I2779AF-08-TT

P2779A PULSECORE | Alldatasheet

Document overview

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Technical content

Features

• Provides up to 15dB of EMI suppression
• FCC approved method of EMI attenuation
• Generates a 1X low EMI spread spectrum clock of the input frequency
• Operates between 20MHz and 38MHz input frequency range
• External loop filter for spread percentage adjustment
• Spreading ranges fr om ±0.25% to ±2.5%
• Ultra low cycle-to-cycle jitter
• Zero-Cycle slip at small deviations
• 3.3 V Operating Voltage
• Low power CMOS design
• Available in 8-pin SOIC and TSSOP Packages
• Available in Industrial temperature operating range (-40º C to 85º C) Product Description The P2779A is a versatile spread spectrum frequency modulator designed specifically for mobile and digital camera and other digital video and imaging applications. The P2779A reduces electromagnetic interference (EMI) at the clock source, which provides system-wide reduction of EMI of all clock dependent signals. The P2779A allows significant system cost savings by reducing the number of circuit board layers and shielding that are traditionally required to pass EMI regulations. The P2779A uses the most efficient and optimized modulation profile approved by the FCC. The P2779A 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 produced by oscillators and most frequency generators. Lowering EMI by increasing a signal’s bandwidth is called spread spectrum clock generation.

Applications

The P2779A is targeted toward mobile 3D graphics chip set applications. Block Diagram VDD PD VSS ModOUT XIN Frequency Divider Feedback Divider Modulation Phase Detector Loop Filter VCO Output Divider PLL Crystal Oscillator XOUT REF LF

rev 0.2 Low-Cost Notebook EMI Reduction IC 2 of 8 Notice: The information in this document is subject to change without notice. Pin Configuration Pin Description Pin# Pin Name Type Description 1 XIN / CLKIN I Connect to crystal or clock input. 2 XOUT O Crystal output. PD I Power-down control pin. Pull low to enable power-down mode. This pin has an internal pull-up resistor.1

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 Loop Filter Selection Table for detail values.) 5 VSS P Ground connection. Connect to system ground. 6 ModOUT O Spread spectrum clock output. 7 REF O Provides a reference cl ock output of the input frequency. 8 VDD P Connect to +3.3 V. Note: 1. Connect to VDD if not used. Loop Filter Selection Table VDD 3.3 V (MHz) FS1 FS0 C1 (pF) (pF) (Ω) (pF) (pF) (Ω) (pF) (pF) (Ω) (pF) (pF) (Ω) 20 1 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 0 270 100,000 510 270 100,0 00 750 270 10,000 1,000 680 6,800 1,200 25-26 1 0 270 100,000 560 270 100,0 00 820 270 12,000 1,200 470 4,700 1,200 27-28 1 0 270 100,000 620 270 100,0 00 1,000 270 6,800 1, 200 330 3,300 1,200 29-30 1 0 270 100,000 750 270 100,0 00 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 1,000 270 100,0 00 1,500 270 5,600 2, 200 270 2,700 2,200 37-38 1 0 270 100,000 1,200 270 100,0 00 1,600 270 3,300 2, 200 270 2,700 2,700 Please contact factory for loop filter values if desired spread settings are not listed. C2 C1 Pin 4 LF PD 4 5 ModOUT VDD VSS XIN / CLKIN XOUT LF REF P2779A

rev 0.2 Low-Cost Notebook EMI Reduction IC 3 of 8 Notice: The information in this document is subject to change without notice. Spread Spectrum Selection The P2779A performs zero cycle slip when set at low percentag e spreading. This prevents any occurrence of system timing error. The optimal setting should minimize system EMI to the fullest without affect ing system performance. The spreading is described as a percentage deviation of the center frequency. (Note that the center frequency is the frequency of the external reference input on XIN/CLKIN, pin 1.) The P2779A is designed for PC peripheral, networking, noteb ook PC, and LCD monitor applications. It is optimized for operation from 20MHz to 38MHz. The P 2779A’s spread percentage selection is determined by the external LF value specified in the Loop Filter Selection Tabl e. The external LF allows the user to fine tune the spread percentage to optimize the EMI reduction benefits of the spread spectrum. Application Schematic PD selection: Power dissipation can be reduced by completely turning off the IC. VDD REF ModOUT VSSLF PD XOUT XIN/CLKIN P2779A +3.3V Modulated 27MHz

