ST1284-xxA8. PARALLEL PORT SINGLE TERMINATION NETWORK WITH ±15kV ESD PROTECTION A.S.D. TM

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1 A.S.D. TM ST284-xxA8 PARALLEL PORT SINGLE TERMINATION NETWORK WITH ±5kV ESD PROTETION MAIN APPLIATIONS EP/EPP Parallel Port termination on: Desktops Notebooks Workstations Servers P Peripherals Set Top Box FEATURES One device for parallel port termination ompliant with IEEE284 standard EMI / RFI noise filtering Highly integrated solution in 28 pin QSOP packages One single device provides the proper termination for 8 datalines, strobe line, 4 control lines and 4 statuts lines In system ESD protection of ±5 kv (air discharge) as per IE level 4 DESRIPTION The ST284-xxA8 is a highly integrated termination for enhanced high speed parallel ports. The integrated termination complies to the IEEE284 Standard recommendations and government EM compatibility requirements. It is built around two basic cells. The first one (ell ) provides line termination, EMI filtering and ESD protection for the Strobe and Datalines while the second one (ell 2) provides EMI filtering and ESD protection for the ontrol and Status lines. In addition, ST284-xxA8 provides extra protection against ESD. When tested according to IE , they withstand ±8kV contact discharges and ±5kV air-discharges, thereby providing to the system the necessary robustness to meet up to level 4 of IE , without the need for additional ESD protection components. ells and 2 are described in more detail in figures and 2. OMPLIES WITH THE FOLLOWING ESD STANDARDS : - IE ±5kV (air discharge) ± 8kV (contact discharge) - MIL STD 883E - Method : lass 3 (human body model). October Ed: 2B SHEMATI DIAGRAM QSOP28 ode 0 4.7kΩ 4.7kΩ 33Ω 80pF ode kΩ 2.2kΩ 33Ω 220pF ode 03 kω 5.kΩ 39Ω 50pF Tolerance ± 0% ± 0% ± 0% ± 20% /6

2 ABSOLUTE MAXIMUM RATINGS (T amb 25 ) Symbol Parameter Value Unit V PP ESD discharge IE , air discharge ±6 kv ESD discharge IE , contact discharge ±9 kv ESD discharge - MIL STD 883E - Method ±25 kv V cc Supply voltage 5.5 V P r Power rating per resistor 00 mw P P Package Power rating W T op Operating temperature range 0 to +70 T stg Storage temperature range -55 to +50 T j Maximum operating junction temperature 25 ELETRIAL HARATERISTIS (T amb = 25 ) Symbol Parameter Test condition Min. Typ. Max. Unit I R Leakage current V cc = 5.0V 0 µa V BR Breakdown voltage I R = ma 6 V V F Forward voltage drop I F = 50mA 0.9 V BASI ELL ONFIGURATIONS The ST284-xxA8 is built around the two basic cells described below which integrate the recommended IEEE284 network and the ESD protection compatible with IE level 4 Fig. :ell for line termination, EMI filtering and ESD protection for the Datalines and Strobe signals. There are 9 of these cells inside the ST284-xxA8. Fig. 2: ell 2 for EMI filtering and ESD protection of the ontrol and Status signals. There are 8 of these cells inside the ST284-xxA8. IEEE284 Recommendation Rp Rp IEEE284 Recommendation 2/6

3 FUNTIONAL DIAGRAM ST284-xxA8 7 Select in 6 Reset 5 Error Autofeed Strobe Bit 3 Bit Bit 3 5 Bit 4 6 Bit 5 7 Bit 6 8 Bit 7 9 Bit Acknowledge Busy 2 Paper Out 3 Select paper APPLIATION INFORMATION The functional diagram here above presents a IEEE284-A connector pinout and show how to connect the ST284-xxA8 in order to correctly terminate and filter the 7 signal lines. The IEEE284-A connector is the P standard for the host connection. ontrol and status lines (from 0 to 7) only require a pull-up resistor (Rp) and a filter capacitor (). The data lines (from 2 to 9) and the STROBE (pin ) also require a termination series resistor () in addition to the pull-up resistor and a filter capacitor. The is connected to pin 20 and the ground to pin 22. The ST284-xxA8 can be used with all 3 types of connectors defined in the IEEE284 standard: - IEEE284-A is a 25DB connector which is the P standard for the host connection. - IEEE284-B is a 36 pin, inch centerline connector used on the peripheral device. - IEEE284- is a new 36 pin, inch centerline connector which can be used for both host and peripherals. 3/6

