asm3p2180a peak reducing emi solution ?20 10 scillc. all rights reserv ed. publication order number: january 2010 C rev. 2 asm3p2180 /d features generates a 1x emi optimized clock output. input frequency: 6mhz - 10mhz 18mhz - 30mhz output frequency: 6mhz - 10mhz 18mhz - 30mhz two selectable d own spread o ptions . selectable frequency range. integrated loop filter components. operates with a 3.3v supply. low - power cmos design. commercial temperature range 8 - pin soic and 8 - pin tssop packages . product description the asm3p2180a is a versatile spread spectrum frequency modulator designed s pecifically for a wide range of clock frequencies. asm3p2180a reduces electromagnetic interference (emi) at the clock source, allowing system wide reduction of emi of down stream clock and data dependent signals. asm3p2180a allows significant system cost s avings by reducing the number of circuit board layers , and shielding that are traditionally required to pass emi regulations. asm3p2180a modulates the output of a single pll in order to spread the bandwidth of a synthesized clock, thereby decreasing the peak amplitudes of its harmonics. this result s in significantly lower system emi compared to the typical narrow band signal produced by oscillators and most clock generators. lowering emi by increasing a signals bandwidth is called spread spectrum clock g eneration. asm3p2180a uses the most efficient and optimized modulation profile approved by the fcc and is implemented by using a proprietary all - digital method. applications the asm3p2180a is targeted towards notebook lcd displays, other displays using an lvds interface, pc peripheral devices and embedded systems . block diagram pll crystal oscillator clkin / xin xout clkout vdd gnd ss% fs modulation
asm3p2180a rev. 2 | page 2 of 8 | www.onsemi.com pin diagram pin description pin# pin name type description 1 clkin / xin i crystal connection or external reference clock input. 2 xo ut o connection for an external crystal. if using an external reference, this pin must be left unconnected. 3 gnd p ground to entire chip. 4 ss% i spread selection input. has an internal pull - up resistor. 5 clkout o modulated clock output. 6 vdd p pow er supply for the entire chip . 7 fs i frequency selection bit. this pin selects the frequency range of operation. ( refer to the frequency range selection table ). h as an internal pull - up resistor. 8 nc - no connect. frequency range selection fs frequenc y range (mhz) 0 6 - 10 1 18 - 30 spread selection table ss% frequency (mhz) deviation (%) (typ) fs=0 fs=1 0 6 18 - 2 8 24 - 1.5 10 30 - 1 1 6 18 - 4 8 24 - 3 10 30 - 2 1 2 3 4 5 6 7 8 vdd nc clkout c lkin / xin xout gnd ss% fs 3p2180a
asm3p2180a rev. 2 | page 3 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 t stg storage temperature - 65 to +125 c t s max. soldering temperature (10 sec) 260 c t j junction temperature 150 c t dv static discharge voltage (as per jedec std22 - a114 - b) 2 kv note: these are stress rati ngs only and are not implied for functional use. exposure to absolute maximum ratings for prolonged periods of time may affec t device reliability. dc electrical characteristics symbol parameter min typ max unit v il input low voltage gnd C 0.3 0.8 v v i h input high voltage 2.0 v dd + 0.3 v i il input low current (pull - up resistors on inputs ss%, fs ) - 27 a i ih input high current 18 a i xol x out output low current (@ 0.4v, v dd = 3.3v) 3 ma i xoh x out output high current (@2.5v, v dd = 3.3v) 4 ma v ol output low voltage (v dd = 3.3v, i ol = 4ma) 0.4 v v oh output high voltage (v dd = 3.3v, i oh = 4ma) 2.5 v i cc dynamic supply current normal mode (3.3v and 10pf loading) 10 15 2 5 ma i dd * static supply current standby mode 7 m a v dd operating v oltage 2.8 3.3 3.7 v t on power up time (first locked clock cycle after power up) 0.18 ms z out clock output impedance 50 *clkin pin pulled to gnd
asm3p2180a rev. 2 | page 4 of 8 | www.onsemi.com ac electrical characteristics symbol parameter min typ max unit clkin input frequency fs=0 6 1 0 m hz fs=1 18 30 clkout output frequency fs=0 6 1 0 mhz fs=1 18 30 t lh * output rise time (measured at 0.8v to 2.0v) 1.2 1.3 1.4 n s t hl * output fall time (measured at 2.0v to 0.8v) 0.8 0.9 1.0 n s t jc jitter (cycle to cycle) 325 p s t d output du ty cycle 45 50 55 % *t lh and t hl are measured into a capacitive load of 15pf typical t est c ircuit +3.3v spread spectrum output (emi suppressed) xin gnd 0.1uf c load xout clkout vdd crystal c1 c2
asm3p2180a rev. 2 | page 5 of 8 | www.onsemi.com package information 8 - pin soic package 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 0 8 0 8 d e h d a1 a2 a l c b e
asm3p2180a rev. 2 | page 6 of 8 | www.onsemi.com 8 - pin tssop package symbol dimensions inches millimeters 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 0 8 0 8 e h a a1 a2 d b c l e
asm3p2180a rev. 2 | page 7 of 8 | www.onsemi.com ordering codes part n umber marking package type temperature asm3p2180af - 08st asm3p2180af 8 - pin soic, tube, pb free commercial asm3p2180af - 08sr asm3p2180af 8 - pin soic, tape and reel, pb free commercial asm3p2180af - 08tt asm3p2180af 8 - pin tssop, tube, pb free commercial asm3p2180af - 08tr asm3p2180af 8 - pin tssop, tape and reel, pb free commercial asm3p2180ag - 08st asm3p2180ag 8 - pin soic, tube, green commercial asm3p2180ag - 08sr asm3p2180ag 8 - pin soic, tape and reel, green commercial asm3p2 180ag - 08tt asm3p2180ag 8 - pin tssop, tube, green commercial asm3p2180ag - 08tr asm3p2180ag 8 - pin tssop, tape and reel, green commercial device ordering information a s m 3 p 2 1 8 0 a f - 0 8 s r licensed under us patent #5,488,627, #6,646,463 and #5,631,920. device pin count x= automotive i= industrial p or n/c = commercial ( - 40c to +125c) ( - 40c to +85c) (0c to +70c) 1 = reserved 6 = power management 2 = non pll based 7 = power management 3 = emi reduction 8 = power manag ement 4 = ddr support products 9 = hi performance 5 = std zero delay buffer 0 = reserved on semiconductor mixed signal product part number r = tape & r eel, t = tube or tray f = lead free and rohs compliant part g = green package, lead free, and rohs o = sot u = msop s = soic e = tqfp t = tssop l = lqfp a = ssop u = msop v = tvsop p = pdip b = bga d = qsop q = qfn x = sc - 70
asm3p2180a 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 semiconduc tor 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 suitabili ty of its products for any particular purpose, n or does scillc assume any liability arising out of the application or use of any product or circuit, and specifically disclai ms any and all liability, including without limitation special, consequential or incidental damages. typical parameters which may including typicals must be publication orde ring 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: o rderlit@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 informa tion, please contact your local sales representative
|
