74LS148 DIP 8-line to 3-line Priority Encoder

The 74LS148 is a high speed TTL integrated circuit designed to provide priority encoding of eight active low data lines to a three bit binary code. This device ensures that only the highest order data line is encoded when multiple inputs are active simultaneously. It is an essential component for interrupt handling in microprocessor systems and for converting decimal or octal switch inputs into binary data for digital processing.

The IC features cascading circuitry in the form of enable inputs and outputs, allowing for easy expansion to encode more than eight lines without the need for external gates. It provides an enable output and a group signal output to indicate whether any valid data is present on the inputs. The low power Schottky technology provides high speed performance with minimal power dissipation, making it suitable for real time data acquisition and priority logic systems.

KEY FEATURES

• 8-line to 3-line priority encoding capability
• Cascading inputs and outputs for easy system expansion
• High speed performance with low power Schottky technology
• Encodes the highest order input when multiple lines are active
• Active low inputs and outputs for standard logic interfacing
• Standard 16 pin dual in line package

SPECIFICATIONS

• Supply Voltage 4.75V to 5.25V
• Operating Temperature 0 to 70 Celsius
• Logic Type TTL Low Power Schottky
• Propagation Delay 14ns
• Typical Power Dissipation 60mW
• High Level Output Current -0.4mA
• Low Level Output Current 8mA

INTERFACES

• 0 Input line 0 active low
• 1 Input line 1 active low
• 2 Input line 2 active low
• 3 Input line 3 active low
• 4 Input line 4 active low
• 5 Input line 5 active low
• 6 Input line 6 active low
• 7 Input line 7 active low
• EI Enable input active low
• EO Enable output active low for cascading
• GS Group signal output active low
• A0 Binary output bit 0
• A1 Binary output bit 1
• A2 Binary output bit 2
• VCC Positive supply voltage
• GND Ground reference