74147 HLF74HC147N 10-to-4 Line Priority Encoder IC

Description

The HLF74HC147N is a 10-to-4 Line Priority Encoder IC manufactured by HLF, housed in a standard 16-pin DIP through-hole package. These high-speed Si-gate CMOS devices are pin-compatible with low power Schottky TTL (LSTTL) and are specified in compliance with JEDEC standard no. 7A.

The 74HC147 accepts data from nine active-LOW inputs (A0 to A8) and provides a binary representation on four active-LOW outputs (Y0 to Y3). A priority is assigned to each input so that when two or more inputs are active simultaneously, the input with the highest priority is represented on the output, with input line A8 having the highest priority. The device provides full 10-line to 4-line priority encoding by using the implied decimal "zero" — the "zero" is encoded when all nine data inputs are HIGH, forcing all four outputs HIGH, meaning no dedicated tenth input pin is needed.

This encoding function makes the 74HC147 especially useful for converting the output of a 10-position rotary or keypad switch into a compact 4-bit BCD code, greatly simplifying wiring and logic in code converters, keypad encoders, and digital control systems.

Key Specifications

• Function: 10-to-4 line priority encoder (9 active-LOW inputs, 4 active-LOW BCD outputs)
• Logic Family: High-Speed CMOS (HC)
• Package: 16-pin PDIP (through-hole)
• Operating Voltage: 2V to 6V
• Operating Temperature: -40°C to +125°C
• Propagation Delay: ~160ns @ 2V / ~27ns @ 6V (25°C)
• Output Current: 5.2mA @ 6V
• Manufacturer: HLF

Common Applications

• 10-position rotary/keypad switch encoding
• Code converters and BCD generators
• Priority-based digital input handling
• Keypad and control panel interfacing in digital systems

Package Includes

• 1 x HLF74HC147N IC (16-pin DIP)