What this dual nanopower comparator is for
The TLV3402CD: Its headline feature is a maximum quiescent current of 950 nA per channel — that is the entire budget for both comparators active, no standby trick needed. The trade-off is a 300 µs max propagation delay, so this part targets low-frequency threshold sensing: battery-voltage monitors, over-temperature flags, power-good indicators, and wake-up circuits where the comparator sits on the rail continuously. The CMOS and open-drain output options let it interface directly to a microcontroller GPIO or a logic-level interrupt line without a pull-up resistor on the CMOS side.
950 nA quiescent — the battery-life number
At 950 nA max for both channels, the TLV3402CD draws less than 1 µA from the supply rail. In a battery-powered sensor node running from a 240 mAh coin cell, this comparator alone consumes about 0.4% of the battery capacity per year just sitting there. That is the decision driver: if your system needs a comparator that never sleeps and the signal is slow (temperature, voltage level, pressure), this part lets you skip the duty-cycle overhead. The 250 pA max input bias current at 15 V means the external resistor divider for the threshold reference can use high-value resistors without loading the input — a 10 MΩ divider string adds only 2.5 µV of offset error from the bias current.
300 µs propagation delay — the speed envelope
The 300 µs max propagation delay is the anchor for the application space. This comparator handles DC threshold crossing: a battery dropping below a threshold, a thermistor voltage crossing a trip point, a capacitor charging past a reference.
Supply range and output flexibility
The 2.5 V to 16 V single-supply range (or ±1.25 V to ±8 V dual-supply) covers common rails without a secondary regulator.
CMRR and PSRR — noise rejection on a tight power budget
Typical CMRR of 88 dB and PSRR of 105 dB are strong numbers for a nanopower comparator. They mean the threshold accuracy holds up when the common-mode voltage shifts or the supply rail has ripple.