LNK6778V Equivalent & Substitute Parts

Part Overview

The LNK6778V is an offline switch integrated circuit manufactured by Power Integrations, designed for flyback converter topologies in isolated power management applications. This LinkSwitch™-HP series device operates at 120kHz to 136kHz switching frequency with 47W power output capability and 725V breakdown voltage rating. The component is Active status with full RoHS compliance and REACH unaffected designation. Substitute parts are identified when design requirements permit variation in specific electrical parameters while maintaining functional compatibility within the same package and topology constraints.

Substiute Parts

LNK6778V

Power IntegrationsIn Stock: 777LNK6778V Datasheet

Current PartRFQ

LNK6768V

Power IntegrationsIn Stock: 6170LNK6768V Datasheet

Parametric EquivalentRFQ

LNK6777V

Power IntegrationsIn Stock: 3606LNK6777V Datasheet

Parametric EquivalentRFQ

LNK6779V

Power IntegrationsIn Stock: 11842LNK6779V Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LNK6778V is determined by strict adherence to the following parameters:

Fixed Substitution Criteria (Must Match Exactly):

• Manufacturer: Power Integrations
• Series: LinkSwitch™-HP
• Topology: Flyback
• Package / Case: 12-SDIP (0.412", 10.46mm), 11 Leads, Exposed Pad
• Supplier Device Package: eDIP-12
• Mounting Type: Through Hole
• Frequency - Switching: 120–136 kHz
• Duty Cycle: 64%
• Output Isolation: Isolated
• Internal Switch(s): Yes
• Fault Protection: Current Limiting, Over Load, Over Temperature, Over Voltage, Short Circuit
• Operating Temperature: −40°C to +150°C (TJ)
• RoHS Status: RoHS Compliant
• REACH Status: REACH Unaffected

Variable Parameters (Permitted Variation):

• Voltage - Breakdown: 650V to 725V
• Power (Watts): 41W to 54W
• Moisture Sensitivity Level (MSL): 1 (Unlimited) to 3 (168 Hours)

The three substitute parts (LNK6768V, LNK6777V, LNK6779V) meet all fixed criteria while varying only in breakdown voltage rating, power output capability, and moisture sensitivity classification.

Parameter Comparison

Engineering Selection Recommendations

LNK6768V Selection Criteria: The LNK6768V operates at 650V breakdown voltage, 100V lower than the LNK6778V. This substitute is suitable for applications where input voltage stress is lower or where the reduced voltage rating aligns with system design margins. Power output remains at 47W. Moisture sensitivity classification matches the main part at MSL 3 (168 Hours). All compliance certifications (RoHS, REACH, ECCN EAR99) are identical. Inventory availability is significantly higher at 6100 pieces.

LNK6777V Selection Criteria: The LNK6777V maintains 725V breakdown voltage matching the LNK6778V but delivers reduced power output of 41W versus 47W. This substitute is applicable in designs where lower power delivery is acceptable or where thermal constraints benefit from reduced power dissipation. Moisture sensitivity is improved to MSL 1 (Unlimited), eliminating time-dependent storage constraints. All other electrical and compliance parameters remain equivalent.

LNK6779V Selection Criteria: The LNK6779V maintains 725V breakdown voltage and provides increased power output of 54W, exceeding the LNK6778V by 7W. This substitute is suitable for applications requiring higher power delivery within the same package and topology. Moisture sensitivity classification matches the main part at MSL 3 (168 Hours). Inventory availability is highest among all options at 11778 pieces. All compliance certifications remain identical.

All substitute parts maintain Active product status and full compliance with RoHS and REACH regulations, ensuring long-term availability and regulatory acceptance.

Frequently Asked Questions (FAQ)

Q1: Can LNK6768V replace LNK6778V in any application?

A: LNK6768V is a direct substitute only in applications where the input voltage stress permits operation at 650V breakdown rating. The 725V rating of LNK6778V provides additional voltage margin. If your design operates below 650V input stress, LNK6768V is functionally equivalent. If your design requires 725V margin, LNK6768V is not suitable.

Q2: What is the difference between LNK6777V and LNK6778V?

A: The primary difference is power output: LNK6777V delivers 41W while LNK6778V delivers 47W. Both maintain 725V breakdown voltage and identical switching frequency. LNK6777V offers improved moisture sensitivity (MSL 1 vs. MSL 3), eliminating bake-out time requirements. Select LNK6777V if your application power requirement is 41W or lower and you benefit from unlimited storage conditions.

Q3: When should LNK6779V be selected over LNK6778V?

A: LNK6779V provides 54W power output compared to 47W for LNK6778V. Select LNK6779V when your application requires higher power delivery within the same eDIP-12 package and flyback topology. Both maintain 725V breakdown voltage and identical switching characteristics. LNK6779V has the highest inventory availability.

Q4: Are all substitute parts pin-compatible with LNK6778V?

A: Yes. All substitute parts use the identical 12-SDIP (0.412", 10.46mm) package with 11 leads and exposed pad. All are eDIP-12 supplier packages with through-hole mounting. Direct PCB substitution is possible without layout modification.

Q5: Do substitute parts have the same fault protection features?

A: Yes. All substitute parts (LNK6768V, LNK6777V, LNK6779V) include identical fault protection: Current Limiting, Over Load, Over Temperature, Over Voltage, and Short Circuit protection.

Q6: What does MSL 1 (Unlimited) versus MSL 3 (168 Hours) mean for component handling?

A: MSL 3 (168 Hours) requires bake-out at 125°C for 24 hours if the component has been exposed to ambient humidity for more than 168 hours before soldering. MSL 1 (Unlimited) has no time-dependent storage constraint and requires no bake-out procedure. LNK6777V offers MSL 1, simplifying supply chain and assembly logistics.

Q7: Are all substitute parts RoHS compliant?

A: Yes. All substitute parts (LNK6778V, LNK6768V, LNK6777V, LNK6779V) are RoHS Compliant and REACH Unaffected with identical ECCN EAR99 and HTSUS 8542.39.0001 classifications.

Q8: Can I use LNK6779V if my design only requires 47W output?

A: Yes. LNK6779V is rated for 54W maximum output but operates at lower power levels. If your design requires 47W, LNK6779V functions as a direct substitute with additional power margin. No design modification is required.

Q9: Which substitute has the best inventory availability?

A: LNK6779V has the highest inventory at 11778 pieces, followed by LNK6768V at 6100 pieces, and LNK6777V at 3500 pieces. LNK6778V has 732 pieces in stock.

Q10: Do all parts operate at the same switching frequency?

A: Yes. All parts (LNK6778V, LNK6768V, LNK6777V, LNK6779V) operate at 120–136 kHz switching frequency with 64% duty cycle, ensuring identical EMI characteristics and transformer design compatibility.