HCC/HCF4047B CMOS Monostable/Astable Multivibrator

Overview

The HCC4047B (extended temperature range) and HCF4047B (intermediate temperature range) are monolithic integrated circuits belonging to the "B" series of CMOS devices. These versatile ICs function as precision monostable/astable multivibrators, providing stable timing control for a wide range of digital applications. Manufactured using silicon gate CMOS technology, these devices offer the low power consumption typical of CMOS circuits while providing robust performance across specified temperature ranges.

The 4047B series features a built-in oscillator that can be configured for either monostable (one-shot) or astable (free-running) operation. The device includes all necessary circuitry to generate accurate output pulses whose duration (in monostable mode) or frequency (in astable mode) is determined by external timing components. With its 14-pin DIP or SOIC package options, the 4047B is suitable for both prototyping and production applications.

Key Features

• Monostable (one-shot) or astable (free-running) operation selectable by control pin
• Built-in oscillator requiring only external RC components for timing
• Wide supply voltage range: 3V to 18V DC
• Low power consumption: typically 10nW at 5V DC
• High noise immunity: 0.45 VDD (typ.)
• Symmetric output characteristics in astable mode
• Retriggerable/non-retriggerable option in monostable mode
• Buffered outputs (Q and Q̅) capable of driving two low-power TTL loads
• Available in extended (HCC) and intermediate (HCF) temperature range versions
• Standardized symmetrical output characteristics

Applications

The HCC/HCF4047B finds use in numerous timing and waveform generation applications, including:

• Precision timing circuits
• Frequency division and multiplication
• Pulse width modulation (PWM) systems
• Time delay generation
• Envelope detection circuits
• Frequency synthesis
• Clock generation for digital systems
• Switch debouncing circuits
• Sequential timing systems
• Test equipment and instrumentation

Electrical Characteristics

Absolute Maximum Ratings

• Supply Voltage (VDD): -0.5V to +20V
• Input Voltage (VIN): -0.5V to VDD + 0.5V
• DC Input Current (IIN): ±10mA
• Power Dissipation (PD): 200mW
• Storage Temperature Range (TSTG): -65°C to +150°C

Recommended Operating Conditions

• Supply Voltage Range (VDD): 3V to 18V
• Input Voltage Range (VIN): 0V to VDD
• Operating Temperature Range:
  • HCC4047B: -55°C to +125°C
  • HCF4047B: -40°C to +85°C

DC Electrical Characteristics

• Quiescent Current (IDD): 1μA max at 5V, 25°C
• Input Leakage Current (IIN): ±100nA max at 18V, 25°C
• Output Drive Current (IO):
  • Source: 1.3mA min at 5V
  • Sink: 1.3mA min at 5V
• Input Capacitance (CIN): 7.5pF typical

AC Electrical Characteristics

• Maximum Clock Frequency (fCLK): 8MHz typical at 10V
• Propagation Delay (tPHL, tPLH): 200ns typical at 10V
• Transition Time (tTHL, tTLH): 100ns typical at 10V
• Monostable Pulse Width Accuracy: ±1% typical with stable components

Functional Description

The HCC/HCF4047B contains all the necessary circuitry to operate as either a monostable or astable multivibrator. The operating mode is selected by the state of the ASTABLE/MONOSTABLE input pin (pin 10). When pin 10 is high, the device operates in astable mode; when low, it functions as a monostable multivibrator.

Monostable Operation

In monostable mode, the device generates a single output pulse of predetermined duration in response to an input trigger. The pulse width is determined by the external RC network connected to pins 1, 2, and 3. The monostable can be configured for either retriggerable or non-retriggerable operation through appropriate connection of the RETRIGGER input (pin 5).

Astable Operation

In astable mode, the device operates as a free-running oscillator, generating a continuous square wave output. The oscillation frequency is determined by the external RC components connected to pins 1, 2, and 3. The astable configuration provides both Q and Q̅ outputs with 50% duty cycle (when using the internal oscillator).

Package Information

The HCC/HCF4047B is available in standard 14-pin packages:

• DIP-14 (Dual In-line Package):
  • Body dimensions: 19.3mm x 6.35mm
  • Lead pitch: 2.54mm
  • Package material: Molded plastic
• SO-14 (Small Outline Package):
  • Body dimensions: 8.65mm x 3.9mm
  • Lead pitch: 1.27mm
  • Package material: Molded plastic

Pin Configuration

• Pin 1: C - External timing capacitor connection
• Pin 2: R - External timing resistor connection
• Pin 3: RC - Common connection for timing components
• Pin 4: ASTABLE OUTPUT - Complementary output in astable mode
• Pin 5: RETRIGGER - Retrigger input for monostable mode
• Pin 6: Q̅ - Inverted output
• Pin 7: VSS - Ground
• Pin 8: Q - True output
• Pin 9: OUTPUT ENABLE - Active low output enable
• Pin 10: ASTABLE/MONOSTABLE - Mode selection input
• Pin 11: TRIGGER - Negative edge trigger input
• Pin 12: TRIGGER - Positive edge trigger input
• Pin 13: EXTERNAL RESET - Active low reset input
• Pin 14: VDD - Positive supply voltage

Design Considerations

When designing with the HCC/HCF4047B, several factors should be considered:

• Timing