hbwhelp@micrel.com or (408) 955-1690 8 Functional Desc" />
參數(shù)資料
型號: SY89841UMG
廠商: Micrel Inc
文件頁數(shù): 14/15頁
文件大小: 0K
描述: IC MUX 2:1 LVDS RPE 16-MLF
標(biāo)準(zhǔn)包裝: 100
系列: SY89
類型: 多路復(fù)用器
電路: 1 x 2:1
獨(dú)立電路: 1
電壓電源: 單電源
電源電壓: 3 V ~ 3.6 V
工作溫度: -40°C ~ 85°C
安裝類型: 表面貼裝
封裝/外殼: 16-VFQFN 裸露焊盤,16-MLF?
供應(yīng)商設(shè)備封裝: 16-MLF?(3x3)
包裝: 管件
產(chǎn)品目錄頁面: 1090 (CN2011-ZH PDF)
其它名稱: 576-2095-5
SY89841UMG-ND
Micrel, Inc.
SY89841U
February 2005
M9999-021405
hbwhelp@micrel.com or (408) 955-1690
8
Functional Description
RPE MUX and Fail-Safe Input
The SY89841U is optimized for clock switchover
applications where switching from one clock to
another clock without runt pulses (short cycles) is
required. It features two unique circuits:
Runt-Pulse Eliminator (RPE) Circuit
The RPE MUX provides a “glitchless” switchover
between two clocks and prevents any runt pulses
from occurring during the switchover transition. The
design of both clock inputs is identical (i.e., the
switchover sequence and protection is symmetrical
for both input pair, IN0 or IN1. Thus, either input pair
may be defined as the primary input). If not required,
the RPE function can be permanently disabled to
allow the switchover between inputs to occur
immediately. If the CAP pin is tied directly to VCC,
the RPE function will be disabled and the multiplexer
will function as a normal multiplexer.
Fail-Safe Input (FSI) Circuit
The FSI function provides protection against a
selected input pair that drops below the minimum
amplitude requirement. If the selected input pair
drops sufficiently below the 100mV minimum single-
ended input amplitude limit (VIN), or 200mV
differentially (Vdiff_IN), the output will latch to the last
valid clock state.
RPE and FSI Functionality
The basic operation of the RPE MUX and FSI
functionality is described with the following four case
descriptions. All descriptions are related to the true
inputs and outputs. The primary (or selected) clock
is called CLK1; the secondary (or alternate) clock is
called CLK2. Due to the totally asynchronous
relation of the IN and SEL signals and an additional
internal protection against metastability, the number
of pulses required for the operations described in
cases 1-4 can vary within certain limits. Refer to
“Timing Diagrams” section for detailed information.
Case #1: Two Normal Clocks and RPE Enabled
In this case, the frequency difference between the
two running clocks, IN0 and IN1, must not be greater
than 1.5:1. For example, if the IN0 clock is 500MHz,
the IN1 clock must be within the range of 334MHz to
750MHz.
If the SEL input changes state to select the alternate
clock, the switchover from CLK1 to CLK2 will occur
in three stages.
Stage 1: The output will continue to follow CLK1
for a limited number of pulses.
Stage 2: The output will remain LOW for a
limited number of pulses of CLK2.
Stage 3: The output follows CLK2.
CLK1
CLK2
SEL
OUTPUT
Select CLK1
Stage 1
Stage 2
Stage 3
Select CLK2
3 to 5 falling edges
of CLK1
4 to 5 falling edges
of CLK2
Runt pulse eliminated
from output
Timing Diagram 1
相關(guān)PDF資料
PDF描述
D38999/20WG11SE CONN RCPT 11POS WALL MNT W/SCKT
SY89842UMG IC MUX CML RPE 2:1 PREC 16-MLF
HIN232CB IC TXRX RS-232 5V 16-SOIC
SY89840UMG IC MUX 2:1 LVPECL DIFF 16MLF
MS27496E21F39P CONN RCPT 39POS BOX MNT W/PINS
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
SY89841UMG TR 功能描述:編碼器、解碼器、復(fù)用器和解復(fù)用器 Precision 2:1 LVDS MUX w/ RPE & FSI (I Temp, Green) RoHS:否 制造商:Micrel 產(chǎn)品:Multiplexers 邏輯系列:CMOS 位數(shù): 線路數(shù)量(輸入/輸出):2 / 12 傳播延遲時(shí)間:350 ps, 400 ps 電源電壓-最大:2.625 V, 3.6 V 電源電壓-最小:2.375 V, 3 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-44 封裝:Tray
SY89841UMGTR 制造商:MICREL 制造商全稱:Micrel Semiconductor 功能描述:Precision LVDS Runt Pulse Eliminator 2:1 Multiplexer
SY89842U 制造商:MICREL 制造商全稱:Micrel Semiconductor 功能描述:Precision CML Runt Pulse Eliminator 2:1
SY89842U_10 制造商:MICREL 制造商全稱:Micrel Semiconductor 功能描述:Precision CML Runt Pulse Eliminator 2:1
SY89842UMG 功能描述:編碼器、解碼器、復(fù)用器和解復(fù)用器 Precision 2:1 CML MUX w/ RPE & FSI (I Temp, Green) RoHS:否 制造商:Micrel 產(chǎn)品:Multiplexers 邏輯系列:CMOS 位數(shù): 線路數(shù)量(輸入/輸出):2 / 12 傳播延遲時(shí)間:350 ps, 400 ps 電源電壓-最大:2.625 V, 3.6 V 電源電壓-最小:2.375 V, 3 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-44 封裝:Tray