SS7519

SS7519 SSC | Alldatasheet

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Technical content

www.SiliconStandard.com 1 of 5 SS7519

FEATURES

!" Meets SCSI-1, SCSI-2, Ultra3 and Ultra320 Standards. !" Auto-selectable Multimode single-ended or Low Voltage Differential termination. !" Current limit and thermal shutdown protection. !" Ground driver integrated for single-ended operation !" Compatible with active-negation drivers.

DESCRIPTION

The SS7519 multimode SCSI terminator is both a single-ended and a low voltage differential terminator that meets the specifications of SCSI Parallel Interface (SPI-4). The SS7519 also provides backward compatibility to the SCSI-1, SCSI-2 and Single-Ended specifications. The Multimode terminator contains all the functions required to terminate and auto detect for SCSI devices without hardware fluctuation. Auto-Selectable is achieved by using voltage detection on the DIFFSENSE signal. The SS7519 senses the DIFFSENSE line while sourcing the DIFFSENSE signal with LVD levels. The DIFFSENSE line being grounded indicates that one or more SE devices are attached on the bus. The SS7519 switches to the termination mode that is appropriate for the bus based on the value of the DIFFSENSE input voltage. For the Single-Ended termination, the active terminator will pull R XN to 2.85V and RXP to a hard ground. The SS7519 can sink 22mA per line as required by the SCSI specification. The Single-Ended resistor will maintain 110Ω ±5%. For LVD termination, the SS7519 integrates two current sources with nine accuracy resistor strings. This architecture yields a 105Ω ±5% differential and 226Ω ±10% common mode impedance. A fail-safe bias of 110mV is sustained when no drivers are connected to the SCSI bus. If the SS7519 detects a HVD SCSI device on the bus, all the signals will be set to a high impedance state. TPWR TPWR R9N R8N HS GND R7N R7P R6N R6P DIFF_CAP DIFFSENSE M/S R9P R8P VRFF RIP RIN R2P R2N HS GND R3P R3N R4P R4N R5P ISO GND R5N SS7519 - TSSOP28 Multi-mode SCSI Terminator Rev.2.01 6/06/2003

www.SiliconStandard.com 2 of 5 SS7519 PIN DESCRIPTION P I N S Y M B O L D E S C R I P T I O N 27,28 TPWR 4.0V to 5.75V power input pin. Connect to SCSI bus power line. A 4.7µF capacitor and a 0.1µF high frequency capacitor are recommended between TPWR and ground. 1 VREF Reference V oltage. Must be decoupled with a 4.7µF capacitor to ground as shown in Figure 1. 6,22 1 4 HS GND GND Heat Sink Ground. These should be connected to large area PC board ground trace in order to increase the power dissipation capability. 2,4,7,9,11,18 20,23,25 RxP Termination lines. These lines switch to hard ground in SE mode and are the positive lines for LVD mode. All lines are in high impedance when HVD is detected. 3,5,8,10,12 19,21,24,26 RxN Termination lines. These lines switch to the active lines in SE mode and are the negative lines for LVD mode. All lines are in high impedance when HVD is detected. 1 3 ISO Isolate pin. This pin used to shut down the terminator if the terminator is not connected at the end of the bus. Connecting the pin to ground will activate the terminator in normal operation. The terminator will be disabled when the pin is in high state. An internal pull-down resistor assures that the SS7519 will operate as normal if the ISO pin is left floating. 15 M/S Mode select pin. When pull high, master mode will enable the DIFFSEN drive SCSI bus. The DIFFSENSE driver is off when this pin is connected to ground. 1 6 DIFFSENSE Mode Sense pin. This signal will drive 1.3V to the SCSI bus during the Master mode in order to detect which type of device is connected to the SCSI bus. On power up, the SS7519 will try to deliver LVD level to the DIFFSENSE line. If only LVD SCSI devices are on the bus, the DIFFSENSE signal will be successfully driven to 1.3V and the terminator will configure the system for LVD operation. If any SE device is on the bus, it will present a grounding level to the DIFFSENSE line. This will cause the SS7519 to configure into SE operation. The SS7519 will go into shutdown mode if DIFFSENSE detects a high voltage level. 17 DIF_CAP DIFFSENSE CAPACITOR. This pin should be connected to a 0.1uF capacitor to ground and 20KΩ resistor to SCSI bus DIFFSENSE line for DIFFSEN filter. RECOMMENDED OPERATING CONDITIONS PARAMETER SYMBOL MIN TYP. MAX UNITS Tpwr V oltage V term 4.0 5.75 V Operating Temperature T op 0 70 ℃ Lead Temperature (Soldering 10 seconds) Tsod 300 ℃ Rev.2.01 6/06/2003