27 MHz

0.1µF VDD

rev 0.2 Low-Cost Notebook EMI Reduction IC 4 of 8 Notice: The information in this document is subject to change without notice. Absolute Maximum Ratings Symbol Parameter Rating Unit VDD, VIN Voltage on any pin with respect to Ground -0.5 to +4.6 V TSTG Storage temperature -65 to +125 °C TA Operating temperature -40 to +85 °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. 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 - 60 - µA IIH Input high current - 0 - µA IXOL XOUT output low current (at 0.4 V, V DD = 3.3V) - 10 - mA IXOH XOUT output high current (at 2.5 V, V DD = 3.3V) - 10 - mA VOL Output low voltage (V DD = 3.3V, IOL = 20 mA) - - 0.4 V VOH Output high voltage (V DD = 3.3V, IOH = 20 mA) 2.5 - - V IDD Static supply current - 3 - mA ICC Dynamic supply current (3.3 V, 25 pF loading, 32 MHz) - 12 - mA VDD Operating volta ge 3.0 3.3 3.6 V tON Power-up time (first locked cycle after power up) - 7 - mS ZOUT Clock output impedance - 28 - Ω Symbol Parameter Min Typ Max Unit fIN Input frequency 20 - 38 MHz fOUT Output frequency 20 - 38 MHz tLH 1 Output rise time (measured at 0.8 V to 2.0 V) - 1 - nS tHL 1 Output fall time (measured at 2.0 V to 0.8 V) - 1 - nS tJC Jitter (Cycle to cycle) - ±175 - pS tD Output duty cycle 45 50 55 % Note: 1. tLH and tHL are measured into a capacitive load of 15 pF

rev 0.2 Low-Cost Notebook EMI Reduction IC 5 of 8 Notice: The information in this document is subject to change without notice.

Package Information

8-lead (150-mil) SOIC Package D E H D A2 A θ L C B e Dimensions Inches Millimeters Symbol 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

rev 0.2 Low-Cost Notebook EMI Reduction IC 6 of 8 Notice: The information in this document is subject to change without notice. E H A D B C L θ e 8-lead Thin Shrunk Small Outline Package (4.40-MM Body) Dimensions Inches Millimeters Symbol Min Max Min Max A 0.043 1.10 A1 0.002 0.006 0.05 0.15 A2 0.033 0.037 0.85 0.95 B 0.008 0.012 0.19 0.30 c 0.004 0.008 0.09 0.20 D 0.114 0.122 2.90 3.10 E 0.169 0.177 4.30 4.50 e 0.026 BSC 0.65 BSC H 0.252 BSC 6.40 BSC L 0.020 0.028 0.50 0.70 θ 0° 8° 0° 8° Note: Controlling dimensions are millimeters TSSOP – 0.0325 grams unit weight

rev 0.2 Low-Cost Notebook EMI Reduction IC 7 of 8 Notice: The information in this document is subject to change without notice.

