MT9046AN View Datasheet(PDF) - Zarlink Semiconductor Inc

Part Name

Description

MFG CO.

MT9046AN

T1/E1 System Synchronizer with Holdover

Zarlink Semiconductor Inc 

MT9046

Data Sheet





–-2---A0-- 

OutputT1 = InputT1×10





–--2--1-0--8-

OutputT1 = 20×10

= 2.5UI(T1)

OutputE1

=

Out

putT1

×

(---1---U-----I--T----1----)

(1UIE1)

OutputE1 = OutputT1 × ((---64---48---48---nn----ss--))-= 3.3UI(T1)

Note that the resulting jitter transfer functions for all combinations of inputs (8 kHz, 1.544 MHz, 2.048 MHz) and

outputs (8 kHz, 1.544 MHz, 2.048 MHz, 4.096 MHz, 8.192 MHz, 16.384 MHz, 19.44 MHz) for a given input signal

(jitter frequency and jitter amplitude) are the same.

Since intrinsic jitter is always present, jitter attenuation will appear to be lower for small input jitter signals than for

large ones. Consequently, accurate jitter transfer function measurements are usually made with large input jitter

signals (e.g., 75% of the specified maximum jitter tolerance).

Frequency Accuracy

Frequency accuracy is defined as the absolute tolerance of an output clock signal when it is not locked to an

external reference, but is operating in a free running mode. For the MT9046, the Freerun accuracy is equal to the

Master Clock (OSCi) accuracy.

Holdover Accuracy

Holdover accuracy is defined as the absolute tolerance of an output clock signal, when it is not locked to an external

reference signal, but is operating using storage techniques. For the MT9046, the storage value is determined while

the device is in Normal Mode and locked to an external reference signal.

The absolute Master Clock (OSCi) accuracy of the MT9046 does not affect Holdover accuracy, but the change in

OSCi accuracy while in Holdover Mode does.

Capture Range

Also referred to as pull-in range. This is the input frequency range over which the synchronizer must be able to pull

into synchronization. The MT9046 capture range is equal to ±230 ppm minus the accuracy of the master clock

(OSCi). For example, a 32 ppm master clock results in a capture range of 198 ppm.

Lock Range

This is the input frequency range over which the synchronizer must be able to maintain synchronization. The lock

range is equal to the capture range for the MT9046.

Phase Slope

Phase slope is measured in seconds per second and is the rate at which a given signal changes phase with respect

to an ideal signal. The given signal is typically the output signal. The ideal signal is of constant frequency and is

nominally equal to the value of the final output signal or final input signal.

Time Interval Error (TIE)

TIE is the time delay between a given timing signal and an ideal timing signal.

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Zarlink Semiconductor Inc.

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