sy89843u Micrel Semiconductor, sy89843u Datasheet
sy89843u
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sy89843u Summary of contents
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... General Description The SY89843U is a low jitter PECL, 2:1 differential input multiplexer (MUX) optimized for redundant source switchover applications. Unlike standard multiplexers, the SY89843U unique 2:1 Runt Pulse Eliminator (RPE) MUX prevents any short cycles or “runt” pulses during switchover. In addition, a unique Fail-Safe Input ...
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Typical Application May 2007 Simplified Example Illustrating RPE (Runt Pulse Elimination) Circuit when Primary Clock Fails 2 hbwhelp@micrel.com M9999-052207-B or (408) 955-1690 ...
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... Ordering Information Part Number Package Type SY89843UMG (2) SY89843UMGTR Notes: 1. Contact factory for die availability. Dice are guaranteed Tape and Reel. Pin Configuration May 2007 Operating Range MLF-24 Industrial MLF-24 Industrial = 25°C, DC Electricals Only. A ® 24-Pin MLF (MLF-24) 3 Package Marking Lead Finish ...
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Pin Description Pin Number Pin Name 5, 2 IN0, /IN0, 23, 20 IN1, /IN1 4, 22 VT0, VT1 VREF-AC0 3, 21 VREF-AC1 15 SEL 10, VCC 13, 19 Q0, /Q0 11, 12 Q1, /Q1 ...
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... Ambient Temperature (T Package Thermal Resistance ® MLF (θ Still-Air ............................................................... 50°C/W ® MLF (Ψ Junction-to-Board .............................................. 30°C/W °C (4) Condition No load, max See Figure 1a. Note 5 See Figure 1b. 5 SY89843U (2) ) .............................+2.375V to +2.625V CC )........................... –40°C to +85° Min Typ Max 2.375 2.5 2.625 3.0 3.3 3 ...
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LVPECL Outputs DC Electrical Characteristics V = 2.5V ±5% or 3.3V ±10 Symbol Parameter V Output HIGH Voltage Output Low Voltage Output Voltage Swing OUT Differential Output ...
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AC Electrical Characteristics V = 2.5V ±5% or 3.3V ±10 Symbol Parameter f Maximum Operating Frequency MAX t Differential Propagation Delay In-to Differential Propagation Delay pd Tempco Temperature Coefficient t Output-to-Output Skew SKEW Part-to-Part Skew t ...
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... Functional Description RPE MUX and Fail-Safe Input The SY89843U 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 ...
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Case #2 Input Clock Failure: Switching from a selected clock stuck HIGH to a valid clock (RPE enabled). If CLK1 fails HIGH before the RPE MUX selects CLK2 (using the SEL pin), then the switchover will occur in three stages. ...
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Case #3 Input Clock Failure: Switching from a selected clock stuck Low to a valid clock (RPE enabled). If CLK1 fails LOW before the RPE MUX selects CLK2 (using the SEL pin), the switchover will occur in two stages. May ...
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... If the selected input clock fails to a floating, static, or extremely low signal swing, including 0mV, the FSI Power-On Reset (POR) Description The SY89843U includes an internal power-on reset (POR) function to ensure the RPE logic starts- known logic state once the power-supply voltage is stable ...
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Typical Operating Characteristics V = 3.3V, GND = 0V, V • 400mV CC IN May 2007 , t /t ” 300ps 50Ÿ –2V 25°C, unless otherwise stated. A ...
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... Micrel, Inc. Functional Characteristics V = 3.3V, GND = 0V, V • 400mV CC IN May 2007 , t /t ” 300ps 50Ÿ –2V SY89843U = 25°C, unless otherwise stated. A M9999-052207-B hbwhelp@micrel.com or (408) 955-1690 ...
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... Micrel, Inc. Singled-Ended and Differential Swings Figure 1a. Single-Ended Voltage Swing Input and Output Stages Figure 2a. Simplified Differential Input Stage May 2007 Figure 1b. Differential Voltage Swing Figure 2b. Simplified LVPECL Output Stage 14 hbwhelp@micrel.com SY89843U M9999-052207-B or (408) 955-1690 ...
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Input Interface Applications Figure 3a. LVPECL Interface (DC-Coupled) Figure 3d. CML Interface (AC-Coupled) May 2007 Figure 3b. LVPECL Interface (AC-Coupled) Figure 3e. LVDS Interface 15 Option: may connect Figure 3c. CML Interface (DC-Coupled) M9999-052207-B hbwhelp@micrel.com ...
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LVPECL Output Interface Applications LVPECL has a high input impedance, a very low output impedance (open emitter), and a small signal swing which results in low EMI. LVPECL is ideal for driving 50Ω and 100Ω controlled impedance transmission lines. There ...
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Product Information MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http:/www.micrel.com The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no ...