Quad high-speed comparator with LVDS/RSPECL outputs
The LMH7324SQ/NOPB is a quad high-speed comparator from Texas Instruments, described as a quad 700 ps high-speed comparator. It delivers a maximum propagation delay of 0.74ns, making it suitable for timing-critical signal chains where the comparator's decision time directly sets the system's latency budget. The outputs are differential, available as LVDS or RSPECL levels — the LVDS swing reduces EMI and power on long traces, while RSPECL provides a larger voltage swing for legacy logic families. This dual-output flexibility lets the same comparator drive either a modern FPGA bank or an older ECL-based receiver without a level translator.
Parametric fit: speed, supply, and temperature
With four elements in a single 32-WFQFN exposed-pad package (5x5 mm), the LMH7324SQ/NOPB packs four independent comparators into a compact footprint. The exposed pad aids thermal conduction to the PCB ground plane, critical when all four channels switch at high speed simultaneously. The supply range spans 5 V to 12 V single supply, or ±2.5 V to ±6 V dual supply — this covers standard 5 V and 3.3 V logic rails as well as ±5 V analog supplies. The 80 dB typical CMRR and 75 dB PSRR mean the threshold accuracy holds up against common-mode noise and supply ripple, which matters when the comparator is used in a noisy switching regulator feedback loop. Operating temperature from -40°C to 125°C covers industrial and automotive under-hood environments. The 20.8 mV hysteresis provides clean switching on slow edges without external positive feedback components. Maximum input bias current is 5 µA at 5 V, and maximum input offset voltage is 9.5 mV at 5 V — these are the DC accuracy limits that set the minimum detectable signal. The 7.5 mA maximum quiescent current per channel is modest for a 0.74 ns comparator, keeping the thermal rise manageable in the 5x5 mm QFN.