MAX985EUK-T: A High-Performance Single Comparator IC by Analog Devices/Maxim Integrated

The MAX985EUK-T is a precision single comparator integrated circuit (IC) manufactured by Analog Devices Inc./Maxim Integrated. Despite its obsolete status, this IC remains a popular choice among engineers due to its exceptional performance in voltage comparison applications. This comprehensive guide covers its specifications, features, and real-world applications to help you understand why it's still relevant in modern electronics.

Detailed Technical Specifications

Package and Configuration

The MAX985EUK-T comes in a compact SC-74A, SOT-753 surface-mount package, measuring just 2.9mm 1.6mm 1.1mm. This miniature footprint makes it ideal for space-constrained PCB designs while maintaining excellent thermal performance.

Electrical Characteristics

• Supply Voltage Range: 2.5V to 5.5V (single supply) or 1.25V to 2.75V (dual supply)
• Input Offset Voltage: 5mV maximum at 5.5V
• Input Bias Current: 1pA typical at 5.5V
• Propagation Delay: 450ns maximum
• Quiescent Current: 24 A maximum

Performance Metrics

• Common-Mode Rejection Ratio (CMRR): 80dB minimum
• Power Supply Rejection Ratio (PSRR): 80dB minimum
• Output Drive Capability: 8mA sink/source current
• Hysteresis: 3mV typical for improved noise immunity

Key Advantages

1. Rail-to-Rail Operation

The comparator features rail-to-rail input capability, allowing it to handle signals across the entire supply voltage range. This makes it particularly useful in low-voltage applications where signal integrity is crucial.

2. Ultra-Low Power Consumption

With a maximum quiescent current of just 24 A, the MAX985EUK-T excels in battery-powered applications. Its power efficiency doesn't compromise performance, maintaining fast response times even at minimal power levels.

3. Enhanced Noise Immunity

The combination of 80dB CMRR/PSRR and built-in 3mV hysteresis makes this comparator exceptionally resistant to both power supply fluctuations and input signal noise.

Applications in Modern Electronics

Industrial Control Systems

The MAX985EUK-T is widely used in industrial automation for:

• Threshold detection in sensor interfaces
• Over-voltage/under-voltage protection circuits
• Window comparator configurations for process control

Consumer Electronics

Its small size and low power make it ideal for:

• Battery level monitoring in portable devices
• Signal conditioning in audio equipment
• Touch sensor interfaces

Automotive Electronics

The wide temperature range (-40 C to +85 C) enables reliable operation in:

• Engine control units
• Battery management systems
• Safety monitoring circuits

Design Considerations

PCB Layout Guidelines

For optimal performance:

• Use a solid ground plane beneath the package
• Keep input traces short and away from noisy signals
• Place bypass capacitors (0.1 F) close to the power pins

Thermal Management

While the SOT-753 package has good thermal characteristics, in high-density designs:

• Ensure adequate airflow around the component
• Consider using thermal vias for heat dissipation

Alternatives and Cross-References

For designers needing alternatives, consider these comparable devices:

• MAX9025 (similar specs in ultra-small package)
• LTC1540 (lower power, slower response)
• TS881 (higher speed alternative)

Purchasing Information

While the MAX985EUK-T is officially obsolete, we maintain stock of this reliable comparator to support legacy designs and specialized applications. Our inventory includes:

• Genuine Analog Devices/Maxim Integrated parts
• Multiple quantity options (tubes, reels, or individual units)
• Competitive pricing with volume discounts

For engineers working on new designs, we recommend exploring our range of current-production comparators with similar or improved specifications. Our technical support team can help identify the best alternative for your specific application requirements.

Search for MAX985EUK-T on Google to visit our product page and access datasheets, application notes, and design resources. Our comprehensive technical library and expert support make us the preferred source for precision analog components.