5V SDH/SONET 2.5Gb/s PAF SEMICONDUCTOR St) m@ 5V power supply @ Up to 2.5Gbps operation @ 25mA peak drive current @ Separate modulation control @ Separate output enable for laser safety @ Differential inputs for data @ 75KQ input pulldown resistor @ Designed for use with SY88923, SY88904 or SY88905 @ ESD protection of 2000V @ Available in a tiny 10-pin (3mm) TSSOP PIN CONFIGURATIONS LASER DIODE DRIVER SY88922 DESCRIPTION The SY88922 is a high speed current switch for driving a semiconductor laser diode in optical transmission applications. The output current, or modulation current IMoD, is DC current controlled by IRSET, current through the resistor RSET. The output OUT is HIGH when output enable is HIGH. The device incorporates complementary open collector outputs with a capability of driving peak current of 25mA. The resistor REXT must be placed between OUT and Vcc to dissipate the worst case power. RSER is recommended to compensate for laser diode matching issues. The SY88922 utilizes the high performance bipolar ASSET technology. APPLICATIONS _ CJ @ 1.25Gbps Gigabit Ethernet EN LY] 19] veo lm 531Mbps and 1062Mbps Fibre Channel Om let |) eoview Pel OUT 622Mbps SONET Ow [a once pe] OUT @ Gigabit Interface Converter Vrer [4] 17] GND @ 2.5Gb/s SDH/SONET Rset [5] 16] GND BLOCK DIAGRAM Vcc REXT OUT OUT RSER DIN I Internal Logic DIN to Laser Diode 4 ENG _s BIAS Control 40X Bae | Vcc Modulation Control 4 GND GND VREF RSET Ku RSET 1999 Micrel-Synergy Rev.: B Amendment: /0 Issue Date: November 1999SEMICONDUCTOR SY88922 PPINNAMES TRUTH TABLE Pin Function Vcc Most positive power supply input, +5V for PECL operation. GND Ground Din, Din These differential PECL 100K compatible inputs receive NRZ data. EN This PECL 100K compatible input enables Laser Driver. Modulation current goes to zero when asserted HIGH. OUT, OUT Open collector outputs from the modulation buffer drive these differential current outputs. VREF Voltage reference for use with RSET. RSET An external resistor sets up the source current for modulation Imod. NOTES: 1. L= LOW, H = HIGH, X = don't care 2. H=lout=OmA ABSOLUTE MAXIMUM RATINGS") Symbol Rating Value Unit Vcc Power Supply Voltage 0 to +7.0 Vv Vi Input Voltage 0 to Vcc Vv lo Output Current 25 mA TA Operating Temperature Range 0 to +85 C Tstore Storage Temperature Range 55 to +125 C Piot Power Dissipation 250 mw NOTE: 1. Permanentdevice damage may occur if ABSOLUTE MAXIMUM RATINGS are exceeded. This is a stress rating only and functional operation is notimplied at conditions other than those detailed in the operational sections of this data sheet. Exposure to ABSOLUTE MAXIMUM RATING conditions for extended periods may affect device reliability. OPERATIONING CONDITIONS) Symbol Rating Value Unit Vcc Power Supply Voltage +4.5 to +5.5 Vv REXT Resistor to Dissipate Power 10 to 50 9 RSER Laser Diode Serial Resistor 0 to 50 9 RSET Resistor to Adjust Current 1500 to 50,000 9 @JA Thermal Resistance of Package to Ambient(2) 113 C/W CouT Capacitance