SS8218 SSC | Alldatasheet
Document overview
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Technical content
Features
Auto-selectable multi-mode Single-Ended or LVD Termination Meets SCSI-1, SCSI-2, SCSI-3 SPI Ultra (Fast-20), Ultra 2(SPI-2 LVD), Ultra160 (SPI-3 LVD) standards. Supports active negation 3pF channel capacitance Thermal protection Hot-swap compatible 5% tolerance on SE and LVD termination resistance 28 and 36 pin SSOP package 28 Pin SSOP: Pin Compatible with DS2119 36 Pin SSOP: Pin Compatible with DS2118, LX5241 and UCC5630
Applications
Server and workstation High-end PC Industrial PC Disk Array (RAID) SCSI cable General Description The SS8218 Multi-mode LVD/SE SCSI terminator pro- vides a smooth transition to the next generation of the SCSI Parallel Interface (SPI-3). It automatically senses the bus, via DIFFSENS, and switches the ter- mination to either single-ended (SE) or low voltage differential (LVD) SCSI, dependent on which type of devices are connected to the bus. If the SS8218 de- tects a HVD SCSI device, it switches to a high imped- ance state. For a 16-bit Wide SCSI bus to be opera- tional, three SS8218 terminators are needed. The Multi-mode terminator contains all functions re- quired to terminate and auto detect and switch modes for SCSI Parallel Interface (SPI) bus architectures. For the SE termination, one regulator and nine precision 110ohm resistors are used. For the LVD termination, the SS8218 integrates 18 regulated supplies with nine precision resistor strings. Pin Configuration R1- R1+ R2- NC/HS GND R3+ R3- R4+ R4- R5+ R5- DISCNCT GND TPWR R9- R9+ R8+ R8- R7- R6- R6+ DIFFB DIFFSENSE M/S 28Pin SSOP/TSSOP VREF R2+ TPWR R7+ NC/HS GND NC NC R1+ R1- R2- HS/GND HS/GND R3+ R3- R4+ R4- R5+ R5- DISCNCT GND TPWR HVD LVD SE R9- R9+ R8- R8+ HS/GND HS/GND HS/GND R7- R7+ R6- R6+ DIFFB DIFFSENSE M/S VREF R2+ HS/GND 36Pin SSOP R1- R1+ R2- NC/HS GND R3+ R3- R4+ R4- R5+ R5- DISCNCT GND TPWR R9- R9+ R8+ R8- R7- R6- R6+ DIFFB DIFFSENSE M/S 28Pin SSOP/TSSOP VREF R2+ TPWR R7+ NC/HS GND R1- R1+ R2- NC/HS GND R3+ R3- R4+ R4- R5+ R5- DISCNCT GND TPWR R9- R9+ R8+ R8- R7- R6- R6+ DIFFB DIFFSENSE M/S 28Pin SSOP/TSSOP VREF R2+ TPWR R7+ NC/HS GND NC NC R1+ R1- R2- HS/GND HS/GND R3+ R3- R4+ R4- R5+ R5- DISCNCT GND TPWR HVD LVD SE R9- R9+ R8- R8+ HS/GND HS/GND HS/GND R7- R7+ R6- R6+ DIFFB DIFFSENSE M/S VREF R2+ HS/GND 36Pin SSOP
www.SiliconStandard.com 2 of 11 SS8218 Rev.2.01 6/06/2003
Ordering Information
PART NUMBER TEMP. RANGE PIN-PACKAGE FEATURE SS8218-S4TB 0ºC-70ºC SSOP-28 pin / Tube DISCNCT does not disable VREF SS8218-S4TR 0ºC-70ºC SSOP-28 pin / Tape & Reel DISCNCT does not disable VREF SS8218-S5TB 0ºC-70ºC SSOP-36 pin / Tube DISCNCT does not disable VREF SS8218-S5TR 0ºC-70ºC SSOP-36 pin / Tape & Reel DISCNCT does not disable VREF SS8218-D3TB 0ºC-70ºC TSSOP-28 pin / Tube DISCNCT does not disable VREF SS8218-D3TR 0ºC-70ºC TSSOP-28 pin / Tape & Reel DISCNCT does not disable VREF Note: DIFFSENSRefers to the SCSI bus signal. DIFFSENSERefers to the SS8218 pin name and internal circuitry relating to differential sensing. DIFFB Refers to the SS8218 pin name and internal circuitry relating to monitoring the DIFFSENS line. Functional