The MAX921 series is a family of single-supply, low-voltage comparators with ultra-low power consumption. The series’ static current is less than 4 µA over temperature (MAX921/MAX922), and includes an internal 1.182 V ±1% voltage reference, programmable hysteresis, and TTL/CMOS outputs that sink and source current. Ideal for 3 V or 5 V single-supply applications, the MAX921 series operates from a single +2.5 V to +11 V supply (or a ±1.25 V to ±5 V dual supply), and each comparator’s input voltage range swings from the negative supply rail to within 1.3 V of the positive supply. The MAX921 series’ unique output stage continuously sources as much as 40 mA. By eliminating power-supply glitches that commonly occur when comparators change logic states, the MAX921 series minimizes parasitic feedback, making them easier to use. The single MAX921 and dual MAX923 provide a unique and simple method for adding hysteresis without feedback and complicated equations, simply by using the HYST pin and two resistors.
The MAX921‑MAX924 family provides ultra‑low‑power comparators with internal 1.182 V reference, programmable hysteresis, and TTL/CMOS‑compatible outputs that can continuously source up to 40 mA. They operate from a single +2.5 V to +11 V supply or a dual +1.25 V to +5.5 V supply, with input ranges extending to within 1.3 V of the positive rail.
The datasheet includes absolute maximum ratings, electrical characteristics for 3 V and 5 V operation, pin descriptions for 8‑ and 16‑pin packages, and ordering information such as temperature ranges and package codes. Typical operating circuits and performance graphs illustrate response time, output voltage, and source/sink currents.
| Supply Voltage Range (single) | +2.5 V to +11 V |
|---|---|
| Supply Voltage Range (dual) | +1.25 V to +5.5 V |
| Quiescent Current | Ultra‑Low 4 µA |
| Continuous Output Source Current | 40 mA |
| Reference Voltage | 1.182 V ±1 % |
| Input Offset Voltage | 2.5 V ±10 mV |
| Power Dissipation (Ta = +70 °C) | Up to 727 mW (8‑pin DIP) |
Each comparator can continuously source up to 40 mA.
They operate from a single +2.5 V to +11 V supply or a dual +1.25 V to +5.5 V supply.
The devices include an internal 1.182 V reference with ±1 % tolerance.