AP1509-12SG-13 Equivalent & Substitute Parts

Part Overview

The AP1509-12SG-13 is a buck switching regulator IC manufactured by Diodes Incorporated, designed to deliver a fixed 12V output at 2A from an input voltage range of 4.5V to 22V. This component operates at a switching frequency of 150kHz and is packaged in an 8-SOIC surface mount configuration.

The AP1509-12SG-13 is classified as obsolete. Identifying equivalent and substitute parts is necessary to maintain design continuity, ensure supply chain reliability, and support ongoing production or maintenance requirements for systems utilizing this regulator.

Substiute Parts

AP1509-12SG-13

Diodes IncorporatedIn Stock: 750AP1509-12SG-13 Datasheet

Current PartRFQ

LM2599SX-12/NOPB

Texas InstrumentsIn Stock: 3501LM2599SX-12/NOPB Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AP1509-12SG-13 is determined by the following critical parameters:

• Fixed output voltage of 12V
• Positive output configuration
• Buck topology (step-down regulation)
• Single output
• Switching frequency of 150kHz
• Surface mount packaging
• RoHS3 compliance

The LM2599SX-12/NOPB qualifies as a substitute based on matching these core electrical and functional specifications. Both devices deliver 12V fixed output, employ buck topology, operate at 150kHz switching frequency, and maintain RoHS3 compliance. The substitute part is actively manufactured and available in production quantities, addressing the obsolescence of the original part.

Parameter Comparison

Engineering Selection Recommendations

The LM2599SX-12/NOPB is an active substitute for the obsolete AP1509-12SG-13. Both devices share identical output voltage (12V), switching frequency (150kHz), and buck topology. The substitute part offers enhanced specifications including higher maximum input voltage (40V vs. 22V), increased output current capability (3A vs. 2A), and extended operating temperature range (-40°C to 125°C vs. -20°C to 85°C).

Both parts maintain ROHS3 compliance and identical MSL ratings, ensuring compatibility with current manufacturing and environmental standards. The LM2599SX-12/NOPB is currently in active production with substantial inventory availability, providing supply chain continuity for applications previously using the AP1509-12SG-13.

Package differences exist between the two devices. The original part uses 8-SOIC packaging, while the substitute employs TO-263-8 (D2PAK) packaging. PCB layout modifications are required to accommodate the different package footprint and pin configuration.

Frequently Asked Questions (FAQ)

Q: Can the LM2599SX-12/NOPB directly replace the AP1509-12SG-13 without PCB modifications?

A: No. While both devices are functionally equivalent buck regulators with 12V fixed output, they use different package types. The AP1509-12SG-13 uses 8-SOIC packaging, and the LM2599SX-12/NOPB uses TO-263-8 (D2PAK) packaging. PCB layout redesign is required to accommodate the different footprint and pin arrangement.

Q: What are the key electrical parameters that determine substitution compatibility?

A: The critical parameters are fixed output voltage (12V), buck topology, switching frequency (150kHz), positive output configuration, and single output. Both the original and substitute parts match these specifications, making them functionally equivalent for applications within their respective current and voltage ratings.

Q: Does the higher output current rating of the LM2599SX-12/NOPB (3A vs. 2A) affect compatibility?

A: The higher current rating of the substitute part does not negatively impact compatibility. Applications designed for 2A operation will function correctly with a 3A-rated device. The substitute part provides additional headroom for current delivery without affecting voltage regulation or switching characteristics.

Q: Are there thermal or operating temperature considerations when switching to the LM2599SX-12/NOPB?

A: The LM2599SX-12/NOPB operates across a wider temperature range (-40°C to 125°C) compared to the AP1509-12SG-13 (-20°C to 85°C). This extended range provides greater flexibility for applications in extreme environments. Both parts maintain identical MSL ratings and RoHS compliance.

Q: What is the impact of the different maximum input voltage specifications?

A: The LM2599SX-12/NOPB accepts input voltages up to 40V, while the AP1509-12SG-13 is limited to 22V. For applications operating within the original 4.5V to 22V input range, this difference is not a constraint. The substitute part provides additional input voltage margin for designs requiring higher input voltage tolerance.