Any-to-any-frequency clock multiplier and jitter attenuator

September 04, 2014 // By Graham Prophet
Microsemi’s ZL30252 and ZL30253 are any-to-any frequency clock multiplier and jitter attenuator clock management ICs that offer 250 fsec jitter in a 5 x 5 mm footprint, and are targeted for use in a variety of communications applications.

Jitter performance as a clock multiplier is 160 fsec in the 12 kHz - 20 MHz band and as a jitter attenuator is 250 fsec in the 12 kHz – 20 MHz band, to provide communication equipment designers with a timing solution that meets industry-leading jitter requirements imposed by 100 Gbpsec PHY devices.

The ZL30252 and ZL30253 devices also simplify design with precise frequency conversion from any input frequency, 1 kHz to 1.25 GHz, to any output frequency, 1 Hz to 1.035 GHz, and jitter attenuation bandwidths from 14 Hz to 500 Hz. When combined with Microsemi's ZL402xx series fan-out buffers, the ZL30252 and ZL30253 provide complete timing solutions for complex systems such as wireless base stations, wireless backhaul, wired infrastructure, SONET/ SDH, GE, 10G/40G/100G Ethernet, optical, storage and broadcast video applications.

The parts have highly configurable output clocks and offer automatic self-configuration at power-up. This supports up to four different configurations easily selected using two device pins. Key features include:

  1. Any-to-any frequency conversion with 0 ppm error (inputs: 1 kHz - 1.25 GHz, outputs: 1 Hz – 1 GHz);
  2. Digital PLL with programmable bandwidth from 14 Hz to 500 Hz;
  3. Input clock monitoring and automatic or manual input switching;
  4. Three universal clock inputs connect to any signal format at any voltage and up to three differential outputs or six CMOS outputs;
  5. Operates as numerically controlled oscillator (NCO);
  6. Configurable output signal format and voltage for direct interface without additional components.

The ZL30252 and ZL30253 offer NCO mode in which output frequencies can be controlled with very high resolution by system software. This capability allows the devices to replace solutions using large, expensive, fixed-frequency voltage-controlled oscillators (VCXOs) with a small, low-cost and any output clock solution.

The ZL30252 and ZL30253 are also flexible building-blocks that system designers can use in various parts of their design. For example, they can be used as a master clock jitter attenuator and multiplier for other