sg588 low emi clock generator for digital camera approved product international microcircuits, inc. 525 los coches st. rev.1.4 1/12/2000 milpitas, ca 95035 tel: 408-263-6300 fax: 408-263-6571 page 1 of 7 product features the imisg588 is a clock generator that integrates clock requirements for digital camera. it integrates a spectrum spread technology, a modulation technique designed specifically for reducing emi at the fundamental frequency and its harmonics. the imisg588 generates three output clocks: a buffered reference output (4fsc) of the crystal and 2 other clocks (clk1,clk2) generated by the internal phase lock loops. clk1 clock is modulated output for emi attenuation. the imisg588 is packaged in a 16pin tssop package for minimum occupation of board space. support clock requirements for digital camera application. integrates spectrum spread technology for emi attenuation. 30 ma buffer switching current 16 pin tssop package. pin configuration pin description xin, xout - forms an on-chip reference oscillator when connected to terminals of an external parallel resonant crystal, 14.318mhz for ntsc. xin may also serve as input for an externally generated reference signal. 4fsc C buffered reference output clock of the crystal. clk1 and clk2 C clk1 and clk2, are derived from the reference crystal oscillator by using phase-locked loop (pll). clk1 integrates a proprietary frequency modulation technique called spread spectrum clock generation (sscg) to reduce the electro magnetic interference (emi) found in high speed digital systems. the amount of modulation (spread %) of clk1 is +/- 0.5% or +/-0.1% center-spread. modulation frequency of spread is 31.3995khz. see table 1 for frequencies and function. sel1 and sel2 C these pins are used to select the clock frequencies, spread on/off and spread bandwidth to be modulated +/-0.5% or +/-0.1%. see table 1. these pins have internal pull-up resistors. clk2on C this pin is used to enable/disable clk2 output. when low, clk2 to be disabled, low state. when high (default), clk2 to be enabled. this pin has an internal pull-up resistor. ss_reset C this pin is used to reset location of sscg profile. when signal goes high to low, the location of sscg profile is reset to the reference frequency. this pin has an internal pull-up resistor. vdd C circuit positive power supply. vss C circuit ground. 4fsc 1 vdd 2 sel3 3 vss 4 xin 5 clk2on 6 xout 7 sel1 8 vdd vss clk2 vdd vss sel2 ss reset clk1 16 15 14 13 12 11 10 9
sg588 low emi clock generator for digital camera approved product international microcircuits, inc. 525 los coches st. rev.1.4 1/12/2000 milpitas, ca 95035 tel: 408-263-6300 fax: 408-263-6571 page 2 of 7 block diagram loop filter vco xout xin xtal reference oscilator 7 5 1 4fsc buf phase detector divider divider 9 clk1 buf sscg rom sscg devider multiplexer and logic sel3 sel1 sel2 ss_ reset 8 11 3 10 2 vdd 13 vdd 12 15 vss vss vss 4 vco divider loop filter divider and logic phase detector divider 14 6 clk2 clk2on buf vdd 16 vdd
sg588 low emi clock generator for digital camera approved product international microcircuits, inc. 525 los coches st. rev.1.4 1/12/2000 milpitas, ca 95035 tel: 408-263-6300 fax: 408-263-6571 page 3 of 7 frequency selection and sscg mode table frequencies [mhz] sel1 sel2 sel3 clk2on 4fsc clk1 clk2 h h h h xtal buffer 71.877264+/-0.1% 48.008015 h h l h xtal buffer 71.877264 48.008015 h l h h xtal buffer 71.877264+/-0.5% 48.008015 h l l h xtal buffer 96.016031+/-0.1% 48.008015 l h h h xtal buffer 114.545440+/-0.1% 96.016031 l h l h xtal buffer 114.545440 96.016031 l l h h xtal buffer 114.545440+/-0.5% 96.016031 l l