TL494IN Equivalent & Substitute Parts

Part Overview

The TL494IN is a multi-topology DC-DC controller IC manufactured by Texas Instruments, designed for buck, boost, flyback, forward converter, full-bridge, half-bridge, and push-pull regulator applications. It provides positive output step-up, step-down, and step-up/step-down functionality through a transistor driver output configuration. The TL494IN 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 system support.

Substiute Parts

TL494IN

Texas InstrumentsIn Stock: 20433TL494IN Datasheet

Current PartRFQ

TL594INSR

Texas InstrumentsIn Stock: 6523TL594INSR Datasheet

MFR RecommendedRFQ

TL594IN

Texas InstrumentsIn Stock: 7158TL594IN Datasheet

MFR RecommendedRFQ

AZ494AP-E1

Diodes IncorporatedIn Stock: 35472AZ494AP-E1 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the TL494IN are identified based on the following critical parameters that determine functional compatibility:

Primary Compatibility Criteria:

• Voltage supply range (7V ~ 40V)
• Switching frequency range (1kHz ~ 300kHz)
• Output configuration (Positive)
• Number of outputs (2)
• Output type (Transistor Driver)
• Operating temperature range (-40°C ~ 85°C)
• RoHS3 compliance

Substitution Categories:

Category 1: Direct Pin-Compatible Replacement (Same Package) TL594IN maintains identical 16-DIP through-hole packaging and pinout compatibility with the TL494IN. Both devices share the same base product number (TL594) and support identical topologies and output configurations. The TL594IN offers improved duty cycle capability (97% vs. 45%) and active product status.

Category 2: Surface Mount Alternative (Different Package) TL594INSR provides equivalent functionality in 16-SOIC surface mount packaging. This substitute requires PCB redesign but offers the same electrical specifications as TL594IN with active product status and improved duty cycle performance.

Category 3: Alternative Manufacturer (Different Topology Focus) AZ494AP-E1 from Diodes Incorporated operates within the same supply voltage and temperature ranges but is limited to buck topology with fixed 4.95V output. This part is obsolete and suitable only for legacy system maintenance.

Parameter Comparison

Engineering Selection Recommendations

Recommended Primary Substitute: TL594IN

The TL594IN is the optimal direct replacement for the TL494IN. Both devices maintain identical 16-DIP through-hole packaging, pinout compatibility, and support for multi-topology DC-DC converter applications. The TL594IN offers superior duty cycle capability (97% maximum vs. 45% maximum) and maintains active product status, ensuring long-term availability and supply chain stability. All electrical parameters remain within compatible ranges for existing designs. ROHS3 compliance and operating temperature specifications are identical.

Recommended Secondary Substitute: TL594INSR

The TL594INSR provides equivalent electrical functionality to the TL494IN with identical supply voltage, switching frequency, and output configuration specifications. This surface mount alternative (16-SOIC package) is suitable for new designs or PCB redesigns requiring compact form factors. Active product status ensures sustained availability. Implementation requires PCB layout modifications due to package differences.

Not Recommended: AZ494AP-E1

The AZ494AP-E1 from Diodes Incorporated is unsuitable as a general substitute due to obsolete product status and restricted functionality. This part is limited to buck topology with fixed 4.95V output, eliminating support for boost and push-pull converter configurations required by the TL494IN. Use only for legacy system maintenance where original specifications are no longer required.

Frequently Asked Questions (FAQ)

Q: Can TL594IN directly replace TL494IN without PCB modifications?

A: Yes. The TL594IN maintains identical 16-DIP through-hole packaging and pinout with the TL494IN. No PCB layout changes are required. Both devices support the same multi-topology converter applications and output configurations.

Q: What is the primary difference between TL494IN and TL594IN?

A: The TL594IN offers improved maximum duty cycle capability (97% vs. 45%) and maintains active product status. Both devices share identical supply voltage ranges, switching frequency specifications, and output configurations. The TL594IN is the recommended replacement for new production.

Q: Is TL594INSR compatible with existing TL494IN designs?

A: TL594INSR provides equivalent electrical functionality but requires PCB redesign due to different packaging (16-SOIC surface mount vs. 16-DIP through hole). Pin assignments differ between package types. Use only in new designs or when PCB modification is feasible.

Q: Why is AZ494AP-E1 not recommended as a substitute?

A: The AZ494AP-E1 is obsolete and functionally limited to buck topology with fixed 4.95V output. The TL494IN supports multiple topologies (buck, boost, flyback, forward converter, full-bridge, half-bridge, push-pull) with programmable output. Substitution would eliminate design flexibility and converter functionality.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. TL594IN, TL594INSR, and AZ494AP-E1 are all ROHS3 compliant, matching the TL494IN compliance status.

Q: What supply voltage range applies to all substitutes?

A: TL594IN and TL594INSR support 7V ~ 40V supply voltage, identical to TL494IN. AZ494AP-E1 supports 7V ~ 36V, which is slightly more restricted.

Q: Can I use TL594INSR in a through-hole design?

A: No. TL594INSR is a surface mount device (16-SOIC package). For through-hole applications, use TL594IN or TL494IN. Surface mount conversion requires PCB redesign and different assembly processes.