BL431 ADJUSTABLE PRECISION ZENER SHUNT REGULATOR DESCRIPTION BL431 Outline Drawing The BL431 is a three- terminal adjustable regulator with a guaranteed thermal stability over applicable temperature ranges. The output voltage may be set to any value between V R E F (approximately 2 . 5 V) and 36 V with two external SOT 23 resistors. This device has typical dynamic output impedance of 0 . 2 Ω . Active output circuitry TO -92 provides a very sharp turn - on characteristic, making these devices excellent replacement for zener diodes in many applications. FEATURE Programmable output voltage to 36 V Low dynamic output impedance 0 . 2 Ω typical Sink current capability of 1 . 0 mA to 100 mA Equivalent full- range temperature coefficient of 50 ppm/ ℃ typical Temperature compensated for operation over full rated operating temperature range Low output noise voltage Fast turn on response BLOCK DIAGRAM PIN CONNECTION Page1 www.belling.com.cn V1.5 BL431 SOT23 Marking ABSOLUTE MAXIMUM RATINGS Operating temperature range applies unless otherwise specified.) Characteristic Cathode Voltage Cathode Current Range (continuous) Reference Input Current Range Power Dissipation Operating Temperature Range Store temperature Range PD Symbol Vka Value 37 Unit V Ika - 10 ~+ 150 mA 10 770 230 0 ~+ 70 - 65 ~+ 150 mA IR E F TO-92 SOT 23 -3 Topr Tstg mW ℃ ℃ ELECTRICAL CHARACTERISTICS (Ta= 25 ℃ unless otherwise specified) Page2 www.belling.com.cn V1.5 BL431 Parameter Reference Voltage Deviation of Reference Input Voltage Over Temperature Ratio of the Change in Reference Voltage to the Change in Cathode Voltage Reference Input Current Deviation of Reference Input Current Over Temperature Minimum Cathode Current for Regulation Off- State Current Dynamic Output Impedance Conditions TO 92 +/- 0 . 5 % +/- 1 . 0 % +/- 2 . 0 % Vz= V R E F SOT 23 Ii= 10 mA +/- 0 . 5 % +/- 1 . 0 % +/- 2 . 0 % Symbol Min Typ Max Unit VR E F 2.487 2.475 2 . 440 2.500 2.513 2 . 525 2.55 V VR E F 2 . 482 2 . 470 2 . 440 2 . 495 2 . 508 2 . 520 2.55 V Vz= V R E F, Ii= 10 mA Vdev - 8.0 17 mV - - 1. 0 -2 . 7 Δ Vz - -0 . 5 -2 . 0 R 1 = 10 k Ω , R 2 = ∞ I1 = 10 mA IR E F - 2.0 4.0 μ A R 1 = 10 k Ω , R 2 = ∞ I1 = 10 mA ∝ IR E F - 0.4 1.2 μ A Vz= V R E F Iz( min) - 0.4 1.0 mA Vz= 36 V, V R E F= 0 V Vz= V R E F, Iz= 1 to 100 mA, f< 1 . 0 k Hz Iz(off) - 0. 05 1.0 μ A Rz - - 0. 50 Ω Iz= 10 mA Vz= V R E F~ 10 V Δ V R E F / Vz= 10 ~ 36 V m V/ V TEST CIRCUIT II IN II IN R1 IREF IN Iz Iz V REF Vz I R EF R2 Iz OFF VREF Note: Vz= V R E F (1 + R 1 /R 2 )+ IR E F *R 1 1. . Test circuit for Vz= V R E F 2.Test circuit for Vz> V R E F Page3 www.belling.com.cn 3 . Test circuit for off - state current V1.5 BL431 APPLICATION CIRCUIT V+ V+ Vo VR EF 30 R1 0.01uF R2 R1 Vo Vo = ( 1+R1/R2 ) V R2 REF Vo = ( 1+R1/R2 ) V 1. . Shunt Regulator REF 2 . Series Regulator V+ IN LM780 7805 5 OUT COMMON Vo V+ R1 OUT IN R2 Vth=2.5V Von=2V Voff=V+ GND Vo = ( 1+R1/R2 ) V REF Vo M IN = V REF + 5 V 3 . Output Control of a Three 4 . Single Supply Comparator with Terminal Fixed Regulator Temperature Compensated Threshold 5 . Higher Current Shunt Regulator V+ Vo R1 R2 Vo=(1 + R 1 /R 2 )*V R E F Page4 6 . Crow Bar Vo V+ R1 R2 Vlimit=(1 + R 1 /R 2 )*V R E F www.belling.com.cn V1.5 BL431 CHARACTERISTIC CURVES Page5 www.belling.com.cn V1.5 BL431 STABILITY BOUNDARY CONDITIONS: Test Circuit for Stability Boundary: Page6 www.belling.com.cn V1.5 BL431 Appendix： TO- 92 Package Outline Dimension ： TO- 92 ： Page7 www.belling.com.cn V1.5 BL431 SOT- 23 - 3 Package Outline Dimension ： Taping Diagram： Page8 www.belling.com.cn V1.5 BL431 Page9 www.belling.com.cn V1.5