the sy89421v is a digital phase locked loop based on micrel-synergy's differential pll technology. it is capable of operating in the 30mhz to 560mhz reference input frequency range, and up to 2000mhz with the hfin input and an external vco. use of a phase-frequency detector results in excellent pll locking and tracking characteristics. error correction voltages are generated by the detector if either phase or frequency deviations occur. the vco has a frequency range covering more than a 2:1 ratio from 480mhz to 1120mhz. feedback for the loop is realized by connecting fout, fout to fin, fin by means of external circuitry. this allows the flexibility of inserting additional circuitry off-chip in the feedback paths, such as an additional divider and/or buffer. pulldown resistors are required for the fout and fout pins. high frequency inputs hfin, hfin and corresponding outputs hfout, hfout are featured for use with external components such as an active loop filter and a high frequency vco. select pins s1 and s2 are used to program the n divider for optimum vco operation, in other words with the vco in the center of its range. select pin s3 allows bypassing the n divider enabling the pll to output the vco directly. select pin s4 is used to select off-chip or on-chip vco. select pin s5 enables the divide-by-two prescaler, which is useful in frequency doubling applications. all select pins are ttl compatible. features 3.3v and 5v power supply options 1.12ghz maximum vco frequency 30mhz to 560mhz reference input operating frequency external 2.0ghz vco capability low jitter differential design frequency doubler mode pecl differential output external loop filter optimizes performance/cost available in 20-pin soic package description clockworks sy89421v final 5v/3.3v high-performance phase locked loop applications workstations advanced communications high-performance computing pin configuration 1 2 3 4 5 6 7 8 9 10 11 12 13 14 20 19 18 17 16 15 top view soic z20-1 s1 fin fin v ee f1 f2 s5 hfin hfin s4 hfout hfout v cco fout fout v cc s3 rin rin s2 1 rev.: f amendment: /0 issue date: may 2000
2 clockworks sy89421v micrel block diagram loop filter component selection c = 1.0 f 10% (x7r dielectric) r = 560 ? 10% r c f1 f2 s1 s2 s3 rin rin f1 f2 vco fin fin fout fout ?p (1, 2) s5 d hfout hfout hfin hfin s4 ?2 mux 01 loop filter phase-frequency detector ?n (1,2,4,8,10,12,16,20)
3 clockworks sy89421v micrel pin function i/o f1 filter pin 1 i/o f2 filter pin 2 i/o rin reference input i rin inverted reference input i fin feedback input i fin inverted feeback input i hfin high frequency input i hfin inverted high frequency input i hfout high frequency output o hfout inverted high frequency output o fout frequency output o fout inverted frequency output o v cc v cc v cco output v cc v ee v ee (0v) s1 select input 1 (ttl) i s2 select input 2 (ttl) i s3 select input 3 (ttl) i s4 select input 4 (ttl) i s5 select input 5 (ttl) i rin, rin reference frequency inputs. these are differential signal pairs and may be driven differentially or single-ended. fin, fin feedback frequency inputs. these are a differential signal pair and may be driven differentially or single-ended. hfin, hfin high frequency feedback inputs. these are a differential signal pair. differential drive is recommended. f1, f2 these pins are connection points for the loop filter, which is to be provided off-chip. f1 is the high impedance side, f2 is the reference side. the loop filter should be a first order, low pass with a dc block. the difference voltage on these pins will be a dc level, which is controlled by the loop feedback and determined by the required vco frequency. fout, fout frequency outputs for the loops. these are differential, positive referenced, emitter-follower signals and must be terminated off chip. termination in 50 ohms is recommended. hfout, hfout high frequency output. these are a differential signal pair. termination in 50 ohms is recommended. s1, s2, s3, s4, s5 these are the frequency select inputs, and are used to configure the pll. they are compatible with standard ttl signal levels. see the frequency selection table for details of the logic. v cc this is the positive supply for the chip. it should be decoupled and should present a very low impedance in order to assure low-jitter operation. v cco this is the positive supply for the output buffer. it is constrained to be equal to or less than the value of v cc . it should be decoupled and should present a very low impedance for low- jitter. v ee this pin is the negative supply for the chip and is normally connected to ground (0v). pin names pin description
