a8e re AdLib OCR Evaluation systems Advance Data Sheet February 2002 NetLight(c) NLP12 Small Form-Factor Pluggable (SFP) Gigabit Ethernet Laser Transceiver Benefits w6 ~.w . Upgrade path : - OEMs can offer longer-reach and higher-speed solutions, as the end user needs upgrades . Applications . IEEE@ 802 .3z 1000BASE-LX Available in a small form factor, LC Receptacle connector metal package, the NLP12 SFP Transceiver is a high-performance, cost-effective, optical transceiver for Gigabit Ethernet applications . Features . Multisource agreement (MSA) compliant SFP package . LC duplex receptacle . Metal package for superior EMI performance . 1300 nm FP laser transmitter with automatic output power control (1000BASE-LX version) . 850 nm VCSEL laser transmitter with automatic output power control (1000BASE-SX version) . Transmitter disable input . Hot-pluggable electrical interface . Wide dynamic range . TTL signal-detect output . Low power dissipation . Single 3 .3 V power supply . ac-coupled data inputs and outputs . Operating temperature range of 0 C to 85 C (1000BASE-LX only) . Serial identification (EEPROM) . IEEE 802 .3z 1000BASE-SX Description The NLP12 small form-factor pluggable (SFP) transceiver is a high-speed, cost effective optical transceiver that is intended for 1 .25 Gbits/s Gigabit Ethernet 1000BASE-LX and 1000BASE-SX applications . The transceiver features Agere Systems' optics and is packaged in a narrow-width metal housing with an LC duplex receptacle. This receptacle fits into an RJ-45 form factor outline . The SFP package pinout conforms to a multisource SFP transceiver agreement . The transmitter features ac-coupled differential data inputs. The transmitter also features a TTL logic level disable input and a transmitter fault indicator output. The receiver features differential ac-coupled data outputs and a TTL logic level loss-of-signal output. AdLib OCR Evaluation NetLight NLP12 Small Form-Factor Pluggable (SFP) Gigabit Ethernet Laser Transceiver Advance Data Sheet February 2002 Absolute Maximum Ratings Stresses in excess of the absolute maximum ratings can cause permanent damage to the device . These are absolute stress ratings only. Functional operation of the device is not implied at these or any other conditions in excess of those given in the operations sections of the data sheet. Exposure to absolute maximum ratings for extended periods can adversely affect device reliability . Parameter Symbol Min Max Unit Tst9 -40 85 C Tc VccT, R 0 85 C 0 3.8 V Storage Temperature Range Case Temperature Range Supply Voltage NLP12-10-AA, 1300 nm FP Table 1 . Recommended Operating Conditions Parameter Case Temperature Range Supply Voltage D ata R ate 2 Symbol Min Typ Max Unit Tc 0 - 85 C VccT, R 3.135 - 3.465 V - - 1 .2 5 - Gbitsts Agere Systems Inc . Advance Data Sheet February 2002 AdLib OCR Evaluation NetLight NLP12 Small Form-Factor Pluggable (SFP) Gigabit Ethernet Laser Transceiver NLP12-10-AA 1300 nm FP (continued) Transceiver Optical and Electrical Characteristics Table 2. Transmitter Optical and Electrical Characteristics (TC = 0 C to 85 C, VCC = 3.135 V-3 .465 V) Parameter Symbol Min Max Unit Po PO DIS -9.5 - -3 -35 dBm dBm kc 1285 1343 nm AXRnas - 2.8 nm Dynamic Extinction Ratio EXT 9 - dB Optical Output Rise/Fall Time (20%-80%) tR/tF - 260 ps Total Transmitter Jitter added at TP21 Tj - 227 ps Relative Intensity Noise RIN - -120 db/Hz Power Supply Current ICCT - 150 mA VINp-p 300 1600 mVp-p Transmit Disable Voltage3 VD Vcc - 1 .3 VCC V Transmit Enable Voltage3 VEN VEE VEE + 0.8 V Transmit Disable Assert Time4 t-off - 10 ps Transmit Disable Negate Times ton - 1 ms VFAULTH VFAULTL Vcc - 1 .3 0 VCC 0.5 V V Transmit Fault Assert Time6 t-fault - 100 ps Transmit Fault Reset Time7 t-reset 10 - ps Optical Output Power: Average Disabled Optical Wavelength Spectral Width Input Data Voltage-Differentia12 Transmit Fault Output Voltage Level 1. 