LM3489MMX Equivalent & Substitute Parts

Part Overview

The LM3489MMX is a buck regulator positive output step-down DC-DC controller IC manufactured by Texas Instruments in 8-VSSOP packaging. This device functions as a transistor driver for step-down topology applications with a single output phase, operating across a supply voltage range of 4.5V to 35V with switching frequency up to 1MHz and 100% maximum duty cycle. The LM3489MMX is classified as obsolete, necessitating identification of active equivalent and substitute parts to maintain design continuity and ensure long-term component availability for production and field support.

Key Parameters

Parameter	Value
Manufacturer	Texas Instruments
Category	Power Management (PMIC)
Function	Step-Down Buck Regulator Controller
Output Type	Transistor Driver
Topology	Buck
Number of Outputs	1
Output Phases	1
Voltage Supply Range (Vcc/Vdd)	4.5V ~ 35V
Switching Frequency	Up to 1MHz
Duty Cycle (Max)	100%
Operating Temperature	-40°C ~ 125°C (TJ)
Package / Case	8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
Supplier Device Package	8-VSSOP
Mounting Type	Surface Mount
Grade	Automotive
Qualification	AEC-Q100
RoHS Status	RoHS non-compliant
Moisture Sensitivity Level (MSL)	1 (Unlimited)

Substitute Part Grouping Explanation

Substitution of the LM3489MMX is determined by strict equivalence across the following critical parameters:

Electrical Equivalence Criteria:

Voltage supply range: 4.5V ~ 35V
Output topology: Buck (step-down)
Output configuration: Positive
Number of outputs: 1
Output phases: 1
Duty cycle maximum: 100%
Operating temperature range: -40°C ~ 125°C (TJ)
Synchronous rectifier: No
Clock sync: No

Mechanical & Packaging Equivalence Criteria:

Package type: 8-VSSOP, 8-TSSOP, or 8-MSOP
Mounting type: Surface Mount
Moisture sensitivity level: 1 (Unlimited)

Compliance & Certification Criteria:

Grade: Automotive
Qualification: AEC-Q100
REACH Status: REACH Unaffected
ECCN: EAR99

Substitute parts are grouped into two categories: LM3489 series variants (direct functional equivalents with identical control features) and LM3485 series variants (parametric equivalents with reduced feature set). All listed substitutes maintain identical electrical performance within the specified operating parameters and are qualified for automotive applications under AEC-Q100 standards.

Parameter Comparison

Part Number	Manufacturer	Product Status	Voltage Supply (Vcc/Vdd)	Switching Frequency	Duty Cycle (Max)	Operating Temperature	Package	Grade	AEC-Q100	RoHS Status	Inventory (Pcs)
LM3489MMX	Texas Instruments	Obsolete	4.5V ~ 35V	Up to 1MHz	100%	-40°C ~ 125°C	8-VSSOP	Automotive	Yes	RoHS non-compliant	1547
LM3489MM/NOPB	Texas Instruments	Active	4.5V ~ 35V	Up to 1MHz	100%	-40°C ~ 125°C	8-VSSOP	Automotive	Yes	ROHS3 Compliant	15700
LM3489MMX/NOPB	Texas Instruments	Active	4.5V ~ 35V	Up to 1MHz	100%	-40°C ~ 125°C	8-VSSOP	Automotive	Yes	ROHS3 Compliant	16371
LM3489QMM/NOPB	Texas Instruments	Active	4.5V ~ 35V	Up to 1MHz	100%	-40°C ~ 125°C	8-MSOP	Automotive	Yes	ROHS3 Compliant	10684
LM3489QMMX/NOPB	Texas Instruments	Active	4.5V ~ 35V	Up to 1MHz	100%	-40°C ~ 125°C	8-VSSOP	Automotive	Yes	ROHS3 Compliant	3060
LM3489MM	Texas Instruments	Last Time Buy	4.5V ~ 35V	Up to 1MHz	100%	-40°C ~ 125°C	8-VSSOP	Automotive	Yes	ROHS3 Compliant	2300
LM3485MM/NOPB	Texas Instruments	Active	4.5V ~ 35V	Not specified	100%	-40°C ~ 125°C	8-VSSOP	Not specified	Not specified	ROHS3 Compliant	96400
LM3485MMX/NOPB	Texas Instruments	Active	4.5V ~ 35V	Not specified	100%	-40°C ~ 125°C	8-VSSOP	Not specified	Not specified	ROHS3 Compliant	55100
LM3485Q1MM/NOPB	Texas Instruments	Active	4.5V ~ 35V	Not specified	100%	-40°C ~ 125°C	8-VSSOP	Automotive	Yes	ROHS3 Compliant	2140

