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Details, datasheet, quote on part number:P2010A-08TT
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Datasheet text preview:
PRELIMINARY Specification
Alliance Semiconductor®
P2010A
Low Frequency EMI Reduction IC
FEATURES · · · · · · · FCC approved method of EMI attenuation Provides up to 20 dB of EMI suppression Generates a low EMI spread spectrum clock of the input frequency Optimized for 10 MHz to 35MHz input frequency range Internal loop filter minimizes external components and board space 4 selectable spread ranges SSON control pin for spread spectrum enable and disable options produced by oscillators and most frequency generators. Lowering EMI by increasing a signal's bandwidth is called "spread spectrum clock generation". APPLICATIONS The P2010 is targeted towards the embedded controller market and PC peripheral markets including scanners, facsimile, MFP's, printers, PDA, IA , and GPS devices. Figure 1 P2010 Pin Diagram
XIN/ CLK XOUT FS0 VSS
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Characterizes to work with EMI-Lator®, EMC simulation program. Low cycle-to-cycle jitter Wide operating range (3V to 5V) 16 mA output drives TTL or CMOS compatible outputs Low power CMOS design Available in 8 pin SOIC and TSSOP
PRODUCT DESCRIPTION The P2010 is a selectable spread spectrum frequency modulator designed specifically for PC peripheral and embedded controller markets . The P2010 reduces electromagnetic interference (EMI) at the clock source which provides system wide reduction of EMI of all clock dependent signals. The P2010 allows significant system cost savings by reducing the number of circuit board layers and shielding that are traditionally required to pass EMI regulations. The P2010 uses the most efficient and optimized modulation profile approved by the FCC and is implemented in a proprietary all-digital method. The P2010 modulates the output of a single PLL in order to "spread" the bandwidth of a synthesized clock and, more importantly, decreases the peak amplitudes of its harmonics. This results in significantly lower system EMI compared to the typical narrow band signal
1 2 3 4
8 7 6 5
VDD SR0 ModOUT SSON
May, 2002 Revision F
PulseCore A Division of Alliance Semiconductor 3160 De La Cruz Blvd., Suite 200 · Santa Clara · CA · 95054 Tel (408) 748-6988 · Fax (408) 748-0009 http://www.pulsecore.com 1 of 1
PRELIMINARY Specification
Alliance Semiconductor® Figure 2 P2010 Block Diagram
SR0 FS0 SSON VDD
P2010A
Modulation XIN XOUT Feedback Divider Crystal Oscillator Frequency Divider
PLL
Phase Detector
Loop Filter
VCO
Output Divider
ModOUT
P2010 Block Diagram VSS
Table 1 - Spread Range Selection FS0 1 1 0 0 PIN DESCRIPTION PIN # 1 2 3 4 5 6 7 8 Name XIN/CLK XOUT FS0 VSS SSON ModOUT SR0 VDD Type I I I P I O I P Description Connect to crystal or externally generated clock signal. Connect to crystal. No connect if externally generated clock signal is used. Digital logic input used to select Input Frequency Range (see Table 1). This pin has an internal pull-up resistor. Ground Connection. Connect to system ground. Digital logic input used to enable Spread Spectrum function (Active Low). Spread Spectrum function enable when low. This pin has an internal pulllow resistor. Spread Spectrum Clock Output. Digital logic input used to select Spreading Range (see Table 1). This pin has an internal pull-up resistor. Connect to +3.3V or +5.0V SR0 0 1 0 1 Spreading Range +/- 1.50% +/- 2.50% +/- 1.25% +/- 2.00% Input Frequency 10 MHz to 20 MHz 10 MHz to 20 MHz 20 MHz to 35 MHz 20 MHz to 35 MHz Modulation rate (Fin/10)*20.83 KHz (Fin/10)*20.83 KHz (Fin/10)*20.83 KHz (Fin/10)*20.83 KHz
May, 2002 Revision F
PulseCore A Division of Alliance Semiconductor 3160 De La Cruz Blvd., Suite 200 · Santa Clara · CA · 95054 Tel (408) 748-6988 · Fax (408) 748-0009 http://www.pulsecore.com 2 of 2
PRELIMINARY Specification
Alliance Semiconductor® SPREAD SPECTRUM SELECTION Table 1 illustrates the possible spread spectrum options. The optimal setting should minimize system EMI to the fullest without affecting system performance. The spreading is described as a percentage deviation of the center frequency (Note: the center frequency is the frequency of the external reference input on CLKIN, Pin 1). Example of a typical printer or scanner application that operates on a clock frequency of 16 MHz: A spreading selection of FS0=1 and SR0=1 provides a percentage deviation of +/-2.50%* (see Table 1) of Fcen. This results in the frequency on ModOUT being swept from 16.40 MHz to 15.60 MHz at a modulation rate of 33.33 KHz (see Table 1). This particular example (see Figure 3) given here is a common EMI reduction method for scanner, printer, or embedded applications and has already been adopted by most of the leading manufacturers.
NOTE: Spreading range selection varies from different system manufacturers and their designs.
P2010A
Figure 3 - P2010 Application Schematic for Flat-Bed Scanner
16MHz Crystal Input
1 2 3 4
XIN/CLK XOUT FS0 VSS
P2010
VDD SR0 ModOUT SSON
8 7 6 5
Connected to CLK input pin of the system 0.1uF VDD
May, 2002 Revision F
PulseCore A Division of Alliance Semiconductor 3160 De La Cruz Blvd., Suite 200 · Santa Clara · CA · 95054 Tel (408) 748-6988 · Fax (408) 748-0009 http://www.pulsecore.com 3 of 3
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