Description The SS8218 is used in multi-mode active termination applications, where single ended (SE) and low voltage differential (LVD) devices might coexist. The LVD ter- mination section consists of 18 source/sink amplifiers (VTOP, VBOT), biasing circuitry and nine precision resistor strings (RTOP, RMID, RBOT). The SE termi- nation section consists of a 2.85V source/sink regula- tor with 9 precision 110ohm resistor. The DIFFSENSE section consists of a 1.3V, 5mA driver and a sensing circuit (Figure 1) DIFFSENS is used to identify which types of SCSI devices are present on the bus. If the voltage on DIFFSENS is between 0-0.5V the bus is single-ended; if it is between 0.7-1.9V the bus is LVD; and if it is greater than 2.4V, the bus is HVD. The SS8218 DIFFB pin monitors the DIFFSENS line to determine the proper operating mode of the device; this mode is indicated by the SE/LVD/HVD outputs. HVD Isolation Mode The SS8218 identifies that there is an HVD (high voltage differential) device on the SCSI bus and isolates the termination pins from the bus. When DISCNCT is pulled high, the termination pins are isolated from the SCSI bus, and the bus mode indicators (SE/LVD/HVD) as well as VREF remains active. During thermal shutdown, the termination pins are isolated from the SCSI bus and VREF becomes high impedance. The DIFFSENSE driver is shut down during either of these two events. To ensure proper operation, the TPWR pin should be connected to the SCSI bus TERMPWR line. As with all analog circuitry, the TERMPWR lines should be by- passed locally. A 2.2µF capacitor and a 0.01µF high frequency capacitor is recommended between TPWR and ground and placed as close as possible to the SS8218. The 8218 should be placed as close as possible to the SCSI connector to minimize signal and power trace length, thereby resulting in less input ca- pacitance and reflections which can degrade the bus signals. The DIFFSENSE pin can drive the SCSI DIFFSENS line (when M/S is pulled high) to determine the SCSI bus operating mode. The SS8218 switches to the ter- mination mode that is appropriate for the bus based on the value of the DIFFSENS voltage. These modes are: LVD mode LVD termination is provided by a precision resistor string with two amplifiers. This configuration yields a 105 Ω differential and 150 Ω common mode impedance. A fail safe bias of 112mV is maintained when no drivers are connected to the SCSI bus. SE mode When the external driver for a given signal line turns off, the active terminator will pull that signal line to 2.85 volts (quiescent state). When used with an active negation driver, the power amp can sink 22mA per line while keeping the voltage reference in regula- tion. The terminating resistors maintain their 110 Ω value. To maintain the specified regulation, a 4.7µF capacitor is required between the VREF pin and ground of each SS8218. A high frequency cap (0.1µF ceramic recom- mended) can also be placed on the VREF pin in ap- plications that use fast rise/fall time drivers. A typical SCSI bus configuration is shown in Figure2. An internal pull down resist or assures that the SS8218 will be terminating the bus if the DISCNCT pin is left floating.
