ASM3P2853AG-08SR

ASM3P2853A Peak EMI Reducing Solution Features • Generates an EMI optimized clock signal at output. • Input frequency: 25MHz. • Frequency outputs: o USB Clock (48MHz unmodulated) o 50MHz (modulated), ±1% centre spread • Modulation rate: 39KHz. • Spread Spectrum ON/OFF control • Supply voltage range 2.5V ± 5%. • Available in 8-Pin SOIC package. by reducing the number of circuit board layers and shielding that are required to pass EMI regulations. The ASM3P2853A modulates the output of PLL in order to spread the bandwidth of a synthesized clock, thereby decreasing 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 clock generators. Lowering EMI by increasing a signal’s bandwidth is called spread spectrum clock generation. Product Description The ASM3P2853A is a versatile spread spectrum frequency modulator. The ASM3P2853A reduces electromagnetic interference (EMI) at the clock source. The ASM3P2853A allows significant system cost savings Applications ASM3P2853A is targeted towards EMI management for high speed digital applications such as PC peripheral devices, consumer electronics and embedded controller systems. Block Diagram VDD PWDNB XIN XOUT Crystal Oscillator PLL1 USB Clock (48MHz Unmodulated) SSONB PLL2 50MHz Modulated VSS ©2010 SCILLC. All rights reserved. JANUARY 2010 – Rev. 2 Publication Order Number: ASM3P2853/D ASM3P2853A Pin Configuration XIN XOUT VDD VSS 1 2 3 4 8 7 50MHz USB Clock SSONB PWDNB ASM3P2853A 6 5 Pin Description Pin# Pin Name XIN Type Description Connection to crystal or external reference frequency input. This pin has dual 1 I functions. It can be connected either to an external crystal or an external reference clock. Connection to crystal. If using an external reference clock, this pin must be left unconnected. Power supply for the analog and digital blocks. Ground to entire chip. Power-down control pin. Pull low to enable the power-down mode. Connect to VDD, if not used. Digital logic input used to enable spread spectrum function (Active LOW). Spread spectrum is enabled when LOW, disabled when HIGH. Clock output-1 (48MHz unmodulated). Clock output-2 (50MHz modulated). 2 3 4 5 6 7 8 XOUT VDD VSS PWDNB SSONB USB Clock 50MHz O P P I I O O Rev. 2 | Page 2 of 7 | www.onsemi.com ASM3P2853A Absolute Maximum Ratings Symbol VDD, VIN TSTG Ts TJ TDV Storage temperature Max. Soldering Temperature (10 sec) Junction Temperature Static Discharge Voltage (As per JEDEC STD22- A114-B) Parameter Rating -0.5 to +4.6 -65 to +125 260 150 2 Unit V ° C ° C ° C KV Voltage on any pin with respect to Ground 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 Supply Voltage Ambient Operating Temperature Range Crystal Resonator Frequency Output Driver Load Capacitance Symbol VDD TA FXIN CL Condition / Description 2.5V ± 5% Min 2.375 -40 Typ 2.5 25 Max 2.625 +85 Unit V ° C MHz - - 15 pF Crystal Specifications Fundamental AT cut parallel resonant crystal Nominal frequency Frequency tolerance Operating temperature range Storage temperature Load capacitance Shunt capacitance ESR 25MHz ±50ppm or better at 25° C -25° to +85° C C -40° to +85° C C 18pF 7pF maximum 25Ω Note: CY is Load Capacitance and Rx is used to prevent oscillations at overtone frequency of the Fundamental frequency. Typical Crystal Interface Circuit R Crystal XIN CY Rx XOUT CY CY = 2*(CP – CS), Where CP = Load capacitance of crystal from crystal vendor datasheet CS = Stray capacitance due to CIN, PCB, Trace etc. Rev. 2 | Page 3 of 7 | www.onsemi.com ASM3P2853A DC Electrical Characteristics Parameter Overall Supply Current, Dynamic Supply Current, Static IDD IDDL VDD = 2.5V, FXIN = 25MHz, CL = 15pF VDD = 2.5V, XIN = 0, PWDNB = 0 7 13 12 20 mA uA Symbol Conditions / Description Min Typ Max Unit All input pins High-Level Input Voltage Low-Level Input Voltage High-Level Input Current Low-Level Input Current (pull-up) VIH VIL IIH IIL VDD = 2.5V VDD = 2.5V 1.7 0.7 25 -25 V V µA µA Clock Outputs High-Level Output Source Current Low-Level Output Sink Current High-Level Output Source Current Low-Level Output Sink Current IxOH IxOL IOH VDD = 2.5V ,V(XIN) = 0, VO = 2V VDD = V(XIN) = 2.5V, VO = 0.4V VO = 2 V -15 15 8 mA mA mA IOL VO = 0.4V - 8 - mA Output Impedance ZO - 42 - Ω Rev. 2 | Page 4 of 7 | www.onsemi.com ASM3P2853A AC Electrical Characteristics Parameter Rise Time 1 1 Symbol tr Conditions / Description Measured from 20% to 80% of the signal level Measured from 80% to 20% of the Min - Typ 2 Max - Unit nS Fall Time Jitter tf tjc tp signal level - 1.5 250 175 - nS pS pS (Cycle-to-Cycle) Jitter (Period) Clock Duty Cycle Ratio of pulse width (as measured from td rising edge to next falling edge at VDD/2) to one clock period Note: 1. CL = 15 pF, Input clock frequency = 25MHz 45 50 55 % Typical Application Schematic using ASM3P2853A Device 25MHz fundamental Crystal 1 XIN XOUT VDD 50MHz USB Clock 8 7 Modulated 50MHz output Un-modulated 48MHz output 27pF 2 27pF 3 4 +2.5V 0.1uF SSONB B VSS PWDNB ASM3P2853A 6 5 Rev. 2 | Page 5 of 7 | www.onsemi.com ASM3P2853A Package Information 8-Pin SOIC package E H D A2 A θ e A 1 B C L D Dimensions Inches Min A1 A A2 B C D E e H L θ 0.004 0.053 0.049 0.012 0.007 Symbol Max 0.010 0.069 0.059 0.020 0.010 Millimeters Min Max 0.10 1.35 1.25 0.31 0.18 4.90 BSC 3.91 BSC 1.27 BSC 6.00 BSC 0.41 0° 1.27 8° 0.25 1.75 1.50 0.51 0.25 0.193 BSC 0.154 BSC 0.050 BSC 0.236 BSC 0.016 0° 0.050 8° Coplanarity ≤ 4 mil Rev. 2 | Page 6 of 7 | www.onsemi.com ASM3P2853A Ordering Code Part number ASM3P2853AG-08SR Marking AEC Package Configuration 8-pin SOIC, TAPE & REEL, Green Temperature Range 0° to +70° C 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. Note: This product utilizes US Patent #6,646,463 Impedance Emulator Patent issued to PulseCore Semiconductor, dated 11-11-2003. are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes ON Semiconductor and 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. 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