TL431C, TL431AC, TL431I, TL431AI, TL431M, TL431Y ADJUSTABLE PRECISION SHUNT REGULATORS SLVS005I - JULY 1978 - REVISED AUGUST 1998 D D D D D D D PACKAGE (TOP VIEW) Equivalent Full-Range Temperature Coefficient . . . 30 ppm/C 0.2- Typical Output Impedance Sink-Current Capability . . . 1 mA to 100 mA Low Output Noise Adjustable Output Voltage . . . Vref to 36 V Available in a Wide Range of High-Density Packages CATHODE ANODE ANODE NC 8 2 7 3 6 4 5 REF ANODE ANODE NC JG, P, OR PW PACKAGE (TOP VIEW) description CATHODE NC NC NC The TL431 and TL431A are 3-terminal adjustable shunt regulators with specified thermal stability over applicable automotive, commercial, and military temperature ranges. The output voltage can be set to any value between Vref (approximately 2.5 V) and 36 V with two external resistors (see Figure 17). These devices have a typical output impedance of 0.2 . Active output circuitry provides a very sharp turn-on characteristic, making these devices excellent replacements for Zener diodes in many applications, such as on-board regulation, adjustable power supplies, and switching power supplies. 1 8 2 7 3 6 4 5 REF NC ANODE NC PK PACKAGE (TOP VIEW) REF ANODE CATHODE LP PACKAGE (TOP VIEW) The TL431C and TL431AC are characterized for operation from 0C to 70C, and the TL431I and TL431AI are characterized for operation from -40C to 85C. The TL431M is characterized for operation over the full military temperature range of -55C to 125C. CATHODE ANODE REF KTP PACKAGE (TOP VIEW) NC CATHODE NC REF NC FK PACKAGE (TOP VIEW) 4 3 2 1 20 19 18 5 17 6 16 7 15 8 14 9 10 11 12 13 CATHODE ANODE ANODE REF NC NC NC ANODE NC NC NC NC NC NC NC NC NC NC NC 1 NC - No internal connection Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. Copyright 1998, Texas Instruments Incorporated PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. On products compliant to MIL-PRF-38535, all parameters are tested unless otherwise noted. On all other products, production processing does not necessarily include testing of all parameters. POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 1 TL431C, TL431AC, TL431I, TL431AI, TL431M, TL431Y ADJUSTABLE PRECISION SHUNT REGULATORS SLVS005I - JULY 1978 - REVISED AUGUST 1998 AVAILABLE OPTIONS PACKAGED DEVICES TA SMALL OUTLINE (D) 0C to 70C TL431CD TL431ACD -40C to 85C TL431ID TL431AID -55C to 125C CHIP CARRIER (FK) TL431MFK CERAMIC DIP (JG) PLASTIC FLANGE MOUNT (KTP) TO-226AA (LP) PLASTIC DIP (P) SOT-89 (PK) SHRINK SMALL OUTLINE (PW) TL431CKTPR TL431CLP TL431ACLP TL431CP TL431ACP TL431CPK TL431CPW TL431ILP TL431AILP TL431IP TL431AIP TL431IPK CHIP FORM (Y) TL431Y TL431MJG The D and LP packages are available taped and reeled. Add R suffix to device type (e.g., TL431CDR). The KTP and PK packages are only available taped and reeled. Chip forms are tested at TA = 25C. symbol REF ANODE CATHODE functional block diagram CATHODE + REF _ Vref ANODE 2 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 TL431C, TL431AC, TL431I, TL431AI, TL431M, TL431Y ADJUSTABLE PRECISION SHUNT REGULATORS SLVS005I - JULY 1978 - REVISED AUGUST 1998 equivalent schematic CATHODE 800 800 20 pF REF 150 3.28 k 2.4 k 7.2 k 4 k 10 k 20 pF 1 k 800 ANODE All component values are nominal. POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 3 TL431C, TL431AC, TL431I, TL431AI, TL431M, TL431Y ADJUSTABLE PRECISION SHUNT REGULATORS SLVS005I - JULY 1978 - REVISED AUGUST 1998 TL431Y chip