I2781AG-08SR

P2781 ONSEMI | Alldatasheet

Document overview

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• PDF pages: 8

Technical content

Features

• Provides up to 15dB of EMI suppression
• FCC approved method of EMI attenuation
• Generates a 1X, 2X, and 4X low EMI spread spectrum clock of the input frequency
• Input frequency range from 3 to 78MHz
• External loop filter for spread % adjustment
• Spreading ranges from ±0.25% to ±5.0%
• Ultra low cycle-to-cycle jitter
• Zero-cycle slip
• 3.3V operating voltage range
• Ultra-low power CMOS design
• P278xA is available in an 8 pin SOIC Package Product Description The P278xA is a versatile spread spectrum frequency modulator designed specifically for digital camera and other digital video and imaging applications. The P278xA reduces electromagnetic interference (EMI) at the clock source, which provides system wide reduction of EMI of all clock dependent signals. The P278xA allows significant system cost savings by reducing the number of circuit board layers and shielding that are traditionally required to pass EMI regulations. The P278xA uses the most efficient and optimized modulation profile approved by the FCC. The P278xA 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 result in significantly lower system EMI compared to the typical narrow band signal produced by oscillators and most frequency generators. Lowering EMI by increasing a signal’s bandwidth is called spread spectrum clock generation.

Applications

The P278xA is targeted towards MFP, xDSL, fax modem, set-top box, USB controller, DSC, and embedded systems. Block Diagram Crystal Oscillator Frequency Divider Feedback Divider Phase Detector Modulation Output Divider VCO XIN / CLKIN XOUT FS0 FS1 LF VDD VSS PLL ModOUT

Rev. 2 | Page 2 of 8 | www.onsemi.com Pin Configuration Pin Description (P278xA) Pin# Pin Name Type Description 1 XIN/CLKIN I Connect to crystal or clock input. This pin has dual functions. It can be connected either to an external crystal or an external reference clock. 2 XOUT O Crystal connection. If using an external reference, this pin must be left unconnected.

3 FS1 I Digital logic input used to select input frequency range (see the Input Frequency

Selection Table ). This pin has an internal pull-up resistor.

4 LF I

External Loop Filter for the PLL. By changing the value of the CRC circuit, the percentage spread can be adjusted accordingly. See the Loop Filter Selection Table for detail value. 5 VSS I Ground Connection. Connect to system ground . 6 ModOUT O Spread Spectrum Clock Output.

7 FS0 I Digital logic input used to select input frequency range (see the Input Frequency

Selection Table ). This pin has an internal pull-up resistor. 8 VDD P Connect to +3.3 V Input Frequency Selection Table FS1 FS0 Input (MHz) Output Frequency Scaling (MHz) Modulation Rate (KHz) P2781A P2782A P2784A 0 0 3 to 9 3 to 9 6 to 18 12 to 36 Fin / 128 0 1 10 to 19 10 to 19 20 to 38 40 to 76 Fin / 256 1 0 20 to 38 20 to 38 40 to 76 80 to 152 Fin / 512 1 1 39 to 78 39 to 78 78 to 156 156 to 312 Fin / 10 24 Standard pin Configuration offered in both 8 pin SOIC Packages. FS1 LF FS0 VDD VSS 4 5 P278xA XIN / CLKIN ModOUT XOUT

