SY89425 Datasheet | Micrel Semiconductor

DUAL SONET OC-12 CLOCK SYNTHESIZER Features s Two independently-powered 622.08MHz clock sources one chip s Differential PECL outputs s TTL/CMOS patible inputs s SONET pliant jitter performance (≤0.01UI) s Choice of three reference frequencies for each PLL s Only 395m W per PLL (typ) s plies with Bellcore, CCITT and ANSI standards s Single +5 volt power supply s Fully patible with industry standard 10KH I/O levels s Available in 28-pin PLCC package Clock Works™ SY89425 DESCRIPTION Micrel-Synergy's SY89425 Dual Phase Locked Loop (PLL) consists of two totally separate, SONET pliant 622.08MHz clock generators on one chip. The user may select to power both PLLs or PLL A only. Each PLL produces a low-jitter OC-12/STS-12 clock rate from an input reference clock of 38.88, 51.84, or 77.76MHz. When using both PLLs, it is not necessary that they share a mon reference clock (e.g., PLL A may operate from an STS-1 reference of 51.84MHz, while PLL B operates from an OC-3/STS-3 reference of 77.76MHz). The SY89425 operates from a single +5 volt supply, and requires only a simple series RC loop filter for each PLL. Coupling Micrel-Synergy's advanced PLL technology with our proprietary ASSET™ bipolar process has produced a clock generator IC which exceeds applicable Bellcore and ANSI specifications, while setting a new standard for performance and flexibility. TYPICAL APPLICATION +5V +5V PIN CONFIGURATION FLTRAN FLTRAP RSTA VCCA GND RFCKA (TTL) VCCA VCCOA RSTA (TTL) 25 24 23 22 21 20 19 VCCA CLOCK IN 0.1u F SEL39A SEL78A RFCKA VCCA 26 27 28 1 2 3 4 5 6 7 8 9 10 11 18 17 16 CK622AP CK622AN VCCOA GND VCCOB CK622BN CK622BP FLTRAN FLTRAP PLL A CK622AP (PECL) CK622AN PLCC TOP VIEW 15 14 13 12 RFCKB 622.08MHz 500Ω SEL39A (TTL) SEL78A...