www.SiliconStandard.com 3 of 11 SS8218 Rev.2.01 6/06/2003 Block Diagram (Figure 1) DIFFB DIFFSENSE SE LVDHVD THERMAL SHUTDOWN CIRCUITRY DISCNCT CONTROL LOGIC VREF DIFFSENSE CIRCUITRY REFERENCE GENERATION VREF
110 Ohms
( ) X 9 X 9 RTOP9 RMID9 RBOT9 M/S DIFFB DIFFSENSE SE LVDHV D THERMAL SHUTDOWN CIRCUITRY DISCNCT CONTROL LOGIC VR E F DIFFSENSE CIRCUITRY REFERENCE GENERATION VR E F +_+ ( ) X 9 X 9 RTO P9 RMID9 RBOT9 M/S
www.SiliconStandard.com 4 of 11 SS8218 Rev.2.01 6/06/2003 SCSI Bus Configuration (Figure 2) TPWR M/S DISCNCT DIFFSENSE CONTROL LINES (9) DIFFSENS TPWR TERMPWR 20K VREF DIFFB 0.1µF DIFFSENSE DIFFB VREF TERMPWR TPWR M/S DISCNCT DIFFB VREF TPWR DIFFB VREF TPWR DATA LINES (9) VREF DIFFB TPWR VREF DIFFB DATA LINES (9) 2.2µF 2.2µF 2.2µF 2.2µF 2.2µF 2.2µF M/S DISCNCT M/S DISCNCT M/S DISCNCT M/S DISCNCT 4.7µF 4.7µF 4.7µF 4.7µF 4.7µF 4.7µF 0.1µF 20K TPWR M/S DISCNCT DIFFSENSE CONTROL LINES (9) DIFFSENS TPWR TERMPWR 20K VREF DIFFB 0.1µF DIFFSENSE DIFFB VREF TERMPWR TPWR M/S DISCNCT DIFFB VREF TPWR DIFFB VREF TPWR DATA LINES (9) VREF DIFFB TPWR VREF DIFFB DATA LINES (9) 2.2µF 2.2µF 2.2µF 2.2µF 2.2µF 2.2µF M/S DISCNCT M/S DISCNCT M/S DISCNCT M/S DISCNCT 4.7µF 4.7µF 4.7µF 4.7µF 4.7µF 4.7µF 0.1µF 20K SS8218 SS8218 SS8218 SS8218 TPWR M/S DISCNCT DIFFSENSE CONTROL LINES (9) DIFFSENS TPWR TERMPWR 20K VREF DIFFB 0.1µF DIFFSENSE DIFFB VREF TERMPWR TPWR M/S DISCNCT DIFFB VREF TPWR DIFFB VREF TPWR DATA LINES (9) VREF DIFFB TPWR VREF DIFFB DATA LINES (9) SS8218SS8218 2.2µF 2.2µF 2.2µF 2.2µF 2.2µF 2.2µF M/S DISCNCT M/S DISCNCT M/S DISCNCT M/S DISCNCT 4.7µF 4.7µF 4.7µF 4.7µF 4.7µF 4.7µF 0.1µF 20K
www.SiliconStandard.com 5 of 11 SS8218 Rev.2.01 6/06/2003 Recommended Operating Conditions PARAMETER SYMBOL MI N TYP MAX UNITS Vtpwr (SE) 4.0 5 5.5 Termpower Voltage Vtpwr (LVD) 2.9 5 5.5 V Logic 0 Vil -0.3 +0.8 V Logic 1 Vih 2.0 V tpwr+0.3 V Operating Temperature Tamb 0 70 °C
Electrical Characteristics
Unless otherwise specified, these specifications apply over the operating ambient temperature range of PARAMETER SYMBOL Condition MIN TYP MAX UNITS LVD Terminator Section Differential Mode Termination Resistance Rdm 100 105 110 Ohms Common Mode Termination Resistance Rcm 110 150 190 Ohms Differential Mode Bias Vdm All lines Open 100 112 125 mV Common Mode Bias Vcm 1.125 1.25 1.375 V Single Ended Terminator Section Output Capacitance Cout Note 3 pF SE Termination Resistance Rse Vline = 0-3.0 volts 104.5 110 115.5 Ohms SE Voltage Reference Vref 2.79 2.85 2.93 Volts SE output Current Iose Vline = 0.2 volts 25.4 mA Regulator Section Line Regulation LIREG 1.0 2.5 % Load Regulation LOREG 1.3 3.5 % Current Limit ILIM 350 mA Sink Current ISINK 200 mA DC Section SE mode (No Load) 4 Termpower Current Itpmr LVD mode (No Load) 20 mA Input Leakage High Iih -1.0 µA Input Leakage Low Iil 1.0 µA Output Current High Ioh V out = 2.4 volts;SE/LVD/HVD Pins only -1.0 mA Output Current Low Iol V out=0.4 volts;SE/LVD/HVD Pins only 4.0 mA DIFFSENS Section DIFFSENS SE Operating Range Vseor -0.3 0.5 V DIFFSENS LVD Operating Range V lvdor 0.7 1.9 V DIFFSENS HVD Operating Range V hvdor 2.4 Vtpwr+0.3 V DIFFSENSE Driver Output Voltage V dso M/S=1; I ds = 0-5mA 1.2 1.4 V DIFFSENSE Driver Source Current I dsh M/S = 1; V dso=0V 5 15 mA DIFFSENSE Driver Sink Current Idsl M/S=1; V dso=2.75V 20 200 µA Note: Guaranteed by Design.
