VITESSE SEMICONDUCTOR CORPORATION Preliminary Data Sheet VSC7924 SONET/SDH 2.5Gb/s Laser Diode Driver Features Applications • Rise Times Less Than 100ps • SONET/SDH at 622Mb/s, 1.244Gb/s, and 2.488Gb/s • High-Speed Operation (Up to 2.5Gb/s NRZ Data) • Full-Speed Fibre Channel (1.062Gb/s) • Single-Ended Operation • Single Power Supply • Direct Access to Modulation and Bias FETs • Data Density Monitors • 24-Pin Ceramic Package General Description The VSC7924 is a single 5V supply, 2.5Gb/s laser diode driver with direct access to the laser modulation and bias FETs. Laser bias and modulation currents are set by external components allowing precision monitoring and setting of the current levels. Data inputs accept ECL levels. Data density outputs are provided to allow the user to adjust the laser bias in high unbalanced data applications. VSC7924 Block Diagram IOUT NIOUT MK NMK DIN VREF IBIAS IMOD VIP *TERM VIB MIP MIB *Terminated to Off-chip Capacitor G52156-0, Rev 3.0 05/01/01 © VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012 Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: [email protected] Internet: www.vitesse.com Page 1 VITESSE SEMICONDUCTOR CORPORATION Preliminary Data Sheet VSC7924 SONET/SDH 2.5Gb/s Laser Diode Driver Table 1: Signal Pin Reference Signal Type Level # Pins In ECL 1 Data Input MK, NMK Out ECL 2 Data Density Differential Outputs NIOUT Out 1 Laser Modulation Current Output (Complementary) DIN Description IOUT Out 1 Laser Modulation Current Output (To Laser Cathode)) VSS Pwr Pwr 5 Negative Voltage Rail GND Pwr Pwr 8 Positive Voltage Rail VIP In DC 1 Modulation Gate Node MIP In DC 1 Modulation Source Node VIB In DC 1 Bias Gate Node MIB In DC 1 Bias Source Node VREF In DC 1 Data Input Reference TERM In DC 1 Data Input Reference Total Pins 24 Table 2: Absolute Maximum Ratings Symbol Rating Limit VSS Negative Power Supply Voltage VCC to -6.0V TJ Maximum Junction Temperature -55°C to + 125°C TSTG Storage Temperature -65°C to +150°C Table 3: ECL Input and Outputs Symbol Parameter Min Typ Max Units Conditions VIN Input Voltage Swing 300 800 mV Peak-to-peak, VREF = -1.3V VOH ECL Output High Voltage -1200 -700 mV 50Ω to -2.0V VOL ECL Output Low Voltage -2000 -1600 mV 50Ω to -2.0V Max Units Table 4: Recommended Operating Conditions Symbol Parameter Min GND Positive Voltage Rail VSS Negative Voltage Rail -5.5 TCl Operational Temperature(1) -40 TJ Junction Temperature Typ 0 -5.2 Conditions V -4.9 V 85(2) °C 125 °C Power dissipation = 1.25W NOTES: (1) Lower limit of specification is ambient temperature and upper limit is case temperature. (2) See “Calculation of the Maximum Case Temperature” section for detailed maximum temperature calculations. Page 2 © VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012 Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: [email protected] Internet: www.vitesse.com G52156-0, Rev 3.0 05/01/01 VITESSE SEMICONDUCTOR CORPORATION Preliminary Data Sheet VSC7924 SONET/SDH 2.5Gb/s Laser Diode Driver Table 5: Power Dissipation Symbol Parameter Min Typ Max Units Conditions IVSS Power Supply Current (VSS) 220 mA VSS = -5.5V, IMOD = IBIAS = 0mA PD Total Power Dissipation 1120 mW VSS = -5.5V, IMOD = IBIAS = 0mA, RLOAD = 25Ω to GND PDMAX Maximum Power Dissipation 1815 mW VSS = -5.5V, IMOD = 60mA, IBIAS = 50mA, IOUT = 0V Max Units 50 mA Table 6: Laser Driver DC Electrical Specifications Symbol Parameter Min IBIAS Programmable Laser Bias Current 2 IMOD Programmable Modulation Current 2 Typ Conditions 60 mA V IBIAS = 50mA V IMOD= 60mA V VSS = -5.2V VIB Laser Bias Control Voltage VSS + 2.1 VIP Laser Modulation Control Voltage VSS + 2.1 VOCM Output Voltage Compliance GND -2.2V Table 7: Laser Driver AC Electrical Specifications Symbol tR, tF Parameter Min Typ Output Rise and Fall Times Max Units 100 ps Conditions 25Ω load, 20%-80%, 15mA < IMOD < 60mA, IBIAS = 20mA Table 8: Package Thermal Specifications