Features: ·FCC approved method of EMI attenuation.
·Provides up to 15dB EMI reduction.
·Generates a 4X REF EMI spread output
·Spectrum clock of the input frequency.
·Optimized for input frequency range from 10 to 20MHz.
·External Loop Filter for configurability and flexibility in application and design (spread percentage adjust)
·Reference Output
·Power Down Mode
·Very Low Cycle-to-Cycle Jitter.
·3.3V operating Range
·CMOS / TTL compatible inputs and outputs
·Available in 8-pin SOIC and 8-pin TSSOP packages.ApplicationThe ASM3P2109A is targeted towards the Consumerand PC/Data Processing, or Computation markets. Entertainment devices, LCD displays, Notebook computers, PC peripheral devices, embedded systems, PDA's, and hand held devices provide a platform to take full advantage of the feature set of the ASM3P2109A.
Pinout
Specifications
|
Symbol |
Parameter |
Rating |
Units |
| VDD,Vin |
Voltage on any pim with respect to ground |
-0.5 to 7.0 |
Volts |
| TSTG |
Storage Temperature |
-65 to +125 |
Degrees C |
| TA |
Operating Temperature |
0 to 70 |
Degrees C |
Note:These are Stress ratings Only,and functional operation is not implied.Exposure to absolute maximum ratings for extended periods may affect device reliability...
DescriptionThe ASM3P2109A device is a versatile spread spectrum Frequency Synthesizer / Modulator designed specifically for a wide Range of input clock frequencies from 10MHz to 20MHz with a 4X multiplier for output clock frequencies from 40MHz to 80 MHz.
The ASM3P2109A generates an EMI reduced clock signal from a crystal, ceramic resonator, or system clock. The ASM3P2109A generates a range of modulation rates and deviations (spread) from Center Frequency based upon the input frequency, and is set / determined via an external filter network ( see Loop Filter Selection table )
The ASM3P2109A reduces Electro Magnetic Interference (EMI), at the Clock Source, allowing system wide reduction of EMI on downstream clock and data dependant signals.
The resulting EMI reduction provides for significant cost savings by reducing the number of circuit board layers and shielding that are traditionally associated with designs in order to achieve EMI ASM3P2109A regulatory compliance.
The ASM3P2109A modulates the output of a single PLL in order to "spread" the bandwidth of a synthesized clock, thereby decreasing the Peak amplitudes of its associated harmonics. This results in significantly lower radiated EMI compared to the narrow band signal produced by standard oscillators and most clock synthesizers & generators. This technique of lowering EMI by increasing the signals bandwidth is called Spread Spectrum Clocking (SSC). The ASM3P2109A utilizes the most efficient and optimized modulation profile approved by the FCC, and is implemented using a proprietary, All- Digital method.
ASM3P2109A Data Sheet
