DESCRIPTION
Micrel-Synergys SY89426 Multi-Output Phase Locked Loop (PLL) is a SONET compliant clock generator providing 622.08MHz, 155.52MHz and retimed reference clock outputs. The PLL produces low jitter OC-12/STS-12 and OC-3/STS-3 rate clocks from an input reference clock of 38.88, 51.84, or 77.76MHz. Additionally, the input reference clock is retimed and provided as a TTL/CMOS compatible output, which may be disabled to minimize switching noise. The SY89426 operates from a single +5 volt supply, and requires only a simple series RC loop filter.

FEATURES
■ Single chip source for 622.08MHz and 155.52MHz clocks
■ 622.08MHz output is differential PECL, 155.52MHz output is single-ended PECL
■ TTL/CMOS compatible inputs and reference output
■ SONET compliant jitter performance (≤0.01UI)
■ Choice of three reference frequencies
■ Only 395mW (typ)
■ Complies with Bellcore, CCITT and ANSI standards
■ Single +5 volt power supply
■ Fully compatible with industry standard 10KH I/O levels
■ Available in 28-pin PLCC package