information This chip, when properly assembled, displays characteristics similar to those of the TL431C. Thermal compression or ultrasonic bonding can be used on the doped-aluminum bonding pads. The chip can be mounted with conductive epoxy or a gold-silicon preform. Bonding Pad Assignments (1) CATHODE (1) (2) ANODE TL431Y (3) REF 41 (3) (2) Chip Thickness: 15 Mils Typical Bonding Pads: 4 x 4 Mils Minimum TJ(max) = 150C Tolerances Are 10%. All Dimensions Are in Mils. Pins 2, 3, 6, and 7 Are Connected Together. Pins 4 and 5 Are Not Connected. 51 absolute maximum ratings over operating free-air temperature range (unless otherwise noted) Cathode voltage, VKA (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 V Continuous cathode current range, IKA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -100 mA to 150 mA Reference input current range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -50 A to 10 mA Continuous total power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Dissipation Rating Tables 1 and 2 Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -65C to 150C Case temperature for 60 seconds: FK package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260C Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds: D, P, or PW package . . . . . . . . . . . . 260C Lead temperature 1,6 mm (1/16 inch) from case for 60 seconds: JG, LP, or PK package . . . . . . . . . . 300C Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. NOTE 1: Voltage values are with respect to the anode terminal unless otherwise noted. 4 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 TL431C, TL431AC, TL431I, TL431AI, TL431M, TL431Y ADJUSTABLE PRECISION SHUNT REGULATORS SLVS005I - JULY 1978 - REVISED AUGUST 1998 DISSIPATION RATING TABLE 1 - FREE-AIR TEMPERATURE PACKAGE TA = 25C POWER RATING DERATING FACTOR ABOVE TA = 25C TA = 70C POWER RATING TA = 85C POWER RATING TA = 125C POWER RATING D 725 mW 5.8 mW/C 464 mW 377 mW -- FK 1375 mW 11 mW/C 880 mW 715 mW 275 mW JG 1050 mW 8.4 mW/C 672 mW 546 mW 210 mW KTP 1800 mW 14.5 mW/C 1147 mW 943 mW -- LP 775 mW 6.2 mW/C 496 mW 403 mW -- P 1000 mW 8 mW/C 640 mW 520 mW -- PK 500 mW 4 mW/C 320 mW 260 mW -- PW 525 mW 4.2 mW/C 336 mW -- -- DISSIPATION RATING TABLE 2 - CASE TEMPERATURE PACKAGE TC = 25C POWER RATING DERATING FACTOR ABOVE TC = 25C TC = 70C POWER RATING TC = 85C POWER RATING PK 3125 mW 25 mW/C 2000 mW 1625 mW recommended operating conditions Cathode voltage, VKA Cathode current, IKA C suffix Operating free-air temperature range, TA POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 MIN MAX Vref 1 36 V 100 mA 0 70 I suffix -40 85 M suffix -55 125 UNIT C 5 TL431C, TL431AC, TL431I, TL431AI, TL431M, TL431Y ADJUSTABLE PRECISION SHUNT REGULATORS SLVS005I - JULY 1978 - REVISED AUGUST 1998 electrical characteristics over recommended operating conditions, TA = 25C (unless otherwise noted) TEST CIRCUIT PARAMETER TEST CONDITIONS IKA = 10 mA TL431C UNIT MIN TYP MAX 2440 2495 2550 mV 4 25 mV -1.4 -2.7 -1 -2 mV V Vref Reference voltage 2 VKA = Vref, VI(dev) Deviation of reference voltage over full temperature range (see Figure 1) 2 VKA = Vref, IKA = 10 mA, TA = Full range DVref DVKA Ratio of change in reference voltage to the change in cathode voltage 3 IKA = 10 mA Iref Reference current 3 IKA = 10 mA, R1 = 10 k, R2 = 2 4 A II(dev) Deviation of reference current over full temperature range (see Figure 1) 3 IKA = 10 mA, R1 = 10 k, R2 = , TA = Full range 0.4 1.2 A Imin Minimum cathode current for regulation 2 VKA = Vref 0.4 1 mA Ioff Off-state cathode current 4 0.1 1 A |zKA| Dynamic impedance (see Figure 1) 1 VKA = 36 V, Vref = 0 IKA = 1 mA to 100 mA, VKA = Vref, f 1 kHz 0.2 0.5 VKA = 10 V - Vref VKA = 36 V - 10 V Full temperature range is 0C to 70C for the TL431C. The deviation parameters Vref(dev) and Iref(dev) are defined as the differences between the maximum and minimum values obtained over the recommended temperature range. The average full-range temperature coefficient of the reference voltage, Vref, is defined as: a + Maximum Vref V Vref I(dev) V at 25C ref ppm C 10 VI(dev) 6 DTA Minimum Vref TA where: TA is the recommended operating free-air temperature range of the device. Vref can be positive or negative, depending on whether minimum Vref or maximum Vref, respectively, occurs at the lower temperature. Example: maximum Vref = 2496 mV at 30C, minimum Vref = 2492 mV at 0C, Vref = 2495 mV at 25C, TA = 70C for TL431C a + 4 mV 2495 mV Vref 70C 10 6 [ 23 ppmC Because minimum Vref occurs at the lower temperature, the coefficient is positive. Calculating Dynamic Impedance The dynamic impedance is defined as: |z KA| + DDVI KA KA When the device is operating with two external resistors (see Figure 3), the total dynamic impedance of the circuit is given by: DV |zKA| 1 R1 |z | DI R2 + [ ) Figure 1. Calculating Deviation Parameters and Dynamic Impedance 6 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 TL431C, TL431AC, TL431I, TL431AI, TL431M, TL431Y ADJUSTABLE PRECISION SHUNT REGULATORS SLVS005I - JULY 1978 - REVISED AUGUST 1998 electrical characteristics over recommended operating conditions, TA = 25C (unless otherwise noted) PARAMETER TEST CIRCUIT TEST CONDITIONS IKA = 10 mA TL431I UNIT MIN TYP MAX 2440 2495 2550 mV 5 50 mV -1.4 -2.7 -1 -2 mV V Vref Reference voltage 2 VKA = Vref, VI(dev) Deviation of reference voltage over full temperature range (see Figure 1) 2 VKA = Vref, IKA = 10 mA, TA = Full range DVref DVKA Ratio of change in reference voltage to the change in cathode voltage 3 IKA = 10 mA Iref Reference current 3 IKA = 10 mA, R1 = 10 k, R2 = 2 4 A II(dev) Deviation of reference current over full temperature range (see Figure 1) 3 IKA = 10 mA, R1 = 10 k, R2 = , TA = Full range 0.8 2.5 A Imin Minimum cathode current for regulation 2 VKA = Vref 0.4 1 mA Ioff Off-state cathode current 4 0.1 1 A |zKA| Dynamic impedance (see Figure 1) 2 VKA = 36 V, Vref = 0 IKA = 1 mA to 100 mA, VKA = Vref, f 1 kHz 0.2 0.5 VKA = 10 V - Vref VKA = 36 V - 10 V Full temperature range is -40C to 85C for the TL431I. electrical characteristics over recommended operating conditions, TA = 25C (unless otherwise noted) PARAMETER TEST CIRCUIT TEST CONDITIONS Vref Reference voltage 2 VKA = Vref, VI(dev) Deviation of reference voltage over full temperature range (see Figure 1) IKA = 10 mA 2 VKA = Vref, IKA = 10 mA, TA = Full range DVref DVKA Ratio of change in reference voltage to the change in cathode voltage 3 IKA = 10 mA Iref Reference current 3 II(dev) Deviation of reference current over full temperature range (see Figure 1) Imin VKA = 10 V - Vref VKA = 36 V - 10 V TL431M MIN TYP MAX 2400 2495 2600 22 UNIT mV mV -1.4 -3 -1 -2.3 mV V IKA = 10 mA, R1 = 10 k, R2 = 2 8* A 3 IKA = 10 mA, R1 = 10 k, R2 = , TA = Full range 1 Minimum cathode current for regulation 2 VKA = Vref 0.4 1.5 mA Ioff Off-state cathode current 4 0.1 3 A |zKA| Dynamic