Symbol θJCC G52156-0, Rev 3.0 05/01/01 Parameter Thermal Resistance from junction-to-case Min Typ 25 Max Units °C/W Conditions Ceramic Package © VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012 Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: [email protected] Internet: www.vitesse.com Page 3 VITESSE SEMICONDUCTOR CORPORATION Preliminary Data Sheet VSC7924 SONET/SDH 2.5Gb/s Laser Diode Driver Calculation of the Maximum Case Temperature The VSC7924 is designed to operate with a maximum junction temperature of 125°C. The rise from the case to junction is determined by the power dissipation of the device. The power dissipation is determined by the VSS current plus the operating IMOD and IBIAS currents. The power of the chip is determined by the following formula: PD = (-VSS * ISS) + ((VIOUT – VSS) * IMOD) + ((VIBIAS – VSS) * IBIAS) For example with: VSS IMOD IBIAS VIBIAS VIOUT = = = = = -5.2V 40mA 20mA -2.0V -2.0V PD = (-5.2 * 220mA) + ((5.2 - 2.0) * 40mA) + ((5.2-- 2.0) * 20mA) PD = 1144mW + 128mW + 64mW = 1.336W The thermal rise from junction to case is θJC * PD. For the ceramic package, θJC = 25°C/W. Thus the thermal rise is: 25°C/W * 1.336W = 33.4°C The maximum case temperature is: 125°C – 33.4°C = 91.6°C The absolute maximum power dissipation of the device is at: VSS IMOD IBIAS VIBIAS VIOUT = = = = = PD = -5.5V 60mA 50mA 0V 0V (5.5 * 220mA) + (5.5 * 60mA) + (5.5mA * 50mA) PD = 1.815W This will net a maximum junction to case thermal rise of: 1.815W * 25°C/W = 45.4°C This situation will allow maximum case temperature of: 125°C – 45.4°C = 79.6°C Page 4 © VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012 Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: [email protected] Internet: www.vitesse.com G52156-0, Rev 3.0 05/01/01 VITESSE SEMICONDUCTOR CORPORATION Preliminary Data Sheet VSC7924 SONET/SDH 2.5Gb/s Laser Diode Driver Input Termination Schemes Figure 1: Input Structure OV (GND) 1.4k 1400Ω 1.4kΩ 1400 DIN X • Nominal VREF = -1.3V • 1400, 4300 Ohm Resistor on die, nominal values + - VREF X TERM X 12pF 3Ω 4.3k 4300Ω 4.3k 4300Ω Nominal VREF = 1.3V 1.4kΩ, 4.3kΩ resistor on die, nominal values GND -5.2V (VSS) Figure 2: Single-Ended AC Coupled GND 0.1µF DIN + X SOURCE TERM or VREF 50Ω - X 0.1µF -2V VSS GND Figure 3: Single Ended AC Coupled with Offset Adjust GND 0.1µf SOURCE 50Ω DIN X + VREF - X GND 3 VSS 2000 2kΩ X TERM 4.3kΩ 4300 VSS G52156-0, Rev 3.0 05/01/01 0.1µf GND © VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012 Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: [email protected] Internet: www.vitesse.com Page 5 VITESSE SEMICONDUCTOR CORPORATION Preliminary Data Sheet VSC7924 SONET/SDH 2.5Gb/s Laser Diode Driver Figure 4: Control Signals VIP and VIB I (MIB) 50 mA VIB 1.5V (Typical) 2.1V (Maximum) Typical Bias Current v.s. Bias Voltage I (MIP) 60 mA VIP 1.5V (Typical) 2.1V (Maximum) Typical Modulation Current v.s. Modulation Voltage Figure 5: Simplified Output Structure NIOUT X VIP IOUT X OUTPUT DIFF PAIR X IMOD Page 6 X VIB IBIAS X X MIP MIB © VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012 Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: [email protected] Internet: www.vitesse.com G52156-0, Rev 3.0 05/01/01 VITESSE SEMICONDUCTOR CORPORATION Preliminary Data Sheet VSC7924 SONET/SDH 2.5Gb/s Laser Diode Driver Figure 6: Pad Assignments for VSC7924 Die 1720 1620 50 120 120 150 30 PAD 34 PAD 33 PAD 32 PAD 31 PAD 30 PAD 29 VREF VSS VSS VSS VSS VIP PAD 28 PAD 27 PAD 26 MIP MIP MIB PAD 1 DIN PAD 25 VIB PAD 2 VSS PAD 24 GND0 PAD 3 DIN PAD 23 OUT PAD 4 GND PAD 22 OUT PAD 5 GND PAD 21 GND0 PAD 6 GND PAD 20 NOUT PAD 7 VSS PAD 19 VSS PAD 8 VSS PAD 18 VSS TERM PAD 9 TERM PAD 10 GND PAD 11 50 50 1620 1720 GND GND GND GND NMARK MARK PAD 12 PAD 13 PAD 14 PAD 15 PAD 16 PAD 17 50 Dimensions in micrometers. 