MAX9021AXK-T Equivalent & Substitute Parts

Part Overview

The MAX9021AXK-T is a general-purpose CMOS comparator with rail-to-rail output and TTL compatibility, housed in a 5-TSSOP (SC-70-5) surface mount package. This part is currently listed as obsolete, making equivalent substitutes necessary for new designs and production continuity. The comparator operates across a wide supply voltage range (2.5V to 5.5V single supply, or ±1.25V to ±2.75V dual supply) and is suitable for precision signal comparison applications requiring low input offset voltage and minimal quiescent current.

Substiute Parts

MAX9021AXK-T

Analog Devices Inc./Maxim IntegratedIn Stock: 3657MAX9021AXK-T Datasheet

Current PartRFQ

MAX9021AXK+T

Analog Devices Inc./Maxim IntegratedIn Stock: 5681MAX9021AXK+T Datasheet

DirectRFQ

AZV3001FZ4-7

Diodes IncorporatedIn Stock: 16321AZV3001FZ4-7 Datasheet

MFR RecommendedRFQ

LMV7219M5

National SemiconductorIn Stock: 1406LMV7219M5 Datasheet

MFR RecommendedRFQ

LMV7219M5X/NOPB

National SemiconductorIn Stock: 41205LMV7219M5X/NOPB Datasheet

MFR RecommendedRFQ

NCS2202SQ1T2G

onsemiIn Stock: 3871NCS2202SQ1T2G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the MAX9021AXK-T is determined by the following critical parameters:

Electrical Compatibility Requirements:

• Supply voltage range must encompass or match the original 2.5V ~ 5.5V single supply specification
• Output type must maintain CMOS, rail-to-rail, or TTL compatibility for direct circuit replacement
• Input offset voltage, bias current, and quiescent current must be within acceptable tolerances for the application
• Propagation delay and hysteresis characteristics must not degrade system performance

Physical Compatibility Requirements:

• Package type must be surface mount with pin-compatible or functionally equivalent footprint
• 5-pin configuration required for single comparator element

Regulatory & Supply Chain Requirements:

• Active product status preferred for long-term availability
• RoHS3 compliance required for environmental standards
• MSL rating should not exceed the original specification

The substitute parts listed below meet these criteria with varying degrees of parameter alignment. Selection depends on specific application requirements and tolerance for parameter variation.

Parameter Comparison

Engineering Selection Recommendations

Direct Pin-Compatible Replacement (Recommended for Immediate Substitution):

MAX9021AXK+T is the optimal choice for direct replacement. It is manufactured by the same company (Analog Devices/Maxim Integrated), maintains identical electrical specifications, uses the same SC-70-5 package, and carries active product status. This part requires no circuit redesign and provides the highest compatibility assurance. It is ROHS3 compliant with MSL rating 1, matching the original part's environmental specifications.

Alternative Substitutes (Require Circuit Evaluation):

NCS2202SQ1T2G (onsemi) offers the same SC-70-5 package footprint with active product status and ROHS3 compliance. However, it features open-drain output instead of CMOS rail-to-rail TTL, requiring pull-up resistor configuration. It operates across a wider supply range (0.85V ~ 6V) and extended temperature range (-40°C ~ 105°C), but exhibits higher quiescent current (17µA) and hysteresis (20mV).

LMV7219M5X/NOPB (National Semiconductor) provides push-pull rail-to-rail output with significantly faster propagation delay (20ns vs. 8µs) and lower quiescent current (1.8mA). However, it uses a different package (SOT-23-5), operates at a narrower supply range (2.7V ~ 5V), and has reduced temperature range (-40°C ~ 85°C). This part is suitable only if circuit board redesign is acceptable.

AZV3001FZ4-7 (Diodes Incorporated) offers superior input offset voltage (0.5mV typical) and extremely fast propagation delay (0.8µs typical) with push-pull output. However, it uses a 6-pin DFN package requiring PCB layout changes, has higher hysteresis (13mV), and reduced operating temperature range (-40°C ~ 85°C). MSL rating 3 requires controlled storage conditions.

Compliance & Availability:

All substitute parts maintain ROHS3 compliance and EAR99 export classification. MAX9021AXK+T and NCS2202SQ1T2G have unlimited MSL ratings, while AZV3001FZ4-7 requires 168-hour moisture control. Current inventory levels support production requirements across all options.

Frequently Asked Questions (FAQ)

Q: Can MAX9021AXK+T be used as a direct drop-in replacement for MAX9021AXK-T?

A: Yes. MAX9021AXK+T is electrically and physically identical to the obsolete MAX9021AXK-T. Both parts share the same SC-70-5 package, identical pin configuration, and matching electrical specifications. No circuit modifications are required. The primary difference is product status: MAX9021AXK+T is active, ensuring continued availability.

Q: What is the key difference between CMOS rail-to-rail TTL output and open-drain output?

A: CMOS rail-to-rail TTL output (MAX9021AXK-T, MAX9021AXK+T) actively drives the output high and low to the supply rails, providing direct logic-level compatibility. Open-drain output (NCS2202SQ1T2G) requires an external pull-up resistor to establish a high logic level, offering flexibility in output voltage selection but requiring additional circuit components.

Q: Why does NCS2202SQ1T2G have higher quiescent current than the original part?

A: NCS2202SQ1T2G operates across a much wider supply range (0.85V ~ 6V) and extended temperature range (-40°C ~ 105°C), requiring additional bias circuitry for stable operation across these extremes. This results in higher quiescent current (17µA vs. 5µA) despite similar functional performance.

Q: Can LMV7219M5X/NOPB replace MAX9021AXK-T without PCB changes?

A: No. LMV7219M5X/NOPB uses SOT-23-5 package instead of SC-70-5, requiring PCB layout redesign. Additionally, it operates at a narrower supply range (2.7V ~ 5V) and reduced temperature range (-40°C ~ 85°C). Substitution is only viable if circuit board redesign is acceptable and application requirements align with the narrower specifications.

Q: What does MSL rating 1 (Unlimited) mean for component handling?

A: MSL rating 1 (Unlimited) indicates the component can be stored indefinitely at room temperature without moisture absorption concerns. No special dry-pack storage or baking procedures are required before soldering. This simplifies inventory management and reduces handling complexity compared to higher MSL ratings.

Q: Is AZV3001FZ4-7 suitable for high-speed applications?

A: AZV3001FZ4-7 offers significantly faster propagation delay (0.8µs typical vs. 8µs maximum for the original part), making it suitable for higher-speed signal comparison. However, its 6-pin DFN package requires PCB redesign, and its reduced operating temperature range (-40°C ~ 85°C) may not meet all application requirements. Evaluation against specific timing and temperature specifications is necessary.

Q: Which substitute part has the lowest power consumption?

A: MAX9021AXK+T and the original MAX9021AXK-T share identical quiescent current specifications (5µA maximum). Among active substitutes, AZV3001FZ4-7 has comparable quiescent current (6µA typical). LMV7219M5X/NOPB has significantly higher quiescent current (1.8mA), making it unsuitable for battery-powered or ultra-low-power applications.

Q: Can multiple substitute parts be used interchangeably in the same design?

A: No. Each substitute part has different electrical characteristics, package types, and output configurations. Interchangeability is limited to MAX9021AXK+T, which is electrically and physically identical to the obsolete MAX9021AXK-T. Other substitutes require individual circuit evaluation and potential redesign.