impedance (see Figure 1) 1 VKA = 36 V, Vref = 0 IKA = 1 mA to 100 mA, VKA = Vref, f 1 kHz 0.2 0.9* A * On products compliant to MIL-PRF-38535, this parameter is not production tested. Full temperature range is -55C to 125C for the TL431M. POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 7 TL431C, TL431AC, TL431I, TL431AI, TL431M, TL431Y ADJUSTABLE PRECISION SHUNT REGULATORS SLVS005I - JULY 1978 - REVISED AUGUST 1998 electrical characteristics over recommended operating conditions, TA = 25C (unless otherwise noted) TEST CIRCUIT PARAMETER TEST CONDITIONS IKA = 10 mA TL431AC UNIT MIN TYP MAX 2470 2495 2520 mV 4 25 mV -1.4 -2.7 -1 -2 mV V Vref Reference voltage 2 VKA = Vref, VI(dev) Deviation of reference voltage over full temperature range (see Figure 1) 2 VKA = Vref, IKA = 10 mA, TA = Full range DVref DVKA Ratio of change in reference voltage to the change in cathode voltage 3 IKA = 10 mA Iref Reference current 3 IKA = 10 mA, R1 = 10 k, R2 = 2 4 A II(dev) Deviation of reference current over full temperature range (see Figure 1) 3 IKA = 10 mA, R1 = 10 k, R2 = , TA = Full range 0.8 1.2 A Imin Minimum cathode current for regulation 2 VKA = Vref 0.4 0.6 mA Ioff Off-state cathode current 4 0.1 0.5 A |zKA| Dynamic impedance (see Figure 1) 1 VKA = 36 V, Vref = 0 IKA = 1 mA to 100 mA, VKA = Vref, f 1 kHz 0.2 0.5 VKA = 10 V - Vref VKA = 36 V - 10 V Full temperature range is 0C to 70C for the TL431AC. electrical characteristics over recommended operating conditions, TA = 25C (unless otherwise noted) TEST CIRCUIT PARAMETER TEST CONDITIONS IKA = 10 mA UNIT MIN TYP MAX 2470 2495 2520 mV 5 50 mV -1.4 -2.7 -1 -2 mV V Vref Reference voltage 2 VKA = Vref, VI(dev) Deviation of reference voltage over full temperature range (see Figure 1) 2 VKA = Vref, IKA = 10 mA, TA = Full range DVref DVKA Ratio of change in reference voltage to the change in cathode voltage 3 IKA = 10 mA Iref Reference current 3 IKA = 10 mA, R1 = 10 k, R2 = 2 4 A II(dev) Deviation of reference current over full temperature range (see Figure 1) 3 IKA = 10 mA, R1 = 10 k, R2 = , TA = Full range 0.8 2.5 A Imin Minimum cathode current for regulation 2 VKA = Vref 0.4 0.7 mA Ioff Off-state cathode current 4 0.1 0.5 A |zKA| Dynamic impedance (see Figure 1) 2 VKA = 36 V, Vref = 0 IKA = 1 mA to 100 mA, VKA = Vref, f 1 kHz 0.2 0.5 VKA = 10 V - Vref VKA = 36 V - 10 V Full temperature range is -40C to 85C for the TL431AI. 8 TL431AI POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 TL431C, TL431AC, TL431I, TL431AI, TL431M, TL431Y ADJUSTABLE PRECISION SHUNT REGULATORS SLVS005I - JULY 1978 - REVISED AUGUST 1998 electrical characteristics over recommended operating conditions, TA = 25C (unless otherwise noted) TEST CIRCUIT PARAMETER Vref Reference voltage DVref DVKA Ratio of change in reference voltage to the change in cathode voltage 3 Iref Reference input current Imin Minimum cathode current for regulation Ioff |zKA| VKA = Vref, MIN TYP MAX UNIT IKA = 10 mA VKA = 10 V - Vref 2495 mV -1.4 -1 mV V 3 VKA = 36 V - 10 V IKA = 10 mA, R1 = 10 k, R2 = 2 A 2 VKA = Vref 0.4 mA Off-state cathode current 4 0.1 A Dynamic impedance 2 VKA = 36 V, Vref = 0 IKA = 1 mA to 100 mA, VKA = Vref, f 1 kHz 0.2 Calculating dynamic impedance: 2 TL431Y TEST CONDITIONS IKA = 10 mA + DD V KA I KA When the device is operating with two external resistors (see Figure 3), the total dynamic impedance of the circuit is given by: The dynamic impedance is defined