644.53125 MHz

Optical Timing Clock

RF Monolithics, Inc.

Phone: (972) 233-2903

Fax: (972) 387-8148

E-mail: info@rfm.com

Page 2 of 7

RFM Europe

Phone: 44 1963 251383

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http://www.rfm.com

©2001 by RF Monolithics, Inc. The stylized RFM logo are registered trademarks of RF Monolithics, Inc.

OP4012B-041003

OP4012B Performance Parameters

The OP4012B has been developed to achieve high performance in five parameters critical to optical data communications

applications:

Low Jitter and Phase Noise - low clock jitter (or low phase noise in the frequency domain) is critical to achieving low bit error

rates in optical data communications systems. The OP4012B provides very low free-running jitter and phase noise as shown

in Figures 1 and 2. This makes the OP4012B an excellent reference for the generation or regeneration of low-jitter clocks

and data streams. The OP4012B achieves this performance over its full -40 to +85 °C operating temperature range using

RFM's patented SAW oscillator architecture.

Single-Sideband Phase Noise

Figure 1

High Power Supply Noise Immunity - the OP4012B uses both differential active devices and differential SAW technology to

minimize the effects of power supply noise on jitter and phase noise, as shown in Figures 2 and 3. Optical data communi-

cations circuits must switch relatively high levels of current, making power supply noise immunity an important clock require-

ment.

der locked conditions for reference signals with ±100 ppm or better stability over the OP4012B's full operating temperature

and supply voltage range. This allows a PLL based on the OP4012B to be designed with a well-controlled loop bandwidth

and damping factor, avoiding problems such a jitter peaking, etc. The voltage tuning characteristic of the OP4012B is mono-

tonic from 0 to 3.3 V, supporting reliable acquisition of phase lock. Figure 4 shows typical OP4012B tuning characteristics.