TL494CNG Equivalent & Substitute Parts

Part Overview

The TL494CNG is a Buck, Push-Pull Regulator controller IC manufactured by onsemi in the SWITCHMODE™ series. This part operates as a positive output step-down and step-up/step-down DC-DC controller with transistor driver output configuration. The TL494CNG is currently classified as obsolete, making identification of equivalent and substitute parts essential for design continuity and procurement planning. Substitute parts must maintain functional compatibility across critical electrical parameters including supply voltage range, switching frequency, duty cycle, and output topology support.

Substiute Parts

TL494CNG

onsemiIn Stock: 4168TL494CNG Datasheet

Current PartRFQ

TL494CDR2G

onsemiIn Stock: 17458TL494CDR2G Datasheet

DirectRFQ

AZ494AP-E1

Diodes IncorporatedIn Stock: 35472AZ494AP-E1 Datasheet

SimilarRFQ

TL494CN

onsemiIn Stock: 139122TL494CN Datasheet

SimilarRFQ

TL494IN

onsemiIn Stock: 20445TL494IN Datasheet

SimilarRFQ

TL594CN

onsemiIn Stock: 9496TL594CN Datasheet

SimilarRFQ

TL594IN

Texas InstrumentsIn Stock: 7158TL594IN Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the TL494CNG are classified into two categories based on electrical and mechanical compatibility:

Direct Substitutes (Package Variant): Parts that maintain identical electrical specifications and base product lineage but differ in packaging format. The TL494CDR2G qualifies as a direct substitute, offering the same functional performance in a surface-mount 16-SOIC package instead of through-hole DIP.

Functional Equivalents (Same Topology Family): Parts that share the same core topology (Buck, Push-Pull), output configuration (Positive), control features (Dead Time Control, Frequency Control), and supply voltage range (7V ~ 40V), but may differ in switching frequency, duty cycle maximum, temperature range, or RoHS compliance status. These include TL494CN, TL494IN, TL594CN, and TL594IN from onsemi, as well as TL594IN from Texas Instruments.

Cross-Manufacturer Alternatives (Similar Function): The AZ494AP-E1 from Diodes Incorporated provides buck topology functionality but with fixed output voltage (4.95V), reduced output current (200mA), and lower switching frequency (40kHz), making it suitable only for specific fixed-output applications.

Substitution eligibility is determined by matching: supply voltage range, topology support, output configuration, control features, and package compatibility with the target application.

Parameter Comparison

Engineering Selection Recommendations

For Direct Package Substitution (Surface Mount Requirement): The TL494CDR2G is the optimal choice when surface-mount packaging is required. It maintains identical electrical specifications to the TL494CNG while offering active product status and ROHS3 compliance. This part is suitable for new designs or board revisions requiring SMD assembly.

For Through-Hole Designs (Pin-Compatible Replacement): The TL494IN provides through-hole 16-DIP compatibility with extended operating temperature range (-40°C ~ 85°C) compared to the TL494CNG (0°C ~ 70°C). Both parts share identical electrical specifications. However, TL494IN carries obsolete product status.

For Active Product Status with Extended Functionality: The TL594IN from Texas Instruments is the only active product among through-hole options. It supports expanded topology options (Boost, Flyback, Forward Converter, Full-Bridge, Half-Bridge in addition to Buck and Push-Pull) and offers programmable switching frequency (1kHz ~ 300kHz) with 97% maximum duty cycle. This part provides greater design flexibility and long-term availability assurance. Note that synchronous rectifier support is not available in this variant.

For Fixed-Output Applications Only: The AZ494AP-E1 from Diodes Incorporated is limited to fixed 4.95V output applications with 200mA output current and 40kHz switching frequency. This part is not suitable for general-purpose buck or push-pull controller applications requiring programmable output voltage or higher current capability.

Compliance Considerations: For applications requiring RoHS3 compliance, select TL494CDR2G, TL594IN, or AZ494AP-E1. The TL494CN and TL594CN from onsemi are RoHS non-compliant.

Frequently Asked Questions (FAQ)

Q: Can TL494CDR2G replace TL494CNG in existing through-hole PCB designs? A: No. TL494CDR2G uses 16-SOIC surface-mount packaging while TL494CNG uses 16-DIP through-hole packaging. PCB layout and footprint modifications are required. For through-hole designs, use TL494CN or TL494IN instead.

Q: What is the primary difference between TL494 and TL594 series controllers? A: The TL594 series supports expanded topology options including Boost, Flyback, Forward Converter, Full-Bridge, and Half-Bridge configurations, while TL494 is limited to Buck and Push-Pull topologies. TL594 also offers higher maximum duty cycle (96-97% vs 48%) and wider switching frequency range (1kHz-300kHz vs fixed 200kHz or 300kHz).

Q: Is TL594IN a direct replacement for TL494CNG? A: TL594IN is functionally compatible for Buck and Push-Pull applications but not a direct replacement. Key differences include: TL594IN lacks synchronous rectifier support, offers wider topology support, provides programmable switching frequency, and is manufactured by Texas Instruments (active status) rather than onsemi. Pin compatibility must be verified for the specific application circuit.

Q: Why is TL494CNG obsolete and what are my options? A: TL494CNG is obsolete due to product lifecycle discontinuation by onsemi. For new designs, use TL594IN (active status, extended functionality). For existing designs requiring the same specifications, TL494IN provides compatibility with extended temperature range. For surface-mount designs, TL494CDR2G offers active status and RoHS3 compliance.

Q: Can AZ494AP-E1 replace TL494CNG? A: No. AZ494AP-E1 is a fixed-output buck regulator (4.95V, 200mA) designed for specific applications. TL494CNG is a programmable controller supporting multiple topologies and output configurations. AZ494AP-E1 is not suitable as a general-purpose replacement.

Q: What temperature range should I specify for new designs? A: For new designs, TL594IN supports -40°C ~ 85°C operating range, providing broader environmental coverage than TL494CNG (-0°C ~ 70°C). This extended range is beneficial for industrial and automotive applications.

Q: Are there any pin-compatibility concerns between substitute parts? A: All through-hole 16-DIP variants (TL494CNG, TL494CN, TL494IN, TL594CN, TL594IN, AZ494AP-E1) share identical 16-pin DIP footprints. However, internal circuit topology and control pin functions may differ. Verify application circuit compatibility before substitution, particularly for TL594 series and AZ494AP-E1 which have different functional capabilities.