The Spread Spectrum PLL is designed to multiply an input clock by a fixed-point number between 92 and 184 with frequency spreading capability suitable for PC and consumer electronics applications that require low EMI. It does not provide any deskew functionality. It contains a 1-64 divider at the reference clock input, a 1-256 or larger integer divider and a 1-256 or larger fractional divider in the internal feedback path, with as many as 4 bits of precise fractional-N control, and a 1-8 divider at the output. It can generate precise and adjustable frequency spreading depths (1.5% typical and up to around 10%) and rates (30KHz typical). The outputs are 50% duty cycle for all output divider values.

SPREAD SPECTRUM PLL SPECIFICATION SHEET
PART: TCI-T18LP-SSMPLL
Version: 1.5

 

Divided reference frequency range

978KHz – 4.89MHz

Total output frequency range

11.2MHz – 450MHz

/1 output frequency range

90MHz – 450MHz

(VCO output internally divided by 2 for 50% DC)

Reference divider values

1–64

Integer feedback divider values

92–184

Fractional feedback divider bits

8

Output divider values

1–8

/1 output multiples of div. reference

92–184

Bandwidth adjustment div. range

1–512

Spreading depth adjustment range (typ)

0% – +/–1.5%

Spreading rate adjustment range (typ)

15KHz – 4MHz

Feedback signal delay (max)

n/a (FB internal)

Output duty cycle (nom, tol)

50%, +/–2%

Static phase error (max)

n/a

Period jitter (P-P) (max)

Input-to-output jitter (P-P) (max)


Power dissipation (nom)

Reset pulse width (min)

5us

Reset /1 output frequency range

45MHz – 225MHz

Lock time (min allowed)

Freq. overshoot (full-~/half-~) (max)

Area (including isolation) (max)


Number of PLL supply pkg. pins

1 VDDA, 1 VSSA (preferred)

Low freq. supply noise est. (P-P) (max)

10% VDDA

Low freq. sub. noise est. (P-P) (max)

10% VDDA

Ref. input jitter (period, P-P) (max)

Reference H/L pulse width (min)


Process technology

TSMC CL018LP 180nm

Supply voltage (VDD, VDDA) (nom, tol)

1.8V, +/–10%

Junction temperature (nom, min, max)

70C, –40C, 125C

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