LM7808ACT Linear Voltage Regulator Equivalent & Substitute Parts

Part Overview

The LM7808ACT is a linear voltage regulator IC manufactured by onsemi, designed to provide a fixed positive 8V output at 1A current capacity in a TO-220-3 through-hole package. This device is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support, maintenance, and production continuity. The LM7808ACT serves applications requiring stable 8V regulation with thermal and short-circuit protection in industrial and consumer electronics.

Substiute Parts

LM7808ACT

onsemiIn Stock: 1210LM7808ACT Datasheet

Current PartRFQ

MC78M08ABTG

onsemiIn Stock: 1224MC78M08ABTG Datasheet

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MC7808CTG

onsemiIn Stock: 1512MC7808CTG Datasheet

Parametric EquivalentRFQ

L7808CV

STMicroelectronicsIn Stock: 205332L7808CV Datasheet

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L7808CV-DG

STMicroelectronicsIn Stock: 62152L7808CV-DG Datasheet

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MC7808ABTG

onsemiIn Stock: 1609MC7808ABTG Datasheet

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MC78M08CTG

onsemiIn Stock: 1168MC78M08CTG Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution for the LM7808ACT is determined by the following critical parameters:

• Output Voltage: Must be fixed at 8V
• Output Current Capacity: Minimum 1A (higher ratings are acceptable for drop-in replacement)
• Input Voltage Rating: Maximum 35V or higher
• Package Type: TO-220-3 through-hole configuration
• Protection Features: Over temperature and short circuit protection required
• Output Configuration: Positive fixed output only

Substitute parts are grouped into two categories:

Category 1 - Full Parametric Equivalents (1A Output) Parts with identical or superior output current (1A or higher), matching voltage specifications, and compatible packaging. These provide direct replacement capability.

Category 2 - Reduced Current Substitutes (500mA Output) Parts with lower output current capacity (500mA). These are suitable only when circuit design permits reduced current delivery and do not provide full backward compatibility.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: MC7808CTG

MC7808CTG is the preferred substitute for LM7808ACT. It maintains identical electrical specifications (8V output, 1A current, 2V dropout voltage, 8 mA quiescent current) and is currently in active product status, ensuring long-term availability and supply chain stability. Both parts operate within the same temperature range (0°C ~ 125°C) and share the TO-220-3 package configuration. RoHS3 compliance of MC7808CTG provides regulatory advantage over the obsolete LM7808ACT.

Secondary Recommendations: L7808CV and L7808CV-DG

L7808CV and L7808CV-DG (STMicroelectronics) provide higher output current capacity (1.5A versus 1A), making them suitable for applications requiring additional current margin. Both maintain 8V output, 35V maximum input, and 2V dropout voltage specifications. These parts are compatible with existing TO-220-3 board layouts. PSRR performance is lower (56dB versus 73dB), which may impact noise-sensitive applications.

Reduced Current Alternative: MC78M08CTG and MC78M08ABTG

MC78M08CTG and MC78M08ABTG deliver 500mA output current and are suitable only when circuit design accommodates reduced current delivery. MC78M08ABTG extends operating temperature to -40°C ~ 125°C, providing wider temperature coverage. These parts are not recommended for direct replacement in designs requiring full 1A capacity.

Compliance Considerations

All recommended substitutes maintain RoHS3 compliance and REACH unaffected status, matching the regulatory profile of the original LM7808ACT. TO-220-3 package compatibility ensures mechanical and thermal interface equivalence across all substitute options.

Frequently Asked Questions (FAQ)

Q: Can MC7808CTG directly replace LM7808ACT in existing designs?

A: Yes. MC7808CTG provides identical electrical performance (8V output, 1A current, 2V dropout voltage) and shares the TO-220-3 package. No circuit modifications are required. MC7808CTG is currently in active production status, providing supply continuity.

Q: What is the difference between L7808CV and L7808CV-DG?

A: Both parts are electrically identical, delivering 8V at 1.5A with 2V dropout voltage. The difference is in packaging designation and supplier traceability. Both are suitable substitutes for LM7808ACT when higher current capacity is beneficial.

Q: Can MC78M08CTG replace LM7808ACT?

A: MC78M08CTG is not a direct replacement. It delivers only 500mA output current compared to the 1A requirement of LM7808ACT. Use MC78M08CTG only if circuit design permits reduced current delivery and load requirements do not exceed 500mA.

Q: Are there temperature range differences between substitutes?

A: Yes. LM7808ACT and most substitutes operate 0°C ~ 125°C. MC7808ABTG and MC78M08ABTG extend the lower limit to -40°C, providing wider temperature coverage for industrial applications. Select based on specific operating environment requirements.

Q: Do all substitutes maintain the same thermal characteristics?

A: All substitutes use the TO-220-3 package, providing equivalent thermal interface and mounting compatibility. Quiescent current varies slightly (6 mA to 8 mA), with minimal impact on thermal performance in typical applications.

Q: What is PSRR and why does it vary among substitutes?

A: PSRR (Power Supply Rejection Ratio) measures the regulator's ability to reject input voltage ripple. LM7808ACT specifies 73dB at 120Hz. Substitutes range from 56dB to 80dB. Higher PSRR (80dB in MC78M08 variants) provides better noise rejection; lower PSRR (56dB in L7808 variants) may require additional filtering in noise-sensitive circuits.

Q: Are all substitutes RoHS compliant?

A: Yes. All recommended substitutes maintain RoHS3 compliance and REACH unaffected status, matching regulatory requirements of the original LM7808ACT.