TL431QDBZTG4 Datasheet/PDFPMIC - Voltage Reference
TL431QDBZTG4 is a type of programmable shunt voltage regulator from Texas Instruments. This three-terminal integrated circuit consists of a precision 2.5V reference and an external series resistor. It was designed for use as a programmable shunt regulator, series regulator, replacement for zener diodes as well as other voltage control devices.
The reference voltage of TL431QDBZTG4 is designed to be adjustable via a single external resistor (R1). This resistor allows the user to set the output voltage with a high-accuracy to any value between 1.24V and 36V. The reference voltage is also protected by an overtemperature shutdown circuit. Aside from that, the reference voltage is immune to line transients and other AC line disturbances. Moreover, it is capable of driving up to 100mA with a 0.1V voltage regulation.
The TL431QDBZTG4 chip is widely used in multiple applications. It is used for programming the output of switching power supplies and linear regulators. It is also used to adjust the voltage in automotive systems, telecom systems, and industrial process controls. Furthermore, TL431QDBZTG4 can also be used in applications with high ripple rejection requirements such as LED lighting, LED driver and LED backlighting.
Working Principle
The working principle of the TL431QDBZTG4 voltage reference lies in the operation of its comparator. The comparator compares a reference voltage at its positive input to the feedback voltage at its negative input. The output of the comparator then drives the regulated voltage of the linear regulator directly. The controlled voltage is regulated within a few microvolts of the programmed Set Point.
The programming of the device is done via the R1 external resistor. This external resistor sets the output voltage level of the device. The output voltage is determined by the following formula: VOUT = 2.5V * (1+R1/R2). R2 is internal and is around 27kOhms.
The TL431QDBZTG4 chip comes with overvoltage protection. This feature ensures that the output voltage does not exceed its maximum rating. In case of an overvoltage situation, the device will shut down until the voltage returns to normal. This feature helps prevent accidental damage to the device or connected components.
Summary
TL431QDBZTG4 is a type of programmable shunt voltage regulator from Texas Instruments. The reference voltage is designed to be adjustable via a single external resistor and is capable of driving up to 100mA with a 0.1V voltage regulation. It is widely used in multiple applications such as programming the output of switching power supplies and linear regulators, and adjusting the voltage in automotive systems, telecom systems, and industrial process controls. The working principle of the device lies in the operation of its comparator, which compares a reference voltage at its positive input to the feedback voltage at its negative input. The output of the comparator then drives the regulated voltage of the linear regulator directly.