TL2843D Equivalent & Substitute Parts

Part Overview

The TL2843D is a boost, flyback, and forward regulator controller IC manufactured by Texas Instruments, designed for positive output step-up and step-up/step-down DC-DC conversion applications. This device operates as a transistor driver with frequency control capabilities across a 7.6V to 30V supply voltage range. The TL2843D is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity. Active alternatives with identical or compatible electrical and mechanical specifications are available to ensure uninterrupted component sourcing.

Substiute Parts

TL2843D

Texas InstrumentsIn Stock: 3039TL2843D Datasheet

Current PartRFQ

TL2843DR

Texas InstrumentsIn Stock: 6320TL2843DR Datasheet

MFR RecommendedRFQ

UC2843BDG

onsemiIn Stock: 3434UC2843BDG Datasheet

MFR RecommendedRFQ

UC2843BDR2G

onsemiIn Stock: 4015UC2843BDR2G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the TL2843D is determined by strict alignment of electrical and mechanical parameters. The following criteria establish valid equivalency:

Primary Substitution Criteria:

• Identical package type: 14-SOIC (0.154", 3.90mm Width)
• Matching supply voltage range: 7.6V ~ 30V
• Equivalent switching frequency capability: Up to 500kHz
• Same output configuration: Positive
• Identical control features: Frequency Control
• Compatible topologies: Boost, Flyback, Forward (or subset thereof)
• Matching duty cycle specifications: 97% or higher
• Same output type: Transistor Driver
• Identical number of outputs and phases: 1 output, 1 phase

Secondary Compatibility Factors:

• RoHS3 compliance maintained
• MSL rating of 1 (Unlimited)
• Surface mount mounting type

The TL2843DR (Texas Instruments, active status) is a direct equivalent with identical electrical specifications and packaging. The UC2843BDG and UC2843BDR2G (onsemi) are functionally compatible alternatives with minor topology variations (Boost, Flyback only versus Boost, Flyback, Forward) and slightly reduced duty cycle maximum (96% versus 97%), but maintain all critical electrical parameters and package compatibility.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: TL2843DR

The TL2843DR is the preferred substitute for the obsolete TL2843D. This part maintains identical electrical specifications, including the full 97% maximum duty cycle, complete topology support (Boost, Flyback, Forward), and extended operating temperature range (-40°C to 85°C). Both devices are manufactured by Texas Instruments and carry ROHS3 compliance. The TL2843DR is currently in active production status, ensuring long-term availability. The only difference is packaging format: TL2843DR is supplied in Tape & Reel (TR) configuration, which is standard for production environments.

Secondary Alternatives: UC2843BDG and UC2843BDR2G

The onsemi UC2843BDG and UC2843BDR2G are functionally compatible alternatives when forward topology support is not required. These parts maintain identical supply voltage range, switching frequency capability, and package dimensions. The UC2843BDR2G is the active production variant with Tape & Reel packaging. Key differences include:

• Reduced maximum duty cycle: 96% versus 97%
• Limited topology support: Boost and Flyback only (Forward topology not supported)
• Narrower operating temperature range: -25°C to 85°C (versus -40°C to 85°C)
• Enhanced output configuration: Isolation Capable designation

These alternatives are suitable for boost and flyback converter designs within the specified temperature range. All substitute parts maintain ROHS3 compliance and MSL rating of 1.

Frequently Asked Questions (FAQ)

Q: Can TL2843DR be used as a direct replacement for TL2843D?

A: Yes. The TL2843DR is a direct equivalent with identical electrical and mechanical specifications. The only difference is packaging format (Tape & Reel versus bulk). Both parts support the same topologies, voltage ranges, switching frequencies, and duty cycle specifications.

Q: What are the key differences between TL2843DR and UC2843BDR2G?

A: The primary differences are: (1) TL2843DR supports Forward topology in addition to Boost and Flyback; UC2843BDR2G supports only Boost and Flyback. (2) TL2843DR has a 97% maximum duty cycle; UC2843BDR2G has 96%. (3) TL2843DR operates from -40°C to 85°C; UC2843BDR2G operates from -25°C to 85°C. Both maintain identical supply voltage range (7.6V ~ 30V), switching frequency (up to 500kHz), and 14-SOIC package dimensions.

Q: Are the UC2843BDG and UC2843BDR2G interchangeable?

A: These parts are electrically identical. The difference is packaging format: UC2843BDG is supplied in bulk; UC2843BDR2G is supplied in Tape & Reel (TR). UC2843BDR2G is the active production variant and is recommended for new designs.

Q: Can I use UC2843BDR2G in a forward converter application?

A: No. The UC2843BDR2G supports only Boost and Flyback topologies. Forward converter designs require the TL2843D, TL2843DR, or equivalent parts that explicitly support Forward topology.

Q: What is the significance of the "Isolation Capable" designation on onsemi parts?

A: The UC2843BDG and UC2843BDR2G are rated for isolation-capable output configurations, meaning they can be used in isolated converter topologies. This is an additional capability that does not restrict their use in non-isolated applications.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. The TL2843D, TL2843DR, UC2843BDG, and UC2843BDR2G are all ROHS3 compliant with MSL rating of 1 (Unlimited moisture sensitivity level).

Q: Which substitute part should I select for a new production design?

A: For new designs, select TL2843DR if Forward topology support is required, or UC2843BDR2G if only Boost and Flyback topologies are needed. Both are active production parts with Tape & Reel packaging suitable for automated assembly. Verify that the operating temperature range (-40°C to 85°C for TL2843DR; -25°C to 85°C for UC2843BDR2G) meets your application requirements.