2. 3. 4. 5. 6. 7. TP2 refers to compliance point specified in 802 .3z, section 38 .2.1 . Differential operation is necessary for optimum performance . TTL compatible interface . Time from rising edge of Tx Disable to when the optical output falls below 10% of nominal . Time from falling edge of Tx Disable to when the modulated optical output rises above 90% of nominal. Time from fault to Tx_Fault on . Time Tx Disable must be held high to reset Tx Fault . Agere Systems Inc. 3 AdLib OCR Evaluation NetLight NLP12 Small Form-Factor Pluggable (SFP) Gigabit Ethernet Laser Transceiver Advance Data Sheet February 2002 NLP12-10-AA, 1300 nm FP (continued) Transceiver Optical and Electrical Characteristics (continued) Table 3. Receiver Optical and Electrical Characteristics (Tc = 0 C to 85 C, Vcc = 3.135 V-3 .465 V) Parameter Average Sensitivityi Stressed Receiver Sensitivity2 Maximum Input Powers Optical Return Loss Power Supply Current Power Supply Noise Rejection Ratio Output Data-Differential3 Data Output Rise/Fall Time Loss-of-Signal Voltage Level Loss-of-Signal Assert Time4 Loss-of-Signal Deassert Times Loss-of-Signal Assert Deassert LOS Hysteresis I Symbol Min Max Unit PI PSTRESS Pnnax ORL ICCR PSNR VOUTP-p tR/tF VLOSH VLOSL t loss on t loss off -3 12 400 Vcc - 1 .3 0 - -20 -14 .4 150 100 1200 175 VCC 0 .8 100 100 dBm dBm dBm dB mA mV MVP-p PS V V las PLOSA PLOSD PHVS -34 -34 0.5 -20 .5 -20 6 dBm dBm dB I I Its I 1 .2 7 -1 PRBS with a BER of 1 x 10-12. 2. The stressed receiver sensitivity is measured using the conformance test signal defined in 802 .3z, section 38 .6 .11 . 3. Differential operation is necessary for optimum performance . 4 . Time from LOS state to Rx LOS assert . 5. Time from nonLOS state to Rx LOS deassert. 4 Agere Systems Inc . Advance Data Sheet February 2002 AdLib OCR Evaluation NetLight NLP12 Small Form-Factor Pluggable (SFP) Gigabit Ethernet Laser Transceiver NLP12-01-AA, 850 nm VCSEL Table 4. Recommended Operating Conditions Parameter Case Temperature Range Supply Voltage Data Rate Symbol Min Typ Max Unit Tc VccT, R 0 - 70 C 3.135 - 3.465 V - - 1 .25 - Gbits/s Transceiver Optical and Electrical Characteristics Table 5. Transmitter Optical and Electrical Characteristics (Tc = 0 C to 70 C, Vcc = 3.135 V - 3.465 V) Parameter Symbol Min Max Unit Po PO DIS -9.5 - 0 -35 dBm dBm kc 830 850 nm AXRnas - 0.85 nm Dynamic Extinction Ratio EXT 9 - dB Optical Output Rise/Fall Time (20%-80%) tR/tF - 260 ps Total Transmitter Jitter added at TP21 Tj - 227 ps Relative Intensity Noise RIN - -117 db/Hz Power Supply Current ICCT - 150 mA VINp-p 300 1600 mVp-p Transmit Disable Voltage3 VD Vcc - 1 .3 VCC V Transmit Enable Voltage3 VEN 0 0.8 V Transmit Disable Assert Time4 t-off - 10 gs Transmit Disable Negate Times ton - 1 ms VFAULTH VFAULTL Vcc - 1 .3 0 VCC 0.8 V V Transmit Fault Assert Time6 t fault - 100 gs Transmit Fault Reset Time7 t-reset 10 - gs Optical Output Power: Average Disabled Optical Wavelength Spectral Width Input Data Voltage-Differentia12 Transmit Fault Output Voltage Level 1. 