MIC38C45BMM Equivalent & Substitute Parts

Part Overview

The MIC38C45BMM is a DC-DC controller IC from Microchip Technology designed for multi-topology power management applications. This device functions as a transistor driver for buck, boost, flyback, and forward converter topologies with positive, isolation-capable output configurations. The MIC38C45BMM is discontinued at DiGi Electronics, making equivalent substitute parts necessary for ongoing design support and procurement.

Substiute Parts

MIC38C45BMM

Microchip TechnologyIn Stock: 802MIC38C45BMM Datasheet

Current PartRFQ

MIC38C45YMM

Microchip TechnologyIn Stock: 1201MIC38C45YMM Datasheet

DirectRFQ

UCC38C45DGK

UnitrodeIn Stock: 1117UCC38C45DGK Datasheet

MFR RecommendedRFQ

UCC38C45DGKR

Texas InstrumentsIn Stock: 1162UCC38C45DGKR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the MIC38C45BMM is determined by the following critical parameters:

• Topology Support: Buck, Boost, Flyback, Forward Converter capability
• Output Configuration: Positive output with isolation capability
• Voltage Supply Range: 7.6V ~ 20V minimum requirement
• Duty Cycle: 50% maximum
• Synchronous Rectifier: Integrated synchronous rectifier support
• Package Type: 8-MSOP surface mount package
• Control Features: Frequency control capability

Substitute parts are grouped into two categories:

Direct Equivalent (Same Manufacturer): MIC38C45YMM maintains identical electrical specifications and topology support as the MIC38C45BMM, with the primary difference being packaging format (Tube vs. Bulk) and product status (Active vs. Discontinued).

Cross-Manufacturer Alternatives: UCC38C45DGK and UCC38C45DGKR from Unitrode/Texas Instruments provide functional substitution with the following considerations: reduced topology support (Boost, Flyback, Forward Converter only—no Buck), lower maximum supply voltage (7.6V ~ 18V vs. 7.6V ~ 20V), higher switching frequency capability (up to 1MHz vs. 500kHz), and different package designation (8-VSSOP).

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement: MIC38C45YMM is the preferred substitute when maintaining the exact electrical specification set is required. This part is manufactured by Microchip Technology with identical topology support, voltage supply range, duty cycle, and synchronous rectifier capability. The MIC38C45YMM is currently active in production and available in Tube packaging. This option is suitable for designs requiring buck topology support and the full 7.6V ~ 20V supply voltage range.

For Cross-Manufacturer Substitution: UCC38C45DGK and UCC38C45DGKR from Unitrode/Texas Instruments are functional alternatives when buck topology is not required in the application. Both parts support boost, flyback, and forward converter topologies with positive output configuration. These alternatives operate within a reduced supply voltage range (7.6V ~ 18V) and lack integrated synchronous rectifier functionality. UCC38C45DGKR in Tape & Reel format with ROHS3 compliance is recommended for high-volume production environments requiring active product status and regulatory compliance.

Compliance Considerations: The original MIC38C45BMM is RoHS non-compliant. MIC38C45YMM and UCC38C45DGKR both meet ROHS3 compliance requirements. Design teams requiring RoHS compliance should select MIC38C45YMM for direct equivalence or UCC38C45DGKR for cross-manufacturer substitution.

Frequently Asked Questions (FAQ)

Q: Can MIC38C45YMM be used as a direct replacement for MIC38C45BMM?

A: Yes. MIC38C45YMM is electrically and functionally identical to MIC38C45BMM. Both support buck, boost, flyback, and forward converter topologies with 7.6V ~ 20V supply voltage, 50% maximum duty cycle, and integrated synchronous rectifier. The primary differences are packaging format (Tube vs. Bulk) and product status (Active vs. Discontinued).

Q: What are the limitations of UCC38C45DGK and UCC38C45DGKR compared to MIC38C45BMM?

A: The UCC38C45 series does not support buck topology, limiting functionality to boost, flyback, and forward converter applications only. Supply voltage range is reduced to 7.6V ~ 18V. Synchronous rectifier functionality is not integrated. Operating temperature range is narrower (0°C ~ 70°C vs. -40°C ~ 85°C). These parts are suitable only for applications that do not require buck topology or extended temperature operation.

Q: Are the 8-MSOP and 8-VSSOP packages pin-compatible?

A: Both packages are 8-pin surface mount packages with 0.118" (3.00mm) width. However, pin assignment and internal die configuration differ between MIC38C45 (8-MSOP) and UCC38C45 (8-VSSOP) series. PCB layout and schematic redesign are required when switching between these package types.

Q: Which substitute part should be selected for new designs?

A: MIC38C45YMM is recommended for new designs requiring full feature parity with the original MIC38C45BMM specification. This part maintains all topology support, voltage range, and temperature specifications while offering active product status and ROHS3 compliance.

Q: What is the impact of removing synchronous rectifier support in UCC38C45 alternatives?

A: Synchronous rectifier integration reduces conduction losses in the output rectification stage. UCC38C45 parts without this feature will exhibit higher power dissipation in rectification circuits. Design thermal analysis and efficiency calculations must be re-evaluated if switching to UCC38C45 alternatives.

Q: Are there temperature derating considerations for UCC38C45 parts?

A: UCC38C45DGK and UCC38C45DGKR operate within 0°C ~ 70°C (TJ) range, compared to MIC38C45BMM at -40°C ~ 85°C (TA). Applications requiring extended temperature operation below 0°C or above 70°C cannot use UCC38C45 alternatives.