Programmable shunt regulator for automotive, commercial and defence applications

The ATL43xLI Programmable Shunt Regulator, from Texas Instruments, is a three-terminal adjustable shunt regulator, providing specified thermal stability over applicable automotive, commercial and defence temperature ranges. The output voltage can be established to any value between Vref (approximately 2.5V) and 36V, with two external resistors. These devices have a typical output impedance of 0.3Ohm. Active output circuitry gives a very sharp turn-on characteristic, making these devices attractive replacements for Zener diodes in many applications. These applications include adjustable power supplies, onboard regulation, and switching power supplies. This device is a pin-to-pin alternative to the TL431LI and TL432LI, with a lower minimum working current to help lessen system power consumption. The ATL432LI device has the identical functionality and electrical specifications as the ATL431LI device but has a different pinout for the DBZ package. The ATL431LI device is offered with two grades, providing initial tolerances (at 25C) of 0.5% for the B grade, and 1%, for the A grade. Low output drift versus temperature also ensures superior stability over the complete temperature range. The devices operation ranges from –40C to +125C. The device is ideal for applications including adjustable voltage and current referencing, voltage monitoring, precision constant current sink/source, secondary side regulation in flyback SMPS, Zener diode replacement, and comparator with integrated reference.