l h xtal buffer 96.016031 48.008015 h h h l xtal buffer 71.877264+/-0.1% disable(low) h h l l xtal buffer 71.877264 disable(low) h l h l xtal buffer 71.877264+/-0.5% disable(low) h l l l xtal buffer 96.016031+/-0.1% disable(low) l h h l xtal buffer 114.545440+/-0.1% disable(low) l h l l xtal buffer 114.545440 disable(low) l l h l xtal buffer 114.545440+/-0.5% disable(low) l l l l xtal buffer 96.016031 disable(low) table-1 frequency ratio xin=14.318180mhz (1) 71.877264mhz: xin * 251/25/2 (2) 96.016031mhz: xin * 228/17/2 (3) 114.545440mhz: xin * 112/7/2 (4) 48.008015mhz: xin * 57*2/17/2 (5) 96.016031mhz: xin * 57*2/17
sg588 low emi clock generator for digital camera approved product international microcircuits, inc. 525 los coches st. rev.1.4 1/12/2000 milpitas, ca 95035 tel: 408-263-6300 fax: 408-263-6571 page 4 of 7 spread spectrum clock generation (sscg) spread spectrum is a modulation technique applied here for maximum efficiency in minimizing electro-magnetic interference radiation generated from repetitive digital signals mainly clocks. a clock accumulates em energy at the center frequency it is generating. spread spectrum distributes this energy over a small frequency bandwidth therefore spreading the same amount of energy over a spectrum. this technique is achieved by modulating the clock around the center of its resting frequency by a certain percentage (which also determines the energy distribution bandwidth). in this device, modulating the clock is center spread from its resting frequency. center spread figure-1
sg588 low emi clock generator for digital camera approved product international microcircuits, inc. 525 los coches st. rev.1.4 1/12/2000 milpitas, ca 95035 tel: 408-263-6300 fax: 408-263-6571 page 5 of 7 maximum ratings voltage relative to vss: -0.3v voltage relative to vdd: 0.3v storage temperature: -30oc to + 125oc operating temperature: 0oc to + 70oc maximum power supply: 5v this device contains circuitry to protect the inputs against damage due to high static voltages or electric field. precautions should be taken to avoid application of any voltage higher than the maximum rated voltages to this circuit. for proper operation, vin and vout should be constrained to the range: vss<(vin or vout) sg588 low emi clock generator for digital camera approved product international microcircuits, inc. 525 los coches st. rev.1.4 1/12/2000 milpitas, ca 95035 tel: 408-263-6300 fax: 408-263-6571 page 6 of 7 package drawing and dimensions bo surfaces roughness: 6+ 27n(rz) d -b- 1.50 e1 1.20 r0.1 b e -c- c 0.07 r0.15 4 [10 typ 0.05 max. 0.05 max. 1.0 1.0 e r0.15 a a1 0.25 a2 r l1 l a 8 b c c1 b1 detail b .08 cb a detail a 14 typ s 16 pin tssop dimensions inches millimeters symbol min nom max min nom max a - - 0.047 - - 1.20 a1 0.002 - 0.0059 0.05 - 0.15 a2 0.032 0.039 0.041 0.8 1.0 1.05 l 0.018 0.024 0.030 0.45 0.60 0.75 b 0.007 - 0.012 0.19 - 0.30 q 0 - 8 0 - 8 e 0.026 bsc 0.65 bsc d 0.193 0.197 0.201 4.90 5.0 5.10 e 0.248 0.252 0.256 6.3 6.4 6.5 e1 0.169 0.173 0.177 4.30 4.40 4.50
sg588 low emi clock generator for digital camera approved product international microcircuits, inc. 525 los coches st. rev.1.4 1/12/2000 milpitas, ca 95035 tel: 408-263-6300 fax: 408-263-6571 page 7 of 7 ordering information part number package type production flow IMISG588BTB 16 pin tssop commercial, 0oc to +70oc note: the ordering part number is formed by a combination of device number, device revision, package style, and screening as shown below. marking: example: imi, date code sg588btb lot# IMISG588BTB flow b = commercial, 0oc to +70oc package t = tssop revision imi device number notes:
|
