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The Complete Guide to 74LS47 Digital Display Driver

The 74LS47 Decoder/Driver is a versatile and efficient component that converts BCD input into a 7-segment display format, making it ideal for digital readouts. This article covers its features, pin configuration, applications, and key details to help you understand how it operates and where it can be used.

Catalog

Overview of the 74LS47 Decoder/Driver

The 74LS47 Decoder/Driver is designed for applications where low power consumption and efficient signal handling are needed. This component works by taking Binary-Coded Decimal (BCD) input and converting it into a format that can control a 7-segment display, commonly used for digital readouts. Internally, it combines several logic elements like NAND gates and AND-OR-INVERT gates to carry out this decoding. These elements work together to ensure that the correct segments on the display are activated based on the BCD input, allowing numbers to be represented clearly on the display. Additionally, the device provides both low and high sink currents, enabling it to manage different types of indicators effectively. This versatility and ease of use make the 74LS47 a practical choice in digital display systems where BCD-to-segment decoding is required.

Pin Configuration of the 74LS47

Detailed CAD Model for the 74LS47

Symbol

Footprint

3D Model

Key Features of the 74LS47

Function: Decoder and Demultiplexer

The 74LS47 acts as both a decoder and a demultiplexer. This dual role enables it to decode Binary-Coded Decimal (BCD) input and direct signals to different output channels, ensuring that your display segments are accurately represented based on input values. The decoder simplifies converting numeric data for readable digital displays.

Technology Family: LS

The 74LS47 belongs to the LS (Low Power Schottky) technology family. This design provides efficient performance with reduced power consumption, making it reliable for various digital applications, especially when power efficiency is a priority.

VCC Range: Minimum 4.75V to Maximum 5.25V

This device operates within a stable VCC range from 4.75V to 5.25V, making it compatible with most standard power supplies. With this range, it can maintain consistent performance across different power levels, giving it flexibility in many circuit setups.

Single-Channel Operation

The 74LS47 has one channel, allowing it to decode a single BCD input into a 7-segment output. This single-channel design keeps the operation simple and is ideal for applications that require straightforward, dedicated BCD-to-7-segment decoding.

Nominal Voltage: 5V

Operating at a nominal voltage of 5V, the 74LS47 aligns with typical supply voltages used in many electronic systems. This compatibility makes it easy to integrate with other components in a circuit, offering smooth operation without special power requirements.

Maximum Frequency: 35 MHz

The 74LS47 can handle frequencies up to 35 MHz, allowing it to work in applications where fast data processing is needed. This high-frequency support means it can perform quickly and maintain clear, accurate displays in dynamic systems.

Propagation Delay (tpd) at Normal Voltage: Maximum 100 ns

The propagation delay of the 74LS47 is 100 nanoseconds at normal voltage, which is the time it takes for an input signal to produce an output change. This short delay ensures that the device provides timely and accurate updates to your display segments.

Configuration: 4:7

The 4:7 configuration allows the 74LS47 to convert 4-bit BCD input data into a 7-segment display output. This setup makes it suitable for applications that need easy BCD-to-display transformations, supporting numbers from 0 to 9.

Output Type: Open-Collector

The open-collector output type of the 74LS47 means it can sink current but not source it. This setup is useful in cases where you want multiple outputs to be connected together or when controlling high-current loads. It provides flexible options for handling various output requirements.

Maximum Low-Level Output Current (IOL): 3.2 mA

With a maximum low-level output current of 3.2 mA, the 74LS47 can reliably drive display segments without excessive power drain. This current rating balances between sufficient output power and energy efficiency, ideal for displays and indicators.

Maximum High-Level Output Current (IOH): -0.05 mA

The high-level output current, capped at -0.05 mA, ensures stable operation and minimizes power usage when the device is not actively driving the segments. This feature helps conserve power, especially in low-power setups where efficiency is needed.

Rating: Catalog

The 74LS47 is categorized under the standard catalog rating, signifying it as a general-purpose part that is readily available and widely used in BCD-to-7-segment display applications. This rating reflects its proven reliability and widespread application.

Operating Conditions for 74LS47

Parameter	SN54LS47	SN74LS47	Unit
Supply Voltage, Vcc	MIN: 4.5 / MAX: 5 - 5.5	NOM: 4.75 - 5 / MAX: 5.25	V
Off-state Output Voltage, VQ (off)	a thru g: 15	a thru g: 15	V
On-state Output Current, Io (on)	a thru g: 12	a thru g: 24	mA
High-Level Output Current, Iqh	B1/RBO: - 50	B1/RBO: - 50	mA
Low-Level Output Current, Iq	51/RBO: 1 - 6	51/RBO: 3.2	mA
Operating Free-Air Temperature, Ta	MIN: -55 / MAX:125	MIN:0 / MAX:70	MIN: 0

