TL3843BD Equivalent & Substitute Parts

Part Overview

The TL3843BD is a Boost, Flyback, Forward Regulator DC-DC Controller IC manufactured by Texas Instruments in 14-SOIC surface mount packaging. This part operates as a positive output step-up/step-down controller with transistor driver output, designed for multi-topology power management applications. The TL3843BD is currently in Last Time Buy status, indicating end-of-life production. Identifying equivalent and substitute parts is necessary to ensure design continuity and maintain supply chain reliability for new production runs and long-term product support.

Substiute Parts

TL3843BD

Texas InstrumentsIn Stock: 1523TL3843BD Datasheet

Current PartRFQ

TL3843BDR

Texas InstrumentsIn Stock: 18257TL3843BDR Datasheet

MFR RecommendedRFQ

NCV3843BVDR2G

onsemiIn Stock: 15779NCV3843BVDR2G Datasheet

MFR RecommendedRFQ

UC3843BDG

onsemiIn Stock: 3137UC3843BDG Datasheet

MFR RecommendedRFQ

UC3843BDR2G

onsemiIn Stock: 3564UC3843BDR2G Datasheet

MFR RecommendedRFQ

UC3843BVDR2G

onsemiIn Stock: 2487UC3843BVDR2G Datasheet

MFR RecommendedRFQ

TL3843D

Texas InstrumentsIn Stock: 1706TL3843D Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the TL3843BD is determined by strict equivalence across the following critical parameters:

• Package / Case: 14-SOIC (0.154", 3.90mm Width) — mechanical and electrical pin compatibility
• Output Type: Transistor Driver — functional output stage requirement
• Voltage - Supply (Vcc/Vdd): 7.6V ~ 30V — input voltage range compatibility
• Frequency - Switching: Up to 500kHz — maximum switching frequency capability
• Duty Cycle (Max): 96% or higher — maximum duty cycle support
• Operating Temperature: 0°C ~ 70°C minimum range — thermal operating envelope
• RoHS Status: ROHS3 Compliant — regulatory compliance requirement
• Mounting Type: Surface Mount — assembly process compatibility

Substitute parts are grouped into two categories: MFR Recommended substitutes (direct replacements with active product status) and Parametric Equivalents (functionally equivalent parts with minor parameter variations).

Parameter Comparison

Engineering Selection Recommendations

For new production designs, TL3843BDR is the primary recommended substitute. This part maintains Texas Instruments manufacturing continuity, carries Active product status ensuring long-term availability, and is electrically and mechanically identical to the TL3843BD across all critical parameters. The TL3843BDR is available in Cut Tape and Digi-Reel packaging, providing supply chain flexibility.

UC3843BDR2G and UC3843BVDR2G are secondary alternatives from onsemi with Active product status. Both parts meet all electrical and mechanical requirements. UC3843BVDR2G offers extended operating temperature range (-40°C ~ 105°C) compared to the original specification, providing thermal margin for demanding applications. UC3843BDG is marked Obsolete and should be avoided for new designs despite meeting parametric requirements.

NCV3843BVDR2G is an automotive-qualified alternative (AEC-Q100) with extended temperature range (-40°C ~ 125°C) and Active status. This part is suitable for applications requiring automotive-grade reliability and thermal performance beyond standard industrial specifications.

TL3843D is a parametric equivalent from Texas Instruments with marginally higher maximum duty cycle (97% vs 96%) and Last Time Buy status. This part should be considered only when TL3843BDR availability is constrained.

Frequently Asked Questions (FAQ)

Q: Can I use UC3843BDR2G as a direct replacement for TL3843BD?

A: Yes. UC3843BDR2G meets all critical electrical and mechanical parameters: 14-SOIC package, 7.6V ~ 30V supply voltage, up to 500kHz switching frequency, 96% maximum duty cycle, and transistor driver output. Pin-to-pin compatibility is maintained. The part carries Active product status from onsemi.

Q: What is the difference between TL3843BDR and UC3843BVDR2G?

A: Both parts are electrically equivalent across switching frequency, duty cycle, supply voltage, and output configuration. The primary differences are manufacturer (Texas Instruments vs onsemi) and operating temperature range. UC3843BVDR2G supports -40°C ~ 105°C versus TL3843BDR's 0°C ~ 70°C, providing extended thermal capability. UC3843BVDR2G is available in Cut Tape & Digi-Reel packaging.

Q: Why is UC3843BDG listed as Obsolete?

A: UC3843BDG is marked Obsolete by onsemi, indicating discontinued production and no guaranteed future availability. Although it meets all parametric requirements, new designs should specify active alternatives such as UC3843BDR2G or TL3843BDR to ensure supply chain continuity.

Q: Is NCV3843BVDR2G suitable for automotive applications?

A: Yes. NCV3843BVDR2G carries AEC-Q100 automotive qualification and is graded for automotive use. It meets all electrical and mechanical requirements of the TL3843BD and provides extended operating temperature range (-40°C ~ 125°C). This part is appropriate for automotive power management designs.

Q: What packaging options are available for substitute parts?

A: TL3843BDR is available in Cut Tape (CT) and Digi-Reel packaging. UC3843BDR2G is supplied in Tape & Reel (TR). UC3843BVDR2G is available in Cut Tape & Digi-Reel. NCV3843BVDR2G is supplied in Cut Tape. All parts maintain the 14-SOIC package form factor required for mechanical compatibility.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All listed substitute parts carry ROHS3 Compliant status, meeting regulatory requirements for hazardous substance restrictions. Moisture Sensitivity Level (MSL) is 1 (Unlimited) across all parts, indicating no moisture sensitivity constraints during storage and handling.