Analog Devices Inc./Maxim Integrated MAX981CPA

Overview

MAX981CPA from Maxim Integrated is a single-channel, ultra-low-power comparator with integrated 1.182V ±2% voltage reference and programmable hysteresis via HYST pin. It operates from 2.5V to 11V single supply (or ±1.25V to ±5.5V dual supply), features open-drain output sinking to GND, supports rail-to-rail input down to V− and within 1.3V of V+, and draws ≤4µA quiescent current over 0°C to +70°C - ideal for battery-powered threshold detection in portable instrumentation.

For engineers reviewing the MAX981CPA datasheet, MAX981CPA pinout, MAX981CPA application, or MAX981CPA equivalent, key selection criteria include its guaranteed 4µA max supply current at extended temperature, ±2% reference accuracy, separate GND pin enabling bipolar-to-single-ended level translation, and HYST-pin-based hysteresis configuration without external feedback.

Technical Context

The MAX981CPA integrates a precision bandgap reference referenced to V− (not GND) and a single comparator with internal hysteresis control logic tied to the HYST pin. Its open-drain output connects to a dedicated GND terminal, decoupling sink behavior from V− and enabling robust level-shifting across supply domains.

Input common-mode range extends from V− to (V+ − 1.3V); absolute input voltage tolerance allows operation up to ±0.3V beyond rails. Propagation delay is 12µs (high-to-low) with 10mV overdrive and 100pF load, while reference output sustains ±6µA source/sink capability with 100µVRMS noise (100Hz–100kHz).

Key Specifications

Pinout & Package

MAX981CPA is housed in an 8-pin plastic DIP package (0.300" width), with pins arranged in standard dual-inline format and lead finish compatible with SnPb and RoHS-compliant reflow profiles.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar comparator applications.

Compared with MAX971CPA, the MAX981CPA trades ±1% reference accuracy for cost-sensitive designs where ±2% suffices; versus TLV3701CPA, it delivers integrated reference and GND-referenced output - eliminating three external components but operating at slightly higher quiescent current.

Availability

MAX981CPA is available at Aetrix Electronics and suitable for battery-powered instrumentation, portable medical devices, and industrial sensor interfaces requiring stable component supply with long-term lifecycle support.

Supply support for MAX981CPA includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) designs precision analog and mixed-signal ICs for power, sensing, and interface applications in industrial, automotive, and consumer systems.

The MAX981CPA belongs to Maxim's ultra-low-power comparator family targeting energy-constrained applications such as wearables, remote sensors, and backup power monitors - emphasizing micropower operation, integrated references, and flexible supply architecture.

FAQ

What is the maximum supply voltage for MAX981CPA in single-supply operation?

The MAX981CPA supports a single-supply voltage range of 2.5V to 11V. When operated with V− connected to GND, the maximum total supply voltage (V+ − V−) remains 11V. Exceeding 11V risks permanent damage per Absolute Maximum Ratings - confirmed in the datasheet's "POWER REQUIREMENTS" table under "Supply Voltage Range".

Can MAX981CPA be used with dual supplies, and how is V− connected?

Yes, MAX981CPA operates from dual supplies ranging from ±1.25V to ±5.5V. In this mode, V− is connected to the negative rail (e.g., −5V), V+ to the positive rail (e.g., +5V), and GND (Pin 1) remains connected to system ground - enabling true bipolar input operation while maintaining GND-referenced output sinking.

How does the HYST pin function in MAX981CPA, and what is its voltage range?

The HYST pin on MAX981CPA accepts a voltage from (REF − 0.05V) to REF to set hysteresis bandwidth. A 50mV difference yields up to 100mV hysteresis band. This is implemented internally - no external feedback loop - and is explicitly defined in the "Hysteresis Input Voltage Range" electrical characteristic table for MAX9_1/MAX982/MAX9_3 variants.

Is the internal reference of MAX981CPA referenced to GND or V−?

The internal 1.182V reference of MAX981CPA is referenced to V−, not GND. This is stated in the "Voltage Reference" section: "The internal bandgap voltage reference has an output of 1.182V above V−." Therefore, REF = V− + 1.182V, which impacts all resistor-divider threshold calculations and must be accounted for in circuit design.

What is the output sink capability of MAX981CPA, and how is it affected by supply voltage?

MAX981CPA's open-drain output sinks current to the dedicated GND pin (Pin 1), not V−. At V+ = 5V, it delivers ≤0.8mA with VOL ≤ 0.4V (I_OUT = 0.8mA). Sink capability degrades at lower V+: at 3V supply, typical sink current drops to ~0.4mA - data confirmed in "Output Low Voltage" specs and "SINK CURRENT AT LOW SUPPLY VOLTAGES" typical curve (TOC14).