MIC79050-4.2BS Equivalent & Substitute Parts

Part Overview

The MIC79050-4.2BS is a single-cell lithium-ion battery charger IC in SOT-223-3 surface mount packaging, manufactured by Microchip Technology. This device provides constant and pulsed charging current control with integrated fault protection including over-current, over-temperature, reverse battery, and reverse current protection. The part is rated for 4.2V battery pack voltage with a maximum supply voltage of 16V and operates across the temperature range of -40°C to 125°C (junction temperature).

The MIC79050-4.2BS is currently listed as obsolete. Identifying equivalent substitute parts is necessary to maintain design continuity, ensure supply chain reliability, and support ongoing production requirements for applications utilizing this charger topology.

Substiute Parts

MIC79050-4.2BS

Microchip TechnologyIn Stock: 4710MIC79050-4.2BS Datasheet

Current PartRFQ

MIC79050-4.2YS

Microchip TechnologyIn Stock: 15076MIC79050-4.2YS Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the MIC79050-4.2BS is determined by strict equivalence across the following critical parameters:

• Battery Chemistry & Cell Count: Lithium Ion, single-cell configuration
• Charge Voltage: 4.2V battery pack voltage
• Supply Voltage Rating: Maximum 16V input
• Charging Current Mode: Constant and pulsed charging capability
• Fault Protection Features: Over-current, over-temperature, reverse battery, and reverse current protection
• Operating Temperature Range: -40°C to 125°C (junction temperature)
• Package Type: SOT-223-3 surface mount package with TO-261-4 and TO-261AA case compatibility
• Manufacturer: Microchip Technology

The MIC79050-4.2YS meets all these criteria and is classified as a direct manufacturer substitute. Both parts share the same base product number (MIC79050) and are functionally equivalent across all specified electrical and mechanical parameters.

Parameter Comparison

Engineering Selection Recommendations

The MIC79050-4.2YS is the direct substitute for the obsolete MIC79050-4.2BS. Both parts are manufactured by Microchip Technology and provide identical electrical and mechanical functionality for single-cell lithium-ion battery charging applications at 4.2V.

The MIC79050-4.2YS offers the following advantages for new designs and production transitions:

• Active Product Status: Currently in active production with established supply chain availability (14,970 pcs in stock versus 4,654 pcs for the obsolete variant)
• Regulatory Compliance: ROHS3 compliant, meeting current environmental and regulatory requirements
• Packaging: Supplied in tube packaging, suitable for automated assembly processes

The MIC79050-4.2BS, while RoHS non-compliant and obsolete, may remain suitable for legacy applications where regulatory compliance is not a requirement and existing inventory is available. However, for new designs and ongoing production, the MIC79050-4.2YS is the recommended selection.

Frequently Asked Questions (FAQ)

Q: Can the MIC79050-4.2YS be used as a direct replacement for the MIC79050-4.2BS in existing designs?

A: Yes. Both parts are electrically and mechanically equivalent across all specified parameters including battery chemistry, charge voltage, supply voltage rating, charging current modes, fault protection features, operating temperature range, and SOT-223-3 package type. No circuit modifications are required.

Q: What is the difference between the MIC79050-4.2BS and MIC79050-4.2YS?

A: The primary differences are product status and regulatory compliance. The MIC79050-4.2BS is obsolete and RoHS non-compliant, while the MIC79050-4.2YS is an active product with ROHS3 compliance. Both parts are functionally identical for charging applications.

Q: Are there any packaging differences between these parts?

A: Both parts use the SOT-223-3 surface mount package with TO-261-4 and TO-261AA case compatibility. The MIC79050-4.2YS is supplied in tube packaging, while the MIC79050-4.2BS packaging type is not specified in the available data.

Q: What is the moisture sensitivity level (MSL) difference, and does it affect substitution?

A: The MIC79050-4.2BS has MSL 1 (unlimited shelf life), while the MIC79050-4.2YS has MSL 3 (168-hour limit after moisture exposure). For standard manufacturing and storage conditions, this difference does not affect functional substitution. Proper moisture control during storage and handling is required for the MIC79050-4.2YS per IPC-A-610 standards.

Q: Is the MIC79050-4.2YS suitable for new product designs?

A: Yes. The MIC79050-4.2YS is the recommended choice for new designs due to its active product status, ROHS3 compliance, and established supply chain availability.