Overview
The TL431ACD is a three-terminal adjustable shunt regulator produced by Texas Instruments. It is part of the TL431 and TL432 family, known for their specified thermal stability over a wide range of temperatures, including automotive, commercial, and military applications. The device allows for adjustable output voltage between approximately 2.5V and 36V using two external resistors. It features active output circuitry with a sharp turn-on characteristic, making it an excellent replacement for Zener diodes in various applications such as on-board regulation, adjustable power supplies, and switching power supplies.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Reference Voltage Tolerance at 25°C | 0.5% (B grade), 1% (A grade), 2% (Standard grade) | % |
| Adjustable Output Voltage | Vref to 36V | V |
| Operating Temperature Range | -40°C to 125°C | °C |
| Typical Temperature Drift | 6 mV (C temp), 14 mV (I temp, Q temp) | mV |
| Typical Output Impedance | 0.2 Ω | Ω |
| Sink-Current Capability | 1 mA to 100 mA | mA |
| Minimum Cathode Current for Regulation | 0.5 mA | mA |
| Off-State Cathode Current | 180 nA to 500 nA | nA |
Key Features
- Reference voltage tolerance at 25°C: 0.5% (B grade), 1% (A grade), 2% (Standard grade)
- Adjustable output voltage: Vref to 36V
- Operation from -40°C to 125°C
- Typical temperature drift: 6 mV (C temp), 14 mV (I temp, Q temp)
- Low output noise
- Typical output impedance: 0.2 Ω
- Sink-current capability: 1 mA to 100 mA
- Active output circuitry with a sharp turn-on characteristic
Applications
- Rack server power
- Industrial AC/DC power supplies
- AC inverter and variable frequency (VF) drives
- Servo drive control modules
- Notebook PC power adapter designs
- On-board regulation
- Adjustable power supplies
- Switching power supplies
Q & A
- What is the TL431ACD?
The TL431ACD is a three-terminal adjustable shunt regulator produced by Texas Instruments.
- What is the adjustable output voltage range of the TL431ACD?
The output voltage can be set to any value between approximately 2.5V and 36V using two external resistors.
- What are the temperature ranges for the TL431ACD?
The device operates from -40°C to 125°C.
- What is the typical output impedance of the TL431ACD?
The typical output impedance is 0.2 Ω.
- What is the sink-current capability of the TL431ACD?
The sink-current capability ranges from 1 mA to 100 mA.
- Can the TL431ACD replace Zener diodes in some applications?
- What are some common applications of the TL431ACD?
- How does the TL431ACD handle temperature drift?
The device has a low output drift versus temperature, with typical temperature drifts of 6 mV (C temp) and 14 mV (I temp, Q temp).
- What are the different grades of the TL431ACD based on reference voltage tolerance?
The TL431ACD is available in three grades: B grade (0.5% tolerance), A grade (1% tolerance), and Standard grade (2% tolerance).
- What is the minimum cathode current required for regulation in the TL431ACD?
The minimum cathode current for regulation is approximately 0.5 mA.
