DSC2144FE2-E0017 crystal-less? configurable clock generator general description the DSC2144FE2-E0017 is a programmable, high performance dual hcsl output oscillator utilizing micrel's proven silicon mems technology to provide excellent jitter and stability while incorporating high output frequency flexibility. the DSC2144FE2-E0017 allows the user to independently modify the frequency of each output using i2c interface. the user can also select from two pre-programmed default output frequencies using the frequency select pin. applications consumer electronics storage area networks - sata, sas, fibre channel passive optical networks - epon, 10g-epon, gpon, 10g-gpon ethernet - 1g, 10gbase-t/kr/lr/sr, and fcoe hd/sd/sdi video & surveillance pci express automotive features frequency and output formats: - hcsl 100/125mhz - hcsl 100/125mhz low rms phase jitter: <1ps (typ) 25ppm frequency stability -20c to +70c ext. commercial temperature range high supply noise rejection: -50dbc i2c programmable frequencies excellent shock & vibration immunity - qualified to mil-std-883 high reliability - 20x better mtf than quartz oscillators supply range of 2.25 to 3.6v aec-q100 automotive qualified 14-pin 3.2mm x 2.5mm qfn package block diagram vss vdd/vdd2 control circuitry mems pll 2 m1 m2 2 clk1+ clk1- 100mhz hcsl clk2+ clk2- 100mhz hcsl oe fs micrel inc. 2180 fortune drive san jose, ca 95131 usa tel +1 (408) 944-0800 fax + 1 (408) 474-1000 http://www.micrel.com may 06, 2015 revision 1.0 tcghelp@micrel.com or (408) 955-1690 2962
micrel, inc. DSC2144FE2-E0017 ordering information ordering part number industrial temperature range shipping package DSC2144FE2-E0017 -20c to +70c tube 14-pin 3.2mm x 2.5mm qfn DSC2144FE2-E0017t -20c to +70c tape and reel 14-pin 3.2mm x 2.5mm qfn devices are green and rohs compliant. sample material may have only a partial top mark. pin configuration 14-pin 3.2mm x 2.5mm qfn oe nc nc gnd clk2+ clk2- clk1- clk1+ sda scl cs_bar vdd2 vdd fs pin description pin number pin name pin type pin function 1 oe i enables outputs when high and disables outputs when low 2 nc leave unconnected or connect to ground 3 nc leave unconnected or connect to ground 4 gnd pwr ground 5 sda i i2c serial data 6 scl i i2c serial clock 7 cs_bar i i2c chip select (active low) 8 clk1+ o positive hcsl output 9 clk1- o negative hcsl output 10 clk2- o negative hcsl output 11 clk2+ o positive hcsl output 12 vdd2 pwr power supply for hcsl output clk2, 1.65v to 3.6v (vdd2 vdd) 13 vdd pwr power supply 14 fs i frequency select pin, see table 1 for details may 06, 2015 2 revision 1.0 tcghelp@micrel.com or (408) 955-1690 2962
micrel, inc. DSC2144FE2-E0017 operational description the DSC2144FE2-E0017 is a dual output hcsl oscillator consisting of a mems resonator and a supporting pll ic. the two hcsl outputs are generated through independent 8-bit programmable dividers from the output of the internal pll. DSC2144FE2-E0017 allows for easy programming of theoutput frequencies using i2c interface. upon power-up, the output frequencies are controlled by an internal pre-programmed memory (otp). this memory stores all coefficients required by the pll for two different default frequency pairs. the control pin (fs) selects the initial pair. once the device is powered up, a new output frequency pair can be programmed using i2c pins. programming details are provided in the programming guide. when oe (pin 1) is floated or connected to vdd, the DSC2144FE2-E0017 is in operational mode. driving oe to ground will disable both output drivers (hi- impedance mode). output clock frequencies frequency select bits are weakly tied high so if left unconnected the default setting will be [1] and the device will output the associated frequency highlighted in bold. freq (mhz) freq select bit [fs] - default is [1] 0 1 clk1 125 100 clk2 125 100 table 1. pin-selectable output frequencies absolute maximum ratings item min. max. units condition supply voltage -0.3 +4.0 v input voltage -0.3 vdd + 0.3 v junction temp - +150 c storage temp -55 +150 c soldering temp - +260 c 40sec max. esd hbm mm cdm - 4000 400 1500 v 1000+ years of data retention on internal memory may 06, 2015 3 revision 1.0 tcghelp@micrel.com or (408) 955-1690 2962
