■ DESCRIPTION

MB88155 is a clock generator for EMI (Electro Magnetic Interference) reduction. The peak of unnecessary radi ation noise (EMI) can be attenuated by making the oscillation frequency slightly modulate periodically with the internal modulator. For modulation, the MB88155 supports both center-spreading and down-spreading. It has a non-modulated clock output pin (REFOUT) as well as a modulated clock output pin (CKOUT) .

■ FEATURES

• Input frequency : 12.5 MHz to 50 MHz (Multiplied by 1)

12.5 MHz to 20 MHz (Multiplied by 4)

• Output frequency : CKOUT 12.5 MHz to 80 MHz

REFOUT The same as input frequency (not multiplied)

• Modulation rate : ± 0.5, ± 1.0 (center spread) , − 1.0, − 2.0 (Down spread)

• Equipped with oscillation circuit : range of oscillation 12.5 MHz to 40 MHz (Fundamental oscillation)

40 MHz to 48 MHz (3rd overtone)

• Modulation clock output Duty : 40 to 60

• Modulation clock cycle − cycle jitter : MB88155-1xx 12.5 MHz to 20 MHz less than 150 ps

MB88155-1xx 20 MHz to 50 MHz less than 100 ps

MB88155-4xx less than 200 ps

• Low current consumption by CMOS process : 5 mA (24 MHz : Typ-sample, no load)

• Power supply voltage : 3.3 V ± 0.3 V

• Operating temperature : − 40 °C to + 85 °C

• Package : 8-pin plastic TSSOP