onsemi MC14049BDR2G Hex Inverting Buffer/Converter: Datasheet, Pinout, and Application Circuit Guide
The onsemi MC14049BDR2G is a member of the 4000 Series of CMOS logic integrated circuits, renowned for their high noise immunity and wide operating voltage range. This specific IC is a hex inverting buffer/converter, meaning it contains six independent inverting buffers within a single 16-pin package. Its primary function is to isolate, buffer, and convert logic signal levels, making it a versatile component in various digital and mixed-signal applications.
Datasheet Overview and Key Specifications
Understanding the datasheet is crucial for proper implementation. The MC14049B operates over a wide supply voltage range, typically from 3.0 V to 18 V, allowing it to interface with both TTL and higher voltage CMOS logic families. Key absolute maximum ratings include a DC supply voltage range of -0.5 V to +18 V and a power dissipation of 500 mW.
Its electrical characteristics are defined at specific supply voltages (e.g., 5.0 V, 10 V, 15 V). Important parameters include:
High-Level Output Current (IOH): -4.2 mA max at VDD = 10V
Low-Level Output Current (IOL): 8.4 mA max at VDD = 10V
High-Level Output Voltage (VOH): Typically 9.95 V at VDD = 10V (no load)
Low-Level Output Voltage (VOL): Typically 0.05 V at VDD = 10V (no load)
Propagation Delay (tPHL, tPLH): Approximately 100 ns at VDD = 10V and CL = 50 pF
These specs highlight its capability to drive relatively high current loads, such as LEDs or small relays, compared to standard logic gates.
Pinout Configuration
The MC14049BDR2G comes in a standard SOIC-16 package. The pinout is as follows:
Pins 1 to 6: Buffer Inputs (A1 to A6)
Pins 2 to 4, 6 to 8, 10 to 12, 14 to 16: Not connected (NC). Note: Some manufacturers may have slight variations; always check the datasheet.
Pins 9, 7, 5, 3, 1, 15: Buffer Outputs (Q1 to Q6) – Outputs are in the same physical order as inputs but on the opposite side of the IC.
Pin 8: Ground (VSS)
Pin 16: Supply Voltage (VDD)
Application Circuit Guide
The MC14049B is incredibly versatile. Here are two common application circuits:
1. Logic Level Converter/Shifter:
This is one of its most classic uses. The IC can convert signals from a high-voltage domain to a low-voltage one, or vice versa. For example, to interface a 12V CMOS sensor with a 5V microcontroller:
Connect VDD to the high-voltage source (12V).
Connect VSS to the common ground.
The high-voltage signal is applied to an input pin.
The corresponding output pin provides the inverted signal, but now swinging between 0V and 12V. A simple resistor divider can be added to the output if a non-inverted 5V logic level is required.
2. Crystal Oscillator Circuit:
The high input impedance and gain of the buffers make the MC14049B ideal for building simple oscillator circuits.
One of the inverters is configured as a Pierce oscillator by connecting a crystal resonator between its input and output.
Two capacitors are connected from each crystal terminal to ground to provide the necessary phase shift and ensure stable oscillation.
Another inverter on the same chip can be used to buffer and square up the output signal for the rest of the system.
Other applications include waveform shaping, driving high-current loads like LEDs, and serving as a simple analog amplifier when biased in its linear region.
The onsemi MC14049BDR2G remains a fundamental and highly reliable component for logic level translation, signal buffering, and oscillation generation. Its wide operating voltage range, robust output drive capability, and simple six-inverter architecture ensure its continued relevance in both modern and legacy electronic designs, from industrial controls to hobbyist projects.
Keywords: Hex Inverting Buffer, Logic Level Shifter, CMOS IC, Wide Voltage Range, Signal Converter