as: z KA [ |z + V I |z | KA ) | 1 R1 R2 PARAMETER MEASUREMENT INFORMATION Input VKA Input VKA IKA IKA Vref R1 Iref R2 Vref Figure 2. Test Circuit for VKA = Vref V KA +V ) ) ref 1 R1 R2 I ref R1 Figure 3. Test Circuit for VKA > Vref Input VKA Ioff Figure 4. Test Circuit for Ioff POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 9 TL431C, TL431AC, TL431I, TL431AI, TL431M, TL431Y ADJUSTABLE PRECISION SHUNT REGULATORS SLVS005I - JULY 1978 - REVISED AUGUST 1998 TYPICAL CHARACTERISTICS Table 1. Graphs FIGURE Reference input voltage vs Free-air temperature 5 Reference input current vs Free-air temperature 6 Cathode current vs Cathode voltage 7, 8 Off-state cathode current vs Free-air temperature 9 Ratio of delta reference voltage to change in cathode voltage vs Free-air temperature 10 Equivalent input noise voltage vs Frequency 11 Equivalent input noise voltage over a 10-second period 12 Small-signal voltage amplification vs Frequency 13 Reference impedance vs Frequency 14 Pulse response 15 Stability boundary conditions 16 Table 2. Application Circuits FIGURE 10 Shunt regulator 17 Single-supply comparator with temperature-compensated threshold 18 Precision high-current series regulator 19 Output control of a 3-terminal fixed regulator 20 High-current shunt regulator 21 Crowbar circuit 22 Precision 5-V 1.5-A regulator 23 Efficient 5-V precision regulator 24 PWM converter with reference 25 Voltage monitor 26 Delay timer 27 Precision current limiter 28 Precision constant-current sink 29 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 TL431C, TL431AC, TL431I, TL431AI, TL431M, TL431Y ADJUSTABLE PRECISION SHUNT REGULATORS SLVS005I - JULY 1978 - REVISED AUGUST 1998 TYPICAL CHARACTERISTICS REFERENCE VOLTAGE vs FREE-AIR TEMPERATURE REFERENCE CURRENT vs FREE-AIR TEMPERATURE 2600 5 VKA = Vref IKA = 10 mA R1 = 10 k R2 = IKA = 10 mA Vref = 2550 mV 2560 I ref - Reference Current - A V ref - Reference Voltage - mV 2580 2540 2520 Vref = 2495 mV 2500 2480 2460 Vref = 2440 mV 2440 4 3 2 1 2420 2400 -75 -50 -25 0 25 50 75 100 0 -75 125 TA - Free-Air Temperature - C Data is applicable only within the recommended operating free-air temperature ranges of the various devices. Data is for devices having the indicated value of Vref at IKA = 10 mA, TA = 25C. -50 -25 50 75 100 125 Figure 6 CATHODE CURRENT vs CATHODE VOLTAGE CATHODE CURRENT vs CATHODE VOLTAGE 150 800 VKA = Vref TA = 25C VKA = Vref TA = 25C 100 I KA - Cathode Current - A I KA - Cathode Current - mA 25 Data is applicable only within the recommended operating free-air temperature ranges of the various devices. Figure 5 125 0 TA - Free-Air Temperature - C 75 50 25 0 -25 -50 600 Imin 400 200 0 -75 -100 -2 -200 -1 0 2 1 3 -1 VKA - Cathode Voltage - V 0 1 2 3 VKA - Cathode Voltage - V Figure 7 Figure 8 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 11 TL431C, TL431AC, TL431I, TL431AI, TL431M, TL431Y ADJUSTABLE PRECISION SHUNT REGULATORS SLVS005I - JULY 1978 - REVISED AUGUST 1998 TYPICAL CHARACTERISTICS RATIO OF DELTA REFERENCE VOLTAGE TO DELTA CATHODE VOLTAGE vs FREE-AIR TEMPERATURE OFF-STATE CATHODE CURRENT vs FREE-AIR TEMPERATURE - 0.85 VKA = 36 V Vref = 0 VKA = 3 V to 36 V - 0.95 2 V ref / V KA - mV/V I off - Off-State Cathode Current - A 2.5 1.5 1 0.5 0 -75 -1.05 -1.15 -1.25 -1.35 -50 -25 0 25 50 75 100 -1.45 -75 125 TA - Free-Air Temperature - C Data is applicable only within the recommended operating free-air temperature