Texas Instruments SN74LS247NG4

Overview

SN74LS247NG4 from Texas Instruments is a 7-segment BCD-to-7-segment decoder/driver IC designed for direct interface to common-anode LED displays. It features active-low open-collector outputs, TTL-compatible inputs, and operates over 0°C to 70°C with supply voltage of 4.75 V to 5.25 V. Used in digital instrumentation, panel meters, and industrial control readouts.

For engineers reviewing the SN74LS247NG4 datasheet, SN74LS247NG4 pinout, SN74LS247NG4 application, or SN74LS247NG4 equivalent, key selection criteria include its active-low output drive capability, built-in lamp test and blanking functions, and compatibility with legacy TTL logic families in display subsystems.

Technical Context

The SN74LS247NG4 implements combinational logic decoding of 4-bit binary-coded decimal (BCD) inputs into seven active-low segment drive signals (a–g). Its internal circuitry includes ripple-blanking input (RBI), lamp test (LT̅), and blanking input (BI̅) for cascaded display control and fault verification.

It uses standard bipolar TTL process technology, delivering typical propagation delay of 30 ns (max 45 ns) and output sink current up to 40 mA per segment - sufficient to directly drive common-anode LEDs without external transistors in low-density applications.

Key Specifications

Pinout & Package

SN74LS247NG4 is supplied in a 16-pin plastic dual in-line package (PDIP-N), with 0.300-inch body width and standard through-hole mounting footprint.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar BCD-to-7-segment decoder applications.

Compared with SN74LS47N and 74HC4511, the SN74LS247NG4 delivers guaranteed TTL-level compatibility, precise open-collector sink performance, and full legacy feature support - making it the optimal choice for maintaining or repairing existing LS-TTL display subsystems without layout or firmware changes.

Availability

SN74LS247NG4 is available at Aetrix Electronics and suitable for digital instrumentation, industrial control panels, and test equipment requiring stable component supply and long-term obsolescence mitigation.

Supply support for SN74LS247NG4 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a U.S.-based semiconductor company founded in 1930, specializing in analog, embedded processing, and logic ICs with global manufacturing and distribution infrastructure.

The SN74LS247NG4 belongs to TI's legacy 74LS logic family, engineered specifically for reliable, low-cost digital display interfacing in commercial-grade instrumentation and control systems.

FAQ

What is the primary function of the SN74LS247NG4?

The SN74LS247NG4 is a BCD-to-7-segment decoder/driver IC that converts 4-bit binary-coded decimal inputs into active-low signals for controlling common-anode 7-segment LED displays. It integrates lamp test, blanking, and ripple-blanking functions - all implemented in standard LS-TTL logic. The SN74LS247NG4 is optimized for static or low-frequency multiplexed display applications where deterministic timing and direct LED drive are required.

Does the SN74LS247NG4 support common-cathode displays?

No, the SN74LS247NG4 does not natively support common-cathode displays. Its outputs are active-low open-collector, designed to sink current from the anodes of common-anode LEDs. Driving a common-cathode display would require external inverters or level-shifting circuitry - which compromises timing, increases component count, and defeats the purpose of the integrated decoder. For common-cathode applications, consider alternatives like the 74LS48 or 74HC4511 with appropriate configuration.

What is the maximum sink current per output pin on the SN74LS247NG4?

Each output pin of the SN74LS247NG4 is rated for a maximum continuous sink current of 40 mA, as specified in the official Texas Instruments datasheet. This allows direct drive of standard low-current LEDs (e.g., 20 mA @ 2.0 V VF) without external transistors. However, total device power dissipation must remain within limits - simultaneous full-segment activation may require derating based on ambient temperature and PCB thermal design. The SN74LS247NG4 datasheet provides detailed thermal resistance and derating curves for sustained operation.

Can the SN74LS247NG4 be used in place of the SN74LS247N or SN74LS247NE4?

Yes, the SN74LS247NG4 is a functionally identical, RoHS-compliant variant of the SN74LS247N and SN74LS247NE4, sharing the same PDIP-16 package, pinout, electrical specifications, and operating temperature range (0°C to +70°C). The "G4" suffix denotes TI's green packaging standard (lead-free, halogen-free), with no change to logic behavior or timing. Designers can substitute SN74LS247NG4 into legacy SN74LS247N/SN74LS247NE4 footprints without modification to schematic or layout.

What are the key differences between SN74LS247NG4 and SN74LS47N?

The SN74LS247NG4 and SN74LS47N share identical pinout and core decoding logic, but differ in output structure: SN74LS247NG4 has true open-collector outputs requiring external pull-ups, while SN74LS47N integrates internal 1.2 kΩ pull-up resistors. This makes SN74LS47N more convenient for simple LED connections but less flexible for interfacing with non-LED loads or higher-voltage rails. Both parts support lamp test and blanking, but SN74LS247NG4 offers greater design adaptability in mixed-voltage or wired-OR systems.