參數(shù)資料
型號: DS21S07AS+T&R
廠商: Maxim Integrated Products
文件頁數(shù): 2/8頁
文件大小: 0K
描述: IC TERMINATOR SCSI 16-SOIC
標準包裝: 1,000
類型: SCSI,LVD,SE
端子數(shù): 9
電源電壓: 4 V ~ 5.5 V
工作溫度: 0°C ~ 70°C
安裝類型: 表面貼裝
封裝/外殼: 16-SOIC(0.295",7.50mm 寬)
供應商設備封裝: 16-SOIC W
包裝: 帶卷 (TR)
DS21S087A
2 of 8
FUNCTIONAL DESCRIPTION
The DS21S07A consists of a bandgap reference, buffer amplifier, and nine termination resistors
(Figure 1). The bandgap reference circuit produces a precise 2.55V level that is fed to a buffer amplifier.
The buffer produces a 2.85V level and can source at least 24mA into each of the termination resistors
when the signal line is low (active). When the driver for a given signal line turns off, the terminator pulls
the signal line to 2.85V (quiescent state). To handle actively negated SCSI signals, the buffer can sink at
least 200mA, and VREF will move less than 60mV. When all lines settle in the quiescent state, the
regulator consumes about 2.5mA. When the DS21S07A is put into power-down mode by bringing
PD
low, the power-down circuitry turns off the transistors on each signal line. This isolates the DS21S07A
from the signal lines and effectively removes it from the circuit. The power-down pin (
PD) has an internal
50k
pullup resistor. To place the DS21S07A into an active state, the PD pin should be left open
circuited. When installed on disk drives or RAID system components, the DS21S07A will not affect the
SCSI bus during a hot plug operation.
To ensure proper operation, both the TERMPWR1 and TERMPWR2 pins must be connected to the SCSI
bus TERMPWR line and both the VREF1 and VREF2 pins must be tied together externally. Each
DS21S07A requires a 4.7
F capacitor connected between the VREF pins and ground. Figure 2 details a
typical SCSI bus configuration. In an 8-bit-wide SCSI bus arrangement (“A” Cable), two DS21S07A’s
would be needed at each end of the SCSI cable to terminate the 18 active signal lines. In a 16-bit-wide
SCSI bus arrangement (“P” Cable), three DS21S07A’s would be needed at each end of the SCSI cable to
terminate the 27 active signal lines.
Figure 1. DS21S087A Block Diagram
相關PDF資料
PDF描述
DS21T05Z/T&R IC TERMINATOR SCSI 150MIL 16SOIC
DS21T07S+T&R IC TERMINATOR SCSI 16-SOIC
DS2250-64-16+ IC MCU 64KB 16MHZ 40-SIMM
DS2251T-128-16 IC MICROCNTRLR 128K 16MHZ 72SIMM
DS2252T-128-16 IC MICROCNTRLR 128K 16MHZ 40SIMM
相關代理商/技術參數(shù)
參數(shù)描述
DS21S07CE 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Interface IC
DS21S07CS 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Interface IC
DS21T05 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:SCSI Terminator
DS21T05S 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 安裝風格:SMD/SMT 封裝 / 箱體:SSOP-36 封裝:Tube
DS21T05S/T&R 制造商:Maxim Integrated Products 功能描述:IC TERMINATOR SCSI 300MIL 16SOIC