2. 3. 4. 5. 6. 7. TP2 refers to compliance point specified in 802 .3z, section 38 .2.1 . Differential operation is necessary for optimum performance . TTL compatible interface . Time from rising edge of Tx_ Disable to when the optical output falls below 10% of nominal . Time from falling edge of Tx Disable to when the modulated optical output rises above 90% of nominal. Time from fault to Tx_Fault on . Time Tx Disable must be held high to reset Tx Fault . Agere Systems Inc. 5 AdLib OCR Evaluation NetLight NLP12 Small Form-Factor Pluggable (SFP) Gigabit Ethernet Laser Transceiver Advance Data Sheet February 2002 NLP12-01-AA, 850 nm VCSEL (continued) Transceiver Optical and Electrical Characteristics (continued) Table 6. Receiver Optical and Electrical Characteristics (Tc = 0 C to 70 C, Vcc = 3.135 V - 3.465 V) Parameter Average Sensitivityi Stressed Receiver Sensitivity :2 62.5 gm Fiber 50 gm Fiber Maximum Input Powers Optical Return Loss Power Supply Current Output Data-Differentia13 Data Output Rise/Fall Time Loss-of-Signal Voltage Level Loss-of-Signal Assert Time4 Loss-of-Signal Deassert Times Loss of Signal Assert Deassert LOS Hysteresis I Symbol Min Max Unit PI - -17 dBm PSTRESS PSTRESS Pnnax ORL ICCR VOUTP-p tR/tF VLOSH VLOSL t loss on t loss off 0 12 370 - dBm dBm dBm dB mA MVP-p Vcc - 1 .3 0 - -12 .5 -13 .5 150 2000 220 PLOSA PLOSD PHVS -34 -34 0.5 I PS V V las VCC 0 .8 100 100 I Its -17 .5 -17 6 I dBm dBm dB 1 .2 7 -1 PRBS with a BER of 1 x 10-12. 2. The stressed receiver sensitivity is measured using the conformance test signal defined in 802 .3z, section 38 .6 .11 . 3. Differential operation is necessary for optimum performance . 4 . Time from LOS state to Rx LOS assert . 5. Time from nonLOS state to Rx LOS deassert. 6 Agere Systems Inc . Advance Data Sheet February 2002 AdLib OCR Evaluation NetLight NLP12 Small Form-Factor Pluggable (SFP) Gigabit Ethernet Laser Transceiver Power Supply Information VCCT VccR SFP MODULE I I 1 0.1 NF 0.1 NF T 1 NH 10 NF I 0.1 NF T 3.3 V 10 NF HOST BOARD 1-1299 (F) Figure 1 . Power Supply Filtering of NLP12 SFP Transceiver Pin Information 20 19 18 VEET 0 TD+ 1 VEET 2 TX FAULT 3 TX DISABLE 17 VEST 4 MOD-DEF(2) 16 VccT 5 MOD-DEF(1) 15 VccR 6 MOD-DEF(0) 14 VEER 7 RATE SELECT 13 RD+ 8 LOS 12 RD- 9 VEER 11 VEER 10 VEER TOP OF BOARD BOTTOM OF BOARD (AS VIEWED THROUGH TOP OF BOARD) Figure 2. NLP12 SFP Transceiver, 20-Pin Configuration, Top View Agere Systems Inc. 1-1298 (F) AdLib OCR Evaluation NetLight NLP12 Small Form-Factor Pluggable (SFP) Gigabit Ethernet Laser Transceiver Advance Data Sheet February 2002 Pin Information (continued) Table 7. Transceiver Pin Descriptions Pin Number Symbol Functional Description Plug Sequence Notes 1 2 3 VeeT TX Fault TX Disable Transmitter Ground Transmitter Fault Indication 1 3 See Note 1 . 4 MOD-DEF2 Module Definition 2 3 5 MOD-DEF1 Module Definition 1 3 6 7 MOD-DEFO Module Definition 0 3 8 LOS Select Between Full or Reduced Receiver Bandwidth Loss of Signal See Note 3, Two-Wire Serial ID Interface See Note 3, Two-Wire Serial ID Interface See Note 3, Grounded in Module 3 See Note 5. VEER RD- Receiver Ground Receiver Ground Inv. Received Data Out 1 1 3 See Note 6. See Note 6. See Note 7. 9 10 11 12 13 14 15 16 17 18 19 20 Transmitter Disable Rate Select VEER VEER VEET I See Note 7. 