DATA SHEET LND431LV Low-voltage Adjustable Precision Shunt Regulators GENERAL DESCRIPTION FEATURES The LND431LV are three-terminal low-voltage adjustable shunt regulators with specified thermal stability. The output voltage may be set to any value between Vref (approximately 1.24V) and 6V with two external resistors. These devices have typical output impedance of 0.2Ω.. • • • • • • PIN CONFIGURATION Equivalent Full-Range Temperature Coefficient 30ppm/ºC Temperature Compensated for Operation Over Full Rated Operating Temperature Range Adjustable Output Voltage Sink Current Capability 1mA to 100mA Low (0.2 Ω Typ) Dynamic Output Impedance Low Output Noise SYMBOL • Linear Dimensions, Inc. • 445 East Ohio Street, Chicago IL 60611 USA • tel 312.321.1810 • fax 312.321.1830 • www.lineardimensions.com • LND431LV ABSOLUTE MAXIMUM RATINGS PARAMETER Cathode voltage (see note 1) Continuous cathode current range Reference input current range Operating free-air temperature rage Lead temperature 1.6mm from case for 10 seconds VALUE 7 -20 to 20 -.050 to 3.0 0 to 70 260 UNITS V mA ºC Note1: Voltage values are with respect to the anode terminal unless otherwise noted RECOMMENDED OPERATING CONDITIONS PARAMETER Cathode voltage, VKA Cathode current, Ik (for regulation) VALUE Vref .1 MAX 6 15 UNITS V mA FUNCTIONAL BLOCK DIAGRAM CATHODE REF + - V REF ANODE • Linear Dimensions, Inc. • 445 East Ohio Street, Chicago IL 60611 USA • tel 312.321.1810 • fax 312.321.1830 • www.lineardimensions.com • LND431LV ELECTRICAL CHARACTERISTICS TEST CIRCUIT 1 PARAMETER SYMBOL Reference input voltage Vref Deviation of reference input voltage over full temperature range Vref(dev) 1 Ratio of change in reference input voltage to the change in cathode voltage ∆Vref/∆VKA 2 Reference input current Iref 2 Deviation of reference input current over full temperature range Minimum cathode current for regulation Off- state cathode current Dynamic impedance TEST CONDITIONS MIN TYP MAX UNIT VKA = Vref, Ik =10mA 1222 1240 1258 mV 4 12 -1.4 -2.7 0.15 0.5 VKA = Vref, IK =10mA, TA = Full range IK=10 mA ∆VKA=6V to Vref IK=10mA, R1=10KΩ, R2=∞ TA =full range IK=10mA, R1=10KΩ, R2=∞ TA =full range Iref(dev) 2 Imin 1 VKA = Vref Ioff 3 |ZKA| 1 VKA = 6 V, Vref= 0 VKA =Vref, IK=1mA to 100mA, f≤ 1KHz mV/V µA 0.05 0.3 55 80 µA 0.001 1 µA 0.2 0.4 Ω PARAMETER MEASUREMENT INFORMATION Test Circuit 1. For VKA =VREF Test Circuit 2. For VKA > VREF • Linear Dimensions, Inc. • 445 East Ohio Street, Chicago IL 60611 USA • tel 312.321.1810 • fax 312.321.1830 • www.lineardimensions.com • LND431LV PARAMETER MEASUREMENT INFORMATION Test Circuit 3. For IOFF TYPICAL CHARACTERISTICS 15 VKA = VREF 175 Cathode Current (µA) T = 25*C A 10 5 0 T = 25*C A 150 125 100 I min 75 50 25 IK I K Cathode Current (mA) 200 VKA = VREF 0 -5 -25 -10 -50 -1 -0.5 0 0.5 1 1.5 -1 VKA Cathode Voltage (V) -0.5 0 0.5 1 1.5 VKA Cathode Voltage (V) Cathode Current v/s Cathode Voltage 1.2440 I K = 10 mA R1 = 10 kΩ 200 V REF - Ref erence Voltage - V I REF - Ref erence Input Current - nA 250 R2 = Open 150 100 50 0 I K = 10 mA 1.2420 1.2400 1.2380 1.2360 1.2340 -50 -25 0 25 50 75 100 T J - Junction Temperature - C Ref Voltage v/s Junction Temperature -50 -25 0 25 50 75 100 T J - Junction Temperature - C Ref Input Current v/s Junction Temperature • Linear Dimensions, Inc. • 445 East Ohio Street, Chicago IL 60611 USA • tel 312.321.1810 • fax 312.321.1830 • www.lineardimensions.com • LND431LV Stability Boundary Condition 16 TA=25°C 14 VKA=Vref 12 Cathode Current - mA Stable 10 8 6 VKA=2 V 4 2 VKA=3V 0 0.001 0.01 0.1 1 10 C L - Load Capacitance - µ F Ceramic Capacitors 1.0 Cathode Current - mA TA=25°C 0.8 VKA=Vref 0.6 Stable 0.4 0.2 For VKA=2 & 3 V Device does not Oscillate 0 0.001 0.01 0.1 1 10 C L - Load Capacitance - µ F Tantalum Capacitors * Stability boundary condition test shows that tantalum capacitors are recommended to minimize the conditions that may cause the device to oscillate. • Linear Dimensions, Inc. • 445 East Ohio Street, Chicago IL 60611 USA • tel 312.321.1810 • fax 312.321.1830 • www.lineardimensions.com • LND431LV 150 Ω 150 Ω I > R1 10 kΩ Vbat VREF C L* C L* Vbat R2 TEST CIRCUIT FOR V KA = VREF TEST CIRCUIT FOR V KA = 2 V, 3 V The Areas under the curves represent conditions that may cause the device to oscillate. For VKA =2V and 3V curves, R2 and Vbat were adjusted to establish the initial VKA and IK conditions with CL =0. Vbat and CL then were adjusted to determine the ranges of stability. TYPICAL APPLICATIONS V+ V out V+ R1 OUTPUT Von = 1.24V VREF Voff = V+ INPUT R2 V(th) = 1.24V GND R1 R2 V out = (1+ ) VREF Figure 1. Shunt Regulator Figure 2. Single-supply comparator With temperature compensated threshold • Linear Dimensions, Inc. • 445 East Ohio Street, Chicago IL 60611 USA • tel 312.321.1810 • fax 312.321.1830 • www.lineardimensions.com •