74LS42 Datasheet PDF – BCD/Decimal Decoder – National

What is 74LS42?

This is a BCD to decimal decoder/driver integrated circuit that is commonly used in digital electronics. It is a Multipurpose Decoder designed to accept four BCD inputs and provide ten mutually exclusive outputs.

Function: BCD/Decimal Decoder

Package: DIP, SOP 16 Pin

Manufacturer: National Semicondcutor ( Texas Instruments )

Pinouts:
74LS42 datasheet

Description

These BCD-to-decimal decoders consist of eight inverters and ten, four-input NAND gates. The inverters are connected in pairs to make BCD input data available for decoding by the NAND gates. Full decoding of input logic ensures that all outputs remain off for all invalid (10± 15) input conditions.

Features

1. Diode clamped inputs

2. Also for applications as 4-line-to-16-line decoders; 3-line-to-8-line decoders

3. All outputs are high for invalid input conditions

Logic Diagram

components

Advantages

1. Can be used with a variety of display types, including LEDs and LCDs

2. Provides a straightforward method of decoding BCD inputs and displaying them on a 7-segment display

National Semiconductor was acquired by Texas Instruments (TI) on September 23, 2011.

Other data sheets are available within the file: 54LS42, 54LS42DMQB, 54LS42FMQB, DM54LS42

74LS42 Datasheet PDF

74LS42 pdf

SE555 Datasheet PDF – Precision Timer – TI

What is SE555?

This is Precision Timer. It is a popular integrated circuit (IC) timer that is widely used in electronic circuits. It is also known as NE555, LM555, or simply 555 timer. The IC is a versatile timer that can be used to generate precise and stable time delays, oscillations, and pulse-width modulation signals.

Part Number: SE555

Function: Precision Timer

Package: PDIP, SOP, TSSOP, SOIC 8 Pin

Manufacturer: Texas Instruments

Pinouts:
SE555 datasheet

Description

These devices are precision timing circuits capable of producing accurate time delays or oscillation. In the time-delay or monostable mode of operation, the timed interval is controlled by a single external resistor and capacitor network. In the astable mode of operation, the frequency and duty cycle can be controlled independently with two external resistors and a single external capacitor.

The threshold and trigger levels normally are two-thirds and one-third, respectively, of Vcc. These levels can be altered by use of the control-voltage terminal. When the trigger input falls below the trigger level, the flip-flop is set, and the output goes high. If the trigger input is above the trigger level and the threshold input is above the threshold level, the flip-flop is reset and the output is low.

The reset (RESET) input can override all other inputs and can be used to initiate a new timing cycle. When RESET goes low, the flip-flop is reset, and the output goes low. When the output is low, a low-impedance path is provided between discharge (DISCH) and ground.

The output circuit is capable of sinking or sourcing current up to 200 mA. Operation is specified for supplies of 5 V to 15 V. With a 5-V supply, output levels are compatible with TTL inputs.

Block Diagram

SE555 Block diagram

Features

1. Timing From Microseconds to Hours
2. Astable or Monostable Operation
3. Adjustable Duty Cycle
4. TTL-Compatible Output Can Sink or Source up to 200 mA

It has a number of useful features, including a wide operating voltage range (typically 4.5V to 18V), low power consumption, and high output current capability. It can be used in a variety of modes, as mentioned earlier, and can generate a range of output signals, including square waves, pulses, and ramps.

Advantages

The SE555 timer is a simple and versatile IC that is widely available and inexpensive. Its ease of use, low cost, and wide range of applications make it a popular choice for both hobbyists and professionals. Additionally, the timer is capable of driving a wide range of loads, including LEDs, motors, and relays, making it useful in a variety of circuits.

Disadvantages

While the timer has many advantages, it also has a few drawbacks. For example, it is not suitable for high-frequency applications due to its limited frequency range (typically up to a few hundred kilohertz). Additionally, the output of the timer can be affected by variations in temperature and supply voltage, which can lead to inaccuracies in timing.
Applications

1. Fingerprint Biometrics
2. Iris Biometrics
3. RFID Reader

 

SE555 Datasheet PDF Download

SE555 pdf

 


Other data sheets are available within the file: NA555, NE555, SA555, NA555D, NA555DG4