1 2 2 Transmitter Ground Transmit Data In Inv. Transmit Data In Transmi tter Grou nd See Note 6. 3 Receiver Ground Receiver Power Transmitter Power VccT VEET TD+ See Note 4. 1 Received Data Out VccR See Note 2, Module Disables on High or Open 3 Receiver Ground RD+ VEER TD- 3 See Note 6. See Note 8. See Note 8. 1 I 3 3 1 See Note 6. I See Note 9. See Note 9. See Note 6. 1 . TX Fault is an open collector/drain output, which should be pulled up with a 4 .7 kn,-10 kQ, resistor on the host board . Pull-up voltage between 2 .0 V and VccT, R + 0 .3 V. When high, output indicates a laser fault of some kind . Low indicates normal operation . In the low state, the output will be pulled to < 0 .8 V. 2. TX -Disable is an input that is used to shut down the transmitter optical output . It is pulled up within the module with a 4 .7 kQ,-10 kQ, resistor. Its states are as follows : - Low (0 V-0 .8 V) : transmitter on ; (>0 .8 V, < 2 .0 V) : undefined . - High (2 .0 V-3.465 V) : transmitter disabled . - Open : transmitter disabled . 3. MOD-DEF 0, 1, 2 . These are the module definition pins . They should be pulled up with a 4.7 kQ,-10 kQ, resistor on the host board. The pullup voltage will be VccT or VccR: - MOD-DEF 0 is grounded by the module to indicate that the module is present . - MOD-DEF 1 is the clock line of two-wire serial interface for serial ID . - MOD-DEF 2 is the data line of two-wire serial interface for serial ID . 4. The rate-select option is not implemented . This pin should not be connected on the host board . 5. LOS (loss of signal) is an open collector/drain output, which should be pulled up with a 4.7 kQ,-10 kQ, resistor. Pull-up voltage between 2 .0 V and VccT, R + 0 .3 V. When high, this output indicates the received optical power is below the worst-case receiver sensitivity (as defined by the standard in use) . Low indicates normal operation . In the low state, the output will be pulled to < 0 .8 V. 6. VEER and VEET may be internally connected within the SFP module. 7. RD/+ : These are the differential receiver outputs . They are ac-coupled 10012, differential lines, which should be terminated with 10012, (differential) at the user SERDES . The ac coupling is done inside the module and is thus not required on the host board . 8. VccR and VccT are the receiver and transmitter power supplies . When the recommended supply filtering network is used, hot plugging of the SFP transceiver module will result in an inrush current of no more than 30 mA greater than the steady state value . VccR and VccT may be internally connected within the SFP transceiver module . 9. TD-/+ : These are the differential transmitter inputs. They are ac-coupled, differential lines with 10012, differential termination inside the module . The ac coupling is done inside the module and is thus not required on the host board . 8 Agere Systems Inc . Advance Data Sheet February 2002 AdLib OCR Evaluation NetLight NLP12 Small Form-Factor Pluggable (SFP) Gigabit Ethernet Laser Transceiver Electrical Schematic 1-130OF Figure 3. Example SFP Host Board Schematic Transceiver Timing Characteristics Table 8. Transceiver Timing Characteristics Parameter Time to Initialize, Including Reset of Tx Fault Serial ID Clock Rate Symbol Min Unit f-serial-clock 1 . Condition : from power on or negation of Tx Fault using Tx Disable. Agere Systems Inc. Condition - - Max Unit 300 ms 100 kHz AdLib OCR Evaluation NetLight NLP12 Small Form-Factor