SN5476J Equivalent & Substitute Parts

Part Overview

The SN5476J is a dual J-K flip-flop logic integrated circuit manufactured by Texas Instruments, featuring preset and reset functionality. This device is classified as a 2-element JK-type flip-flop with complementary outputs, designed for positive edge-triggered applications. The component is housed in a 16-CDIP package and operates across a supply voltage range of 4.5V to 5.5V with a maximum clock frequency of 20 MHz. The SN5476J maintains active product status with 1488 units currently in stock. Equivalent and substitute parts are identified to address inventory availability, performance requirements, or application-specific electrical characteristics that may necessitate component alternatives.

Substiute Parts

SN5476J

Texas InstrumentsIn Stock: 1566SN5476J Datasheet

Current PartRFQ

SN74HC109N

Texas InstrumentsIn Stock: 5016SN74HC109N Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the SN5476J is determined by strict adherence to the following electrical and mechanical parameters:

Core Substitution Criteria:

The substitute part must maintain identical functional classification as a dual J-K flip-flop with 2 elements, 1 bit per element, and complementary output configuration. The trigger type must remain positive edge-triggered. Both preset and reset functionality must be preserved.

Electrical Compatibility Parameters:

Substitute parts must operate within overlapping supply voltage ranges. The SN5476J operates at 4.5V to 5.5V; substitute parts must support this voltage window or a compatible superset range. Clock frequency of the substitute must equal or exceed 20 MHz to ensure timing compatibility. Propagation delay specifications must not exceed the application requirements established by the main part's 40 ns maximum delay at specified conditions.

Output Drive Capability:

Current output specifications (16 mA for SN5476J) establish the minimum load-driving capability required. Substitute parts must provide equivalent or superior output current capacity to maintain circuit functionality.

Quiescent Current Consideration:

The SN5476J draws 20 mA quiescent current. Substitute parts with lower quiescent current may be selected for power-sensitive applications without functional degradation.

Package and Mounting:

The 16-CDIP through-hole package establishes the physical form factor. Substitute parts in equivalent DIP packages with identical pin count and spacing are mechanically compatible.

Compliance and Status:

All substitute parts must maintain active product status and ROHS3 compliance to ensure long-term availability and regulatory conformance.

Parameter Comparison

Engineering Selection Recommendations

SN74HC109N as Substitute for SN5476J:

The SN74HC109N qualifies as a functional substitute based on matching core logic architecture: both devices are dual J-K flip-flops with 2 elements, 1 bit per element, complementary outputs, and positive edge triggering. Both maintain active product status and ROHS3 compliance, ensuring regulatory conformance and long-term component availability.

Electrical Compatibility:

The SN74HC109N operates across a 2V to 6V supply range, which encompasses the SN5476J operating window of 4.5V to 5.5V. At the 5V nominal operating point common to both devices, the SN74HC109N delivers superior performance: 60 MHz clock frequency versus 20 MHz, and 30 ns maximum propagation delay versus 40 ns. These characteristics ensure the substitute meets or exceeds timing requirements of applications designed for the SN5476J.

Output Drive Consideration:

The SN74HC109N provides 5.2 mA output current per line, compared to 16 mA for the SN5476J. Applications requiring the full 16 mA output drive capability must evaluate load impedance and circuit requirements before substitution. Lower-impedance loads may necessitate external buffering or retention of the original SN5476J.

Power Consumption Advantage:

The SN74HC109N draws 4 µA quiescent current versus 20 mA for the SN5476J, representing a 5000-fold reduction in standby power consumption. This characteristic makes the SN74HC109N suitable for battery-powered or power-constrained applications.

Temperature Range Limitation:

The SN74HC109N operates from -40°C to 85°C, compared to the SN5476J range of -55°C to 125°C. Applications requiring operation below -40°C or above 85°C must retain the SN5476J.

Package Compatibility:

Both devices use 16-pin DIP packages with 0.300" (7.62mm) spacing, ensuring mechanical and pin-compatible installation in through-hole PCB designs.

Frequently Asked Questions (FAQ)

Q: Can the SN74HC109N directly replace the SN5476J in all applications?

A: Direct substitution is possible when application requirements fall within the SN74HC109N specifications. The substitute meets functional requirements (dual J-K flip-flop, complementary outputs, positive edge trigger) and electrical requirements (5V operation, timing performance). However, three conditions require evaluation: (1) output current requirements—if the circuit demands the full 16 mA drive capability, the SN74HC109N's 5.2 mA output may be insufficient; (2) operating temperature range—if operation below -40°C or above 85°C is required, the SN5476J must be retained; (3) quiescent current—if the application is power-sensitive, the SN74HC109N's 4 µA standby current provides significant advantage over the SN5476J's 20 mA.

Q: What are the key electrical differences between these parts?

A: The SN74HC109N provides superior clock frequency (60 MHz versus 20 MHz) and faster propagation delay (30 ns versus 40 ns), making it suitable for higher-speed applications. The SN74HC109N operates across a wider supply voltage range (2V to 6V versus 4.5V to 5.5V). The SN74HC109N consumes significantly less quiescent current (4 µA versus 20 mA). The SN5476J provides higher output drive current (16 mA versus 5.2 mA) and operates across a wider temperature range (-55°C to 125°C versus -40°C to 85°C).

Q: Are the packages physically compatible?

A: Yes. Both the SN5476J (16-CDIP) and SN74HC109N (16-DIP) use 16-pin dual inline packages with 0.300" (7.62mm) pin spacing. The devices are pin-compatible and mechanically interchangeable in through-hole PCB designs.

Q: What is the significance of the different supply voltage ranges?

A: The SN5476J operates within a narrow 4.5V to 5.5V window, typical of TTL-compatible logic. The SN74HC109N operates across 2V to 6V, providing flexibility for systems using different supply voltages. At the common 5V operating point, both devices function correctly. Applications using supply voltages outside the 4.5V to 5.5V range (such as 3.3V systems) require the SN74HC109N.

Q: How do propagation delay specifications affect substitution?

A: Propagation delay determines the maximum speed at which the flip-flop responds to input changes. The SN5476J specifies 40 ns maximum delay at 5V with 15 pF load. The SN74HC109N specifies 30 ns maximum delay at 6V with 50 pF load. The SN74HC109N's faster propagation delay ensures it meets timing requirements of circuits designed for the SN5476J. Applications with tight timing constraints should verify that the substitute's delay specification satisfies system requirements.

Q: What output current capability is required for my application?

A: Output current capability determines the maximum load impedance the flip-flop can drive. The SN5476J provides 16 mA, while the SN74HC109N provides 5.2 mA per output. Calculate your load current requirement by dividing the load voltage by load impedance. If load current exceeds 5.2 mA, the SN74HC109N requires external buffering or the SN5476J must be retained. For typical logic-level loads (high-impedance inputs), the SN74HC109N's 5.2 mA is generally sufficient.

Q: Does the lower quiescent current of the SN74HC109N affect circuit operation?

A: No. Quiescent current is the standby power consumption when the device is not switching. Lower quiescent current (4 µA versus 20 mA) reduces overall power consumption without affecting functional operation. This characteristic makes the SN74HC109N advantageous for battery-powered systems or applications where power efficiency is critical.

Q: Are there temperature range considerations for my application?

A: Yes. The SN5476J operates from -55°C to 125°C, while the SN74HC109N operates from -40°C to 85°C. If your application requires operation outside the -40°C to 85°C range, the SN5476J must be used. For standard industrial and commercial temperature ranges (-40°C to 85°C), both devices are suitable.