4 TEHNIAL INFORMATION FREQUENY BEHAVIOR OF DATA AND STROBE SIGNALS Fig. A: Measurement conditions. Fig. A2: Typical frequency response curve for data and strobe signals db TRAKING GENERATOR 50Ω +5V ST284 SPETRUM ANALYSER Vg Vin Vout 50Ω , F (MHz) ESD PROTETION In addition to the requirements of termination and EM compatibility, computing devices are required to be tested for ESD susceptibility. This test is described in the IE and is already in place in Europe. This test requires that a device tolerates ESD events and remain operational without user intervention. The ST284-xxA8 is particularly optimized to perform ESD protection. ESD protection is based on the use of device which clamps at : Vouput = VBR + Rd. IPP This protection function is splitted in 2 stages. As shown in figure A3, the ESD strikes are clamped by the first stage S and then its remaining overvoltage is applied to the second stage through the resistor R. Such a configuration makes the voltage very low at the output. Fig. A3: ST284 ESD clamping behavior. Rg S R S2 Rd V BR Vinput Voutput Rd V BR Rload ESD Surge ST284-xxA8 Device to be protected 4/6

5 To have a good approximation of the remaining voltages at both Vin and Vout stages, we give the typical dynamical resistance value Rd. By taking into account these following hypothesis : Rt>Rd, Rg>Rd and Rload>Rd, it gives these formulas: Rg. VBR + Rd. VPP Vinput = Rg Rt. VBR + Rd. Vinput Voutput = Rt The results of the calculation done for V PP =8kV, Rg=330Ω (IE standard), V BR =7V (typ.) and Rd = Ω (typ.) give: Vinput = 3.2 V Voutput = 7.95 V This confirms the very low remaining voltage across the device to be protected. It is also important to note that in this approximation the parasitic inductance effect was not taken into account. This could be few tenths of volts during few ns at the input side. This parasitic effect is not present at the output side due the low current involved after the resistance R. The measurements done here after show very clearly (Fig. A5) the high efficiency of the ESD protection : - no influence of the parasitic inductances on Vout stage - Voutput clamping voltage very close to V BR (positive strike) and -V F (negative strike) Fig. A4: Measurement conditions. ESD SURGE Vinput ST284 Voutput Fig. A5: Remaining voltage at the input and output of the device during a ±6kV ESD surge (IE ). 5/6

6 PAKAGE MEHANIAL DATA QSOP28 (Plastic) DIMENSIONS L REF. Millimeters Inches Min. Max. Min. Max. b e D 28 5 a A F S E b A a b b D F e 0.64 typ typ. E L S 8 max 8 max FOOTPRINT DIMENSIONS (in millimeters) dim in mm Package General Specifications Lead Plating Tin-Lead Lead Plating Thickness Lead Material 7 µm Min 20 µm Max opper Alloy Lead oplanarity 0.02 mm (0.004") Body Material Molded Epoxy Resine Meets UL94V.0 standard Order code Marking Package Weight Delivery mode Base qty ST284-0A8 ST284-0 QSOP g Tube 48 ST284-0A8RL ST284-0 QSOP g Tape & Reel 2500 ST284-02A8 ST QSOP g Tube 48 ST284-02A8RL ST QSOP g Tape & Reel 2500 ST284-03A8RL ST QSOP g Tape & Reel 2500 Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners STMicroelectronics - All rights reserved. STMicroelectronics GROUP OF OMPANIES Australia - Belgium - Brazil - anada - hina - zech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan - Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States 6/6