NXP MC88915FN55

Драйвер тактового генератора, распределение фанатов, мультиплексорДаTTLCMOS, TTL

Overview

The MC88915FN55 Clock Driver utilizes phase–locked loop technology to lock its low skew outputs’ frequency and phase onto an input reference clock. It is designed to provide clock distribution for high performance PC’s and workstations. The PLL allows the high current, low skew outputs to lock onto a single clock input and distribute it with essentially zero delay to multiple components on a board. The PLL also allows the MC88915FN55 to multiply a low frequency input clock and distribute it locally at a higher (2X) system frequency. Multiple 88915’s can lock onto a single reference clock, which is ideal for applications when a central system clock must be distributed synchronously to multiple boards (see Figure 7). Five “Q” outputs (QO–Q4) are provided with less than 500 ps skew between their rising edges. The Q5 output is inverted (180° phase shift) from the “Q” outputs. The 2X_Q output runs at twice the “Q” output frequency, while the Q/2 runs at 1/2 the “Q” frequency.

Features • Five Outputs (QO–Q4) with Output–Output Skew < 500ps each being phase and frequency locked to the SYNCinput • The phase variation from part–to–part between the SYNC and FEEDBACK inputs is less than 550 ps (derived from the tPD specification, which defines the part–to–part skew) • Input/Output phase–locked frequency ratios of 1:2, 1:1, and 2:1 are available • Input frequency range from 5MHz – 2X_Q FMAX spec • Additional outputs available at 2X and +2 the system “Q” frequency. Also a Q (180° phase shift) output available • All outputs have ±36 mA drive (equal high and low) at CMOS levels, and can drive either CMOS or TTL inputs. All inputs are TTL–level compatible • Test Mode pin (PLL_EN) provided for low frequency testing. Two selectable CLOCK inputs for test or redundancy purposes

Features

Applications

• Sampling clocks for ADC and DAC
• 1 Gigabit Ethernet
• 10 Gigabit Ethernet
• FPGA and processor clocks
• Line cards used in telephone exchange
• Fiber Channel
• PCI express cards
• Infotainment systems
• Medical equipment
• Multi-function printers