sy89838u Micrel Semiconductor, sy89838u Datasheet
sy89838u
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sy89838u Summary of contents
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... General Description The SY89838U is a low jitter, low skew, high-speed 1:8 fanout buffer with a unique, 2:1 differential input multiplexer (MUX) optimized for redundant source switchover applications. multiplexers, the SY89838U unique 2:1 Runt Pulse Eliminator (RPE) MUX prevents any short cycles or “runt” pulses during switchover. In addition, a unique ...
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Typical Application November 2007 2 hbwhelp@micrel.com M9999-112907-C or (408) 955-1690 ...
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... November 2007 Package Operating Type Range MLF-32 Industrial MLF-32 Industrial = +25°C, DC Electrical only. A ® 32-Pin MLF (MLF-32) 3 Package Marking Lead Finish SY89838U with bar line NiPdAu Pb-Free indicator Pb-Free SY89838U with bar line NiPdAu Pb-Free indicator Pb-Free M9999-112907-C hbwhelp@micrel.com or (408) 955-1690 ...
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Pin Description Pin Number Pin Name 1, 3, IN0, /IN0 IN1, /IN1 2, 7 VT0, VT1 31 SEL 9, 19, 22, 32 VCC 30, 28, 26, 24, 18, 16, 14, 12, Q0 – Q7, 29, 27, 25, 23, ...
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Absolute Maximum Ratings Supply Voltage (V ) ...........................-0.5V to +4.0V CC Input Voltage (V ) .................................. -0. Input Current Source or sink current on IN, /IN.............. ±50mA Termination Current Source or sink current ...
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LVDS Outputs DC Electrical Characteristics V = +2.5V ±5 –40° 85° Symbol Parameter V Output Voltage Swing OUT (Q, /Q) V Differential Output Voltage Swing DIFF-OUT |Q - /Q| V Output Common Mode ...
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AC Electrical Characteristics V = +2.5V ±5 –40°C to +85°C, RPE enabled, Input Symbol Parameter f Maximum Operating Frequency MAX t Differential Propagation Delay pd IN-to-Q SEL-to-Q SEL-to-Q t Differential Propagation Delay pd Tempco Temperature ...
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... Functional Description RPE MUX and Fail-Safe Input The SY89838U 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), the switchover will occur in three stages. CLK1 ...
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... SEL Select CLK 1 OUTPUT as in case # case #3 Power-On Reset (POR) Description The SY89838U includes an internal power-on reset (POR) function to ensure the RPE logic starts- known logic state once the power-supply voltage is stable. An external capacitor connected between V and the CAP pin (pin 10) controls the delay for CC the power-on reset function ...
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Typical Operating Characteristics V = 2.5V, GND = 0V, V ≥ 250mV CC IN Propagation Delay Variation vs. Input Rise/Fall Time 1000 900 t (max) pd 800 700 600 500 400 300 200 V IN 100 0 0 100 200 ...
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Singled-Ended and Differential Swings Figure 1a. Singled-Ended Voltage Swing Input Stage November 2007 OUT 350 mV (typical) Figure1b. Differential Voltage Swing Figure 2. Simplified Differential Input Stage DIFF_IN DIFF_OUT 700 mV (typical) ...
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Input Interface Applications Figure 3a. LVPECL Interface (DC-Coupled) Figure 3d. CML Interface (AC-Coupled) November 2007 Figure 3b. LVPECL Interface (AC-coupled) Figure 3e. LVDS Interface (DC-Coupled) 13 option: may connect Figure 3c. CML Interface (DC-Coupled) M9999-112907-C ...
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LVDS Output Interface Applications LVDS specifies a small swing of 325mV typical nominal 1.2V common mode above ground. The common mode voltage has tight limits to permit large variations in ground between an LVDS driver and V V ...
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Package Information November 2007 ® 32-Pin (5mm x 5mm) MLF (MLF-32) 15 M9999-112907-C hbwhelp@micrel.com or (408) 955-1690 ...
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PCB Thermal Consideration for 32-Pin MLF (Always solder, or equivalent, the exposed pad to the PCB) Package Notes: 1. Package meets Level 2 qualification. 2. All parts are dry-packaged before shipment. 3. Exposed pads must be soldered to a ground ...