www.SiliconStandard.com 3 of 5 SS7519 DC CHARACTERISTICS: PARAMETER SYMBOL MIN TYP MAX UNITS TPWR Current Itpwr 35 mA Input Leakage Current High Iih 0 uA Input Leakage Current Low Iil 1.0 uA Output Current High V out = 2.4 V Ioh 0 mA Output Current Low V out = 0.4V Iol 4.0 mA DIFFSEN Output V oltage V ov 1.2 1.4 V DIFFSEN Source Current Isc 5 15 mA DIFFSEN Sink Current Isi 20 200 uA DIFFSEN SE V oltage Range Vse -0.3 0.5 V DIFFSEN LVD V oltage Range Vlvd 0.7 1.9 V DIFFSEN HVD V oltage Range Vhvd 2.4 Vtpwr+0.3 V Single Ended Characteristics PARAMETER SYMBOL MIN TYP MAX UNITS SE Termination Resistance Rse 104.5 110 115.5 Ω SE V oltage Reference Vref 2.70 3.00 V SE Output Current Ioc 25.4 mA LVD Characteristics PARAMETER SYMBOL MIN TYP MAX UNITS Differential Mode Termination Resistance Rd 100 110 Ω Common Mode Termination Resistance Rc 110 226 300 Ω Differential Mode Bias All lines open Vdb 100 125 mV Common Mode Bias Vcb 1.125 1.375 V R E G U L A T O R C h a r a c t e r i s t i c s (0℃℃ ℃℃ to 70 ℃℃ ℃℃) PARAMETER SYMBOL MIN TYP MAX UNITS Source Current Isour 200 230 V out=0.2v mA Sink Current Isink 100 200 mA NOTE: Unless otherwise specified, these specifications apply over the operating ambient temperature range from 0℃℃ ℃℃ to 70 ℃℃ ℃℃. Rev.2.01 6/06/2003

www.SiliconStandard.com 4 of 5 SS7519 TPWR M/S ISO TPWR M/S ISO TPWR M/S ISO TPWR M/S ISO TPWR M/S ISO TPWR M/S ISO VREF DIF_CAP VREF DIF_CAP DIF_CAP VREF DIFFSENDIFFSEN 20k 20k Figure 1. 0.1uF4.7uF 0.1uF TPWR 4.7uF 4.7uF 4.7uF 4.7uF4.7uF TPWR DATA DATA CONTROL Application Schematic SS7519 VREF VREF VREF DIF_CAP DIF_CAPDIF_CAP 27,28 1515 1515 27,28 27,28 27,2827,28 27,28 13 13 1313 13 13 1 1 1 1 1717 1717 16 16 SS7519 SS7519 SS7519 SS7519 SS7519 Rev.2.01 6/06/2003

www.SiliconStandard.com 5 of 5 SS7519 Package Dimensions TSSOP-28 141 1528 E H b D e Seating Plane A1 A2 A L θ See Detail F C Detail F 12°(4X) D y DIMENSIONS IN MILIMETERS DIMENSIONS IN INCHES SYMBOLS MINNOMMAXMINNOMMAX TSSOP-28TSSOP-28 TSSOP-28TSSOP-28 Information furnished by Silicon Standard Corporation is believed to be accurate and reliable. However, Silicon Standard Corporation makes no guarantee or warranty, express or implied, as to the reliability, accuracy, timeliness or completeness of such information and assumes no responsibility for its use, or for infr ingement 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. Rev.2.01 6/06/2003