Rev. 2 | Page 3 of 8 | www.onsemi.com Loop Filter Selection Table VDD 3.3V Contact PulseCore for loop values that are not listed in the table and for component selection values for industrial and automotive temperatures. Input MHz FS1 FS0 (pF) (pF) (ohm) (pF) (pF) (ohm) (pF) (pF) (ohm) (pF) (pF) (ohm) 3 0 0 270 330,000 220 270 330,000 300 270 100,000 390 560 100,000 510 4 0 0 270 100,000 270 270 100,000 390 270 100,000 560 560 100,000 680 5 0 0 270 100,000 390 270 100,000 560 270 100,000 750 560 100,000 910 6 0 0 270 100,000 510 270 100,000 750 270 10,000 1,000 680 6,800 1,200 7 0 0 270 100,000 620 270 100,000 1,000 270 5,600 1,200 330 3,300 1,200 8 0 0 270 100,000 820 270 100,000 1,200 270 12,000 2,200 680 6,800 2,200 9 0 0 270 100,000 1,000 270 100,000 1,500 270 5,600 2,200 270 2,700 2,200 10 0 1 270 100,000 330 270 100,000 510 270 100,000 750 560 100,000 910 11 0 1 270 100,000 390 270 100,000 560 270 100,000 866(1%) 560 100,000 1,100 12 0 1 270 100,000 510 270 100,000 750 270 10,000 1,000 680 6,800 1,200 13 0 1 270 100,000 560 270 100,000 820 270 12,000 1,200 470 4,700 1,200 14 0 1 270 100,000 620 270 100,000 1,000 270 5,600 1,200 330 3,300 1,200 15 0 1 270 100,000 750 270 100,000 1,100 270 3,900 1,200 330 3,300 1,500 16 0 1 270 100,000 820 270 100,000 1,200 270 12,000 2,200 680 6,800 2,200 17 0 1 270 100,000 910 270 100,000 1,300 270 10,000 2,200 390 3,900 2,200 18 0 1 270 100,000 1,000 270 100,000 1,500 270 5,600 2,200 270 2,700 2,200 19 0 1 270 100,000 1,200 270 100,000 1,600 270 3,300 2,200 270 2,700 2,700 20 0 0 270 100,000 330 270 100,000 560 270 100,000 750 560 100,000 910 21-22 1 0 270 100,000 390 270 100,000 620 270 100,000 866 (1%) 560 100,000 1,100 23-24 1 0 270 100,000 510 270 100,000 750 270 10,000 1,000 680 6,800 1,200 25-26 1 0 270 100,000 560 270 100,000 820 270 12,000 1,200 470 4,700 1,200 27-28 1 0 270 100,000 620 270 100,000 1,000 270 6,800 1,200 330 3,300 1,200 29-30 1 0 270 100,000 750 270 100,000 1,100 270 3,900 1,200 330 3,300 1,500 31-32 1 0 270 100,000 820 270 100,000 1,200 270 12,000 2,200 680 6,800 2,200 33-34 1 0 270 100,000 910 270 100,000 1,300 270 10,000 2,200 390 3,900 2,200 35-36 1 0 270 100,000 1,000 270 100,000 1,500 270 5,600 2,200 270 2,700 2,200 37-38 1 0 270 100,000 1,200 270 100,000 1,600 270 3,300 2,200 270 2,700 2,700 39-42 1 1 270 100,000 330 270 100,000 560 270 100,000 750 560 100,000 910 43-46 1 1 270 100,000 390 270 100,000 620 270 100,000 866 (1%) 560 100,000 1,100 47-50 1 1 270 100,000 510 270 100,000 750 270 10,000 1,000 680 6,800 1,200 51-54 1 1 270 100,000 560 270 100,000 820 270 12,000 1,200 470 4,700 1,200 55-58 1 1 270 100,000 620 270 100,000 1,000 270 6,800 1,200 330 3,300 1,200 59-62 1 1 270 100,000 750 270 100,000 1,100 270 3,900 1,200 330 3,300 1,500 63-66 1 1 270 100,000 820 270 100,000 1,200 270 12,000 2,200 680 6,800 2,200 67-70 1 1 270 100,000 910 270 100,000 1,300 270 8,200 2,200 390 3,900 2,200 71-74 1 1 270 100,000 1,000 270 100,000 1,600 270 5,600 2,200 270 2,700 2,200 75-78 1 1 270 100,000 1,200 270 100,000 1,800 270 3,300 2,200 270 2,700 2,700 Note: 1. The BW value is representative of typical conditions.

Rev. 2 | Page 4 of 8 | www.onsemi.com Spread Spectrum Selection The P278xA performs Zero Cycle Slip when set at low percentage spreading. This allows no occurrence of system timing error. 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.) The P2781A is designed for PC peripheral, networking, notebook PC, and LCD monitor applications. It is optimized for operation between 3 to 78MHz range. In the following application schematic example, the P2781A spread percentage selection is determined by the external LF value specified in the Loop Filter Selection Table. The Input Frequency Selection Table specifies the input frequency range. The external LF allows the user to fine tune the spread percentage to optimize the EMI reduction benefits of the spread spectrum. Note: Both logic input pins FS1 and FS0 have to be connected to either VDD or VSS. Do not leave them floating. VDD FS0 ModOUT VSS LF FS1 XOUT XIN/CLKIN P2 78xA +3.3V Modulated 16MHz Clock To target Chip

