- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄93261 > DS2117MB (DALLAS SEMICONDUCTOR) 9-LINE 52 ohm SCSI BUS TERMINATOR, PDSO36 PDF資料下載
參數(shù)資料
| 型號(hào)： | DS2117MB |
| 廠商： | DALLAS SEMICONDUCTOR |
| 元件分類： | Bus Terminator |
| 英文描述： | 9-LINE 52 ohm SCSI BUS TERMINATOR, PDSO36 |
| 封裝： | SSOP-36 |
| 文件頁數(shù)： | 2/9頁 |
| 文件大?。?/td> | 265K |
| 代理商： | DS2117MB |
DS2117M
2 of 9
REFERENCE DOCUMENTS
Small Computer Systems Interface (SCSI-3) SCSI Parallel Interface (SPI)
Project: 0855-M, 1995
Small Computer Systems Interface (SCSI-3) SCSI Parallel Interface 2 (SPI-2) Project: 1142-M, 1998
Small Computer Systems Interface (SCSI-3) SCSI Parallel Interface 3 (SPI-3) Project: 1302-D, 1999
Small Computer Systems Interface (SCSI-3) SCSI Parallel Interface 4 (SPI-4) Project: 1365-D, xxxx
Available from:
American National Standards Institute (ANSI) Phone: (212) 642-4900
Global Engineering Documents 15 Inverness Way East; Englewood, CO 80112 Phone: (800) 854-7179
FUNCTIONAL DESCRIPTION
The DS2117 combines LVD and SE termination with DIFFSENSE sourcing and detection.
A bandgap reference is fed into two amplifiers, which creates a 1.25V reference voltage and a 2.85V
reference voltage. The control logic determines which of these references will be applied to the
termination resistors. If the SCSI bus is in LVD mode, then the 1.25V reference will be used. If the SCSI
bus is in SE mode, then the 2.85V reference will be used. That same control logic will switch in/out
parallel resistors to change the total termination resistance accordingly. Finally, in SE mode the Rp pins
will be switched to ground.
The DIFFSENSE circuitry decodes trinary logic. There will be one of three voltages on the SCSI control
line called DIFFSENS. Two comparators and a NAND gate determine if the voltage is below 0.6V, above
2.15V, or in between. That indicates the mode of the bus to be HVD, SE, or LVD, respectively.
The DS2117M’s DIFF_CAP pin monitors the DIFFSENS line to determine the proper operating mode of
the device; this mode is indicated by the SE/LVD/HVD outputs. The DIFFSENSE pin can also drive the
SCSI DIFFSENS line (when MSTR/SLV = 1) to determine the SCSI bus operating mode. The DS2117M
switches to the termination 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 laser trimmed resistor string with two current
sources. This configuration yields a 105
differential and 150 common mode impedance. A fail-safe
bias of 112 mV 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 22 mA per line while keeping the voltage reference in regulation. The terminating resistors maintain
their 110
value.
HVD Isolation Mode The DS2117M identifies that there is an HVD (high voltage differential) device on
the SCSI bus and isolates the termination pins from the bus.
When ISO is pulled high, the termination pins are isolated from the SCSI bus, Vref is grounded, and the
bus mode indicators (SE/LVD/HVD) remain active. During thermal shutdown, the termination pins are
isolated from the SCSI bus, Vref is grounded, and the bus mode indicators (SE/LVD/HVD) remain
active. The DIFFSENSE driver is shut down during either of these two events.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| DS2118M | 9-LINE SCSI BUS TERMINATOR, PDSO36 |
| DS2119ME | 9-LINE 52 ohm SCSI BUS TERMINATOR, PDSO28 |
| DS2154LN | DATACOM, FRAMER, PQFP100 |
| DS2155GN | DATACOM, FRAMER, PBGA100 |
| DS2155L | DATACOM, FRAMER, PQFP100 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| DS2117MB/T&R | 制造商:Maxim Integrated Products 功能描述:IC TERM SCSI LVD/SE ULT-3 36SSOP |
| DS2117MB/T&R | 功能描述:SCSI 接口集成電路 RoHS:否 制造商:Texas Instruments 工作電源電壓:2.7 V to 5.25 V 電源電流:13 mA 最大工作溫度:+ 70 C 最小工作溫度:0 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SSOP-36 封裝:Tube |
| DS2117MB/T&R/ | 功能描述:SCSI 接口集成電路 RoHS:否 制造商:Texas Instruments 工作電源電壓:2.7 V to 5.25 V 電源電流:13 mA 最大工作溫度:+ 70 C 最小工作溫度:0 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SSOP-36 封裝:Tube |
| DS2117MX/T&R | 制造商:Maxim Integrated Products 功能描述:IC TERM SCSI LVD/SE ULT-3 FCHIP |
| DS2117MX/T&R | 功能描述:IC TERM SCSI LVD/SE ULT-3 FCHIP RoHS:否 類別:集成電路 (IC) >> 接口 - 信號(hào)終端器 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:50 系列:- 類型:SCSI，SE 端子數(shù):9 電源電壓:4 V ~ 5.25 V 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:16-SOIC（0.154"，3.90mm 寬） 供應(yīng)商設(shè)備封裝:16-SOIC 包裝:管件 |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。