integrated circuit systems, inc. general description features ics9158-04 block diagram ics9158-04revc 8/10/98 applications frequency generator and integrated buffer the ics9158-04 is a low cost frequency generator designed specifically for desktop and notebook pc applications. up to six copies of the cpu clock are available, and five or six copies of the bus clock are available depending on the status of the frequency select pins, which eliminates the need for an external buffer. each high drive (25ma) output is capable of driving a 30pf load and has a typical duty cycle of 50/50. the clock outputs are skew controlled to within 250ps. the ics9158-04 makes a gradual transition between frequencies, so that it meets the intel cycle-to-cycle timing specification for 486 and pentium? systems. ? 11 skew-free, high drive cpu/bus clocks ? up to 66 mhz at 3.3v ? 250ps skew between all outputs ? outputs can drive up to 30pf load and 25ma ? 5010% duty cycle ? compatible with 486 and pentium cpus ? selectable 5/6 or 6/5 cpu/bus output ratio ? on-chip loop filter components ? 3.0v - 5.5v supply range ? 24-pin soic package ? ideal for risc or cisc systems such as 486, pentium, powerpc,? etc., requiring multiple cpu and bus clocks. pentium is a trademark of intel corporation. powerpc is a trademark of motorola corporation. note: this data sheet, ics9158-04, is an addendum to the existing ics9158 data sheet. all information in this data sheet supersedes the data found in the original ics9158 data sheet. ics reserves the right to make changes in the device data identified in this publication without further notice. ics advises its customers to obtain the latest version of all device data to verify that any information being relied upon by the customer is current and accurate.
2 ics9158-04 pin configuration 24-pin soic pin description * input pin has internal pull-up to vdd. pin number pin name type description 1 clk1a out cpu clock output. 2 x2 out crystal connection output, which includes output crystal load capacitance. 3x1in crystal connection input, which includes crystal load capacitance and feedback bias for a nominal 14.31818 mhz parallel-resonance 12pf crystal. 4 vdd pwr digital power supply. 5 gnd pwr digital ground. 6 clk1b out cpu clock output. 7 clk1c out cpu clock output. 8 clk1d out cpu clock output. 9 agnd pwr analog ground. 10 oe in output enable. tristates all outputs when low.* 11 clk2e out 2x cpu clock output. 12 gnd pwr digital ground. 13 clk12 out cpu clock output. 14 clk1e out cpu clock output. 15 fs2 out cpu clock frequency select 2.* 16 avdd pwr analog power supply. 17 clk2d out 2x cpu clock output. 18 clk2c out 2x cpu clock output. 19 gnd pwr digital ground. 20 vdd pwr digital power supply. 21 clk2b out 2x cpu clock output. 22 clk2a out 2x cpu clock output. 23 fs1 in cpu clock frequency select #1.* 24 fs0 in cpu clock frequency select #0.*
3 ics9158-01 functionality vdd=5v10% or 3.3v10%, temp=0-70c oe fs2 fs1 fs0 clk2 (mhz) x1, x2 (mhz) clk2(a:e) (mhz) clk1(a:e) (mhz) clk12 (mhz) 100014/6 x x1 14.318 33.3 16.6 33.3 100114/4 x x1 14.318 50 25 50 101014/3 x x1 14.318 66.6 33.3 66.6 101142/10 x x1 14.318 60 30 60 110014/6 x x1 14.318 33.3 16.6 16.6 110114/4 x x1 14.318 50 25 25 111014/3 x x1 14.318 66.6 33.3 33.3 111142/10 x x1 14.318 60 30 30 0 x x x -- 14.318 tristate tristate tristate
4 ics9158-04 ordering information ics9158-04M example: ics xxxx-ppp m package type m=soic pattern number (2 or 3 digit number for parts with rom code patterns) device type (consists of 3 or 4 digit numbers) prefix ics, av=standard device; gsp=genlock device 24 lead soic lead count 24l dimension l 0.604
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