MPC9259 판매점 - 900 MHz LOW VOLTAGE LVDS CLOCK SYNTHESIZER

MOTOROLA

Freescale Semiconductor, Inc. Order Number: MPC9259/D

SEMICONDUCTOR TECHNICAL DATA

Rev 0, 12/2002

Preliminary Information

900 MHz Low Voltage LVDS

Clock Synthesizer

The MPC9259 is a 3.3V compatible, PLL based clock synthesizer

targeted for high performance clock generation in mid-range to

high-performance telecom, networking and computing applications. With

output frequencies from 50 MHz to 900 MHz and the support of differential

LVDS output signals the device meets the needs of the most demanding

clock applications.

Features

• 50 MHz to 900 MHz synthesized clock output signal

• Differential LVDS output

• LVCMOS compatible control inputs

• On-chip crystal oscillator for reference frequency generation

• Alternative LVCMOS compatible reference input

• 3.3V power supply

• Fully integrated PLL

• Minimal frequency overshoot

• Serial 3-wire programming interface

• Parallel programming interface for power-up

• 32 Pin LQFP Package

• SiGe Technology

• Ambient temperature range 0°C to + 70° C

MPC9259

900 MHZ LOW VOLTAGE

CLOCK SYNTHESIZER

FA SUFFIX

32–LEAD LQFP PACKAGE

CASE 873A

Functional Description

The internal crystal oscillator uses the external quartz crystal as the basis of its frequency reference. The frequency of the

internal crystal oscillator or external reference clock signal is multiplied by the PLL. The VCO within the PLL operates over a range

of 800 to 1800 MHz. Its output is scaled by a divider that is configured by either the serial or parallel interfaces. The crystal

oscillator frequency fXTAL, the PLL feedback-divider M and the PLL post-divider N determine the output frequency.

The feedback path of the PLL is internal. The PLL adjusts the VCO output frequency to be M times the reference frequency by

adjusting the VCO control voltage. Note that for some values of M (either too high or too low) the PLL will not achieve phase lock.

The PLL will be stable if the VCO frequency is within the specified VCO frequency range (800 to 1800 MHz). The M-value must be

programmed by the serial or parallel interface.

The PLL post-divider N is configured through either the serial or the parallel interfaces, and can provide one of four division

ratios (1, 2, 4, or 8). This divider extends performance of the part while providing a 50% duty cycle.

The configuration logic has two sections: serial and parallel. The parallel interface uses the values at the M[6:0] and N[1:0]

inputs to configure the internal counters. It is recommended on system reset to hold the P_LOAD input LOW until power becomes

valid. On the LOW–to–HIGH transition of P_LOAD, the parallel inputs are captured. The parallel interface has priority over the

serial interface. Internal pullup resistors are provided on the M[6:0] and N[1:0] inputs prevent the LVCMOS compatible control

inputs from floating. The serial interface centers on a twelve bit shift register. The shift register shifts once per rising edge of the

S_CLOCK input. The serial input S_DATA must meet setup and hold timing as specified in the AC Characteristics section of this

document. The configuration latches will capture the value of the shift register on the HIGH–to–LOW edge of the S_LOAD input.

See the programming section for more information. The TEST output reflects various internal node values, and is controlled by

the T[2:0] bits in the serial data stream. In order to minimize the PLL jitter, it is recommended to avoid active signal on the TEST

output. The PWR_DOWN pin, when asserted, will synchronously divide the FOUT by 16. The power down sequence is clocked

by the PLL reference clock, thereby causing the frequency reduction to happen relatively slowly. Upon de–assertion of the

PWR_DOWN pin, the FOUT input will step back up to its programmed frequency in four discrete increments.

This document contains information on a product under development. Motorola reserves the right to change or discontinue this product without notice.

For More Information On This Product,

Go to: www.freescale.com

MPC9259 반도체 회로 부품 판매점

900 MHz LOW VOLTAGE LVDS CLOCK SYNTHESIZER

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