Presettable shunt regulator
Depending on their location, linear voltage regulators are arranged traditionally into two sub-groups: series and shunt (or parallel) regulators. In practical circuits, series regulators. particularly the popular integrated types in the 78xx family, are normally used since these give good regulation and allow a reasonable output current. Nevertheless, good shunt regulators are also becoming available, for example. Texas Instruments “Irpe TIA31. The commercial version of this, the TIA31C, offers excellent temperature stability and very low dynamic impedance (see table). Although shunt regulators usually function in the same way as a Zener diode, the TI1431C offers a facility that no Zener diode does: the Zener voltage may be set anywhere between 2.5 V and 36 V with the aid of two fixed resistors. To function properly, the device needs a cathode current of not less than 1 mA. The voltage across the IC is tlaenUca, = 2.5(1+R2/R1). if the values of R2 and R3 are not too high, the current through this reference network is negligible pA). 1..()Possible application of the device’s compact 5 V power supply is shown in the diagram.
SOME TECHNICAL DATA
Cathode voltage,Ucat 2.5 V-36 V
Cathode current,Icat 150 mA
Power dissipation (1 m.A. min) 775 mW (at 25 C)
Dynamic impedance 0.5 Ω (typical 0.2 Ω)
Temperature coefficient 30 ppm K-1
A regulator is a device that has the function of maintaining a designated characteristic. It performs the activity of managing or maintaining a range of values in a machine. The measurable property of a device is managed closely by specified conditions or an advance set value, or it can be a variable according to a predetermined arrangement scheme. It can be used generally to connote any set of various controls or devices for regulating or controlling items or objects.
Feature of TI1431C
- 0.4% Initial Voltage Tolerance
- 0.2-Ω Typical Output Impedance
- Fast Turnon (500 ns)
- Sink Current Capability (1 mA to 100 mA)
- Low Reference Current (REF)
- Adjustable Output Voltage (VI(ref) to 36 V)
Applications
- Adjustable Voltage and Current Referencing
- Secondary Side Regulation in Flyback SMPSs
- Zener Replacement
- Voltage Monitoring
- Comparator With Integrated Reference