1.3GHZ DUAL PLL

S1T8825B

13

Channel1 and 2 Programmable Counter Division Ratio, N

N = 2

× (32 × B + A), B ≥ A

Division ratio: 192 to 262142

Example) A Signal of 453 MHz is entered into Fin1, and divided into 25 kHz steps.

(Reference frequency is 12.5 kHz)

453 MHz

÷ 12.5 kHz = 36240, N = 2 × (32 × B + A) = 36240 , 32 × B + A =18120

N = 18120

÷ 32 = 566.25, A = 0.25*32 = 8

∴ B = (566)

Example) A Signal of 462.9 MHz is entered into Fin2, and divided into 25 kHz step.

(Reference frequency is 12.5 kHz)

462.9 MHz

÷ 12.5 kHz = 37032, N = 2 × (32 × B + A) = 37032,

32

× B + A =18516

N = 18516

÷ 32 = 578.625, A = 0.625*32 = 20

∴ B = (578)

PHASE DETECTOR AND CHARGE PUMP CHARACTERISTICS

Phase difference detection Range: -2

π to +2 π

When SW = Low

Figure 6.

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