DFLT18A-7 Equivalent & Substitute Parts

Part Overview

The DFLT18A-7 is an 18V Transient Voltage Suppressor (TVS) diode manufactured by Diodes Incorporated, designed for general-purpose transient voltage protection in surface-mount applications. This unidirectional Zener diode features a 29.2V maximum clamping voltage and 7.71A peak pulse current capability in the PowerDI™ 123 package. The part is Active status and ROHS3 compliant. Substitute parts are identified when equivalent electrical performance parameters and surface-mount compatibility are maintained across alternative manufacturers and package styles.

Substiute Parts

DFLT18A-7

Diodes IncorporatedIn Stock: 9506DFLT18A-7 Datasheet

Current PartRFQ

PTVS18VS1UR,115

Nexperia USA Inc.In Stock: 18836PTVS18VS1UR,115 Datasheet

MFR RecommendedRFQ

SMF18A

MDDIn Stock: 20944SMF18A Datasheet

MFR RecommendedRFQ

SMM4F18A-TR

STMicroelectronicsIn Stock: 4246SMM4F18A-TR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the DFLT18A-7 is determined by the following core electrical parameters: Voltage - Reverse Standoff (18V), Voltage - Breakdown (20V minimum), and Voltage - Clamping (29.2V maximum). All identified substitutes maintain these voltage specifications. Surface-mount packaging and ROHS3 compliance are required. Substitute parts may vary in peak pulse current capability, power dissipation, and package form factor while remaining functionally equivalent for general-purpose transient voltage suppression applications. Operating temperature range and automotive qualification are secondary differentiators noted where applicable.

Parameter Comparison

Engineering Selection Recommendations

All substitute parts maintain Active product status and ROHS3 compliance, meeting baseline regulatory requirements. The PTVS18VS1UR,115 from Nexperia carries AEC-Q101 automotive qualification, suitable for applications requiring automotive-grade components. The SMF18A from MDD provides the lowest peak pulse current specification at 6.8A, appropriate for designs with reduced transient energy requirements. The SMM4F18A-TR from STMicroelectronics offers the highest peak pulse current at 59A and extended operating temperature range to 175°C, suitable for high-energy transient suppression or elevated-temperature environments. Package selection depends on PCB layout constraints: PowerDI™ 123, SOD-123W, SOD-123F/SMF, and DO-222AA each present different footprint and thermal characteristics.

Frequently Asked Questions (FAQ)

Q: Can PTVS18VS1UR,115 replace DFLT18A-7 in all applications? A: Yes, for general-purpose transient voltage suppression. PTVS18VS1UR,115 maintains identical voltage specifications (18V standoff, 20V breakdown, 29.2V clamping) and exceeds peak pulse current capability at 13.7A. The SOD-123W package differs from PowerDI™ 123, requiring PCB layout verification. AEC-Q101 qualification provides additional assurance for automotive applications.

Q: What is the difference between SMF18A and DFLT18A-7? A: Both maintain 18V standoff and 29.2V clamping specifications. SMF18A has lower peak pulse current (6.8A vs. 7.71A) and reduced power dissipation (200W vs. 225W). The SMF/SOD-123FL package is smaller than PowerDI™ 123, suitable for space-constrained designs with lower transient energy levels.

Q: Why does SMM4F18A-TR have a higher clamping voltage (39.3V)? A: SMM4F18A-TR uses different internal design parameters while maintaining the same 18V standoff voltage. The higher clamping voltage reflects its capability to handle significantly higher peak pulse currents (59A at 8/20µs pulse width). This part is suitable for high-energy transient suppression applications where the DO-222AA package and extended temperature range (-55°C to 175°C) provide additional design margin.

Q: Are package differences critical for substitution? A: Yes. PowerDI™ 123, SOD-123W, SOD-123F/SMF, and DO-222AA have different footprints, lead spacing, and thermal characteristics. PCB layout and thermal design must accommodate the selected package. Verify land pattern compatibility before component selection.

Q: Do all substitutes meet the same compliance standards? A: All listed substitutes are ROHS3 compliant with MSL 1 (Unlimited) moisture sensitivity. PTVS18VS1UR,115 includes AEC-Q101 automotive qualification. Verify specific compliance requirements for your application before final selection.