Low-voltage shunt regulator for precision bias and monitoring
The TLV431IDBVR is a low-voltage adjustable shunt regulator from Texas Instruments, designed for applications requiring a precise reference or shunt regulation down to 1.24V. It is a pin-compatible, lower-voltage sibling of the industry-standard TL431, with a tighter ±1.5% reference tolerance and a minimum cathode current of 80 µA, making it suitable for battery-powered or low-headroom designs.
The adjustable output spans from a 1.24V minimum to a 6V maximum, set by two external resistors. The ±1.5% tolerance on the internal reference means the set point stays within 1.5% of the target over temperature and load — tighter than the typical ±2% of the standard TL431, which matters when the reference is used as a comparator threshold or ADC bias. The 80 µA minimum cathode current allows the regulator to operate in low-power circuits where every microamp counts, such as battery-monitoring or always-on bias rails. The 15 mA output current is adequate for driving an optocoupler LED, biasing a transistor base, or providing a local reference for a small ADC.