The MAX976/MAX978/MAX998 are dual/quad/single, high-speed, low-power comparators optimized for +3V/+5V single-supply applications. They achieve a 20ns propagation delay while consuming only 225µA supply current per comparator. The MAX998 features a low-power shutdown mode that places the output in a high-impedance state and reduces supply current to 1nA. The MAX976/MAX978/MAX998 inputs have a common-mode voltage range that extends 200mV below ground. Their outputs are capable of rail-to-rail operation without external pullup circuitry, making these devices ideal for interface with CMOS/TTL logic. All inputs and outputs can tolerate a continuous short-circuit fault condition to either rail. The comparators’ internal hysteresis ensures clean output switching, even with slow-moving input signals. For space-critical applications, the single MAX998 is available in a 6-pin SOT23 package, the dual MAX976 is available in an 8-pin µMAX® package, and the quad MAX978 is available in a 16-pin QSOP package.
The MAX976, MAX978, and MAX998 comparators are optimized for +3 V/+5 V single‑supply applications. They feature a 20 ns propagation delay, low supply current per comparator, and a shutdown mode that reduces current to 1 nA. Their inputs tolerate a common‑mode voltage range extending 200 mV below ground and the outputs can swing rail‑to‑rail without external pull‑up resistors, making them suitable for CMOS/TTL logic interfaces.
Key features include single‑supply operation down to 2.7 V, internal hysteresis for clean switching, and various package options (SOT‑23, uMAX, QSOP). The datasheet provides absolute maximum ratings, detailed electrical characteristics, pin configurations, and design guidelines such as layout recommendations and optional external hysteresis circuits for window‑comparator applications.
| Propagation Delay | 20 ns |
|---|---|
| Supply Current per Comparator | 225 nA |
| Shutdown Supply Current (MAX998) | 1 nA |
| Supply Voltage Range | 2.7 V to 5.5 V |
| Operating Temperature Range | -40 °C to +85 °C |
| Rail‑to‑Rail Output | Yes |
| Common‑Mode Voltage Range | -0.2 V to (VCC - 1.2 V) |
| Power‑Supply Rejection Ratio (PSRR) | 63 dB to 100 dB |
The propagation delay is specified as 20 ns.
Each comparator consumes about 225 nA of supply current.
In shutdown mode the MAX998 draws approximately 1 nA.
They operate from 2.7 V up to 5.5 V.