描述 Description

The MT8941B is a dual digital phase-locked loop providing the timing and synchronization signals for the T1 or CEPT transmission links and the ST-BUS. The first PLL provides the T1 clock (1.544 MHz) synchronized to the input frame pulse at 8 kHz. The timing signals for the CEPT transmission link and the ST-BUS are provided by the second PLL locked to an internal or an external 8 kHz frame pulse signal.

特性 Features

? Provides T1 clock at 1.544 MHz locked to an 8kHz reference clock (frame pulse)

? Provides CEPT clock at 2.048 MHz and ST-BUS clock and timing signals locked to an internal or external 8 kHz reference clock

? Typical inherent output jitter (unfiltered)= 0.07 UI peak-to-peak

?Typical jitter attenuation at: 10 Hz=23 dB,100Hz=43 dB, 5 to 40 kHz ≥ 64 dB

? Jitter-free “FREE-RUN” mode

? Uncommitted two-input NAND gate

? Low power CMOS technology

Applications

? Synchronization and timing control for T1 and CEPT digital trunk transmission links

? ST- BUS clock and frame pulse source