CD4029 Binary-Decade Up-Down Counter


The CD4029 is a versatile integrated circuit that holds a significant place in the world of digital electronics. Its functionality and widespread use make it an essential component for various applications, from digital counters to frequency dividers. In this article, we will delve into the intricacies of the CD4029, exploring its features, specifications, pinout, applications, and alternative options.

What is CD4029?

The CD4029 is a CMOS (Complementary Metal-Oxide-Semiconductor) presettable up/down counter, primarily designed to count binary, BCD (Binary Coded Decimal), and other user-defined codes. It is a 16-pin integrated circuit that offers versatile counting capabilities in both up and down directions. The device is known for its ease of use, reliability, and compatibility with a wide range of digital systems.

Breakdown of CD4029

The CD4029 can be broken down into three main functional components:

  1. Counter Registers: The CD4029 features four counter registers, enabling it to count in various modes, including binary, BCD, and custom-defined sequences.
  2. Presets: It allows users to preset a specific value to the counter, enabling precise counting operations.
  3. Control Logic: The integrated control logic facilitates seamless operation and switching between up and down counting modes.

Features of CD4029:

  1. Versatile Counting: Supports binary, BCD, and user-defined counting.
  2. Presettable: Allows for precise counting by setting an initial value.
  3. Up/Down Counting: Can count in both upward and downward directions.
  4. CMOS Technology: Low power consumption and wide voltage range compatibility.
  5. Ripple Blanking: Minimizes glitches during counting transitions.
  6. Direct Interface: Easy integration with microcontrollers and digital systems.
  7. Clear Inputs: Provides control over clearing the counter.
  8. High-Speed Operation: Suitable for time-critical applications.
  9. Compact Package: Available in various package types for diverse applications.
  10. Reliable Performance: Known for its robust and dependable operation.

Specifications of CD4029:

SpecificationTypical Value
Supply Voltage (VDD)+5V (Standard)
-40°C to +85°C (Extended)
Input Voltage Levels (VIH)70% of VDD (CMOS Logic High)
Input Voltage Levels (VIL)30% of VDD (CMOS Logic Low)
Operating Temperature Range0°C to 70°C (Standard)
Propagation DelayVaries (typically a few ns)
Output CurrentLimited (usually a few mA)
Maximum Clock FrequencyVaries (specified in datasheet)
Package TypesDIP (16-pin), SOIC, CDIP, etc.
  • Supply Voltage (VDD): The CD4029 typically operates with a positive supply voltage of +5 volts (VDD). This voltage is essential for the proper functioning of the IC. However, it’s worth noting that variations of the CD4029 may have different voltage requirements, so always refer to the datasheet for specific voltage ranges.
  • Input Voltage Levels: The CD4029 is compatible with a wide range of input voltage levels, making it versatile for various applications. For CMOS logic, the typical high-level input voltage (VIH) is around 70% of VDD, while the low-level input voltage (VIL) is about 30% of VDD.
  • Operating Temperature Range: The CD4029 is designed to function within a specified temperature range. The standard operating temperature range is from 0°C to 70°C. However, there are variants (e.g., CD4029BEX) that operate over an extended temperature range of -40°C to +85°C, making them suitable for more extreme environmental conditions.
  • Output Current: The output current of the CD4029 is typically limited to a few milliamperes (mA). It’s important not to exceed the maximum output current to prevent damage to the IC. When driving external components, such as LEDs or other digital devices, it’s advisable to use buffer amplifiers or current-limiting resistors.
  • Propagation Delay: The CD4029 has a propagation delay, which is the time it takes for changes at the input to affect the output. The propagation delay varies depending on the specific model and operating conditions but is typically in the range of a few nanoseconds.
  • Power Consumption: As a CMOS device, the CD4029 is known for its low power consumption. It’s suitable for battery-operated or low-power applications, making it energy-efficient.
  • Package Types: The CD4029 is available in various package types, including 16-pin DIP (Dual In-Line Package), SOIC (Small Outline Integrated Circuit), and CDIP (Ceramic Dual In-Line Package). The choice of package depends on the specific application and mounting requirements.
  • Pin Configuration: The CD4029 has a well-defined pinout with 16 pins, each serving a specific function. These pins include clock inputs, preset inputs, count enable inputs, clear inputs, and various outputs for BCD and binary counting.
  • Operating Modes: The IC can operate in different counting modes, including up-counting, down-counting, and various presettable modes. This versatility allows for its use in a wide range of applications.
  • Maximum Clock Frequency: The maximum clock frequency at which the CD4029 can reliably operate is specified in the datasheet. Exceeding this frequency may lead to errors or unreliable counting.
  • Cascading: The CD4029 can be cascaded with other CD4029 or similar ICs to create multi-digit counters for applications requiring larger counting ranges.
  • Clear Function: The clear input allows you to reset the counter to a predefined value, making it useful for controlling the start of counting operations.

It’s essential to refer to the specific datasheet of the CD4029 variant you plan to use, as specifications can vary slightly between models and manufacturers. Understanding these specifications is crucial for designing circuits that operate reliably and meet your application’s requirements.

Pinout of CD4029

Pin NamePin Description
CPClock Pulse Input (Count Enable)
UP/DNUp/Down Count Control Input
A, B, CBCD Inputs for Preset Value Selection
PREPreset Enable Input
CLRClear Counter Input
Q1-Q4BCD Outputs
Q5Binary Output
CARRY/BORCarry/Borrow Output (for cascading multiple chips)
GNDGround (0V)
VDDPositive Supply Voltage (+5V typically)

Pin Name: CP (Clock Pulse Input – Count Enable) [Pin 1]

  • Function: This is the clock input that controls the counting operation. The CD4029 counts up or down with each clock pulse, depending on the state of the UP/DN pin. The counting occurs when a positive transition (from low to high) is detected at this input.