www.SiliconStandard.com 6 of 11 SS8218 Rev.2.01 6/06/2003 Common Mode Bias Vcm - Vtpwr 1.125 1.175 1.225 1.275 1.325 1.375 2.5 3.5 4.5 5.5 Vtpwr Vcm(V) Common Mode Bias Vcm - Temperature 1.125 1.175 1.225 1.275 1.325 1.375 -20 0 20 40 60 80 100 Temperature( ℃) Vcm(V) Common Mode Termination Resistance Rcm - Temperature@Vtpwr=5V 110 120 130 140 150 160 170 180 190 -20 0 20 40 60 80 100 Temperature(ºC) Rcm(Ohm) Common Mode Termination Resistance Rcm - Vtpwr@Temperature=24ºC 110 120 130 140 150 160 170 180 190 2.5 3.5 4.5 5.5 Vtpwr Rcm(Ohm) Differential Mode Termination Resistance Rdm - Vtpwr 100 102 104 106 108 110 2.5 3.5 4.5 5.5 Vtpwr Rdm(Ohm) Differential Mode Termination Resistance Rdm - Temperature 100 102 104 106 108 110 -20 0 20 40 60 80 100 Temperature(ºC) Rdm(Ohm) Differential Mode Bias Vdm - Temperature @Vtpwr=5V 0.1 0.105 0.11 0.115 0.12 0.125 -20 0 20 40 60 80 100 Temperature(ºC) Vdm(V) Differential Mode Bias Vdm - Vtpwr 0.1 0.105 0.11 0.115 0.12 0.125 2.5 3.5 4.5 5.5 Vtpwr Vdm(V) T=80ºC T=-10ºC Vtpwr=5.8V Vtpwr=2.8V T=80ºC T=-10ºC Vtpwr=2.8V Vtpwr=5.8V T=-10ºC T=80ºC
www.SiliconStandard.com 7 of 11 SS8218 Rev.2.01 6/06/2003 SE Termination Resistance Rse - Vtpwr @T=24ºC;Vline=0V 105 106 107 108 109 110 111 112 113 114 115 3.5 4.5 5.5 Vtpwr Rse(Ohm) SE Termination Resistance Rse - Vtpwr @Vline=0V 105 106 107 108 109 110 111 112 113 114 115 -20 0 20 40 60 80 100 Temperature(ºC) Rse(Ohm) SE Termination Resistance Rse - Vtpwr @Vtpwr=5V;T=24ºC 105 106 107 108 109 110 111 112 113 114 115 0123 Vline Rse(Ohm) Vref - Ivref@Vtpwr=5V;T=24ºC 2.79 2.81 2.83 2.85 2.87 2.89 2.91 2.93 -250 -150 -50 50 150 250 350 Ivref(mA) Vref Vref - Temperature@Ivref=0mA 2.79 2.81 2.83 2.85 2.87 2.89 2.91 2.93 -20 0 20 40 60 80 100 Temperature(ºC) Vref Vref - Vtpwr@T=24ºC 2.79 2.81 2.83 2.85 2.87 2.89 2.91 2.93 3.5 4.5 5.5 6.5 Vtpwr Vref Vtpwr=3.8V Vtpwr=5.8V Vtpwr=5.8V Vtpwr=3.8V Ivref=350mA Ivref=-200mA
www.SiliconStandard.com 8 of 11 SS8218 Rev.2.01 6/06/2003 Pin Description (for 28pin SSOP/TSSOP) PIN SYMBOL DESCRIPTION 1 VREF* Reference Voltage. 2.85-volt reference; must be connected to a 4.7µF capacitor. 2-5,7-12, Signal Termination. (X=1,2,3,…..9) Rx+: Ground line for single-ended or positive line for differential applications for the SCSI bus. Rx-: Signal line/active line for single-ended or negative line in differential applications for the SCSI bus. 6,22 NC/ HS GND No Connect/ HS GND. Should be grounded for heat sinking purpose. 13 DISCNCT Disconnect. When pulled high, the SS8218 isolates its bus pins (Rx+, Rx-) from the SCSI bus. 14 GND Ground. Terminator ground pin. Connected to ground. 15 M/S Master/slave. Used to select which terminator is the controlling device. M/S pin high enables the DIFFSENSE driver. 16 DIFFSENSE Output to drive the SCSI bus DIFFSENS line.
