KA5L0365RN Equivalent & Substitute Parts

Part Overview

The KA5L0365RN is an offline switch IC designed for power management applications, specifically configured for flyback and forward converter topologies. Manufactured by onsemi as part of the FPS™ series, this 8-DIP through-hole component operates at 50kHz switching frequency with integrated current limiting, over-temperature, and over-voltage protection. The product is currently obsolete, making identification of compatible substitute parts essential for ongoing system support and new design implementations.

Substiute Parts

KA5L0365RN

onsemiIn Stock: 3719KA5L0365RN Datasheet

Current PartRFQ

FSL136MR

onsemiIn Stock: 26323FSL136MR Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the KA5L0365RN is determined by the following critical parameters:

Package Compatibility: Both the main part and substitute must use 8-DIP (0.300", 7.62mm) through-hole packaging to ensure direct PCB mounting compatibility without layout modifications.

Electrical Specifications: Substitute parts must maintain voltage breakdown rating of 650V and support flyback topology operation. Supply voltage range compatibility is evaluated based on system requirements; the substitute may operate within a different but overlapping range.

Switching Frequency: The main part operates at 50kHz. Substitutes operating at different frequencies (such as 67kHz) remain functionally compatible provided the converter design accommodates the frequency variation.

Fault Protection Features: Core protection mechanisms (current limiting, over-temperature, over-voltage) must be present in substitute parts to maintain system reliability.

Thermal Operating Range: Substitute parts must support the application's temperature requirements within their specified operating range.

The FSL136MR qualifies as a direct substitute based on matching package type, voltage breakdown, topology support, and fault protection capabilities, despite differences in switching frequency, supply voltage range, and operating temperature maximum.

Parameter Comparison

Engineering Selection Recommendations

The FSL136MR is the qualified substitute for the obsolete KA5L0365RN based on the following engineering criteria:

Package and Pinout Compatibility: Both components use identical 8-DIP through-hole packaging, enabling direct PCB replacement without layout modifications.

Electrical Equivalence: Both parts maintain 650V breakdown voltage and 77% duty cycle specifications. The FSL136MR operates within a slightly narrower supply voltage range (8V ~ 26V versus 9V ~ 30V) and lower startup voltage (12V versus 15V), which is acceptable for most applications within the overlapping operating window.

Topology Support: The FSL136MR supports flyback topology, matching the primary converter type of the KA5L0365RN. The KA5L0365RN's forward topology capability is not replicated in the substitute; applications requiring forward topology operation must evaluate alternative parts.

Product Status and Availability: The FSL136MR is active production status with 26,300 units in stock, providing reliable long-term supply compared to the obsolete KA5L0365RN.

Compliance and Certifications: Both parts carry REACH Unaffected status and EAR99 ECCN classification. The FSL136MR includes RoHS3 compliance certification, meeting modern regulatory requirements.

Enhanced Protection Features: The FSL136MR provides additional fault protection including over-load and short-circuit detection beyond the KA5L0365RN's feature set, improving system robustness.

Thermal Performance: The FSL136MR supports extended operating temperature range (-40°C ~ 105°C) compared to the KA5L0365RN (-40°C ~ 85°C), providing greater thermal margin in demanding applications.

Frequently Asked Questions (FAQ)

Q: Can FSL136MR directly replace KA5L0365RN without PCB modifications?

A: Yes. Both components use identical 8-DIP (0.300", 7.62mm) through-hole packaging with matching pin spacing, enabling direct socket replacement. No PCB layout changes are required.

Q: What is the impact of the 67kHz switching frequency in FSL136MR versus 50kHz in KA5L0365RN?

A: The higher switching frequency in FSL136MR may require evaluation of transformer design and EMI filtering characteristics. Converter designs must accommodate the frequency difference through appropriate component selection. This is a design consideration, not a compatibility barrier.

Q: Does FSL136MR support forward converter topology like KA5L0365RN?

A: No. FSL136MR is specified for flyback topology only, while KA5L0365RN supports both flyback and forward topologies. Applications requiring forward topology operation must identify alternative substitute parts.

Q: Are the supply voltage ranges compatible between these parts?

A: The ranges overlap significantly. FSL136MR operates at 8V ~ 26V while KA5L0365RN operates at 9V ~ 30V. Applications operating within the 9V ~ 26V window are fully compatible. Systems requiring operation above 26V or below 9V must verify compatibility with specific application requirements.

Q: What additional protection features does FSL136MR provide?

A: FSL136MR includes over-load and short-circuit protection in addition to the current limiting, over-temperature, and over-voltage protection present in KA5L0365RN. These additional features enhance system reliability without creating compatibility issues.

Q: Is FSL136MR RoHS compliant?

A: Yes. FSL136MR is RoHS3 compliant. KA5L0365RN RoHS status is not specified in available documentation.

Q: What is the startup voltage difference impact?

A: FSL136MR requires 12V startup versus 15V for KA5L0365RN. This lower requirement may improve cold-start performance in low-voltage applications and is not a compatibility concern for systems designed around the original 15V specification.