MP6900DJ-LF-Z Equivalent & Substitute Parts

Part Overview

The MP6900DJ-LF-Z is a secondary-side power supply controller manufactured by Monolithic Power Systems Inc., packaged in TSOT-23-5 surface mount configuration. This device is classified as not for new designs, indicating it has been superseded in the product lifecycle. Finding equivalent or substitute parts is necessary for ongoing support of existing designs, maintenance of legacy systems, and ensuring supply chain continuity for applications requiring secondary-side controller functionality in isolated power supply topologies.

Substiute Parts

MP6900DJ-LF-Z

Monolithic Power Systems Inc.In Stock: 19735MP6900DJ-LF-Z Datasheet

Current PartRFQ

AR2003FV-13

Diodes IncorporatedIn Stock: 12228AR2003FV-13 Datasheet

MFR RecommendedRFQ

LT8309IS5#TRPBF

Analog Devices Inc.In Stock: 3813LT8309IS5#TRPBF Datasheet

MFR RecommendedRFQ

RT8481AGE

Richtek USA Inc.In Stock: 3059RT8481AGE Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the MP6900DJ-LF-Z is determined by the following critical parameters:

Primary Substitution Criteria:

• Application type: Secondary-side controller functionality
• Supply voltage range compatibility: Substitute must operate within or encompass the 8V ~ 24V range
• Package compatibility: TSOT-23-5 or equivalent surface mount packages with identical pinout
• Operating temperature range: -40°C ~ 125°C minimum
• RoHS3 compliance and REACH unaffected status

Substitute Parts Identified:

1. LT8309IS5#TRPBF (Analog Devices Inc.) – Direct package match (TSOT-23-5), identical application, extended supply voltage range (4.5V ~ 40V), lower quiescent current (300 µA vs. 3 mA), active product status.

2. RT8481AGE (Richtek USA Inc.) – Alternative package (SOT-23-6), secondary-side controller application, extended supply voltage range (4.75V ~ 50V), higher quiescent current (500 µA), active product status, reduced operating temperature upper limit (85°C vs. 125°C).

3. AR2003FV-13 (Diodes Incorporated) – Different application focus (active/synchronous rectification controller), different package (14-VFQFN), supply voltage range (4.5V ~ 21V), higher quiescent current (5 mA), active product status.

Parameter Comparison

Engineering Selection Recommendations

LT8309IS5#TRPBF is the primary substitute for MP6900DJ-LF-Z applications. This part maintains identical package geometry (TSOT-23-5), identical application classification (secondary-side controller), and identical operating temperature range (-40°C ~ 125°C). The LT8309IS5#TRPBF offers superior supply voltage range coverage (4.5V ~ 40V encompasses the original 8V ~ 24V specification) and significantly lower quiescent current consumption (300 µA vs. 3 mA). Both parts carry ROHS3 compliance and MSL-1 moisture sensitivity rating. The LT8309IS5#TRPBF maintains active product status, ensuring long-term availability and support.

RT8481AGE serves as an alternative substitute when package footprint flexibility exists. This part maintains secondary-side controller application compatibility and active product status. The RT8481AGE operates across an extended supply voltage range (4.75V ~ 50V) and features a six-pin SOT-23 package versus the five-pin TSOT-23-5 of the original part. The operating temperature upper limit is reduced to 85°C, which may be a constraint for high-temperature applications. Moisture sensitivity is rated MSL-3 (168 hours), requiring controlled storage conditions compared to the original MSL-1 rating.

AR2003FV-13 is not recommended as a direct substitute. Although this part is an active Diodes Incorporated product with ROHS3 compliance, it is classified as an active/synchronous rectification controller rather than a secondary-side controller. The package is significantly different (14-VFQFN vs. TSOT-23-5), requiring complete PCB redesign. The supply voltage range (4.5V ~ 21V) provides only partial overlap with the original specification. This part should be considered only if circuit topology and application requirements explicitly call for active/synchronous rectification control functionality.

Frequently Asked Questions (FAQ)

Q: Can LT8309IS5#TRPBF be used as a direct drop-in replacement for MP6900DJ-LF-Z?

A: Yes, LT8309IS5#TRPBF is a direct drop-in replacement. Both parts use identical TSOT-23-5 packaging with the same pinout, identical secondary-side controller application, and matching operating temperature range (-40°C ~ 125°C). No PCB modifications are required.

Q: What is the key difference between LT8309IS5#TRPBF and RT8481AGE?

A: LT8309IS5#TRPBF maintains the original five-pin TSOT-23-5 package, while RT8481AGE uses a six-pin SOT-23-6 package. LT8309IS5#TRPBF supports the full operating temperature range to 125°C, whereas RT8481AGE is limited to 85°C. Both are active secondary-side controller products with extended supply voltage ranges.

Q: Why is AR2003FV-13 listed if it is not recommended?

A: AR2003FV-13 is included because it was identified in the original part's substitute list. However, it serves a different functional purpose (active/synchronous rectification control vs. secondary-side control) and requires different packaging. It should only be considered if the application topology has been redesigned to utilize active/synchronous rectification control.

Q: What are the moisture sensitivity implications of switching to RT8481AGE?

A: The original MP6900DJ-LF-Z carries MSL-1 (unlimited moisture sensitivity level), while RT8481AGE is rated MSL-3 (168 hours). MSL-3 components require controlled storage at ≤30% relative humidity and must be used within 168 hours of package opening. This increases handling and storage requirements compared to the original part.

Q: Does LT8309IS5#TRPBF support the full 8V ~ 24V supply voltage range of the original part?

A: Yes. LT8309IS5#TRPBF operates across 4.5V ~ 40V, which fully encompasses the original 8V ~ 24V specification. The extended lower voltage limit (4.5V vs. 8V) and extended upper limit (40V vs. 24V) provide additional design flexibility.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All identified substitute parts (LT8309IS5#TRPBF, RT8481AGE, and AR2003FV-13) are ROHS3 compliant and REACH unaffected, matching the environmental compliance status of the original MP6900DJ-LF-Z.