General Description
• The LM431 Series ICs are three-terminal programmable shunt regulators with guaranteed thermal stability over a full operation range. These monolithic ICs voltage reference operate as a low temperature coefficient Zener which is programmable from Vref to 36V with two external resistors. These devices exhibit a wide operating current range of 1.0 to 100mA with a typical dynamic impedance of 0.15 to 0.22Ω. The characteristics of these references make them excellent replacements for Zener diodes in many applications such as digital voltmeters, power supplies and op amp circuitry The 2.5V reference makes it convenient to obtain a stable reference from 5.0V logic supplies, and since the LM431 series operates as a shunt regulator, it can be used as either a positive or negative voltage reference.
• The output voltage of both types can be set to any value between VREF (2.5V) and the corresponding maximum cathode voltage.
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Features
• Programmable Precise Output Voltage from 2.5V to 36V
• High Stability under Capacitive Load
• Low Temperature Deviation
• Can be used in either positive or negative Voltage reference
• Low Dynamic Output Impedance: 0.15 to 0.22Ω Typical
• Operating Current from 1.0mA to 100mA
• Low Output Noise Voltage
• RoHS Compliance

Applications
• Charger
• Voltage Adapter
• Switching Power Supply
• Graphic Card
• Precision Voltage Reference