Quad comparator for industrial and automotive threshold detection
Four independent comparators share a common supply range of 2V to 32V single or ±1V to ±16V dual, with open-collector outputs that can sink up to 20mA typical — enough to drive a small relay or LED directly without a buffer transistor.
The 2V to 32V single-supply range means the LM2901VQDRG4 can run directly off a 24V industrial bus, a 12V automotive battery, or a 5V logic rail without a local regulator — one less component on the BOM. Maximum input offset voltage is 7mV at 32V supply — adequate for most threshold and level-detection applications, though designs requiring sub-mV precision (e.g., current-sense comparators) should budget for a trim network or select a precision comparator. Maximum input bias current is 0.25µA at 5V, which keeps voltage error low when the source impedance is under 10kΩ — a consideration for high-impedance sensor interfaces.
Open-collector output and output current rating
The open-collector output (compatible with CMOS, MOS, and TTL logic families) allows wired-OR connections and level shifting — the pull-up resistor sets the output high voltage, so the comparator can interface a 5V microcontroller from a 24V supply rail. Typical output sink current is 20mA per channel. At this level the voltage drop across the output transistor stays low enough to drive an LED indicator, optocoupler LED, or small relay coil. For loads above 20mA, add an external transistor.
Sourcing is through independent distribution — available stock is existing inventory from excess, overstock, or decommissioned production lines. For new designs or long-term production, consider the active LM2901V series in the same 14-SOIC footprint — the base product number LM2901 covers functionally equivalent quad comparators with the same pinout and supply range. Verify the specific suffix for temperature grade and packaging.