Pluggable (SFP) Gigabit Ethernet Laser Transceiver Transceiver Timing Characteristics (continued) Advance Data Sheet February 2002 OCCURANCE OF FAULT Tx FAULT Module installed except where noted. Tx DISABLE TRANSMITTED SIGNAL Vcc > 3 .15 V t fault Tx-FAULT Tx_DISABLE I 1-1305(F) I Figure 8. t-fault : Tx FAULT Asserted, Tx Signal Not Recovered TRANSMITTED SIGNAL t_init 1-1301 (F) Figure 4 . t init: Tx DISABLE Negated OCCURANCE OF FAULT Tx-FAULT Tx DISABLE Vcc > 3 .15 V TRANSMITTED SIGNAL Tx FAULT OOOY I Lreset Tx_DISABLE t init* * SFP will clear Tx FAULT IN 3 .15 V Tx FAULT Tx FAULT Tx DISABLE Tx DISABLE TRANSMITTED SIGNAL I TRANSMITTED SIGNAL Kwomy !a t_init INSERTION t reset 1-1303(F) Figure 6. t init: Tx_DISABLE Negated Module Hot Plugged 1-1307 (F) Figure 10. t-fault: Tx Disable Asserted Then Negated, Tx Signal Not Recovered Tx DISABLE OPTICAL SIGNAL TRANSMITTED SIGNAL LOS L -on 1-1304 (F) Figure 7. t-off and ton: Tx_DISABLE Asserted Then Negated 10 t init* * SFP will clear Tx FAULT IN 1000 V) IEC61000-4-2 ; 1999 Withstand discharges of 15 kV using a human-body model probe Compliant with standards Electrostatic Discharge (ESD) to Electrical Pins Electrostatic Discharge (ESD) to Optical Connector Electromagnetic Interference (EMI) FCC Part 15 Subpart J Class B, CISPR 22:1997, EN 55022:1998 Class B, VCCI Class I IEC 61000-4-3-1998 Immunity Component Flammabili ty Agere Systems Inc. I UL(R)1950, CSA C22.2 #950, IEC 60950 : 1999 UL 94 V-0 Less than 1 dB change in receiver sensitivity with field strength of Wm 3 RMS, from 10 MHz to 1 GHz . 13 AdLib OCR Evaluation NetLight NLP12 Small Form-Factor Pluggable (SFP) Gigabit Ethernet Laser Transceiver Advance Data Sheet February 2002 Outline Drawings Dimensions are in inches and (millimeters) . Package Outline (56.50) 55 1 4. 0) r I 0.528 (13 .40) 0 I 0.5 39 (13. ' 70) l Iri d .3 0.425 (10.80) d I-d 0.217 (5.50) 0.246 (6 .25) 1-1312 (F) Recommended Panel Opening 0.07 t 0.4 (1 .7 t 0.9) 0.640 ~(16 .25t0.1)~ I 0 .14 (3 .5 t 0.3) Y ~~ 0.41 (10.4 t 0 .1) - - 0.39 (10) REF I\\\\\\\\\\\\\\\\~S SECTION Y-Y 0 .60 I L(15.25 t 0.1) Y ~J 0.02 (0 .4 t 0.1) BEZEL OPENING BELOW PC BOARD 1-1309 (F) 14 Agere Systems Inc . Advance Data Sheet February 2002 AdLib OCR Evaluation NetLight NLP12 Small Form-Factor Pluggable (SFP) Gigabit Ethernet Laser Transceiver Outline Drawings (continued) Dimensions are in inches and (millimeters) . Printed Wiring Board Layout 1 .36 (34.5) SEE NOTE 1 -Y- CROSS-HATCHED AREA DENOTES COMPONENT AND TRACE KEEP-OUT (EXCEPT CHASSIS GROUND) 0.28 (7.2) SEE DETAIL X SEE NOTE 1 (~ .08) 0.39 (10.00) 3 PLACES \ iBS C 0.14 (3.68) 0.07 F(1 .7) 0.34 0 .22 (8 .58) (5 .68) 0.56 (14.25) + 0 0.10 X Y -ASEE NOTE 2 0 .10 (2 .5) 0 . 10 (2 .5) B0 00 .03 O (0 .85 t 0.05) 0.28 (7 .1) I - PIN 1 0 o 0 - , 0.33 (8.48) - - - o 0 0.64 (16.25) 0.07 (1 .7) - 0.08 (2 .0 11 PLACES 0 0.04 8 (1 .05 t 0.05) 1+1 00 . 1(c) SEE NOTE 2 X AO3 10 HOLES THIS AREA DENOTES COMPONENT KEEP-OUT (TRACES ALLOWED) 1 .06 (26.8) 1 .63 (41 .3) O.I7 I (11 .93) 0.38 (9 .6) 0.19 (4 .8) f8 0.04 f8 (0 .95 t 0.05) + o 0.1(c) X AO 9 HOLES SEE NOTE 3 J 0.20 (5 .0) 14 0.39 (10.0) 3 PLACES 0.08 (2'0) 11 PLACES SEE NOTE 2 1 .67 (42.3) 1-1311F Notes : 1 . Datum and basic dimensions established by customer . 2. Pads and vias are chassis ground . 