4 clockworks sy89421v micrel frequency selection table fout hfout s4 s3 s2 s1 n freq. range mhz freq. range mhz 00002 240 ?560 480 ?1120 00014 120 ?280 480 ?1120 00108 60 140 480 ?1120 001116 30 70 480 ?1120 01001 480 ?1120 480 ?1120 01011048 112 480 ?1120 01101240 93.3 480 ?1120 011120 20 56 480 ?1120 10002 hfin divide by 4 hfin divide by 2 10014 hfin divide by 8 hfin divide by 2 10108 hfin divide by 16 hfin divide by 2 101116 hfin divide by 32 hfin divide by 2 11001 hfin divide by 2 hfin divide by 2 110110 hfin divide by 20 hfin divide by 2 111012 hfin divide by 24 hfin divide by 2 111120 hfin divide by 40 hfin divide by 2 maximum feedback s5 divide-by-p frequency (mhz) 0 p = 1 560 1 p = 2 1120 absolute maximum ratings (1) symbol parameter value unit v cc power supply voltage ?.5 to +7.0 v v i ttl input voltage (2) ?.5 to 6.0 v i i ttl input current (2) ?0 to +5.0 ma i out ecl output current ma ?continuous 50 ?surge 100 t store storage temperature ?5 to +150 c t a operating temperature range (3) 0 to +85 c notes: 1. permanent device damage may occur if absolute maximum ratings are exceeded. this is a stress rating only and functional oper ation is not implied at conditions other than those detailed in the operational sections of this data sheet. exposure to absolute maximum r ating conditions for extended periods may affect device reliability. 2. either voltage limit or current limit is sufficient to protect input. 3. all dc and ac electrical characteristics are specified over the operating termperature range.
5 clockworks sy89421v micrel symbol parameter min. typ. max. unit condition v oh output high voltage v cc ?1.025 v cc ?0.780 v v ol output low voltage v cc ?1.810 v cc ?1.520 v v ih input high voltage v cc ?1.165 v cc ?0.780 v v il input low voltage v cc ?1.810 v cc ?1.475 v pecl dc electrical characteristics v cc = v cco = 3.3v or 5.0v 5% ttl dc electrical characteristics symbol parameter min. typ. max. unit condition v ih input high voltage 2.0 v v il input low voltage 0.8 v i ih input high current 20 av in = 2.7v 100 v in = v cc i il input low current ?.3 ma v in = 0.5v v ik input clamp voltage ?1.2 v i in = ?2ma v cc = v cco = 3.3v or 5.0v 5% symbol parameter min. typ. max. unit condition v cc power supply voltage 4.75 5.25 v v cc = v cco i cc power supply current (v cc ) 100ma i cco power supply current (v cco ) 28 ma pecl outputs are open 5v dc electrical characteristics v cc = v cco = 5.0v 5% symbol parameter min. typ. max. unit condition v cc power supply voltage 3.135 3.465 v v cc = v cco i cc power supply current (v cc ) 100ma i cco power supply current (v cco ) 28 ma pecl outputs are open 3.3v dc electrical characteristics v cc = v cco = 3.3v 5%
6 clockworks sy89421v micrel odering package operating code type range sy89421vzc z20-1 commercial sy89421vzctr z20-1 commercial product ordering code symbol parameter min. typ. max. unit condition ? output period jitter 10 15 ps rms p pw output duty cycle 45 50 55 % tr output rise/fall time 300 550 ps tf (20% to 80%) 300 550 rin reference frequency input 560 mhz fin feedback frequency input 560 mhz s5 = 0 1120 mhz s5 = 1 hfin high frequency input 2000 mhz hfout high frequency output 1120 mhz fout frequency output 1120 mhz ac electrical characteristics v cc = v cco = 3.3v or 5.0v 5%
7 clockworks sy89421v micrel 20 lead soic .300" wide (z20-1) rev. 03
8 clockworks sy89421v micrel micrel-synergy 3250 scott boulevard santa clara ca 95054 usa tel + 1 (408) 980-9191 fax + 1 (408) 914-7878 web http://www.micrel.com this information is believed to be accurate and reliable, however no responsibility is assumed by micrel for its use nor for an y infringement of patents or other rights of third parties resulting from its use. no license is granted by implication or otherwise under any patent or pat ent right of micrel inc. ? 2000 micrel incorporated
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