micrel, inc. DSC2144FE2-E0017 specifications (unless specified otherwise: t = 25c) 4 4 4 5 parameter symbol condition min. typ. max. units supply voltage1 vdd 2.25 3.6 v supply current idd oe pin low - output is disabled 21 23 ma supply current2 idd oe pin high - outputs are enabled rl = 50ohms, f01 = f02 = 156.25mhz 60 ma frequency stability f includes frequency variation due to initial tolerance, temp. and power supply voltage 25 ppm aging f first year (@ 25c) 5 ppm startup time3 tsu t = 25c 5 ms input logic levels input logic high input logic low vih vil 0.75 x vdd - - 0.25 x vdd v output disable time tda 5 ns output enable time ten 20 ns pull-up resistor2 pull-up exists on all digital io 40 kohms hcsl outputs output logic levels output logic high output logic low voh vol rl = 50ohms 0.725 - - 0.1 v pk to pk output swing single-ended 750 mv output transition time rise time fall time tr tf 20% to 80% rl = 50ohms, cl = 2pf 200 400 ps frequency clk1 clk2 [fs] = [1] 100 100 mhz output duty cycle sym differential 48 52 % period jitter jper f01 = f02 = 156.25mhz 2.8 psrms integrated phase noise jph 200khz to 20mhz @ 156.25mhz 100khz to 20mhz @ 156.25mhz 12khz to 20mhz @ 156.25mhz 0.25 0.37 1.7 2 psrms notes: 1. pin 12 vdd2, and pin 13 vdd should be filtered with 0.1uf capacitors. 2. output is enabled if oe pin is floated or not connected. 3. tsu is time to 100ppm stable output frequency after vdd is applied and outputs are enabled. 4. output waveform and test circuit figures below define the parameters. 5. period jitter includes crosstalk from adjacent output. may 06, 2015 4 revision 1.0 tcghelp@micrel.com or (408) 955-1690 2962
micrel, inc. DSC2144FE2-E0017 nominal performance parameters (unless specified otherwise: t = 25c, vdd = 3.3v) figure 1. hcsl phase jitter (integrated phase noise) hcsl output waveform figure 2. hcsl output waveform oe 675 msl 1 @ 260c refer to jstd-020c ramp-up rate (200c to peak temp) 3c/sec max. preheat time 150c to 200c 60 - 180 sec time maintained above 217c 60 - 150 sec peak temperature 255 - 260c time within 5c of actual peak 20 - 40 sec ramp-down rate 6c/sec max. time 25c to peak temperature 8 min max. may 06, 2015 5 revision 1.0 tcghelp@micrel.com or (408) 955-1690 2962
micrel, inc. DSC2144FE2-E0017 solder reflow profile figure 3. solder reflow profile package information 7 3.2mm x 2.5mm 14 lead plastic package notes: 6. connect the exposed die paddle to ground. 7. package information is correct as of the publication date. for updates and most current information, go to www.micrel.com. micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this data sheet. this information is not intended as a warranty and micrel does not assume responsibility for its use. micrel reserves the right to change circuitry, specifications and descriptions at any time without notice. no license, whether express, implied, arising by estoppel or otherwise, to any intellectual property rights is granted by this document. except as provided in micrel's terms and conditions of sale for such products, micrel assumes no liability whatsoever, and micrel disclaims any express or implied warranty relating to the sale and/or use of micrel products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. micrel products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. a purchaser's use or sale of micrel products for use in life support appliances, devices or systems is a purchaser's own risk and purchaser agrees to fully indemnify micrel for any damages resulting from such use or sale. ? 2015 micrel, incorporated. may 06, 2015 6 revision 1.0 tcghelp@micrel.com or (408) 955-1690 2962
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