Electronic Components Datasheet Search |
|
LX5219CDW Datasheet(PDF) 4 Page - Microsemi Corporation |
|
LX5219CDW Datasheet(HTML) 4 Page - Microsemi Corporation |
4 / 12 page UL TRA 9-C HANNEL SCSI T ERMINA T O R LX5219 PRODUCT DA T ABOOK 1996/1997 Copyright © 1998 Rev. 1.8 3/98 4 P RODUCTION D ATA S HEET UltraMAX BLOCK DIAGRAM FUNCTIONAL DESCRIPTION THERMAL LIMITING CIRCUIT TERM POWER CURRENT BIASING CIRCUIT 1.4V DISABLE PIN 24mA CURRENT LIMITING CIRCUIT DATA OUTPUT PIN DB(0) 2.85V 1 OF 9 CHANNELS Cable transmission theory suggests to optimize signal speed and quality, the termination should act both as an ideal voltage reference when the line is released (deasserted) and as an ideal current source when the line is active (asserted). Common active terminators, which consist of Linear Regulators in series with resistors (typically 110 Ω), are a compromise. As the line voltage increases, the amount of current decreases linearly by the equation V = I * R. The LX5219, with its unique new architecture applies the maximum amount of current regardless of line voltage until the termination high thresh- old (2.85V) is reached. Acting as a near ideal line terminator, the LX5219 closely reproduces the optimum case when the device is enabled. To enable the device the Disable Pin must be pulled logic High or left Open. During this mode of operation, quiescent current is 6mA and the device will respond to line demands by delivering 24mA on assertion and by imposing 2.85V on deassertion. In order to disable the device, the Disable pin must be driven logic Low. This mode of operation places the device in a sleep state where a meager 275µA of quiescent current is consumed. Additionally, all outputs are in a Hi-Z (impedance) state. Sleep mode can be used for power conservation or to completely eliminate the termi- nator from the SCSI chain. In the second case, termination node ca- pacitance is important to consider. The terminator will appear as a parasitic distributed capacitance on the line, which can detract from bus performance. For this reason, the LX5219 has been optimized to have only 3pF of capacitance per output in the sleep state. An additional feature of the LX5219 is its compatibility with active negation drivers. The device handles up to 60mA of sink current for drivers which exceed the 2.85V output high. Disable Outputs Quiescent (LX5219) Current H Enabled 6mA L HI Z 275µA Open Enabled 6mA POWER UP / POWER DOWN FUNCTION TABLE |
Similar Part No. - LX5219CDW |
|
Similar Description - LX5219CDW |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |