AP3581BMPTR-G1 Equivalent & Substitute Parts

Part Overview

The AP3581BMPTR-G1 is a Buck Regulator Positive Output Step-Down DC-DC Controller IC manufactured by Diodes Incorporated in an 8-SO-EP package. This component functions as a transistor driver for step-down voltage conversion applications with a single output phase. The part is currently classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing design support and production continuity.

Substiute Parts

AP3581BMPTR-G1

Diodes IncorporatedIn Stock: 216117AP3581BMPTR-G1 Datasheet

Current PartRFQ

NCP1587EDR2G

onsemiIn Stock: 2030NCP1587EDR2G Datasheet

MFR RecommendedRFQ

RT8130BGQW

Richtek USA Inc.In Stock: 20374RT8130BGQW Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the AP3581BMPTR-G1 are qualified based on the following core electrical and mechanical parameters:

• Topology & Function: Buck regulator with step-down DC-DC controller functionality
• Output Configuration: Positive output, single phase
• Supply Voltage Range: 4.5V ~ 13.2V compatibility
• Switching Frequency: 300kHz nominal operation
• Duty Cycle: Maximum 80% or higher
• Synchronous Rectifier: Integrated synchronous rectification capability
• Control Features: Enable and Phase Control functionality
• Package Compatibility: Surface mount packages with equivalent pinout and thermal characteristics
• Compliance: ROHS3 compliant, REACH unaffected

Two active substitute parts meet these criteria with acceptable parameter variations within engineering tolerances for buck controller applications.

Parameter Comparison

Engineering Selection Recommendations

NCP1587EDR2G (onsemi) is the primary substitute for direct replacement in existing AP3581BMPTR-G1 designs. This part maintains identical supply voltage range (4.5V ~ 13.2V), package footprint (8-SOIC), and core control features (Enable, Phase Control). The switching frequency of 275kHz and maximum duty cycle of 75% represent minor operational variations acceptable for most buck controller applications. The extended operating temperature range (-40°C ~ 125°C) provides improved thermal margin. Active product status ensures long-term availability and supply chain continuity. ROHS3 compliance and unlimited MSL rating match the original part's environmental specifications.

RT8130BGQW (Richtek USA Inc.) serves as an alternative substitute with enhanced performance characteristics. This part maintains the 300kHz switching frequency and 4.5V ~ 13.2V supply voltage range of the original AP3581BMPTR-G1. The maximum duty cycle of 88% exceeds the original specification, providing additional design flexibility. The 10-WFDFN package offers improved thermal performance through an exposed pad design. Additional Power Good control feature enables enhanced system monitoring. Package footprint change from 8-SOIC to 10-WFDFN requires PCB layout modification. MSL rating of 3 (168 Hours) requires standard moisture control during storage and assembly. Active product status ensures availability.

Both substitutes maintain ROHS3 compliance and REACH unaffected status, meeting regulatory requirements for the original AP3581BMPTR-G1 application.

Frequently Asked Questions (FAQ)

Q: Can NCP1587EDR2G directly replace AP3581BMPTR-G1 without PCB modifications?

A: Yes. The NCP1587EDR2G maintains the same 8-SOIC package footprint and pinout compatibility. No PCB layout changes are required for direct substitution.

Q: What are the key differences between NCP1587EDR2G and RT8130BGQW?

A: NCP1587EDR2G uses an 8-SOIC package matching the original AP3581BMPTR-G1 footprint, while RT8130BGQW uses a 10-WFDFN package requiring PCB redesign. RT8130BGQW offers higher maximum duty cycle (88% vs 75%) and includes Power Good output. NCP1587EDR2G provides extended operating temperature range (-40°C ~ 125°C vs -40°C ~ 85°C).

Q: Does the 275kHz switching frequency of NCP1587EDR2G affect circuit performance compared to the 300kHz original?

A: The 25kHz frequency difference represents an 8% variation. For most buck regulator applications, this variation falls within acceptable design tolerances. Output filter component values may require minor adjustment to maintain target ripple specifications.

Q: Is the 75% maximum duty cycle of NCP1587EDR2G sufficient for my application?

A: The original AP3581BMPTR-G1 specifies 80% maximum duty cycle. NCP1587EDR2G at 75% is suitable for applications requiring duty cycles up to 75%. Applications requiring higher duty cycles should use RT8130BGQW (88% maximum) or verify that the lower duty cycle limit does not constrain your output voltage range.

Q: What is the impact of RT8130BGQW's MSL rating of 3 compared to the original part's MSL rating of 1?

A: MSL 3 (168 Hours) requires moisture control during storage and assembly. Components must be stored in dry conditions and used within 168 hours of moisture barrier bag opening. Standard moisture bake procedures apply if this time window is exceeded. MSL 1 (Unlimited) of the original part and NCP1587EDR2G substitute do not require these precautions.

Q: Does RT8130BGQW's Power Good output provide functional advantages?

A: Power Good is an additional monitoring feature not present in the original AP3581BMPTR-G1. This output can signal system status to external logic. If your application does not require this feature, it remains unused without impact on core buck controller functionality.

Q: Are all three parts ROHS3 compliant?

A: Yes. AP3581BMPTR-G1, NCP1587EDR2G, and RT8130BGQW are all ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory requirements.