Pin Name: UP/DN (Up/Down Count Control Input) [Pin 2]

  • Function: The UP/DN pin determines the counting direction. When it’s held high, the CD4029 counts up, and when it’s held low, it counts down. This pin is essential for selecting the desired counting mode.

Pin Names: A, B, C (BCD Inputs for Preset Value Selection) [Pins 3, 4, 5]

  • Function: These pins allow you to preset the initial value of the counter. By configuring these pins with binary values (0 or 1), you can set the starting count. These pins collectively define a 3-bit binary value, allowing you to set a preset count from 0 to 7.

Pin Name: PRE (Preset Enable Input) [Pin 6]

  • Function: The PRE pin is used to enable or disable presetting the counter. When PRE is high (usually connected to VDD), the counter is enabled to load the preset values from the A, B, C inputs during the next clock pulse.

Pin Name: CLR (Clear Counter Input) [Pin 7]

  • Function: CLR is the clear input. When a high signal is applied to this pin, it resets the counter to zero. This function is useful for initializing counting operations.

Pin Names: Q1, Q2, Q3, Q4 (BCD Outputs) [Pins 8, 9, 10, 11]

  • Function: These pins provide the BCD (Binary Coded Decimal) output. They represent the individual binary bits of the counted value. Q1 is the least significant bit (LSB), and Q4 is the most significant bit (MSB) of the BCD count.

Pin Name: Q5 (Binary Output) [Pin 12]

  • Function: Q5 is the binary output of the counter. It represents the complete binary count, which can be useful in applications requiring binary counting rather than BCD.

Pin Name: CARRY/BOR (Carry/Borrow Output) [Pin 13]

  • Function: This pin provides a carry (or borrow) signal when the counter reaches its maximum (or minimum) count and overflows (or underflows). It’s useful for cascading multiple CD4029 chips to create multi-digit counters.

Pin Name: GND (Ground – 0V) [Pin 14]

  • Function: This is the ground reference for the IC, providing the common ground for the entire circuit.

Pin Name: VDD (Positive Supply Voltage) [Pin 16]

  • Function: VDD is the positive supply voltage input, typically connected to +5 volts. It powers the CD4029 and is essential for its operation.

The CD4029’s pinout is well-defined, making it relatively easy to integrate into digital circuits. Understanding the functions of each pin is crucial for configuring the IC correctly and utilizing its counting capabilities effectively in various applications.

Applications of CD4029

  • Digital Frequency Dividers: CD4029 is frequently used as a key component in digital frequency dividers. It can be employed to divide the frequency of an incoming signal, making it invaluable in applications such as clock signal generation, frequency synthesis, and timekeeping.
  • Event Counters: In scenarios where you need to count events or occurrences, the CD4029 can serve as an event counter. It can tally events in both up and down directions, providing precise counting capabilities for applications like event monitoring and data acquisition.
  • Industrial Automation: Industries often require precise counting and control systems. The CD4029 can be utilized in industrial automation to count products on an assembly line, track inventory, or manage process control operations.
  • Digital Timers: CD4029 can be employed to create digital timers for various purposes. Whether it’s a kitchen timer, countdown timer, or any time-based control system, this IC can be programmed to suit the timing requirements.
  • Digital Control Systems: The CD4029 plays a vital role in digital control systems, allowing for precise control over various processes. It’s commonly used in systems where numerical values need to be controlled or monitored digitally.
  • LED Displays: For applications that require numerical or binary displays, the CD4029 can be used to drive LED displays. This is commonly seen in digital clocks, calculators, scoreboards, and other visual display systems.
  • Sequential Logic Circuits: CD4029 can be part of sequential logic circuits, particularly those requiring sequential counting or state control. It’s an essential component for building custom digital logic systems.
  • Frequency Synthesizers: In electronic communication systems, frequency synthesizers are essential for generating precise frequencies. The CD4029 can be used to help divide or multiply frequencies as needed.
  • Automotive Electronics: Automotive applications often require precise counting and timing, making the CD4029 valuable in various automotive control systems, such as engine management, instrument clusters, and infotainment systems.
  • Educational Electronics Projects: For students and electronics enthusiasts, the CD4029 is an excellent component for learning digital electronics principles. It’s commonly used in educational projects to demonstrate counting, binary coding, and digital logic concepts.

In summary, the CD4029 finds its way into a wide range of applications due to its versatility in counting and presetting functions. Whether it’s dividing frequencies, counting events, controlling processes, or displaying numerical information, this IC is a valuable tool in the world of digital electronics, making it an essential component for both professionals and hobbyists.

Equivalent Alternatives

  • CD4516 – Presettable Up/Down Counter.
  • CD4510 – BCD Up/Down Counter.
  • 74LS192 – Synchronous Up/Down BCD Counter.
  • 74HC193 – 4-bit Binary Up/Down Counter.
  • 74F169 – Synchronous Presettable Binary Counter.

In conclusion, the CD4029 is a fundamental component in the world of digital electronics, offering versatile counting capabilities with ease of use and reliability. Its features, specifications, and applications make it an invaluable tool for various electronic projects and systems. Additionally, it’s important to consider equivalent alternatives when designing circuits, depending on specific requirements.

Datasheet of CD4029

Download CD4029 Binary-Decade Up-Down Counter Datasheet from the link given below.

Leave a Comment