3. Through holes, plating optional. Agere Systems Inc. 15 AdLib OCR Evaluation NetLight NLP12 Small Form-Factor Pluggable (SFP) Gigabit Ethernet Laser Transceiver Advance Data Sheet February 2002 Outline Drawings (continued) Dimensions are in inches and (millimeters) . Printed-Wiring Board Layout (continued) 0 .13 (3.2) 0 .20 (5 .0) 0.04 ~_(o .9) 20 1 0.43 (10.93) j 0 .41 (10.53) GJ F 0.38 (9I6) 0.03 (0 .8) 9 PLACES 0.47 (11.93) 1 J 0.03 (0 .8) 9 PLACES (0 .5 t 0.03) 1+1 0.06 (c) AOS 20 PLACES 0.08 (2 t 0.05) 00 .06 0 (1 .55 t 0.05) 1+ 1 0 0.1(c) A S~ B~S SEE NOTE 2 HOLES L 0.20 DETAIL X 1+ 1 0.06 ~S TYP A~S BOS B S~ 1-1310F Note : Through holes, plating optional . 16 Agere Systems Inc . AdLib OCR NetLight NLP12Evaluation Small Form-Factor Pluggable (SFP) Advance Data Sheet February 2002 Gigabit Ethernet Laser Transceiver Laser Safety Information Class I Laser Product All versions of the transceiver are Class I laser products per CDRH, 21 CFR 1040 Laser Safety requirements . All versions are Class I laser products per IEC 825-1 :1993. The transceiver will be classified with the FDA under Accession Number 0121593-02 (NLP12-10) . CAUTION : Use of controls, adjustments, and procedures other than those specified herein may result in hazardous laser radiation exposure. This product complies with 21 CFR 1040.10 and 1040.11 . Wavelength = 1310 nm (1000BASE-LX version) Wavelength = 850 nm (1000BASE-SX version) Maximum power = 1 .58 mW Because of size constraints, laser safety labeling is not affixed to the module but is attached to the outside of the shipping carton. Product is not shipped with power supply . Notice Unterminated optical receptacles may emit laser radiation . Do not view with optical instruments. Ordering Information Description SFP LC Receptacle Transceiver for 1 .25 Gbits/s 5 km 1000BASE-LX applications SFP LC Receptacle Transceiver for 1 .25 Gbits/s 550 m 1000BASE-SX applications Device Code Comcode NLP12-10-AA 700010638 NLP12-01-AA 700016894 IEEE is a registered trademark of The Institute of Electrical and Electronics Engineers, Inc. EIA is a registered trademark of The Electronic Industries Association . IEC is a registered trademark of The International Electrotechnical Commission. UL is a registered trademark of Underwriters Laboratories, Incorporated . Telcordia Technologies is a trademark of Telcordia Technologies, Inc . ISO is a registered trademark of The International Organization for Standardization . For additional information, contact your Agere Systems Account Manager or the following: INTERNET: http ://www.agere.com E-MAIL: docmaster0agere.com N. AMERICA: Agere Systems Inc ., 555 Union Boulevard, Room 30L-15P-BA, Allentown, PA 18109-3286 1-800-372-2447, FAX 610-712-4106 (In CANADA: 1-800553-2448, FAX 610-712-4106) ASIA : Agere Systems Hong Kong Ltd., Suites 3201 & 3210-12, 32/F, Tower 2, The Gateway, Harbour City, Kowloon Tel. (852) 3129-2000, FAX (852) 3129-2020 CHINA: (86) 21-5047-1212 (Shanghai), (86) 10-6522-5566 (Beijing), (86) 755-695-7224 (Shenzhen) JAPAN: (81) 3-5421-1600 (Tokyo), KOREA: (82) 2-767-1850 (Seoul), SINGAPORE: (65) 778-8833, TAIWAN : (886) 2-2725-5858 (Taipei) EUROPE: Tel. (44) 7000 624624, FAX (44) 1344 488 045 Agere Systems Inc. reserves the right to make changes to the product(s) or information contained herein without notice . No liability is assumed as a result of their use or application. NetLight is a registered trademark of Agere Systems Inc . Copyright 0 2002 Agere Systems Inc . All Rights Reserved February 2002 DS01-310OPTO e re s a 8 " y tems s