MC7809ECDTXM Linear Voltage Regulator Equivalent & Substitute Parts

Part Overview

The MC7809ECDTXM is a linear voltage regulator IC from onsemi that provides a fixed positive 9V output at 1A maximum current in a DPAK surface mount package. This part is classified as obsolete, making equivalent and substitute parts necessary for new designs and ongoing production requirements. The MC7809ECDTXM belongs to the Power Management (PMIC) category and is suitable for applications requiring regulated 9V power delivery with thermal and short-circuit protection.

Substiute Parts

MC7809ECDTXM

onsemiIn Stock: 1182MC7809ECDTXM Datasheet

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MC78M09BDTRKG

onsemiIn Stock: 7216MC78M09BDTRKG Datasheet

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MC78M09CDTRKG

onsemiIn Stock: 10108MC78M09CDTRKG Datasheet

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BA17809FP-E2

Rohm SemiconductorIn Stock: 17905BA17809FP-E2 Datasheet

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L78M09CDT-TR

STMicroelectronicsIn Stock: 21292L78M09CDT-TR Datasheet

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MC78M09CDTG

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Key Parameters

Substitute Part Grouping Explanation

Substitution for the MC7809ECDTXM is determined by the following critical parameters:

• Fixed output voltage of 9V
• Package compatibility: TO-252-3 DPAK surface mount
• Output current capability: minimum 1A (or lower if application permits)
• Maximum input voltage: 35V or higher
• Protection features: Over temperature and short circuit protection
• Operating temperature range: 0°C to 125°C or broader

Substitute parts are grouped into two categories based on output current rating:

Category 1: Full 1A Output Current — Direct replacements maintaining the 1A output specification.

Category 2: Reduced 500mA Output Current — Suitable only for applications where maximum output current does not exceed 500mA.

Parameter Comparison

Engineering Selection Recommendations

For 1A Output Current Applications:

BA17809FP-E2 from Rohm Semiconductor is the primary substitute maintaining full 1A output current capability. This part is active in production status and ROHS3 compliant. The maximum input voltage is 26V, which is lower than the MC7809ECDTXM's 35V specification; verify input voltage does not exceed 26V in your application. Operating temperature range is -40°C to 85°C, which is narrower than the original part's 0°C to 125°C range.

For 500mA Output Current Applications:

MC78M09CDTRKG from onsemi is recommended as the primary substitute for applications where output current does not exceed 500mA. This part is active in production, ROHS3 compliant, and maintains the same 0°C to 125°C operating temperature range as the original. Maximum input voltage is 35V, matching the MC7809ECDTXM specification.

MC78M09BDTRKG from onsemi offers extended operating temperature range (-40°C to 125°C) and is suitable for applications requiring broader temperature performance. This part is active in production status.

L78M09CDT-TR from STMicroelectronics is an alternative 500mA substitute with active production status and ROHS3 compliance. This part includes over-current protection in addition to over-temperature and short-circuit protection.

Obsolete Parts:

MC78M09CDTG from onsemi is classified as obsolete and should not be selected for new designs, despite available inventory.

Frequently Asked Questions (FAQ)

Q: Can I use a 500mA substitute part in place of the MC7809ECDTXM?

A: Only if your application's maximum output current requirement does not exceed 500mA. The MC7809ECDTXM is rated for 1A output current. Using a 500mA-rated part in a 1A application will cause the regulator to exceed its current rating and may result in thermal shutdown or device failure.

Q: What is the difference between the MC78M09CDTRKG and MC78M09BDTRKG?

A: Both parts provide 500mA output current at 9V with identical electrical specifications. The primary difference is operating temperature range: MC78M09CDTRKG operates from 0°C to 125°C, while MC78M09BDTRKG operates from -40°C to 125°C. Select MC78M09BDTRKG if your application requires operation below 0°C.

Q: Is the BA17809FP-E2 a direct replacement for the MC7809ECDTXM?

A: The BA17809FP-E2 maintains the same 1A output current and 9V fixed output voltage in the same TO-252-3 DPAK package. However, the maximum input voltage is 26V compared to 35V for the MC7809ECDTXM, and the operating temperature range is -40°C to 85°C instead of 0°C to 125°C. Verify these specifications are compatible with your application before substitution.

Q: Why is the MC78M09CDTG not recommended despite available inventory?

A: The MC78M09CDTG is classified as obsolete product status. For new designs and long-term production, active status parts ensure continued availability and manufacturer support. Obsolete parts should only be used for legacy system maintenance where no active alternatives are suitable.

Q: Are all substitute parts in the same package?

A: Yes, all substitute parts listed use the TO-252-3 DPAK surface mount package with identical pinout and footprint compatibility. PCB layout changes are not required for package substitution.

Q: What protection features should I verify when selecting a substitute?

A: The MC7809ECDTXM includes over-temperature and short-circuit protection. Most substitute parts maintain these protections. The L78M09CDT-TR additionally includes over-current protection. Verify that your selected substitute includes at minimum over-temperature and short-circuit protection for thermal and fault condition safety.