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. In addition to ultra-fast 700 ps propagation delay, the LMH7322 features dispersion of 5 ps at > 100 mV overdrive, which allows fast and accurate delay control. Its separate input and output supply pins enable the device for level shifting applications, while its low power consumption of 21 mA typical makes the LMH7322 well-suited to power sensitive applications. The LMH7324 is a quad high speed comparator with RSPECL outputs. It has 700ps propagation delay and the overdrive dispersion is less than 20ps from 10mV to 1V overdrive.
Featured High Speed Comparators
LMH7324 Quad High Speed Comparator
LMH7324 Typical Application
The LMH7324 is a quad high speed comparator that provides the industry’s lowest power with sub-nanosecond (700 ps) propagation delay.
The LMH7324 has less than 20ps of dispersion from 10mV to 1V of overdrive, which makes it ideal for applications where the dispersion error cannot be tolerated. It operates with a supply from 5V to 12V, allowing in turn a wide input voltage range. Or, if a wide input voltage range is not needed, it can be operated at a 5V supply, which reduces the power consumption, making the LMH7324 the lowest power high speed quad comparator on the market. Like the LMH7322, the LMH7324 can be used in a variety of logic level translation applications, including but not limited to ECL to RSPECL, PECL to RSECL, PECL to ECL, and Analog input to LVDS. See logic level translation diagrams below and reference the “Interfacing Between Logic Families” application section of the LMH7324 datasheet.
Features:
Propagation delay 700 ps
Overdrive dispersion 10 mV-1V, <20 ps
Fast rise and fall times 160 ps
Wide supply range 5V to 12V
Input common mode range extends 200 mV below negative rail
Internal hysteresis
RSPECL outputs (see application note)
LMH7322 Dual High Speed Comparator
LMH7322 Typical Application
The LMH7322 is a dual high speed comparator that provides the industry’s lowest power (21mA typical) with sub-nanosecond (700 ps) propagation delay.
The LMH7322 can be used to for logic level translation. The feature that facilitates this property is the fact that the input stage and the output stage use different positive power supply pins which can be used at different supply voltages. The negative supply pins are connected together for both parts. Using the power pins at different supply voltages makes it possible to create several logic level translations for logic families. It is possible to translate from logic at negative voltage levels such as ECL to logic at positive levels such as RSPECL and LVDS and vice versa. The LMH7322 can be used in a variety of logic level translation applications, including but not limited to ECL to RSPECL, PECL to RSECL, PECL to ECL, and Analog input to LVDS. See logic level translation diagrams below and reference the “Interfacing Between Logic Families” application section of the LMH7322 datasheet.
Features:
Propagation delay 700 ps
Overdrive dispersion 20 mV-1V 75 ps
Fast rise and fall times 160 ps
Wide supply range 2.7V to 12V
Input common mode range extends 200 mV below negative rail
Adjustable hysteresis
RSPECL outputs (see application note)
(RS)PECL latch inputs (see application note)
LMH7220 Single High Speed Comparator
LMH7220 Typical Application
The LMH7220 is a high speed, low-power single high speed comparator. Its 2.9 ns typical propagation delay and 0.6 ns rise and fall times consume only 6.8 mA supply current at 5V.
The LMH7220 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.
The integrated LVDS outputs optimize power consumption compared to differential outputs such as emitter coupler logic (ECL). These inputs have a common-mode voltage range that extends 200 mV below ground, allowing ground sensing. Since many applications require AC-coupled, low-amplitude and high-frequency signals, the LMH7220 allows signals to swing below ground without the need for level shifting or dual-supply operation.
Features:
Propagation delay @ 100 mV overdrive 2.9 ns
Rise and fall times 0.6 ns
Supply voltage 2.7V to 12V
Supply current 6.8 mA
Temperature range −40°C to 125°C
LVDS output
COMPARATOR PRODUCTS
New Products
LMH7324 - Quad 700 PS High Speed Comparator with RSPECL Outputs
LMH7322 - Dual 700 ps High Speed Comparator with RSPECL Outputs
LMH7220 - Single High Speed Comparator with LVDS Output
