MPC92429 Datasheet, PDF (1/12 Pages) Motorola, Inc – 400 MHz Low Voltage PECL Clock Synthesizer

MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Order Number: MPC92429/D
Rev 0, 09/2003
400 MHz Low Voltage PECL
Clock Synthesizer
MPC92429
The MPC92429 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 25 MHz to 400 MHz and the support of differential
PECL output signals the device meets the needs of the most demanding
clock applications.
400 MHZ LOW VOLTAGE
CLOCK SYNTHESIZER
Features
• 25 MHz to 400 MHz synthesized clock output signal
• Differential PECL output
• LVCMOS compatible control inputs
• On-chip crystal oscillator for reference frequency generation
• 3.3V power supply
• Fully integrated PLL
• Minimal frequency overshoot
• Serial 3-wire programming interface
• Parallel programming interface for power-up
• 32 lead LQFP and 28 PLCC packaging
• SiGe Technology
• Ambient temperature range 0°C to +70°C
• Pin and function compatible to the MC12429 and MPC9229
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 is divided by 16 and then multiplied by the PLL. The VCO within
the PLL operates over a range of 200 to 400 MHz. Its output is scaled by a
divider that is configured by either the serial or parallel interfaces. The
crystal oscillator frequency f_XTAL, the PLL feedback-divider M and the PLL
post-divider N determine the output frequency.
FN SUFFIX
28--LEAD PLCC PACKAGE
CASE 776
FA SUFFIX
32 LEAD LQFP PACKAGE
CASE 873A
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 (200 to 400 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 output driver is driven
differentially from the output divider, and is capable of driving a pair of transmission lines terminated 50Ω to V_CC – 2.0V. The
positive supply voltage for the internal PLL is separated from the power supply for the core logic and output drivers to minimize
noise induced jitter.
The configuration logic has two sections: serial and parallel. The parallel interface uses the values at the M[8:0] 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[8:0] and N[1:0] inputs prevent the LVCMOS compatible control
inputs from floating.
The serial interface centers on a fourteen 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.
 Motorola, Inc. 2003