t f Output Rise/Fall Time (20% to 80%) Note 1. Note 2. Note 3. Condition Min Typ Max 80 Note 2, 3 bits 50 75 AC characteristics are guaranteed by design and characterization. Measured with 622Mbps 0-1 pattern, latch = HIGH. PWD = (Wider pulse – narrower pulse) /2. TIMING DIAGRAM tCLK = 400ps CLK tS tH D Setup/Hold Time Definition 4 Units ps ps Micrel SY88952L TYPICAL OPERATING CHARACTERISTICS(NOTE 1) VCC = 3.3V, TA = 25°C, unless otherwise stated. 160 140 140 120 120 100 100 80 60 60 40 20 20 10000 0 10 100 1000 RBIASMAX (Ω) Bias-Current Monitor Gain vs. Temperature IMOD = 40mA, IBIAS = 50mA 50 40 30 IMOD = 10mA, IBIAS = 10mA 20 10 0 -40 10000 -20 0 20 40 60 TEMPERATURE (°C) IAPCSET vs. RAPCSET 2 IMOD = 40mA, IBIAS = 50mA 50 1.5 40 IAPCSET (mA) GAIN (IBIAS/IBIASMON) 60 30 IMOD = 10mA, IBIAS = 10mA 20 1 0.5 10 0 -40 Note 1. 80 40 100 1000 RMODSET (Ω) 60 GAIN (IMOD/IMODMON) 160 0 10 Modulation-Current Monitor Gain vs. Temperature IBIAS vs. RBIASMAX IBIAS (mA) IMOD (mA) IMOD vs. RMODSET -20 0 20 40 60 TEMPERATURE (°C) 0 1 80 IBIAS and IMOD must never exceed 100mA and 90mA, respectively. 5 10 RAPCSET (KΩ) 100 80 SY88952L Micrel BLOCK DIAGRAM VCC LATCH /Q 0 RD Q D D MUX Q CLK 1 EN VCC 100Ω BIAS BIASMON X40 IBIAS 40 X40 VCC MD 100Ω IMOD 45 RAPCSET Failure Detect MODSET RBIAS MAX SLOW RMODSET VREF CSLOW MODMON /FAIL BIASMAX 5kΩ VCC 6 CAPCSET Micrel SY88952L 32 LEAD EPAD-Micro LEADFRAME™ (MLF-32) Rev. 01 Package EP- Exposed Pad Die CompSide Island Heat Dissipation Heat Dissipation VEE Heavy Copper Plane VEE Heavy Copper Plane PCB Thermal Consideration for 32-Pin MLF™ Package (Always solder to equivalent or PCB) 7 SY88952L Micrel MICREL, INC. 1849 FORTUNE DRIVE TEL + 1 (408) 944-0800 FAX SAN JOSE, CA 95131 USA + 1 (408) 944-0970 WEB http://www.micrel.com This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel, Inc. © 2002 Micrel, Incorporated. 8