16 MHz

0.1µF C2 C1

0 Ohm

2.2 K

Rev. 2 | Page 5 of 8 | www.onsemi.com Absolute Maximum Ratings Symbol Parameter Rating Unit VDD , V IN Voltage on any pin with respect to Ground -0.5 to +4.6 V TSTG Storage temperature -65 to +125 ° C Ts Max. Soldering Temperature (10 sec) 260 ° C TJ Junction Temperature 150 ° C TDV Static Discharge Voltage (As per JEDEC STD22- A114-B) 2 KV Note: These are stress ratings only and are not implied for functional use. Exposure to absolute maximum ratings for prolonged periods of time may affect device reliability. Operating Conditions Parameter Description Min Max Unit VDD Supply Voltage 3.0 3.6 V TA Operating Temperature (Ambient Temperature) -40 + 85 ° C C L Load Capacitance 15 pF C IN Input Capacitance 7 pF (Test condition: All parameters are measured at room temperature (+25° C) unless otherwise stated.) Symbol Parameter Min Typ Max Unit VIL Input low voltage VSS – 0.3 0.8 V VIH Input high voltage 2.0 VDD +0.3 V IIL Input low current (internal input pull-up resistor on FS0 and FS1) 60 µA IIH Input high current (internal input pull-up resistor on FS0 and FS1) 60 µA IXOL XOUT output low current 10 mA IXOH XOUT output high current 10 mA VOL Output low voltage (VDD = 3.3V, I OL = 20mA) 0.4 V VOH Output high voltage (VDD = 3.3V, I OH = 20mA) 2.5 V IDD Static supply current 3 mA ICC Typical dynamic supply current (25pF scope probe loading) 5.2 at 3MHz 21.2 at 82MHz mA VDD Operating voltage 3.0 3.3 3.6 V

Rev. 2 | Page 6 of 8 | www.onsemi.com Symbol Parameter Min Typ Max Unit fIN Input frequency: P278xA 3 78 MHz fOUT Output frequency: P2781A 3 78 P2782A 6 156 P2784A 12 312 tLH P278xA Output rise time (measured at 0.8V to 2.0V, 25pF scope probe loading) 1 nS tHL P278xA Output fall time (measured at 2.0V to 0.8V, 25 pF scope probe loading) 1 nS tJC P2781A Jitter (cycle-to-cycle, ±6sigma, 1000 sweeps, ±0.5% spread, I/O frequency = 16MHz) ±250 pS tD P2781A Output duty cycle deviation (error from 50% duty cycle, 25pF scope probe loading) ±1 @ 3MHz ±2 @ 82MHz % ∆F P278xA Frequency deviation tolerance from BW% stated in the Loop Filter Selection Table -20 0 +20 %

Rev. 2 | Page 7 of 8 | www.onsemi.com

Package Information

D E H D A 1 A2 A θ L C B e Symbol Dimensions Inches Millimeters Min Max Min Max A1 0.004 0.010 0.10 0.25 A 0.053 0.069 1.35 1.75 A2 0.049 0.059 1.25 1.50 B 0.012 0.020 0.31 0.51 C 0.007 0.010 0.18 0.25 D 0.193 BSC 4.90 BSC E 0.154 BSC 3.91 BSC e 0.050 BSC 1.27 BSC H 0.236 BSC 6.00 BSC L 0.016 0.050 0.41 1.27 θ 0° 8° 0° 8° Note: Controlling dimensions are millimeters. SOIC - 0.074 grams unit weight.

Note: This product utilizes US Patent #6,646,463 Impedance Emulator Patent issued to PulseCore Semiconductor, dated 11-11-2003. ON Semiconductor and are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer application by customer's technical experts. SCILLC does not convey any license under its patent rights nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal Opportunity/Affirmative Action Employer. U.S Patent Pending; Timing-Safe and Active Bead are trademarks of PulseCore Semiconductor, a wholly owned subsidiary of ON Semiconductor. This literature is subject to all applicable copyright laws and is not for resale in any manner. PUBLICATION ORDERING INFORMATION LITERATURE FULFILLMENT: Literature Distribution Center for ON Semiconductor P.O. Box 5163, Denver, Colorado 80217 USA Phone: 303-675-2175 or 800-344-3860 Toll Free USA/Canada Fax: 303-675-2176 or 800-344-3867 Toll Free USA/Canada Email: orderlit@onsemi.com N. American Technical Support: 800-282-9855 Toll Free USA/Canada Europe, Middle East and Africa Technical Support: Phone: 421 33 790 2910 Japan Customer Focus Center Phone: 81-3-5773-3850 ON Semiconductor Website: www.onsemi.com Order Literature: http://www.onsemi.com/orderlit For additional information, please contact your local Sales Representative Ordering Codes Ordering # Top Marking Package Type Temperature P2781AF-08ST ABG 8 PIN SOIC, TUBE, Pb Free 0° C to + 70° C P2781AF-08SR ABG 8 PIN SOIC, TAPE AND REEL,Pb Free 0° C to +70° C I2781AF-08ST ABH 8 PIN SOIC, TUBE, Pb Free 0° C to + 70° C I2781AG-08SR ABJ 8 PIN SOIC, TAPE AND REEL, Green 0° C to +70° C P2782AF-08SR ABK 8 PIN SOIC, TAPE AND REEL,Pb Free 0° C to +70° C P2784AF-08SR ABO 8 PIN SOIC, TAPE AND REEL,Pb Free 0° C to +70° C A “microdot” placed at the end of last row of marking or just below the last row toward the center of package indicates Pb-free. Licensed under US patent #5,488,627, #6,646,463 and #5,631,920.