LMX331HAXK-T Equivalent & Substitute Parts

Part Overview

The LMX331HAXK-T is a general-purpose comparator IC manufactured by Analog Devices Inc./Maxim Integrated, housed in a 5-TSSOP SC-70-5 surface-mount package. This device features open-drain output configuration and operates across a 1.8V to 5.5V supply voltage range, making it suitable for low-power signal comparison applications. The part is currently classified as obsolete, necessitating identification of active equivalent alternatives to maintain design continuity and ensure long-term component availability.

Substiute Parts

LMX331HAXK-T

Analog Devices Inc./Maxim IntegratedIn Stock: 1054LMX331HAXK-T Datasheet

Current PartRFQ

MAX9648AXK+T

Analog Devices Inc./Maxim IntegratedIn Stock: 3499MAX9648AXK+T Datasheet

DirectRFQ

LMC7225IM5

Texas InstrumentsIn Stock: 2379LMC7225IM5 Datasheet

MFR RecommendedRFQ

LMV331ICT

STMicroelectronicsIn Stock: 1766LMV331ICT Datasheet

MFR RecommendedRFQ

LMV331IDCKR

Texas InstrumentsIn Stock: 65451LMV331IDCKR Datasheet

MFR RecommendedRFQ

TC75S59F,LF

Toshiba Semiconductor and StorageIn Stock: 1152TC75S59F,LF Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LMX331HAXK-T is determined by the following critical parameters:

• Supply voltage range compatibility (minimum 1.8V to 5.5V overlap required)
• Output type (open-drain configuration preferred for direct replacement)
• Package form factor (5-TSSOP SC-70-5 preferred; SOT-23-5 acceptable with board layout modification)
• Input offset voltage specification (7mV @ 5V or better)
• Input bias current specification (0.25µA @ 5V or lower)
• Propagation delay (600ns or faster acceptable)
• Operating temperature range (minimum -40°C to 85°C required)

Substitute parts are grouped into two categories: direct pin-compatible replacements in SC-70-5 packaging, and functional equivalents in alternative surface-mount packages requiring minor layout adjustments.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: MAX9648AXK+T

The MAX9648AXK+T is the optimal direct replacement for the LMX331HAXK-T. Both devices share identical supply voltage range (1.8V to 5.5V), matching input offset voltage (7mV @ 5V), input bias current (0.25µA @ 5V), and SC-70-5 package configuration. The MAX9648AXK+T is currently in active production status with ROHS3 compliance, ensuring long-term availability and regulatory alignment. The device offers superior propagation delay performance (110ns versus 600ns), providing design margin for timing-critical applications. Inventory availability is substantial at 3,419 pieces.

Secondary Recommendation: LMV331ICT

The LMV331ICT from STMicroelectronics provides pin-compatible SC-70-5 packaging with active product status and ROHS3 compliance. Supply voltage range is restricted to 2.7V to 5V, requiring verification against 1.8V minimum supply requirements in the original design. Input offset voltage and bias current specifications match the original part. Output current capability is higher at 93mA versus 73mA, and propagation delay is marginally faster at 550ns. This part is suitable for designs operating above 2.7V supply voltage.

Tertiary Recommendation: LMV331IDCKR

The LMV331IDCKR from Texas Instruments offers SC-70-5 packaging with active status and ROHS3 compliance. The output type is open-collector rather than open-drain, requiring circuit verification to confirm functional equivalence in the target application. Supply voltage range extends to 5.5V, matching the original specification. Propagation delay matches the original at 600ns. Inventory availability is highest among all substitutes at 65,400 pieces.

Alternative for Extended Supply Range: TC75S59F,LF

The TC75S59F,LF from Toshiba provides the widest supply voltage range (1.8V to 7V) and lowest input bias current (1pA), suitable for ultra-low-power applications. Package form factor is SOT-753 (SC-74A), requiring PCB layout modification. Propagation delay is superior at 200ns. ROHS3 compliance and active product status are confirmed. This part is recommended only when extended supply voltage range or ultra-low bias current is a design requirement.

Not Recommended: LMC7225IM5

The LMC7225IM5 exhibits excessive propagation delay (29µs) compared to the original specification (600ns), making it unsuitable for timing-sensitive applications. Although obsolete status matches the original part, the performance degradation and SOT-23-5 package form factor make this part a poor substitution choice.

Frequently Asked Questions (FAQ)

Q: Can the MAX9648AXK+T be used as a direct drop-in replacement for the LMX331HAXK-T?

A: Yes. Both devices share identical SC-70-5 packaging, supply voltage range (1.8V to 5.5V), input offset voltage (7mV @ 5V), and input bias current (0.25µA @ 5V) specifications. No circuit modifications are required. The MAX9648AXK+T is pin-compatible and functionally equivalent.

Q: What is the difference between open-drain and open-collector output types?

A: Both output types are functionally similar in most applications, requiring external pull-up resistors to establish logic levels. Open-drain uses a MOSFET output stage, while open-collector uses a bipolar transistor. The LMV331IDCKR (open-collector) can substitute for the LMX331HAXK-T (open-drain) in most circuits, but circuit verification is recommended to confirm compatibility with the specific pull-up configuration and load impedance.

Q: Why is the LMX331HAXK-T classified as obsolete?

A: Obsolete classification indicates the manufacturer has discontinued production and no longer provides technical support or warranty coverage. Active alternatives like the MAX9648AXK+T ensure continued design support, availability, and compliance with current regulatory standards.

Q: Can I use the TC75S59F,LF if my design requires operation above 5.5V?

A: Yes. The TC75S59F,LF supports supply voltages up to 7V, exceeding the original specification. However, the SOT-753 package form factor differs from the original SC-70-5, requiring PCB layout modification and verification of pin assignments before implementation.

Q: What is the impact of propagation delay differences between substitute parts?

A: Propagation delay determines the time interval between input signal transition and output response. The MAX9648AXK+T (110ns) provides faster response than the original LMX331HAXK-T (600ns), offering design margin for timing-critical applications. The LMC7225IM5 (29µs) introduces significant delay and is unsuitable for high-speed comparator applications.

Q: Are all recommended substitutes RoHS compliant?

A: All active substitute parts (MAX9648AXK+T, LMV331ICT, LMV331IDCKR, TC75S59F,LF) are ROHS3 compliant. The original LMX331HAXK-T is RoHS non-compliant. Compliance verification is required for applications subject to RoHS regulatory requirements.

Q: What inventory considerations should guide part selection?

A: The LMV331IDCKR offers the highest inventory availability at 65,400 pieces, followed by MAX9648AXK+T at 3,419 pieces. Inventory levels support long-term design continuity and reduce supply chain risk for high-volume production requirements.