Ordering Information

Part number Marking Package Type Temperature P2779AF-08-ST P2779AF 8-Pin SOIC, Tube, Pb Free Commercial P2779AF-08-SR P2779AF 8-Pin SOIC, Tape and Reel, Pb Free Commercial P2779AG-08-ST P2779AG 8-Pin SOIC, Tube, Green Commercial P2779AG-08-SR P2779AG 8-Pin SOIC, Tape and Reel, Green Commercial I2779AF-08-ST I2779AF 8-Pin SOIC, Tube, Pb Free Industrial I2779AF-08-SR I2779AF 8-Pin SOIC, Tape and Reel, Pb Free Industrial I2779AG-08-ST I2779AG 8-Pin SOIC, Tube, Green Industrial I2779AG-08-SR I2779AG 8-Pin SOIC, Tape and Reel, Green Industrial P2779AF-08-TT P2779AF 8-Pin TSSOP, Tube, Pb Free Commercial P2779AF-08-TR P2779AF 8-Pin TSSOP, Tape and Reel, Pb Free Commercial P2779AG-08-TT P2779AG 8-Pin TSSOP, Tube, Green Commercial P2779AG-08-TR P2779AG 8-Pin TSSOP, Tape and Reel, Green Commercial I2779AF-08-TT I2779AF 8-Pin TSSO P, Tube, Pb Free Industrial I2779AF-08-TR I2779AF 8-Pin TSSOP, Tape and Reel, Pb Free Industrial I2779AG-08-TT I2779AG 8-Pin T SSOP, Tube, Green Industrial I2779AG-08-TR I2779AG 8-Pin TSSOP, Tape and Reel, Green Industrial Device Ordering Information P2779A F-08-ST SR - SOIC, T/R TT – TSSOP, TUBE TR - TSSOP, T/R ST – SOIC, TUBE DEVICE NUMBER Flow: P = Commercial Temperature Range (0°C to 70°C) I = Industrial Temperature Range (-40°C to 85°C) Pin Count Deviation (%) and Spread option Identifier F = LEAD FREE AND RoHS COMPLIANT PART G = GREEN PACKAGE, LEAD FREE, and RoHS Licensed under US patent #5,488,627, #6,646,463 and #5,631,920.

rev 0.2 Low-Cost Notebook EMI Reduction IC 8 of 8 Notice: The information in this document is subject to change without notice. © Copyright 2007 PulseCore Semiconductor Corporation. All rights reserved. Our logo and name are trademarks or registered trademarks of PulseCore Semiconductor. All ot her brand and product names may be the trademarks of their respective companies. PulseCore reserves the right to make changes to this document and its products at any time without notice. PulseCore assumes no responsibility for any errors t hat may appear in this document. The data contained herein represents PulseCore’s best data and/or estimates at the time of issuance. PulseCore reserves the right to change or correct this data at any time, without notice. If the product descri bed herein is under development, significant changes to these specifications are possible. The information in this product data sheet is intended to be general descriptive information for potential customers and users, and is not in tended to operate as, or provide, any guarantee or warrantee to any user or customer. PulseCore does not assume any responsibility or liability arising out of the app lication or use of any product described herein, and disclaims any express or implied warrant ies related to the sale and/or use of PulseCore products including liability or warranties related to fitness for a particular purpose, mercha ntability, or infringement of any intellec tual property rights, except as express agreed to in PulseCore’ s Terms and Conditions of Sale (which are available from PulseCore). All sales of PulseCore products are made exclusiv ely according to PulseCore’s Terms and Conditions of Sale. The purchase of products from PulseCore does not convey a license under any patent rights, copyrights; mask works rights, trademarks, or any other intellect ual property rights of PulseCore or third partie s. PulseCore does not authorize its products for use as critical components in life-supporting systems where a malfunction or failure may reasonably be expected to result in significant injury to the user, and the inclusion of PulseC ore products in such life-supporting systems implies that the manufacturer assumes all risk of such use and agrees to indemnify PulseCore against all claims arising from such use. PulseCore Semiconductor Corporation 1715 S. Bascom Ave Suite 200 Campbell, CA 95008 Tel: 408-879-9077 Fax: 408-879-9018 www.pulsecoresemi.com Copyright © PulseCore Semiconductor All Rights Reserved Preliminary Information Part Number: P277A Document Version: v0.2 Note: This product utilizes US Patent # 6,646,463 Impedance Emulator Patent issued to PulseCore Semiconductor, dated 11-11-2003