TL431 Adjustable Precision Shunt Regulator • Programmable Output Voltage to 36V TO-92 Pin Configuration • Low Dynamic Output Impedance 0.2Ω TL431CLP • Sink Current Capability of 0.1 mA to 100 mA CATHODE • Equivalent Full-Range Temperature Coefficient of 50 ppm/oC ANODE R REF • Temperature Compensated for Operation over Full Rated A C Operating Temperature Range SOT— —23 • Low Output Noise Voltage SOT-89 TL431LT1 • Fast Turn on Response TL431CPK 1. REF 2. CATHODE 3. ANODE REF ANODE CATHODE DESCRIPTION The TL431 is a three-terminal adjustable regulator series with a guaranteed thermal stability over applicable temperature ranges. The output voltage may be set to any value between Vref (approximately 2.5 volts) and 36 volts with two external resistors. These devices have a typical dynamic output impedance of 0.2Ω. Active output circuitry provides a very sharp turn-on characteristic, making these devices excellent replacement for zener diodes in many applications. The TL431 is characterized for operation from 0oC to +70oC. SYMBOL C a th o d e (K) FUNCTIONAL BLOCK DIAGRAM Re fe re n c e (R ) C a th o d e (K) + Re fe re n c e (R ) - Anod e (A ) 2 .5 V re f A n o d e (A ) SCHEMATIC DIAGRAM Wing Shing Computer Components Co., (H.K.)Ltd. Homepage: http://www.wingshing.com Tel:(852)2341 9276 Fax:(852)2797 8153 E-mail: [email protected] 4-1 WS TL431 ABSOLUTE MAXIMUM RATINGS (Operating temperature range applies unless otherwise specified) Characteristic Symbol Value Unit VKA 37 V IK -100 ~ +150 mA Reference Input Current Range IREF 0.05 ~ +10 mA Operating Temperature Range Ta 0 ~ +70 o Storage Temperature Range Tstg -65 ~ +150 o Cathode Voltage Cathode Current Range (Continuous) C C RECOMMENDED OPERATING CONDITIONS Characteristic Symbol Test Condition Min Typ Max Unit Cathode Voltage VKA VREF 36 V Cathode Current IK 1.0 100 mA ELECTRICAL CHARACTERISTICS (Ta = 25oC, unless otherwise specified) Characteristic Symbol Test Condition Min Typ Max Unit Reference Input Voltage VREF VKA = VREF, IK = 10mA 2.44 2.495 2.55 V Deviation of Reference Input Voltage OverTemperature (Note 1) VREF(dev) VKA = VREF, IK = 10mA 4 17 mV ∆VKA = 10V-VREF -1.4 -2.7 mV/V ∆KKA = 36V-10V -1.0 -2.0 Ratio of Change in Reference Input Voltage to the Change in Tmin ≤ Ta ≤ Tmax ∆V R EF ∆V K A Cathode Voltage IK = 10mA Reference Input Current IREF IK = 10mA, R1 = 10KΩ, R2 = ∞ 2,0 4 µA Deviation of Reference Input Current Over Full Temperature Range IREF(dev) IK = 10mA, R1 = 10KΩ, R2 = ∞ 0.4 1.2 µA Minimum Cathode Current for Regulation Off-State Cathode Current IK(min) VKA = VREF 0.4 1.0 mA IK(off) VKA = 36V, VREF = 0 0.1 1.0 µA ZKA VKA = VREF, IK = 10mA to 100mA 0.2 0.5 Ω Dynamic Impedance (Note2) Ta = Full Range f ≤ 1.0KHz 4-2 WS TL431 Note: 1. The deviation parameters VREF(dev) and IREF(dev) are defined as the differences between the maximum and minimum values obtained over the rated temperature range. VREF(dev) = VREF(max) - VREF(min) The equivalent full-range temperature coefficient of the reference input voltage, αVREF is defined as: )= ppm αVREF ( °C ( V R EF(dev) V R EF@ ° C ) × 10 6 ∆ Ta where ∆Ta is the rated operating free-air temperature range of the device. αVREF can be positive or negative depending on whether minimum VREF or maximum VREF respectively, occurs at the lower temperature. 2. The dynamic impedance is defined as: ZK A = ∆ VKA ∆ IK When the device is operated with two external resistors (see Figure 2), the total dynamic impedance of the circuit is given by: Z' = ∆V ∆I = Z K A (1+ R1 ) R2 TEST CIRCUITS Fig.2. Test Circuit for VKA ≥ VREF Fig.1. Test Circuit for VKA = VREF Fig.3. Test Circuit for Ioff 4-3 WS TL431 PAD LAYOUT 2 (0 ,0 ) T L 4 3 1 PA D D I A G R A M C h ip size : 1 3 4 5 x 9 9 0 Pa d size : U n it : µm 3 1 4 PAD LOCATION Unit: µm Pad No. Pad Name Description X Y 1 R Reference 235 400 2 K Cathode -505 343.5 3 K Cathode -497.5 -346 4 A Anode -177.5 -341.5 Physical Characteristics 460 ± 40 µm (thickness) Wafers 4 inch Size 1.35 × 0.99 mm Scribe width 90 µm Wafer’s Backside Ti – Ni – Ag: Ti - 0.1 ± 0.02 µm Ni - 0.5 ± 0.1 µm Ag - 0.6 ± 0.1 µm Passivation PSG 4-4