17 DIFFB
DIFFB pin should be connected to a 0.1µF capacitor to GND and 20k resistor to SCSI/Bus DIFFSENS line. An input pin to detect the type of device (differential or single-ended) on the SCSI bus. 27,28 TPWR Terminator Power. Connect to the SCSI TERMPWR line and de-couple with a 2.2µF capacitor. *The VREF keeps the level at 2.85 volt, despite the DISCNCT pin is asserted or not; even the termination mode is changed. (36pin SSOP) PIN SYMBOL DESCRIPTION 1 VREF* Reference Voltage. 2.85-volt reference; must be connected to a 4.7µF capacitor. 2,3 NC No Connect. Do not connect these pins. 4-7,11-16, 22-25, 29-32 Rx+ Rx- Signal Termination. (X=1,2,3,…..9) Rx+: Ground line for single-ended or positive line for differential applications for the SCSI bus. Rx-: Signal line/active line for single-ended or negative line in differential applications for the SCSI bus. 8, 9,10,26, 27,28 HS/GND Heat Sink Ground. Connect to large area PC board traces to increase power dissipation capabil- ity. 17 DISCNCT Disconnect. When pulled high, the SS8218 isolates its bus pins (Rx+, Rx-) from the SCSI bus. 18 GND Ground. Terminator ground pin. Connected to ground. 19 M/S Master/slave. Used to select which terminator is the controlling device. M/S pin high enables the DIFFSENSE driver. 20 DIFFSENSE Output to drive the SCSI bus DIFFSENS line.
21 DIFFB
DIFFB pin should be connected to a 0.1µF capacitor to GND and 20k resistor to SCSI/Bus DIFFSENS line. An input pin to detect the type of device (differential or single-ended) on the SCSI bus. 33 SE Single ended mode indicator. It is HIGH when terminator is operating in SE mode. 34 LVD Low Voltage Differential mode indicator. It is HIGH when terminator is operating in LVD mode. 35 HVD High Voltage Differential mode indicator. It is HIGH when terminator is operating in HVD mode 36 TPWR Terminator Power. Connect to SCSI bus TERMPWR line and decouple with 2.2µF capacitor. *The VREF keeps the level at 2.85 volt, despite the DISCNCT pin is asserted or not; even the termination mode is changed.
www.SiliconStandard.com 9 of 11 SS8218 Rev.2.01 6/06/2003 Package Information (28 pin SSOP) E1 E D e b A C
1.00 REF
L 0.25 θ
www.SiliconStandard.com 10 of 11 SS8218 Rev.2.01 6/06/2003 36 pin SSOP b 0.300 0.450 0.012 0.018 c 0.127 0.254 0.005 0.010 e 0.800 BASIC 0.032 BASIC E 10.033 10.668 0.395 0.420 h 0.381 0.635 0.015 0.025 L 0.508 1.016 0.020 0.040 θ 0 8 0 8 h x 45° C L θ E1 E SEATING PLANE 0.004 C D be A Taping Specification Feed Direction Typical SSOP, TSSOP Package Orientation Feed Direction Typical SSOP, TSSOP Package Orientation
www.SiliconStandard.com 11 of 11 Information furnished by Silicon Standard Corporation is believed to be accurate and reliable. However, Silicon Standard Corporation makes no guarantee or warranty, expre ss or implied, as to the reliability, accuracy, timeliness or completeness of such information and assumes no responsibility for its use, or for infringement of any patent or other intellectual property rights of third parties that may result from its use. Silicon Standard reserves the right to make changes as it deems necessary to any products described herein for any reason, including without limitation enhancement in reliability, functionality or design. No license is granted, whether expressly or by implication, in relation to the use of any products described herein or to the use of any information provided herein, under any patent or other intellectual property rights of Silicon Standard Corporation or any third parties. SS8218 Rev.2.01 6/06/2003 28 pin TSSOP NOTE: 1. Package body sizes exclude mold flash protrusions or gate burrs 2. Tolerance ±0.1mm unless otherwise specified 3. Coplanarity : 0.1mm 4. Controlling dimension is in millimeter. Converted inch dimensions are not necessarily accurate. 5. Follow JEDEC MO-153 DIMENSION IN MM DIMENSION IN INCH E1 E D b A C L θ e