Overview
The SN74121D is a monostable multivibrator integrated circuit produced by Texas Instruments. This component features dual negative-transition-triggered inputs and a single positive-transition-triggered input that can be used as an inhibit input. It provides complementary output pulses and is known for its high noise immunity and temperature stability. The SN74121D is packaged in a 14-pin SOIC (Small Outline Integrated Circuit) package and operates within a temperature range of 0°C to 70°C.
Key Specifications
| Parameter | Value |
|---|---|
| Package | 14-pin SOIC (D) |
| Operating Temperature Range | 0°C to 70°C |
| Supply Voltage | 4.75 V to 5.25 V |
| Propagation Delay | 45 ns |
| Output Current (High, Low) | 400 µA, 16 mA |
| Pulse Width Range | 40 ns to 28 seconds |
| Mounting Type | Surface Mount |
| RoHS Compliance | Yes |
Key Features
- Programmable output pulse width using external resistors and capacitors (Rext/Cext), with a typical internal pulse width of 30-35 ns without external components.
- Internal compensation for virtual temperature independence, ensuring pulse width stability across temperature and supply voltage variations.
- Jitter-free operation up to 90% duty cycle, maintaining stability over a wide range of timing capacitance (10 pF to 10 µF) and resistance (2 kΩ to 40 kΩ).
- Schmitt-trigger input circuitry providing high noise immunity (typically 1.2 volts) and immunity to VCC noise (typically 1.5 volts).
- Inhibit capability through the positive-transition-triggered input.
- TTL-compatible output rise and fall times, independent of pulse length.
Applications
The SN74121D is versatile and can be used in various applications requiring precise timing and pulse generation. Some common uses include:
- Pulse stretching and shaping in digital circuits.
- Timing and delay circuits in electronic systems.
- Reset signal generation in microprocessor and microcontroller systems.
- Noise filtering and signal conditioning due to its Schmitt-trigger inputs.
- General-purpose monostable multivibrator applications where high stability and noise immunity are required.
Q & A
- What is the SN74121D?
The SN74121D is a monostable multivibrator integrated circuit produced by Texas Instruments.
- What package type does the SN74121D come in?
The SN74121D is packaged in a 14-pin SOIC (Small Outline Integrated Circuit) package.
- What is the operating temperature range of the SN74121D?
The operating temperature range is 0°C to 70°C.
- What is the supply voltage range for the SN74121D?
The supply voltage range is 4.75 V to 5.25 V.
- How can the output pulse width be adjusted?
The output pulse width can be adjusted using external resistors and capacitors (Rext/Cext).
- What is the typical internal pulse width without external timing components?
The typical internal pulse width without external timing components is 30-35 ns.
- Does the SN74121D have Schmitt-trigger inputs?
Yes, the SN74121D features Schmitt-trigger input circuitry for improved noise immunity.
- What is the propagation delay of the SN74121D?
The propagation delay is 45 ns.
- Is the SN74121D RoHS compliant?
Yes, the SN74121D is RoHS compliant.
- What are some common applications of the SN74121D?
Common applications include pulse stretching, timing and delay circuits, reset signal generation, and noise filtering.
