LTC6909 Datasheet | Linear Technology

LTC6909 1 to 8 Output, Multiphase Silicon Oscillator with Spread Spectrum Modulation Features Description n 1-, 2-, 3-, 4-, 5-, 6-, 7- or 8-Phase Outputs n One External Resistor Sets the Output Frequency from 12.5k Hz to 6.67MHz n Optional Spread Spectrum Frequency for Improved EMI Performance n ±10% Frequency Spreading n Outputs Can Be Held Low or Floated (Hi-Z) n Three Spread Spectrum Modulation Rates f OUT/16, f OUT/32 and f OUT/64 n 400µA Supply Current n Operates from a Single 2.7V to 5.5V Supply n Fast Start-Up Time n First Cycle Accurate n Outputs Are High Impedance Until Frequency Settles n MS16 Package Applications n Synchronizing Multiple Switching Power Supplies L, LT, LTC, LTM, Linear Technology, the Linear logo and µModule are registered trademarks and Thin SOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 6342817, 6614313, 7417509. The LTC®6909 is an easy to use precision oscillator that can provide 1-, 2-, 3-, 4-, 5-, 6-, 7- or 8-phase synchronized outputs. The LTC6909 also offers spread spectrum frequency modulation (SSFM), which can be enabled to improve electromagnetic patibility (EMC) performance. Eight separate outputs provide up to eight rail-to-rail, 50% duty cycle clock signals. Using three logic inputs, the outputs are configured for phase separation, ranging from 45° to 120° (three to eight phases). The clock outputs can also be held low or configured for Hi-Z. A single resistor, bined with the phase configuration, sets the output frequency, based on the following formula: f OUT = 20MHz - 10k/(RSET - PH) where PH = 3, 4, 5, 6, 7 or 8 The LTC6909 can be used in applications requiring only one or two output phases. Alternatively, the LTC6908 family of parts provides the same two output signals but in a smaller SOT-23 or 2mm × 3mm DFN package. The LTC6908-1 provides plimentary (180°) outputs while the LTC6908-2...