AS7809ATF-E1 Linear Voltage Regulator Equivalent & Substitute Parts

Part Overview

The AS7809ATF-E1 is a linear voltage regulator IC manufactured by Diodes Incorporated, designed to provide a fixed positive 9V output at 1A current capacity in a TO-220-3 through-hole package. This device is classified as obsolete, making equivalent substitute parts necessary for ongoing design support and production continuity. The regulator features integrated over-temperature and short-circuit protection, suitable for applications requiring stable 9V power regulation from input sources up to 29V.

Substiute Parts

AS7809ATF-E1

Diodes IncorporatedIn Stock: 932AS7809ATF-E1 Datasheet

Current PartRFQ

BA17809CP-E2

Rohm SemiconductorIn Stock: 2296BA17809CP-E2 Datasheet

MFR RecommendedRFQ

BA178M09CP-E2

Rohm SemiconductorIn Stock: 2195BA178M09CP-E2 Datasheet

MFR RecommendedRFQ

BA7809CP-E2

Rohm SemiconductorIn Stock: 1786BA7809CP-E2 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the AS7809ATF-E1 is determined by the following critical parameters:

• Fixed output voltage of 9V
• Positive output configuration
• Current output capacity of 1A (or higher)
• Maximum input voltage of 26V or greater
• Voltage dropout specification of 2V or less at rated current
• Through-hole mounting in TO-220 package family
• Operating temperature range supporting -40°C minimum
• RoHS3 compliance and REACH unaffected status

The substitute parts listed below meet these core electrical and mechanical requirements, enabling direct functional replacement in applications designed for the AS7809ATF-E1. Variations in quiescent current, PSRR, and protection feature details do not prevent substitution when the primary parameters align.

Parameter Comparison

Engineering Selection Recommendations

BA17809CP-E2 is the primary recommended substitute. This Rohm Semiconductor part maintains 1A output current capacity, matches the 9V fixed output specification, and holds active product status. The TO-220-3 cropped leads package provides mechanical compatibility with standard through-hole PCB layouts. RoHS3 compliance and REACH unaffected status align with the original part's regulatory requirements.

BA178M09CP-E2 serves as an alternative for applications with reduced current requirements. This part delivers 500mA output, suitable for designs drawing less than 500mA from the 9V rail. Active product status and improved PSRR performance (67dB) offer advantages in noise-sensitive applications. The same regulatory compliance and package family apply.

BA7809CP-E2 is available as a secondary option but carries obsolete product status, limiting its long-term supply viability. This part matches 1A output capacity and includes over-current protection. Selection of this part should account for potential future availability constraints.

All three substitutes support the -40°C minimum operating temperature required by the original specification. Applications requiring the full -40°C to 125°C range of the AS7809ATF-E1 should note that substitute parts are rated to 85°C maximum, which may impact thermal margin calculations in high-temperature environments.

Frequently Asked Questions (FAQ)

Q: Can BA17809CP-E2 replace AS7809ATF-E1 in existing designs without PCB modification?

A: Yes. Both parts use TO-220-3 through-hole packages with identical pin configurations and electrical specifications (9V output, 1A capacity, 2V dropout). The cropped leads variant of BA17809CP-E2 fits standard TO-220 footprints. No circuit redesign is required.

Q: What is the difference between BA17809CP-E2 and BA178M09CP-E2?

A: The primary difference is output current capacity. BA17809CP-E2 delivers 1A, matching the original AS7809ATF-E1 specification. BA178M09CP-E2 is rated for 500mA maximum output. Both maintain 9V fixed output and identical voltage dropout characteristics at their respective current ratings. Select BA178M09CP-E2 only if your application draws 500mA or less.

Q: Does the operating temperature range difference affect substitution?

A: The AS7809ATF-E1 operates to 125°C; all substitutes are rated to 85°C maximum. For applications operating above 85°C ambient or with high internal power dissipation, thermal analysis is required to confirm the substitute part remains within safe operating limits. Standard room-temperature and moderate-temperature applications are unaffected.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. BA17809CP-E2, BA178M09CP-E2, and BA7809CP-E2 are all ROHS3 compliant and REACH unaffected, matching the regulatory status of the original AS7809ATF-E1.

Q: Why is BA7809CP-E2 listed if it is obsolete?

A: BA7809CP-E2 is included for reference and existing inventory considerations. While it meets electrical and mechanical substitution criteria, its obsolete status means supply may be limited. BA17809CP-E2 is preferred for new designs and long-term production due to active product status.

Q: What is the significance of cropped leads in the TO-220-3 package?

A: Cropped leads reduce lead length while maintaining electrical and thermal performance. Standard TO-220-3 and TO-220CP-3 packages are mechanically and electrically interchangeable on PCBs designed for through-hole mounting. Cropped leads may provide improved mechanical stability in high-vibration environments.