The is a three terminal adjustable e nt temperature stability and output current handling capability to 25mA. The output voltage may be set to any chosen voltage between 1.24 and 15 volts by selection of two external divider resistors. The devices can be used as a replacement for zener diodes in many applications e qu mpr me nt ner performance. The ZR2431 is particularly used in the feedback control loop of switch mode power supplies. In this application the device 1.24 volt reference enables the generation of low voltage supplies, typically 3.3 volts or 3 volts.
FEATURES
Surface mount SOT223, SOT89 and SO8 packages TO92 package 2.5% and 1% tolerance Maximum temperature coefficient 52 ppm/°C Temperature compensated for operation over the full temperature range Programmable output voltage to 25mA current sink capability Low output noise
APPLICATIONS
Shunt regulator Series regulator Voltage monitor Over voltage/ under voltage protection Switch mode power supplies
Cathode Voltage (VZ) 15V Cathode Current 50mA Operating Temperature to 85°C Storage Temperature to 125°C Recommended Operating Conditions Min Max Cathode Voltage VREF 15V Cathode Current 100µA 25mA Power Dissipation SOT89 1.5W
ELECTRICAL CHARACTERISTICS TEST CONDITIONS (Unless otherwise stated):Tamb=25°C
PARAMETER Reference Voltage VALUE SYMBOL MIN TYP MAX UNITS CONDITIONS 2.5% Vref V mV mV/V IL=10mA (Fig1), VZ=Vref IL=10mA, VZ=Vref Ta=full range (Fig1) VZ from Vref R2=O/C, IL=10mA Ta=full range (Fig2) VZ=15V, Vref =0V (Fig3) VZ=Vref f=0Hz, IL=10mA
Deviation of Reference Input Vdev Voltage over Temperature Ratio of the change in Vref Reference Voltage to the VZ Change in Cathode Voltage Reference Input Current Iref Deviation of Reference Input Iref Current over Temperature Minimum Cathode Current for Regulation Off-state Current IZmin IZoff
Deviation of reference input voltage, Vdev, is defined as the maximum variation of the reference input voltage over the full temperature range. The average temperature coefficient of the reference input voltage, Vref is defined as: Vmax Vdev x 1000000 Vref (ppm / °C)= Vref (T1-T2) The dynamic output impedance, Rz, is VZ defined as: = IZ Vmin When the device is programmed with two external resistors, R1 and R2, (fig 2) , the dynamic output impedance of the overall Vdev = Vmax - Vmin circuit, R', is defined as: R1 R'=Rz ) R2 With a capacitance of greater than 100pF between cathode and anode, minimum cathode current must be 0.2mA.
|