Equivalent Components to the 74LS47

Part Number	Description	Manufacturer
AM27S23AJCB MEMORY	OTP ROM, 256X8, 30ns, Bipolar, PQCC20, PLASTIC, LCC-20	AMD
AM27S23JCB MEMORY	OTP ROM, 256X8, 45ns, Bipolar, PQCC20, PLASTIC, LCC-20	AMD
N82LS135A MEMORY	OTP ROM, 256X8, 100ns, TTL, PQCC20	Philips Semiconductors
N82S135A MEMORY	OTP ROM, 256X8, 45ns, Bipolar, PQCC20	YAGEO Corporation
63S281NL MEMORY	OTP ROM, 256X8, 45ns, CMOS, PQCC20	Monolithic Memories
63S281ANL MEMORY	OTP ROM, 256X8, 28ns, Bipolar, PQCC28, PLASTIC, LCC-28	Rochester Electronics LLC
63S280NLXXXX MEMORY	OTP ROM, 256X8, 45ns, CMOS, PQCC20	Monolithic Memories
63S281NLXXXX MEMORY	OTP ROM, 256X8, 45ns, CMOS, PQCC20	Monolithic Memories
DM74LS47V1 MEMORY	256X8 OTPROM, 60ns, PQCC20, PLASTIC, LCC-20	Texas Instruments
53S281ANL MEMORY	OTP ROM, 256X8, 40ns, Bipolar, PQCC28, PLASTIC, LCC-28	AMD

Technical Specifications of the 74LS47

Technical specifications, attributes, parameters, and comparable parts for Rochester Electronics, LLC SN74LS47N.

Type	Parameter
Mounting Type	Through Hole
Package / Case	16-DIP (0.300, 7.62mm)
Surface Mount	NO
Operating Temperature	0°C ~ 70°C
Packaging	Tube
JESD-609 Code	e4
Pbfree Code	Yes
Part Status	Obsolete
Moisture Sensitivity Level (MSL)	3 (168 Hours)
Number of Terminations	16
ECCN Code	EAR99
Terminal Finish	Nickel Palladium Gold
HTS Code	8542.39.00.01
Voltage - Supply	4.75V ~ 5.25V
Terminal Position	DUAL
Peak Reflow Temperature (°C)	NOT SPECIFIED
Number of Functions	1
Supply Voltage	5V
Terminal Pitch	2.54mm
Time@Peak Reflow Temperature-Max (s)	NOT SPECIFIED
Pin Count	16
JESD-30 Code	R-PDIP-T16
Qualification Status	Not Qualified
Supply Voltage-Max (Vsup)	5.25V
Supply Voltage-Min (Vsup)	4.75V
Configuration	7 Segment
Interface	BCD
Current - Supply	7mA
Family	LS
Output Polarity	Inverted
Logic IC Type	Seven Segment Decoder/Driver
Display Type	LED
Propagation Delay (tpd)	100 ns
Input Conditioning	Standard
Length	19.175mm
Height Seated (Max)	4.44mm
Width	7.62mm
RoHS Status	Non-RoHS Compliant

Application Circuit Example for 74LS47

Package Details of the 74LS47

Manufacturer Information for 74LS47

Texas Instruments (TI) is a well-known technology company headquartered in Dallas, Texas. TI specializes in designing and manufacturing semiconductors and integrated circuits for a wide range of electronic applications. Their products are widely used by engineers and electronics designers worldwide, with a significant focus on analog chips and embedded processors. These components make up a large part of their business and are known for being reliable and efficient. TI has expanded its reach in technology with digital light processing and education-related devices like calculators and microcontrollers. Holding over 45,000 patents globally as of 2016, TI demonstrates a strong commitment to innovation and quality in semiconductor technology. The 74LS47, like many TI products, reflects this commitment, serving as a dependable component in digital display and logic applications.

Frequently Asked Questions [FAQ]

1. What is the 74LS47 Decoder/Driver?

The 74LS47 is a Low Power Schottky decoder and driver designed to convert Binary-Coded Decimal (BCD) input into a format compatible with 7-segment displays. Inside, it uses NAND gates, input buffers, and a set of seven AND-OR-INVERT gates to perform this conversion efficiently. This configuration allows the device to control display indicators with both low and high sink current, helping display numbers accurately. The internal pairing of NAND gates and drivers ensures that both the BCD data and its complementary data are directed correctly to the display segments.

2. What is the recommended operating temperature range for the 74LS47?

The 74LS47 is designed to operate within a temperature range of 0°C to 70°C. This range supports reliable performance in typical environments, making it suitable for a variety of standard applications where moderate temperature control is in place.

3. What type of package does the 74LS47 use?

The 74LS47 comes in a 16-DIP (Dual In-line Package) with a standard width of 0.300 inches (7.62 mm). This package design allows for easy handling and installation on circuit boards, commonly used for straightforward integration into various electronic setups.

4. How many pins does the 74LS47 have?

The 74LS47 has a total of 16 pins, which include the connections necessary for input, output, and power supply. These pins are arranged to provide efficient access to each function, simplifying connections to the rest of your circuit.