National Semiconductor Corporation, a supplier of high-performance analogue signal-path products, introduced the LMH7322, a dual comparator that provides the industry’s low power (21 mA typical) with sub-nanosecond (700 ps) propagation delay.
The LMH7322 joins the LMH7220 single comparator as part of a new family of single, dual and quad high-speed comparators that feature low-voltage differential signalling (LVDS) and reduced-swing positive emitter-coupled logic (RSPECL) outputs.
National will begin sampling a quad comparator with similar specifications to the LMH7322 in fall 2007.
National’s comparators offer industry-leading power and performance specifications for a wide range of industrial, medical, and test and measurement applications, including oscilloscopes, automated test equipment (ATE) and positron emission tomography (PET) scanners.
The LMH7322 features ultra-fast 700 ps propagation delay and dispersion of 5 ps at >100 mV overdrive, which allows fast and accurate delay control.
Separate input and output supply pins enable level-shifting applications, while the devices’ typical low power consumption of 21 mA makes the LMH7322 well-suited for power-sensitive applications.
The LMH7220’s 2.9 ns typical propagation delay and 0.6 ns rise and fall times consume only 6.8 mA supply current at 5V. Both parts offer guaranteed performance from -40 degrees C to 125 degrees C.
Technical features of the LMH7220 single comparator:
The LMH7220 is a high-speed, low-power single comparator with an operating supply voltage range of 2.7V to 12V for flexible supply options.
Its LVDS output drives 325 mV into a 100-Ohm symmetrical transmission line, allowing a balanced output with reduced noise immunity and electromagnetic interference (EMI) for interfacing to field-programmable gate arrays (FPGAs) and application-specific integrated circuits (ASICs) with LVDS inputs.
National is the supplier of high-speed LVDS products, according to Databean’s 2006 analogue IC Market Share survey.
The LMH7220 has a wide input voltage range that is able to extend from 10V to 200 mV below ground, which allows for ground sensing.
LVDS outputs optimise power consumption compared to differential outputs such as emitter-coupled logic (ECL).
Due to the output drive characteristics, the power consumption remains at a very low level even if the data transmission rate is rising.
Technical features of the LMH7322 dual comparator:
The LMH7322 comparator available from Avnet is a high-speed, dual comparator that also operates from a wide input supply voltage range of 2.7V to 12V.
The device features an input common-mode range that extends 200 mV below the negative rail, and its adjustable hysteresis adds flexibility and minimises state changes due to spurious noise.
The LMH7322 provides fast rise and fall times of 160 ps, and its RSPECL outputs and latch inputs reduce EMI, while providing high-speed operation over a wide temperature range.