Clock generators for embedded communications

AMI Semiconductor (AMIS) has expanded its clock generator product line with a broad family of low-cost 1- and 2-phase-lock loop (PLL) clock ICs.

AMI Semiconductor (AMIS) has expanded its clock generator product line with a broad family of low-cost 1- and 2-phase-lock loop (PLL) clock ICs.

Compact footprints, multiple pin-out options and generation of common frequencies make this line of standard timing devices ideal for dependable clock management in fixed-frequency systems such as digital cameras, computer peripherals, printers, and local area network and gigabit Ethernet hubs.

Several of the devices in the new family are derived from common platforms.

The platforms can be quickly and easily customised for frequencies, pinouts, and features in the final processing layers, similar to a gate array.

First silicon for these semicustom devices can typically be available in four to six weeks, making them a valuable time-to-market alternative to full-custom devices.

Each device in the AMIS 1- and 2-PLL clock generator family uses an onboard crystal oscillator to generate a reference frequency, which is used by the PLLs to generate precision output frequency ratios (ratiometric derivation).

The crystal oscillator is suitable for any fundamental-mode crystals in the 5-30MHz range.

For video systems, which cannot tolerate unpredictable artifacts, dual-PLL models are available that generate three output clocks from the crystal reference by driving the frequency through an array of post-dividers.

These three outputs are "locked" for low phase noise and low jitter, and to reduce EMI from harmonic stacking.

Both 3.3 and 5V versions are available for most models.

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