Overview
The LM431ACM3X/NOPB is a 3-terminal adjustable precision zener shunt regulator produced by Texas Instruments. This device is designed to provide a highly stable and adjustable output voltage, making it an excellent replacement for many Zener diode applications. The LM431 features a sharp turn-on response, low output noise, and low dynamic output impedance, ensuring reliable performance across a wide range of operating conditions.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Cathode Voltage | - | - | 37 | V |
| Reference Voltage | -0.5 | - | - | V |
| Continuous Cathode Current | -10 | - | 150 | mA |
| Reference Input Current | - | - | 10 | mA |
| Internal Power Dissipation (SOT-23 package) | - | - | 0.28 | W |
| Operating Temperature (Commercial) | 0 | - | 70 | °C |
| Operating Temperature (Industrial) | -40 | - | 85 | °C |
| Storage Temperature | -65 | - | 150 | °C |
| Reference Voltage (VREF) | 2.47 | 2.495 | 2.52 | V |
Key Features
- Adjustable Output Voltage: The output voltage can be set at any level greater than 2.5 V up to 36 V using external resistors.
- Temperature Stability: Ensured temperature stability over the full temperature range with an average temperature coefficient of 50 ppm/°C.
- Fast Turn-on Response: Sharp turn-on characteristics make it suitable for replacing many Zener diode applications.
- Low Output Noise: Provides low output noise, enhancing the overall performance of the circuit.
- Low Dynamic Output Impedance: Ensures stable output voltage under varying load conditions.
- Space-Saving Packages: Available in SOIC-8, SOT-23, and TO-92 packages.
Applications
- Adjustable Voltage or Current Linear and Switching Power Supplies: Ideal for applications requiring adjustable voltage or current regulation.
- Voltage Monitoring: Can be used in circuits that require precise voltage monitoring.
- Current Source and Sink Circuits: Suitable for current source and sink applications due to its adjustable output.
- Circuits Requiring Precision References: Provides a precise reference voltage, making it useful in various precision circuits.
- Zener Diode Replacements: Excellent replacement for many Zener diode applications due to its stability and adjustability.
Q & A
- What is the LM431ACM3X/NOPB used for?
The LM431ACM3X/NOPB is a 3-terminal adjustable precision zener shunt regulator used for voltage regulation, voltage monitoring, and as a replacement for Zener diodes in various applications.
- What is the adjustable output voltage range of the LM431?
The output voltage can be set at any level greater than 2.5 V up to 36 V using external resistors.
- What are the key features of the LM431?
Key features include adjustable output voltage, temperature stability, fast turn-on response, low output noise, and low dynamic output impedance.
- In what packages is the LM431 available?
The LM431 is available in SOIC-8, SOT-23, and TO-92 packages.
- What is the operating temperature range for the commercial version of the LM431?
The operating temperature range for the commercial version is 0°C to 70°C.
- What is the maximum cathode voltage for the LM431?
The maximum cathode voltage is 37 V.
- How is the output voltage of the LM431 adjusted?
The output voltage is adjusted using two external resistors that act as a voltage divider network.
- What is the typical reference voltage (VREF) of the LM431?
The typical reference voltage (VREF) is 2.495 V.
- Is the LM431 suitable for high-temperature applications?
Yes, the LM431 is available in industrial versions that operate from -40°C to 85°C.
- What are some common applications of the LM431?
Common applications include adjustable voltage or current linear and switching power supplies, voltage monitoring, current source and sink circuits, and circuits requiring precision references.