ranges of the various devices. -50 -25 Figure 10 EQUIVALENT INPUT NOISE VOLTAGE vs FREQUENCY 260 Vn - Equivalent Input Noise Voltage - nV/ Hz 25 IO = 10 mA TA = 25C 240 220 200 180 160 140 120 100 10 100 1k 10 k f - Frequency - Hz Figure 11 POST OFFICE BOX 655303 50 75 100 125 TA - Free-Air Temperature - C Data is applicable only within the recommended operating free-air temperature ranges of the various devices. Figure 9 12 0 * DALLAS, TEXAS 75265 100 k TL431C, TL431AC, TL431I, TL431AI, TL431M, TL431Y ADJUSTABLE PRECISION SHUNT REGULATORS SLVS005I - JULY 1978 - REVISED AUGUST 1998 TYPICAL CHARACTERISTICS EQUIVALENT INPUT NOISE VOLTAGE OVER A 10-SECOND PERIOD V n - Equivalent Input Noise voltage - V 6 5 4 3 2 1 0 -1 -2 -3 f = 0.1 to 10 Hz IKA = 10 mA TA = 25C -4 -5 -6 0 1 2 3 4 5 6 7 8 9 10 t - Time - s 19.1 V 1 k 500 F 910 2000 F VCC TL431 (DUT) 820 + VCC 1 F TLE2027 AV = 10 V/mV + - 16 k 16 160 k 16 k 1 F TLE2027 To Oscilloscope 22 F - 33 k AV = 2 V/V 0.1 F 33 k VEE VEE Figure 12. Test Circuit for Equivalent Input Noise Voltage POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 13 TL431C, TL431AC, TL431I, TL431AI, TL431M, TL431Y ADJUSTABLE PRECISION SHUNT REGULATORS SLVS005I - JULY 1978 - REVISED AUGUST 1998 TYPICAL CHARACTERISTICS SMALL-SIGNAL VOLTAGE AMPLIFICATION vs FREQUENCY A V - Small-Signal Voltage Amplification - dB 60 IKA = 10 mA TA = 25C 50 Output 15 k IKA 232 40 9 F + 30 - 8.25 k 20 GND 10 0 1k TEST CIRCUIT FOR VOLTAGE AMPLIFICATION 10 k 100 k 1M 10 M f - Frequency - Hz Figure 13 REFERENCE IMPEDANCE vs FREQUENCY |z KA | - Reference Impedance - 100 IKA = 10 mA TA = 25C 1 k Output 10 IKA 50 - + GND 1 TEST CIRCUIT FOR REFERENCE IMPEDANCE 0.1 1k 10 k 100 k 1M 10 M f - Frequency - Hz Figure 14 14 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 TL431C, TL431AC, TL431I, TL431AI, TL431M, TL431Y ADJUSTABLE PRECISION SHUNT REGULATORS SLVS005I - JULY 1978 - REVISED AUGUST 1998 TYPICAL CHARACTERISTICS PULSE RESPONSE 6 TA = 25C Input Input and Output Voltage - V 5 220 Output 4 Pulse Generator f = 100 kHz 3 50 Output GND 2 TEST CIRCUIT FOR PULSE RESPONSE 1 0 -1 0 1 2 3 4 5 6 7 t - Time - s Figure 15 STABILITY BOUNDARY CONDITIONS 100 I KA - Cathode Current - mA 90 80 A VKA = Vref B VKA = 5 V C VKA = 10 V D VKA = 15 Vf 150 TA = 25C IKA + VBATT CL B - 70 Stable 60 C Stable 50 A TEST CIRCUIT FOR CURVE A 40 30 D IKA 20 10 0 0.001 150 R1 = 10 k CL + 0.01 0.1 1 10 R2 CL - Load Capacitance - F - The areas under the curves represent conditions that may cause the device to oscillate. For curves B, C, and D, R2 and V+ were adjusted to establish the initial VKA and IKA conditions with CL = 0. VBATT and CL were then adjusted to determine the ranges of stability. VBATT TEST CIRCUIT FOR CURVES B, C, AND D Figure 16 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 15 TL431C, TL431AC, TL431I, TL431AI, TL431M, TL431Y ADJUSTABLE PRECISION SHUNT REGULATORS SLVS005I - JULY 1978 - REVISED AUGUST 1998 APPLICATION INFORMATION R (see Note A) VI(BATT) VO R1 0.1% Vref TL431 VO R2 0.1% + 1 ) R1 V R2 ref RETURN NOTE A: R should provide cathode current 1 mA to the TL431 at minimum VI(BATT). Figure 17. Shunt Regulator VI(BATT) VO TL431 Von 2 V Voff VI(BATT) Input VIT 2.5 V GND Figure 18. Single-Supply Comparator With Temperature-Compensated Threshold VI(BATT) R (see Note A) 2N222 2N222 30 0.01 F VO 4.7 k TL431 + 1 ) R1 V R2 VO R2 0.1% R1 0.1% NOTE A: R should provide cathode current 1 mA to the