SN74LS42NIn StockTexas Instruments
SN74LS42N is a BCD-to-decimal inverting decoder IC from Texas Instruments in a 16-pin DIP package. It decodes 4-bit BCD input into 10 active-low decimal outputs with standard LS logic. From $2.10, in stock with worldwide shipping.
- Manufacturer
- Texas Instruments
- Package
- Dual-In-Line Packages
- Pin Count
- 16
- Lifecycle
- ACTIVE
- Datasheet
- SN74LS42N Datasheet PDF
- Category
- Integrated Circuit
- Price
- From $2.0951(MOQ 1)
- Temp Range
- ?°C to 70.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- BCD-to-decimal decoding: Converts 4-bit BCD input (0–9) into 10 individual active-low decimal outputs
- Standard LS logic family: Compatible with TTL voltage levels, ensuring broad interoperability with legacy and modern digital systems
- 16-pin DIP package: Through-hole Dual-In-Line Package for easy prototyping and reliable through-board soldering
- Low output current: Max I(ol) of 8 mA suitable for driving LEDs, displays, and standard logic loads
- Single-function device: Dedicated decimal decoder/driver optimized for numeric display and data-routing applications
Applications
The SN74LS42N is widely used in seven-segment display driving circuits, BCD-coded keyboard decoding, and data multiplexing systems where decimal selection is required. It is commonly found in industrial control panels, legacy embedded systems, and educational electronics projects that require straightforward BCD-to-decimal conversion. Its active-low outputs make it ideal for interfacing directly with common-anode display drivers and relay activation circuits.
Specifications
| YTEOL | 15 |
| Family | LS |
| Input Conditioning | STANDARD |
| JESD-30 Code | R-PDIP-T16 |
| JESD-609 Code | e4 |
| Load Capacitance (CL) | 15pF |
| Logic IC Type | DECIMAL DECODER/DRIVER |
| Max I(ol) | 0.008A |
| Number of Bits | 10 |
| Number of Functions | 1 |
| Output Polarity | INVERTED |
| Package Body Material | PLASTIC/EPOXY |
| Package Equivalence Code | DIP16,.3 |
| Package Shape | RECTANGULAR |
| Package Style | IN-LINE |
| Packing Method | TUBE |
| Power Supply Current-Max (ICC) | 10mA |
| Prop. Delay@Nom-Sup | 30ns |
| Propagation Delay (tpd) | 30ns |
| Qualification Status | Not Qualified |
| Supply Voltage-Max (Vsup) | 5.25V |
| Supply Voltage-Min (Vsup) | 4.75V |
| Supply Voltage-Nom (Vsup) | 5V |
| Surface Mount | NO |
| Technology | TTL |
| Temperature Grade | COMMERCIAL |
| Terminal Finish | Nickel/Palladium/Gold (Ni/Pd/Au) |
| Terminal Form | THROUGH-HOLE |
| Terminal Pitch | 2.54mm |
| Terminal Position | DUAL |
| ## SN74LS42N Alternates Showing results | Image |
| Package | Dual-In-Line Packages |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| ECCN | EAR99 |
| HTS Code | 8542.39.00.90 |
| Country of Origin | Malaysia, Mexico |
Alternate & Equivalent Parts
No known alternates. Submit an RFQ and our team can suggest alternatives.
Frequently Asked Questions
What is the SN74LS42N and what does it do?
The SN74LS42N is a BCD-to-decimal inverting decoder IC from Texas Instruments. It accepts a 4-bit BCD input (representing values 0–9) and asserts one of 10 active-low outputs accordingly. It operates in the LS TTL logic family with a load capacitance of 15 pF and a maximum output low current (I(ol)) of 8 mA, making it suitable for driving small loads like indicator LEDs or relay drivers.
What package does the SN74LS42N come in and what are its pin specifications?
The SN74LS42N is housed in a 16-pin Dual-In-Line (DIP) through-hole package (JESD-30 code: R-PDIP-T16). It has 10 decoded outputs and 4 BCD inputs plus power and ground pins. The through-hole DIP format is ideal for breadboard prototyping and hand-soldered PCB assemblies common in industrial and educational applications.
What are common applications for the SN74LS42N?
The SN74LS42N is commonly used in numeric display decoding, BCD keyboard interfaces, multiplexed data routing, and industrial control panels. Its active-low outputs with up to 8 mA sink current can directly drive common-anode LED displays or optocouplers. It is also a popular choice in educational electronics kits and legacy embedded systems requiring TTL-compatible decimal decoding.
Are there modern alternatives or pin-compatible replacements for the SN74LS42N?
Pin-compatible alternatives to the SN74LS42N include the 74HCT42 (CMOS, 3.3 V–5 V compatible) and the CD74HC42E (Texas Instruments CMOS version). For drop-in TTL replacements, the DM74LS42N (Fairchild/ON Semi) is functionally equivalent. When migrating to CMOS families, verify supply voltage and output drive current compatibility, as CMOS variants may differ in I(ol) specs.
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About Texas Instruments
Texas Instruments (TI) is a global semiconductor company headquartered in Dallas, Texas. TI designs and manufactures analog and embedded processing chips used in industrial, automotive, consumer, communications, and enterprise systems.
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| Qty. | Unit Price | Ext. Price |
|---|---|---|
| 1+ | $3.3975 | $3.40 |
| 10+ | $3.0500 | $30.50 |
| 25+ | $2.7900 | $69.75 |
| 31+ | $2.2650 | $70.22 |
| 111+ | $2.0951 | $232.56 |
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