TL494IN Equivalent & Substitute Parts

Part Overview

The TL494IN is a Buck, Push-Pull Regulator controller IC manufactured by onsemi, designed for positive output step-down and step-up/step-down DC-DC conversion applications. This 16-PDIP package device operates with a supply voltage range of 7V to 40V and features a 200kHz switching frequency with 48% maximum duty cycle. The product is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and component sourcing in legacy systems and new designs requiring compatible functionality.

Substiute Parts

TL494IN

onsemiIn Stock: 20445TL494IN Datasheet

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AZ494AP-E1

Diodes IncorporatedIn Stock: 35472AZ494AP-E1 Datasheet

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TL494CN

onsemiIn Stock: 139122TL494CN Datasheet

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TL494IN

onsemiIn Stock: 20445TL494IN Datasheet

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TL594CN

onsemiIn Stock: 9496TL594CN Datasheet

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TL594IN

Texas InstrumentsIn Stock: 7158TL594IN Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the TL494IN are determined by compatibility across the following critical parameters:

Package Compatibility: All substitute parts must use the 16-DIP (0.300", 7.62mm) through-hole package to ensure direct PCB footprint compatibility.

Electrical Functionality: Substitute parts must support step-down and/or step-up/step-down topologies with transistor driver output configuration and dual outputs (2 outputs).

Supply Voltage Range: All substitutes must operate within or encompass the 7V to 40V supply voltage specification.

Operating Temperature Range: Substitutes must support the -40°C to 85°C operating temperature range or a subset thereof.

Control Features: Dead time control and frequency control capabilities are required for functional equivalence.

The substitute parts are grouped into two categories based on these parameters:

Category A - Direct Functional Equivalents (onsemi SWITCHMODE™ Series): TL494CN and TL494IN maintain identical electrical specifications to the main part, differing only in operating temperature range (TL494CN: 0°C ~ 70°C) or packaging designation.

Category B - Extended Topology Equivalents: TL594CN and TL594IN provide enhanced functionality with higher switching frequency capability (300kHz and 1kHz ~ 300kHz respectively) and higher maximum duty cycle (96% and 97% respectively), supporting additional topologies including boost, flyback, forward converter, full-bridge, and half-bridge configurations.

Category C - Fixed Output Alternative: AZ494AP-E1 (Diodes Incorporated) provides buck topology only with fixed 4.95V output and lower current rating (200mA), suitable for applications requiring fixed voltage regulation in the specified output range.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement in Existing Designs: TL494CN provides identical electrical specifications to TL494IN with the same 200kHz switching frequency and 48% duty cycle. Selection between these two onsemi parts depends on operating temperature requirements: TL494CN operates 0°C ~ 70°C, while TL494IN operates -40°C ~ 85°C. Both are obsolete products.

For Extended Topology Support: TL594CN and TL594IN offer enhanced functionality with support for additional converter topologies (boost, flyback, forward converter, full-bridge, half-bridge) beyond the buck and push-pull configurations of the TL494IN. TL594CN maintains the onsemi SWITCHMODE™ series with 300kHz switching frequency and 96% maximum duty cycle. TL594IN, manufactured by Texas Instruments, is the only active product in this group and provides the widest switching frequency range (1kHz ~ 300kHz) with 97% maximum duty cycle and ROHS3 compliance.

For Fixed Voltage Applications: AZ494AP-E1 (Diodes Incorporated) is suitable only for applications requiring fixed 4.95V output regulation with 200mA current capacity. This part operates at 40kHz switching frequency and provides ROHS3 compliance. This option is not recommended for designs requiring programmable or variable output voltage.

Compliance Considerations: TL594IN and AZ494AP-E1 are ROHS3 compliant, while TL494IN, TL494CN, and TL594CN are RoHS non-compliant. For new designs subject to RoHS requirements, TL594IN is the recommended choice.

Frequently Asked Questions (FAQ)

Q: Can TL494CN be used as a direct replacement for TL494IN?

A: TL494CN is electrically equivalent to TL494IN with identical switching frequency (200kHz), duty cycle (48%), supply voltage range (7V ~ 40V), and topology support. The primary difference is operating temperature range: TL494CN operates 0°C ~ 70°C while TL494IN operates -40°C ~ 85°C. Direct substitution is possible if the application operates within the TL494CN temperature range.

Q: What is the advantage of using TL594IN over TL494IN?

A: TL594IN provides extended topology support including boost, flyback, forward converter, full-bridge, and half-bridge configurations, compared to TL494IN's buck and push-pull topologies. TL594IN also offers wider switching frequency range (1kHz ~ 300kHz versus 200kHz fixed), higher maximum duty cycle (97% versus 48%), and is the only active product in this group with ROHS3 compliance.

Q: Is AZ494AP-E1 suitable for all TL494IN applications?

A: No. AZ494AP-E1 is a fixed-output buck regulator with 4.95V output and 200mA current capacity, designed for specific fixed-voltage applications. It does not support the step-up/step-down or push-pull topologies of TL494IN and is not suitable for designs requiring programmable output voltage or higher current delivery.

Q: Are all substitute parts available in the same 16-DIP package?

A: Yes. All substitute parts listed (TL494CN, TL594CN, TL594IN, AZ494AP-E1) use the 16-DIP (0.300", 7.62mm) through-hole package, ensuring PCB footprint compatibility with TL494IN.

Q: Which substitute part is recommended for new designs?

A: TL594IN is recommended for new designs. It is the only active product in this group, provides ROHS3 compliance, supports the widest range of topologies and switching frequencies, and maintains compatibility with the 16-DIP package and -40°C ~ 85°C operating temperature range of the original TL494IN.