TL594CNG Equivalent & Substitute Parts

Part Overview

The TL594CNG is a Buck, Push-Pull Regulator controller IC manufactured by onsemi in the SWITCHMODE™ series. This 16-PDIP through-hole component provides positive output step-down and step-up/step-down DC-DC control functionality with transistor driver output configuration. The part is currently obsolete, making equivalent and substitute parts necessary for ongoing system support and new designs requiring similar control topology and electrical performance.

Substiute Parts

TL594CNG

onsemiIn Stock: 969TL594CNG Datasheet

Current PartRFQ

TL594CDR2G

onsemiIn Stock: 17615TL594CDR2G Datasheet

DirectRFQ

AZ494AP-E1

Diodes IncorporatedIn Stock: 35472AZ494AP-E1 Datasheet

SimilarRFQ

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

Substitution for the TL594CNG is determined by strict alignment of the following critical parameters:

• Function: Step-Down, Step-Up/Step-Down capability
• Topology: Buck, Push-Pull configuration
• Output Type: Transistor Driver
• Output Configuration: Positive
• Number of Outputs: 2
• Voltage - Supply (Vcc/Vdd): 7V ~ 40V range
• Frequency - Switching: 300kHz nominal
• Duty Cycle (Max): 96% or higher
• Synchronous Rectifier: Yes
• Control Features: Dead Time Control, Frequency Control
• Operating Temperature: -40°C ~ 85°C (TA)
• Package / Case: 16-DIP (0.300", 7.62mm) for through-hole mounting

Substitute parts are grouped into two categories:

Direct Equivalent (Package Variant): TL594CDR2G maintains identical electrical specifications but uses surface-mount 16-SOIC packaging instead of through-hole 16-DIP.

Functional Equivalents (Same Base Product, Different Temperature/Status): TL594CN and TL594IN share the same base product number (TL594) with identical electrical parameters and 16-DIP through-hole packaging, differing only in product status and temperature rating specifications.

Similar Topology Alternative: TL494CN and TL494IN provide Buck, Push-Pull topology with identical supply voltage and control features but operate at 200kHz switching frequency with 48% maximum duty cycle, representing a lower-performance variant of the same product family.

Cross-Manufacturer Alternative: AZ494AP-E1 (Diodes Incorporated) provides Buck topology in 16-DIP packaging but with fixed 4.95V output and 200mA current limitation, suitable only for specific fixed-output applications.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Through-Hole Mounting Required)

TL594CN and TL594IN are the primary through-hole substitutes, maintaining identical electrical specifications (300kHz switching frequency, 96% duty cycle, Buck/Push-Pull topology) and 16-DIP packaging. TL594IN is preferred due to active product status and ROHS3 compliance, providing long-term availability and regulatory alignment. TL594CN remains available but carries obsolete status and RoHS non-compliance.

For Surface-Mount Applications

TL594CDR2G provides identical electrical performance in 16-SOIC surface-mount packaging with active product status and ROHS3 compliance. This option is suitable for new designs or PCB redesigns accommodating surface-mount technology.

For Extended Temperature Range Applications

TL594IN (Texas Instruments) offers the widest switching frequency range (1kHz ~ 300kHz) and highest duty cycle (97%), with active product status and ROHS3 compliance. This part provides superior flexibility for applications requiring frequency adjustment beyond the fixed 300kHz specification.

For Cost-Optimized Fixed-Output Applications Only

AZ494AP-E1 (Diodes Incorporated) is limited to fixed 4.95V output with 200mA current capability. This part is suitable only for specific legacy systems designed around these fixed parameters and should not be considered for programmable or variable-output applications.

For Lower-Performance Legacy Systems

TL494CN and TL494IN operate at 200kHz with 48% maximum duty cycle, representing a lower-specification variant. These parts are suitable only for systems originally designed around these reduced performance parameters and should not be used as general replacements for the TL594CNG.

Frequently Asked Questions (FAQ)

Q: Can TL594CDR2G replace TL594CNG in existing through-hole PCB designs?

A: No. TL594CDR2G uses 16-SOIC surface-mount packaging while TL594CNG requires 16-DIP through-hole mounting. PCB redesign is necessary. For through-hole compatibility, use TL594CN or TL594IN.

Q: What is the primary difference between TL594CN and TL594IN?

A: Both maintain identical electrical specifications and 16-DIP through-hole packaging. TL594IN (Texas Instruments) has active product status and ROHS3 compliance, while TL594CN (onsemi) is obsolete and RoHS non-compliant. TL594IN is recommended for new designs and long-term availability.

Q: Why is TL494CN not recommended as a direct replacement?

A: TL494CN operates at 200kHz switching frequency with 48% maximum duty cycle, compared to TL594CNG's 300kHz and 96% specifications. This represents reduced performance and is suitable only for systems originally designed around these lower parameters.

Q: Can AZ494AP-E1 replace TL594CNG?

A: No. AZ494AP-E1 is a fixed-output (4.95V) buck regulator with 200mA current limit, fundamentally different from TL594CNG's programmable controller topology. Use only for legacy systems specifically designed around these fixed parameters.

Q: What compliance considerations apply to substitute selection?

A: TL594IN and TL594CDR2G are ROHS3 compliant with active product status, providing regulatory alignment and long-term availability. TL594CN, TL494CN, and TL494IN are RoHS non-compliant and obsolete, suitable only for legacy system maintenance.

Q: Does TL594IN's wider frequency range (1kHz ~ 300kHz) affect compatibility?

A: No. TL594IN's extended frequency range provides additional design flexibility while maintaining full compatibility with applications designed for fixed 300kHz operation. The wider range does not introduce incompatibility.

Q: Are there pin-to-pin compatibility differences between through-hole substitutes?

A: TL594CN, TL594IN, TL494CN, and TL494IN all use 16-DIP (0.300", 7.62mm) through-hole packaging with identical pinout. Direct socket replacement is possible without PCB modification.