on OUT + OUT 2.5 typical pf NOTES: 1. The voltage drop across RexT and Rser plus Laser Diode should not be greater than 2V. 2. Still air without heatsink.SEMICONDUCTOR SY88922 DC ELECTRICAL CHARACTERISTICS GND = OV; Vcc = +5.0V 10%; Ta = 0C to + 85C Ta =0C Ta = +25C Ta = +85C Symbol Parameter Min. Typ. Max. Min. Typ. Max. Min. Typ. Max. Unit VIH Input HIGH Voltage Vec-1165 _ Vcec-880 |Vcc-1165 _ Vcc-880 | Vcc-1165 _ Vcc-880 mv (DIN, DIN, EN) VIL Input LOW Voltage Vec-1810 _ Vec-1475 | Vcc-1810 _ Vec-1475] Vcc-1810 _ Vec-1475] mV (DIN, DIN, EN) VREF Reference Voltage 3.12 3.00 2.80 Vv NL Input LOW Current() 0.5 _ _ 0.5 _ _ 0.5 _ _ uA (DIN, DIN, EN) IIH Input HIGH Current _ _ 100 _ _ 100 _ _ 100 uA (DIN, DIN, EN) Icc Supply Current() 16 25 16 25 16 25 mA IOL Output LOW Current _ _ 500 _ _ 500 _ _ 500 uA (EN = HIGH) IOUT Modulation Current 5 15 25 5 15 25 5 15 25 mA IRSET Modulation Control 0.125 _ 0.625 0.125 _ 0.625 | 0.125 0.625 mA ARSET =lOUT/IRSET 30 38 44 30 38 44 30 38 44 NOTES: 1. Vi = VIL(Min.) 2. IMOD = 25mA. AC ELECTRICAL CHARACTERISTICS) IMoD =10mA; GND = OV; Vcc = +5V +10%; Ta = 0c to + 85C Ta =0C Ta = +25C Ta= +85C Symbol Parameter Min. | Typ. | Max. | Min. | Typ. | Max. | Min. | Typ. | Max. | Unit Conditions ted D Propagation Delay _ | 1000} 500 | 1000 | | 1000] ps DIN - OUT ted EN Propagation Delay _ | 1000} 450 | 1000 | | 1000] ps EN - OUT tr Rise/Fall Time _ _ 160 _ 110 | 160 _ _ 160 ps Load = 250, tf (20% to 80%) lor Output Current Ringing) | 10 10 10 % NOTES: 1. Rext = RSerR = 250 +1%, RSER connects to Vcc directly without Laser Diode. 2. loH =5 to 25mASEMICONDUCTOR SY88922 PERFORMANCE CURVES lo and Rset 30 LA \ 10 ~ | lo (mA) a Pp] O.Q LLLLILIEPL TIP AL PPT 0.0 2.0K 4.0K 6.0K 8.0K 10K 12K Rset (ohm) PRODUCT ORDERING CODE Ordering Package Operating Code Type Range SY88922KC K10-1 Commercial SY88922KCTR K10-1 CommercialSYNERGY SEMICONDUCTOR oa SY88922 APPLICATION EXAMPLE FOR 3-CHIP SET SOLUTION GBIC Terminal TX_DATA+ TX_DATA- ENABLE/DISABLE RX_LOS RX_DATA+ RX_DATA PTT TTT SSS 1 20kQ, I I WW Vcc ++ t Voc 13 3! 1S | 4 Oo a 1d oie 3 3 VREF | RSET 1 5 wi a 2:78 83 38 OUT i 3 = | DIN I T ; s DIN > SY88922 Out RSER Laser $ $ WW Module rs [dL el ; 7 vec GND Voc a IBIAS | MD \ The value of RSER ; IBIAS SET 0K depends on the Laser Diode. IBIAS FB poy SY88905 41 LoSout PINSET _ 41 LOSIN | L 20K0 Voc GND VREF Vcc Vcc | EN | LOS gh LS of Lg = 88 oO 38 DIN 5 4 Dout i . DIN * Dour SY88923 = 5 Vcc S$ 23 g $ $ g 0.1pF 2 p $ > LOSLVL II l I t | tL dels - Vcc GND VREF Ty SEMICONDUCTOR SY88922 10 LEAD TSSOP (K1 TOP VIEW END VIEW BOTTOM VIEW 1.02 +308 10.040 *8-003) o10 793 (0.004 9.908] Sr 4.90 [0.193] BSC ypa- SEE DETAIL A lL a +908 0.23 B53 z _ BSC 1 10.020] 3.00738 10.118 238843 (0.007 +2203) 10.009 +9883 NOTES: 1, DIMENSIONS ARE IN MM CINCHESI, . CONTROLLING DIMENSION: MM DIMENSION DOES NOT INCLUDE MOLD FLASH OR PROTRUSIONS, EITHER OF WHICH SHALL NOT EXCEED 0.20 (0.008) PER SIDE, FSitaae TO.004T ! Sf. k TT oss 25 cage [0.022 *8.096) ve DETAIL A