GS9076 Data Sheet

44617 - 1

January 2008

16 of 25

4. Detailed Description

The GS9076 is a SD-SDI Serial Digital Reclocker designed to automatically

recover the embedded clock from a digital video signal and re-time the incoming

video data.

The GS9076 will recover the embedded clock signal and re-time the data from a

SMPTE 259M-C compliant digital video signal.

Using the functional block diagram (page 2) as a guide, Slew Rate Phase Lock

Loop (S-PLL) on page 16 to Lock and LOS on page 20 describes each aspect of

the GS9076 in detail.

4.1 Slew Rate Phase Lock Loop (S-PLL)

The term “slew” refers to the output phase of the PLL in response to a step change

at the input. Linear PLLs have an output phase response characterized by an

exponential response whereas an S-PLL’s output is a ramp response (see

Figure 4-1). Because of this non-linear response characteristic, traditional small

signal analysis is not possible with an S-PLL.

Figure 4-1: PLL Characteristics

0.2

0.1

0.0

INPUT

OUTPUT

SLEW PLL RESPONSE

0.2

0.1

0.0

INPUT

OUTPUT

LINEAR (CONVENTIONAL) PLL RESPONSE