SN74LS145DRG4 Texas Instruments Integrated Circuit (Small Outline Packages) In Stock
SN74LS145DRG4 is a BCD-to-decimal decoder and driver from Texas Instruments in the 74LS logic family, housed in a 16-pin SOIC package. It decodes 4-bit BCD inputs into 10 active-low open-collector outputs with 80 mA maximum sink current at 3 V output low level. Suitable for driving LEDs, relays, and display segments in industrial and consumer digital display systems.
- Manufacturer
- Texas Instruments
- Package
- Small Outline Packages
- Pin Count
- 16
- Lifecycle
- OBSOLETE
- Datasheet
- SN74LS145DRG4 Datasheet PDF
- Category
- Integrated Circuit
- Temp Range
- ?°C to 70.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- BCD-to-decimal (1-of-10) decoder with open-collector outputs
- 80 mA maximum sink current per output for direct LED or relay drive
- Low-power Schottky (LS) family logic with standard TTL compatibility
- 10 decoded active-low outputs for decimal digit selection
- 16-pin SOIC package with 45 pF load capacitance rating
- RoHS-compliant e4 finish for lead-free assembly
Applications
The SN74LS145DRG4 is used in seven-segment display decoders, keyboard matrix decoders, and legacy industrial control panels where BCD-encoded data must be converted to individual decimal digit drive lines. Its 80 mA open-collector outputs allow direct connection to LED indicator arrays and small reed relays without external driver transistors. The device is also used in legacy industrial automation PLC systems and embedded front-panel controllers needing BCD output decoding.
Specifications
| YTEOL | 0 |
| Additional Feature | ION MAX=80MA @ VOL MAX=3V |
| Family | LS |
| Input Conditioning | STANDARD |
| JESD-30 Code | R-PDSO-G16 |
| JESD-609 Code | e4 |
| Load Capacitance (CL) | 45pF |
| Logic IC Type | DECIMAL DECODER/DRIVER |
| Max I(ol) | 0.08A |
| Number of Functions | 1 |
| Output Characteristics | OPEN-COLLECTOR |
| Output Polarity | INVERTED |
| Package Body Material | PLASTIC/EPOXY |
| Package Equivalence Code | SOP16,.25 |
| Package Shape | RECTANGULAR |
| Package Style | SMALL OUTLINE |
| Peak Reflow Temperature (Cel) | 260 |
| Power Supply Current-Max (ICC) | 13mA |
| Prop. Delay@Nom-Sup | 50ns |
| Propagation Delay (tpd) | 50ns |
| Qualification Status | Not Qualified |
| Supply Voltage-Max (Vsup) | 5.25V |
| Supply Voltage-Min (Vsup) | 4.75V |
| Supply Voltage-Nom (Vsup) | 5V |
| Surface Mount | YES |
| Technology | TTL |
| Temperature Grade | COMMERCIAL |
| Terminal Finish | NICKEL PALLADIUM GOLD |
| Terminal Form | GULL WING |
| Terminal Pitch | 1.27mm |
| Terminal Position | DUAL |
| Time@Peak Reflow Temperature-Max (s) | 30 |
| ## SN74LS145DRG4 Alternates Showing results | Image |
| Package | Small Outline Packages |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| Moisture Sensitivity Level | MSL 1 |
| ECCN | EAR99 |
| HTS Code | 8542.39.00.60 |
Alternate & Equivalent Parts
Compatible alternatives and drop-in replacements for SN74LS145DRG4:
Frequently Asked Questions
How much current can each output of SN74LS145DRG4 sink to drive LEDs or relays directly?
Each open-collector output of SN74LS145DRG4 can sink up to 80 mA at a maximum output low voltage of 3 V, enabling direct drive of standard indicator LEDs and small reed relays without external transistors. This simplifies circuit design and reduces component count in 10-position display decoder applications.
Which logic family does SN74LS145DRG4 belong to, and is it compatible with standard 5V TTL inputs?
The SN74LS145DRG4 is part of the 74LS low-power Schottky family, fully compatible with standard 5 V TTL input levels. It accepts 4-bit BCD input codes and produces 10 decoded open-collector outputs, making it a direct replacement in systems using older 7445 or SN54145 BCD decoder ICs.
In a legacy industrial control panel, how does SN74LS145DRG4 simplify BCD-to-decimal decoding for indicator lights?
SN74LS145DRG4 takes a 4-bit BCD input from a microcontroller or counter and directly drives 10 indicator lights in sequence, with each active-low open-collector output capable of sinking 80 mA. This eliminates discrete transistor driver circuits and reduces board area on through-hole or surface-mount industrial panels operating from a 5 V supply.
What is the typical propagation delay of SN74LS145DRG4, and does it limit use in high-speed scanning applications?
The SN74LS145DRG4 achieves propagation delays typical of the 74LS family, around 10 ns to 20 ns at 5 V supply and 45 pF load capacitance. While this is adequate for display multiplexing at kilohertz scan rates, designers needing sub-nanosecond decoding for high-speed applications above 10 MHz should consider faster CMOS logic families such as 74HC or 74LVC.
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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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