1) 2) 3) 4) 5) Die size = 1620µm x 1620µm Actual die size = 1720µm x 1720µm (after the die are cut up) Pad size = 120µm x 120µm Pad pitch = 150µm Space between pads = 30µm G52156-0, Rev 3.0 05/01/01 © VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012 Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: [email protected] Internet: www.vitesse.com Page 7 VITESSE SEMICONDUCTOR CORPORATION Preliminary Data Sheet VSC7924 SONET/SDH 2.5Gb/s Laser Diode Driver VSS VSS VIP MIP MIB 24 23 22 21 20 19 18 GND 3 16 IOUT GND 4 15 GND GND 5 14 NIOUT VSS 6 7 8 9 10 11 13 12 MK GND NMK 17 GND 2 GND DIN GND 1 TERM VSS Note: Page 8 VREF Pin Diagram for 24-Pin Ceramic Package VIB VSS Package bottom plate is connected to GND within the package. Package lid is electrically unconnected. © VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012 Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: [email protected] Internet: www.vitesse.com G52156-0, Rev 3.0 05/01/01 VITESSE SEMICONDUCTOR CORPORATION Preliminary Data Sheet VSC7924 SONET/SDH 2.5Gb/s Laser Diode Driver Package Information - 24 Pin Ceramic Package (Formed Leads) Top View A 24 23 22 21 20 19 INDEX E 18 1 2 17 3 16 4 15 5 14 6 13 Key mm In A 9.5 0.374 B 7.7 0.303 C 2.0 0.079 D 1.27 0.050 E 0.30 0.012 F 1.7 0.067 G 0.6 0.024 H 11.5 0.453 I 0.125 0.005 J 8.51 0.335 A 7 8 9 10 D 11 12 Side View B G I F J H C NOTES: Drawing not to scale. Package #: 101-312-0 Issue #:1 L id #: 101-303-1 Issue #:1 G52156-0, Rev 3.0 05/01/01 © VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012 Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: [email protected] Internet: www.vitesse.com Page 9 VITESSE SEMICONDUCTOR CORPORATION Preliminary Data Sheet VSC7924 SONET/SDH 2.5Gb/s Laser Diode Driver Package Information - 24 Pin Ceramic Package (Straight Leads) Top View A 24 23 22 21 20 19 INDEX E 18 1 Key mm In A 9.5 0.374 B 7.7 0.303 C 5.8 .230 D 1.27 0.050 E 0.30 0.012 F 1.7 0.067 G 0.6 0.024 H 9.53 0.375 2 17 I 0.125 0.005 3 16 J 8.51 0.335 4 15 5 14 6 13 A 7 8 9 10 D 11 12 Side View B I G C H F C NOTES: Drawing not to scale. Package #: 101-000-0 Issue #:1 Page 10 © VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012 Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: [email protected] Internet: www.vitesse.com G52156-0, Rev 3.0 05/01/01 VITESSE SEMICONDUCTOR CORPORATION Preliminary Data Sheet VSC7924 SONET/SDH 2.5Gb/s Laser Diode Driver Ordering Information The order number for this product is formed by a combination of the device number, and package style. VSC7924 XX Device Type VSC7924: 2.5Gb/s Laser Diode Driver Package Style KF: (Ceramic - Straight Leads) KFL: (Ceramic- Formed Leads) Notice Vitesse Semiconductor Corporation (“Vitesse”) provides this document for informational purposes only. This document contains pre-production information about Vitesse products in their concept, development and/or testing phase. All information in this document, including descriptions of features, functions, performance, technical specifications and availability, is subject to change without notice at any time. Nothing contained in this document shall be construed as extending any warranty or promise, express or implied, that any Vitesse product will be available as described or will be suitable for or will accomplish any particular task. Vitesse products are not intended for use in life support appliances, devices or systems. Use of a Vitesse product in such applications without written consent is prohibited. G52156-0, Rev 3.0 05/01/01 © VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012 Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: [email protected] Internet: www.vitesse.com Page 11 VITESSE SEMICONDUCTOR CORPORATION Preliminary Data Sheet SONET/SDH 2.5Gb/s Laser Diode Driver Page 12 © VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012 Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: [email protected] Internet: www.vitesse.com VSC7924 G52156-0, Rev 3.0 05/01/01