TL431 at minimum VI(BATT). Figure 19. Precision High-Current Series Regulator 16 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 ref TL431C, TL431AC, TL431I, TL431AI, TL431M, TL431Y ADJUSTABLE PRECISION SHUNT REGULATORS SLVS005I - JULY 1978 - REVISED AUGUST 1998 APPLICATION INFORMATION VI(BATT) IN uA7805 OUT Common VO R1 TL431 + 1 ) R1 V R2 Minimum V + V ) 5 V VO ref ref O R2 Figure 20. Output Control of a 3-Terminal Fixed Regulator VI(BATT) VO R1 VO + 1 ) R1 V R2 ref TL431 R2 Figure 21. High-Current Shunt Regulator VI(BATT) VO R1 TL431 R2 C (see Note A) NOTE A: Refer to the stability boundary conditions in Figure 16 to determine allowable values for C. Figure 22. Crowbar Circuit POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 17 TL431C, TL431AC, TL431I, TL431AI, TL431M, TL431Y ADJUSTABLE PRECISION SHUNT REGULATORS SLVS005I - JULY 1978 - REVISED AUGUST 1998 APPLICATION INFORMATION IN VI(BATT) LM317 8.2 k OUT Adjust VO 5 V, 1.5 A 243 0.1% TL431 243 0.1% Figure 23. Precision 5-V 1.5-A Regulator VO 5 V VI(BATT) Rb (see Note A) 27.4 k 0.1% TL431 27.4 k 0.1% NOTE A: Rb should provide cathode current 1-mA to the TL431. Figure 24. Efficient 5-V Precision Regulator 12 V VCC 6.8 k 5V 10 k - 10 k 0.1% TL431 10 k 0.1% + X Not Used TL598 Feedback Figure 25. PWM Converter With Reference 18 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 TL431C, TL431AC, TL431I, TL431AI, TL431M, TL431Y ADJUSTABLE PRECISION SHUNT REGULATORS SLVS005I - JULY 1978 - REVISED AUGUST 1998 APPLICATION INFORMATION R3 (see Note A) VI(BATT) R4 (see Note A) R1B R1A TL431 R2A V + 1 ) R1B R2B High Limit + 1 ) R1A V R2A Low Limit ref ref LED on When Low Limit < VI(BATT) < High Limit R2B NOTE A: R3 and R4 are selected to provide the desired LED intensity and cathode current 1 mA to the TL431 at the available VI(BATT). Figure 26. Voltage Monitor 650 12 V 2 k R TL431 Off Delay +R C In * 12 V 12 V V ref C On Figure 27. Delay Timer RCL 0.1% VI(BATT) R1 TL431 IO I out + RV ) I R1 + ref CL KA V I(BATT) I O h FE )I KA Figure 28. Precision Current Limiter POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 19 TL431C, TL431AC, TL431I, TL431AI, TL431M, TL431Y ADJUSTABLE PRECISION SHUNT REGULATORS SLVS005I - JULY 1978 - REVISED AUGUST 1998 APPLICATION INFORMATION VI(BATT) IO IO TL431 + VR ref S RS 0.1% Figure 29. Precision Constant-Current Sink 20 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with TI's standard warranty. Testing and other quality control techniques are utilized to the extent TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed, except those mandated by government requirements. CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE ("CRITICAL APPLICATIONS"). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, AUTHORIZED, OR WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT DEVICES OR SYSTEMS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF TI PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE FULLY AT THE CUSTOMER'S RISK. In order to minimize risks associated with the customer's applications, adequate design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right of TI covering or relating to any combination, machine, or process in which such semiconductor products or services might be or are used. TI's publication of information regarding any third party's products or services does not constitute TI's approval, warranty or endorsement thereof. Copyright 1998, