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Details, datasheet, quote on part number:US431LCL
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Datasheet text preview:
US431L/431AL
LOW -VOLTAGE ADJUSTABLE PRECISION SHUNT REGULATOR
PRELIMINARY DATASHEET
FEATURES
SOT23-5 package 0.5% Voltage Reference Initial Accuracy (US431AL) Low Operational Cathode Current (80 uA max) Unconditionally Stable with only 1uF Adjustable Output from 1.24V to 6V 0.25 Typical Output Impedance Pin to Pin Compatible with TLV431
DESCRIPTION
The US431L product is a 3 terminal adjustable shunt regulator that can also be used as a precision voltage reference. Its output voltage may be set to any value between Vref(1.24V) and 6V with two external resistors as shown in the typical application circuit. Other applications of this device include the use as a merged amplifier and reference in applications such as Linear regulator or as the secondary side controller in low voltage power supply applications. The US431L only requires 80uA maximum quiescent current before regulating, making it ideal as a voltage reference for battery type applications.
APPLICATIONS
Precision Voltage Reference Linear Regulator Controller Secondary Side Controller for the Low Voltage Power Supply Applications
TYPICAL APPLICATION
RB
V IN
R1
VO US431
R2 Co
R1 Vo = Vref × 1 + R2
431app1-1.0
Typical application of the US431L as a shunt regulator / voltage reference.
PACKAGE ORDER INFORMATION
Ta (°C) 0 TO 70 0 TO 70 5 LEAD SOT23-5 US431LCL US431ALCL 3 PIN PLASTIC TO-92 US431LCZ US431ALCZ 8 PIN PLASTIC SOIC US431LCS US431ALCS
Rev. 1.2 5/11/98
2-1
US431L/431AL
ABSOLUTE MAXIMUM RATINGS
Input Voltage (Vin) .... 7V Continuous Cathode Current Range ........ -20 mA to +20 mA Reference Current Range ...... -0.05 mA to 3 mA Storage Temperature Range ........ -65°C TO 150°C Operating Junction Temperature Range .... 0°C TO 150°C
PACKAGE INFORMATION
5 PIN SOT 23 (L)
TOP VIEW
3 PIN PLASTIC TO-92 (Z)
BOTTOM VIEW 1 2
8 PIN PLASTIC SOIC (S)
TOP VIEW
NC 1 NC 2 Cathode
3
5 Anode
Ref Anode Cathode
Cathode Anode
1
8 Ref 7 NC 6 Anode 5 NC
NC 2
3 4 Ref
3
NC 4
JA = 450°C/W
JA = 162°C/W
JA=160°C/W
ELECTRICAL SPECIFICATIONS
Unless otherwise specified ,these specifications apply over Ta=0 to 70 °C, CO =1uF. Typical values refer to Ta=25 °C.Low duty cycle pulse testing are used which keeps junction and case temperatures equal to the ambient temperature. PARAMETER SYM TEST CONDITION MIN TYP MAX UNITS Reference Voltage Vref IK=10mA,VKA=Vref,Ta=25°C 1.228 1.240 1.252 V US431L IK=10mA,VKA=Vref 1.221 1.240 1.259 Reference Voltage Vref IK=10mA,VKA=Vref,Ta=25°C 1.234 1.240 1.246 V US431AL IK=10mA,VKA=Vref 1.228 1.240 1.252 Vref deviation over full Vref(dev) VKA=Vref, IK=10mA 4 12 mV temperature range Note 1 Ratio of Vref change to dVref/dVKA IK=10mA , dVKA=Vref to 6 V -1.5 -2.7 mV/V Cathode voltage change Reference pin current IK=10mA , R1=10k , R2=open 0.15 0.5 uA Iref deviation over full Iref(dev) IK=10mA , R1=10k , R2=open 0.05 0.3 uA temperature range Note 1 Minimum cathode current IK(min) VKA=Vref 55 80 uA Off state cathode current Ioff VKA=6V , Vref=0V 0.001 0.1 uA Dynamic impedance Zka0 VKA=Vref, f<1 kHz, 0.25 0.4 IK=0.1 to 15 mA , Note 2
Note 1 : The deviation parameters, Vref(dev) and Iref(dev) are defined as the differences between the maximum and the minimum values obtained over the rated temperature range. The average full range temperature coeficient of the reference input voltage is defined as : Vref ( d e v ) 6 × 10 Vref ( 25° C ) Vref = TA Where: Vref unit is ppm/ ° C TA is the rated operating free air temperature of the device. Vref can be positive or negative depending on whether minimum Vref or maximum Vref, respectively occurs at the lower temperature. Note 2 : Thedynamic impedance when VKA = Vref is defined as : VKA IK When the device is operating with two external Zka0 = resistors (see Figure 2), the total dynamic impedance of the circuit is given by: Zka = V R1 = Zka0 × 1 + I R2
2-2
Rev. 1.2 5/11/98
US431L/431AL
Pin Descriptions
SOT 23 PIN# 4 3 TO 92 PIN# 1 3 8 PIN SOIC PIN# 8 1 PIN SYMBOL Ref Cathode Pin Description A resistor divider from this pin to the Cathode pin and ground sets the output voltage. The output of the shunt regulator .A minimum of 1uF capacitor must be connected from this pin to Anode pin to insure unconditional stability. Ground pin. This pin must be connected to the lowest potential in the system & all other pins must be at higher potential with respect to this pin. These pins are not connected internally.
5
2
3,6
Anode
1,2
NA
2,4,5,7
NC
BLOCK DIAGRAM
Cathode
Ref
+
1.24V
431blk1-1.0
Anode
Figure 1 - Simplified block diagram of the US431L
Rev. 1.2 5/11/98
2-3
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