|
Details, datasheet, quote on part number:ZR2431G01
| |
Datasheet text preview:
ADJUSTABLE PRECISION ZENER SHUNT REGULATOR
ISSUE 3 DECEMBER 1997 DEVICE DESCRIPTION
The ZR2431 is a three terminal adjustable shunt regulator offering excellent temperature stability and output current handling capability up 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 f o r zener diodes in many applications requi ring an i mprovement in zener performance. T h e 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.
ZR2431
F EATURES
· · · · · · · · · · · · ·
Surface mount SOT23, 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 100µA to 25mA current sink capability Low output noise
APPLICATIONS
Shunt regulator Series regulator Voltage monitor Over voltage/ under voltage protection Switch mode power supplies
SCHEMATIC DIAGRAM
VZ Vref
Gnd
4-154
ZR2431
ABSOLUTE MAXIMUM RATING
Cathode Voltage (VZ) 15V Cathode Current 50mA Operating Temperature -40 to 85°C Storage Temperature -55 to 125°C Recommended Operating Conditions Min Max Cathode Voltage VREF 15V Cathode Current 100µA 25mA Power Dissipation (Tamb=25°C, Tjmax=150°C) SOT23 330mW SOT223 2W SO8 780mW TO92 780mW 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 1.0% 1.209 1.24 1.271 V 1.228 1.24 1.252 4.0 0.5 8.0 2.0 mV mV/V IL=10mA (Fig1), VZ=Vref IL=10mA, VZ=Vref Ta=full range (Fig1) VZ from Vref to 10V IZ=10mA (Fig2) R1=10k, R2=O/C, lL=10mA (Fig2) R1=10k, R2=O/C, IL=10mA Ta=full range (Fig2) VZ=15V, Vref =0V (Fig3) VZ=Vref (Fig1), 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
0.02 0.11 0.4 0.02 0.2 30 10 100 30
µA µA µA µA
Dynamic Output Impedance RZ
0.25 2
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: RZ = 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 (1+ ) R2 With a capacitance of greater than 100pF between cathode and anode, minimum cathode current must be 0.2mA.
T1 Temperature T2
4-155
ZR2431
TYPICAL CHARACTERISTICS TYPICAL CHARACTERISTICS
Change in Reference Output Voltage(mV)
140
Vref = Vz
2
Iz = 10mA
130
Iz=10mA
1 0 -1 -2 -3 -4 -5 0 5 10 15
Reference Current (nA)
120 110 100 90 80 -40
-20
0
20
40
60
80
Temperature (°C)
Cathode Voltage (V)
Reference Current v Temperature
Minimum Cathode Current(µA)
26
Vref = Vz
Change in Vref v Cathode Voltage
10
Vref = Vz 1mA
24 22 20 18 16 14 -40
Dynamic Impedance ()
10mA
1
-20
0
20
40
60
80
0.1 100
1k
10k
100k
Temperature (°C)
Frequency (Hz)
Cathode Current v Temperature
Dynamic Impedance v Frequency
1.244
2.0
Reference Voltage (V)
1.240 1.238 1.236 1.234 1.232 -40
Power Dissipation (W)
1.242
Iz=10mA
SOT 89
SOT 223
1.0
SO8/TO92 SOT23
0 -20 0 20 40 60 80 25 50 75 85 100
Temperature (°C)
Ambient Temprature (°C)
Reference Voltage v Temperature
Power Dissipation Derating
4-156
|
|
