AD8561ARU

The AD8561ARU is one member of the AD8561 series.The AD8561 is a single 7 ns comparator with separate input and output sections. Separate supplies enable the input stage to be operated from5 V dual supplies and +5 V single supplies.Fast 7 ns propagation delay makes the AD8561 a good choice for timing circuits and line receivers. Propagation delays for rising and falling signals are closely matched and track over temperature.This matched delay makes the AD8561 a good choice for clock recovery, since the duty cycle of the output will match the duty cycle of the input.

Features of the AD8561ARU are:(1)7 ns propagation delay at 5 V; (2)single supply operation: 3 V to 10 V; (3)low power; (4)latch function; (5)TSSOP packages.The AD8561 has the same pinout as the LT1016, with lower supply current and a wider common-mode input range, which includes the negative supply rail.As with any high speed comparator or amplifier, proper design and layout techniques should be used to ensure optimal performance from the AD8561. The performance limits of high speed circuitry can easily be a result of stray capacitance, improper ground impedance or other layout issues.

The absolute maximum ratings of the AD8561ARU can be summarized as:(1)total analog supply voltage:+14 V;(2)storage temperature range:-65 to 150;(3)digital supply voltage:+14 V;(4)lead temperature range:300;(5)operating temperature range:+-40 to 85;(6)analog positive supplydigital positive supply:600 mV;(7)input voltage:7 V;(8)differential input voltage:8 V.Minimizing resistance from source to the input is an important consideration in maximizing the high speed operation of the AD8561.Source resistance in combination with equivalent input capacitance could cause a lagged response at the input,thus delaying the output. The input capacitance of the AD8561 in combination with stray capacitance from an input pin to ground could result in several picofarads of equivalent capacitance. A combination of 3 kW  source resistance and 5 pF of input capacitance yields a time constant of 15 ns, which is slower than the 5 ns capability of the AD8561. Source impedances should be less than 1 kW  for the best performance.