HCC/HCF4543B BCD-to-Seven Segment Decoder/Driver/Latch

Overview

The HCC/HCF4543B is a monolithic integrated circuit fabricated in MOS (Metal Oxide Semiconductor) technology. It is designed to convert Binary-Coded Decimal (BCD) input into the corresponding seven-segment display outputs. This device is capable of driving common-cathode or common-anode displays, making it highly versatile for numeric display applications. The 4543B features a built-in latch, allowing the displayed value to be held even when the input changes, ensuring stable output during multiplexing operations.

This component is particularly useful in applications requiring numeric display control, such as digital clocks, instrumentation panels, and industrial control systems. Its low power consumption and wide operating voltage range make it suitable for both battery-powered and line-operated devices.

Features

• BCD-to-Seven Segment Decoding: Converts 4-bit BCD input to seven-segment outputs for driving numeric displays.
• Latch Function: Integrated storage latch holds the display value when the latch enable (LE) signal is active.
• Flexible Display Options: Can drive both common-cathode and common-anode displays through the phase input (PH).
• Wide Operating Voltage Range: 3V to 18V DC, making it compatible with various logic families.
• Low Power Consumption: Typical standby current of 1µA at 5V, ideal for battery-operated devices.
• High Noise Immunity: CMOS technology provides excellent noise rejection characteristics.
• Display Blanking: Includes a blanking input (BI) to turn off all segments when activated.

Applications

The HCC/HCF4543B finds use in a wide range of applications where numeric display is required. Some typical applications include:

• Digital clocks and timers
• Electronic measuring instruments
• Industrial control panels
• Automotive dashboard displays
• Consumer electronics (microwaves, washing machines)
• Calculator and point-of-sale displays
• Test and measurement equipment

Electrical Characteristics

Absolute Maximum Ratings

• Supply Voltage (VDD): -0.5V to +20V
• Input Voltage (VIN): -0.5V to VDD + 0.5V
• Operating Temperature Range: -55°C to +125°C
• Storage Temperature Range: -65°C to +150°C

DC Electrical Characteristics

(VDD = 5V ±10%, TA = 25°C unless otherwise specified)

• High-Level Input Voltage (VIH): 3.5V min
• Low-Level Input Voltage (VIL): 1.5V max
• High-Level Output Voltage (VOH): 4.95V min (IOH = -0.4mA)
• Low-Level Output Voltage (VOL): 0.05V max (IOL = 0.4mA)
• Input Leakage Current (IIN): ±0.1µA max
• Quiescent Supply Current (IDD): 1µA max

AC Electrical Characteristics

• Propagation Delay (BCD to Output): 400ns typical (CL = 50pF)
• Latch Enable Pulse Width: 200ns min
• Maximum Clock Frequency: 5MHz typical

Package Information

The HCC/HCF4543B is available in multiple package options to suit different application requirements:

• DIP-16: 16-pin Dual In-line Package (300 mil width)
• SO-16: 16-pin Small Outline Package (150 mil width)
• TSSOP-16: 16-pin Thin Shrink Small Outline Package

Pin Configuration (DIP-16)

• Pin 1: Latch Enable (LE)
• Pin 2: Blanking Input (BI)
• Pin 3: Phase Input (PH)
• Pin 4-7: BCD Inputs (D, C, B, A)
• Pin 8: VSS (Ground)
• Pin 9-15: Segment Outputs (a, b, c, d, e, f, g)
• Pin 16: VDD (Positive Supply)

Functional Description

The HCC/HCF4543B operates by converting the 4-bit BCD input (pins 4-7) into the corresponding seven-segment outputs (pins 9-15). The phase input (pin 3) determines whether the outputs are active-high (for common-cathode displays) or active-low (for common-anode displays). When the latch enable (pin 1) is high, the input data is latched and the display remains unchanged even if the BCD input changes. The blanking input (pin 2) when activated turns off all segment outputs regardless of other input states.

Truth Table

The following table shows the relationship between BCD inputs and seven-segment outputs (for common-cathode display with PH=1):

• BCD 0000: Displays "0" (segments a,b,c,d,e,f on)
• BCD 0001: Displays "1" (segments b,c on)
• BCD 0010: Displays "2" (segments a,b,g,e,d on)
• BCD 0011: Displays "3" (segments a,b,g,c,d on)
• BCD 0100: Displays "4" (segments f,g,b,c on)
• BCD 0101: Displays "5" (segments a,f,g,c,d on)
• BCD 0110: Displays "6" (segments a,f,g,e,c,d on)
• BCD 0111: Displays "7" (segments a,b,c on)
• BCD 1000: Displays "8" (all segments on)
• BCD 1001: Displays "9" (segments a,b,c,d,f,g on)

Design Considerations

When implementing the HCC/HCF4543B in a design, several factors should be considered:

• Display Type: Ensure proper configuration of the PH input for your specific display type (common-cathode or common-anode).
• Current Limiting: For LED displays, appropriate current-limiting resistors should be used on each segment output.
• Power Supply Decoupling: A 0.1µF ceramic capacitor should be placed close to the VDD pin for noise suppression.
• Unused Inputs: All unused inputs