Engineering Selection Recommendations

Primary Substitutes (LM3489 Series - Direct Functional Equivalents):

LM3489MM/NOPB, LM3489MMX/NOPB, LM3489QMMX/NOPB, and LM3489QMM/NOPB are active production parts that maintain full functional equivalence to the LM3489MMX. These parts retain identical control features (current limit and enable), switching frequency capability (up to 1MHz), and automotive qualification (AEC-Q100). All primary substitutes are ROHS3 compliant, addressing regulatory requirements that the original LM3489MMX does not meet. LM3489MM/NOPB and LM3489MMX/NOPB offer the highest inventory availability (15700 and 16371 units respectively) and are recommended as first-choice replacements.

Secondary Substitutes (LM3485 Series - Parametric Equivalents):

LM3485MM/NOPB, LM3485MMX/NOPB, and LM3485Q1MM/NOPB are parametric equivalents that satisfy core electrical requirements (4.5V to 35V supply, 100% duty cycle, -40°C to 125°C operating range, buck topology, single output phase) but do not specify switching frequency or control features in available documentation. LM3485Q1MM/NOPB maintains automotive grade and AEC-Q100 qualification. The LM3485 series offers significantly higher inventory availability (96400 and 55100 units for MM and MMX variants respectively), making these options suitable for applications where the reduced feature specification does not impact circuit performance.

Compliance Consideration:

All active substitute parts are ROHS3 compliant, whereas the original LM3489MMX is RoHS non-compliant. This transition addresses evolving regulatory requirements for new production and long-term supply chain sustainability.

Frequently Asked Questions (FAQ)

Q: Can LM3489MM/NOPB directly replace LM3489MMX in existing designs?

A: Yes. LM3489MM/NOPB is functionally equivalent to LM3489MMX across all specified electrical parameters: 4.5V to 35V supply voltage, up to 1MHz switching frequency, 100% duty cycle, identical control features (current limit and enable), and automotive AEC-Q100 qualification. The primary difference is ROHS3 compliance in the substitute part. Mechanical compatibility is confirmed through identical 8-VSSOP packaging and surface mount mounting type.

Q: What is the difference between LM3489 and LM3485 series substitutes?

A: The LM3489 series (LM3489MM, LM3489MM/NOPB, LM3489MMX/NOPB, LM3489QMMX/NOPB, LM3489QMM/NOPB) are direct functional equivalents with specified switching frequency (up to 1MHz) and control features (current limit, enable). The LM3485 series (LM3485MM/NOPB, LM3485MMX/NOPB, LM3485Q1MM/NOPB) are parametric equivalents that meet core electrical requirements but do not specify switching frequency or control features. Both series maintain identical supply voltage range (4.5V to 35V), duty cycle (100%), and operating temperature (-40°C to 125°C).

Q: Are there packaging differences between substitute options?

A: Most substitutes use 8-VSSOP packaging identical to the original LM3489MMX. LM3489QMM/NOPB uses 8-MSOP packaging, which is mechanically compatible (both are 0.118" width, 3.00mm) but may require PCB layout verification. All substitutes are surface mount devices with MSL rating of 1 (Unlimited).

Q: Which substitute offers the best inventory availability?

A: LM3485MM/NOPB provides the highest inventory (96400 units), followed by LM3485MMX/NOPB (55100 units). Among LM3489 series direct equivalents, LM3489MMX/NOPB (16371 units) and LM3489MM/NOPB (15700 units) offer the best availability.

Q: Is automotive qualification maintained across all substitutes?

A: Automotive grade and AEC-Q100 qualification are maintained in LM3489 series substitutes and LM3485Q1MM/NOPB. LM3485MM/NOPB and LM3485MMX/NOPB do not specify automotive grade or AEC-Q100 qualification in available documentation. For automotive applications, LM3489 series or LM3485Q1MM/NOPB are recommended.

Q: What is the significance of the "/NOPB" suffix?

A: The "/NOPB" suffix indicates the part is supplied without plumbum (lead-free), confirming ROHS3 compliance. Parts without this suffix (such as LM3489MM) may have different lead specifications. Verify lead-free requirements for your application before selection.

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