TL3845DR Equivalent & Substitute Parts

Part Overview

The TL3845DR is a boost, flyback, and forward converter regulator controller IC manufactured by Texas Instruments in a 14-SOIC package. This device functions as a positive output step-up/step-down DC-DC controller with transistor driver output capability. The part is currently in active production status with 6940 units in stock.

Substitute parts become necessary when the TL3845DR reaches end-of-life status, when alternative sourcing is required for supply chain continuity, or when design requirements necessitate extended operating temperature ranges or enhanced switching frequency capabilities. The TL3845BDR, while functionally equivalent, carries a Last Time Buy status, making it a transitional option. The UC3845BDR2G and UC3845BVDR2G from onsemi provide active production alternatives with enhanced specifications.

Substiute Parts

TL3845DR

Texas InstrumentsIn Stock: 6972TL3845DR Datasheet

Current PartRFQ

TL3845BDR

Texas InstrumentsIn Stock: 3256TL3845BDR Datasheet

Parametric EquivalentRFQ

UC3845BDR2G

onsemiIn Stock: 3550UC3845BDR2G Datasheet

MFR RecommendedRFQ

UC3845BVDR2G

onsemiIn Stock: 3196UC3845BVDR2G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the TL3845DR is determined by strict adherence to the following core parameters:

Critical Matching Parameters:

• Package / Case: 14-SOIC (0.154", 3.90mm Width)
• Voltage - Supply (Vcc/Vdd): 7.6V ~ 30V
• Duty Cycle (Max): 48%
• Output Type: Transistor Driver
• Function: Step-Up, Step-Up/Step-Down
• Output Configuration: Positive
• Topology: Boost, Flyback (minimum requirement)
• Number of Outputs: 1
• Mounting Type: Surface Mount

All substitute parts listed meet these critical parameters. Variations in switching frequency capability, operating temperature range, and product status are noted but do not disqualify substitution when the above parameters align.

Parameter Comparison

Engineering Selection Recommendations

TL3845BDR (Texas Instruments): This part maintains identical electrical and thermal specifications to the TL3845DR with matching 0°C ~ 70°C operating temperature range. However, its Last Time Buy status indicates limited future availability. Selection of this substitute is appropriate only for near-term production requirements where existing design validation and supply chain infrastructure can be leveraged before transition to alternative sources.

UC3845BDR2G (onsemi): This part is in active production status and meets all critical electrical parameters. It provides enhanced switching frequency capability (up to 500kHz versus 100kHz) and isolation-capable output configuration. Operating temperature range remains 0°C ~ 70°C (TA), matching the TL3845DR. This substitute is suitable for applications requiring active production status and higher frequency operation within the specified temperature envelope.

UC3845BVDR2G (onsemi): This part is in active production status and provides the widest operating temperature range (-40°C ~ 105°C TA) among all substitutes. It matches all other critical electrical parameters and offers enhanced switching frequency capability (up to 500kHz). Selection of this substitute is recommended for applications requiring extended temperature operation or long-term supply chain stability with an active production part.

Frequently Asked Questions (FAQ)

Q: Can TL3845BDR be used as a direct replacement for TL3845DR?

A: Yes. The TL3845BDR is electrically and mechanically equivalent to the TL3845DR, with identical supply voltage range (7.6V ~ 30V), duty cycle (48%), switching frequency (100kHz), and operating temperature (0°C ~ 70°C). Both are packaged in 14-SOIC. However, the TL3845BDR carries Last Time Buy status, limiting future availability.

Q: What is the difference between UC3845BDR2G and UC3845BVDR2G?

A: Both parts are manufactured by onsemi and are in active production. The primary difference is operating temperature range: UC3845BDR2G operates from 0°C ~ 70°C (TA), while UC3845BVDR2G operates from -40°C ~ 105°C (TA). All other electrical parameters, including supply voltage, duty cycle, and switching frequency capability, are identical. Selection depends on the thermal requirements of the application.

Q: Are the onsemi UC3845 parts pin-compatible with the Texas Instruments TL3845?

A: Both the UC3845BDR2G and UC3845BVDR2G are packaged in 14-SOIC (0.154", 3.90mm Width), matching the TL3845DR package. Pin compatibility is confirmed by the identical package specification and matching functional topology (Boost, Flyback, Transistor Driver output).

Q: Can I use UC3845BDR2G or UC3845BVDR2G in applications originally designed for TL3845DR?

A: Yes, provided the application does not require forward converter topology. The UC3845 parts support Boost and Flyback topologies but do not list Forward Converter capability. If forward converter operation is required, the TL3845DR or TL3845BDR must be used. All other electrical parameters (supply voltage, duty cycle, output configuration) are compatible.

Q: What is the significance of the higher switching frequency capability in UC3845 parts?

A: The UC3845BDR2G and UC3845BVDR2G support switching frequencies up to 500kHz, compared to 100kHz for the TL3845DR. This enhanced capability allows for smaller passive component sizing in the power stage, potentially reducing board area and cost. However, the 100kHz specification of the TL3845DR remains the baseline requirement; higher frequency operation is optional and depends on circuit design.

Q: Are all listed substitutes RoHS3 compliant?

A: Yes. All parts listed—TL3845DR, TL3845BDR, UC3845BDR2G, and UC3845BVDR2G—are ROHS3 compliant with Moisture Sensitivity Level 1 (Unlimited) and REACH Unaffected status.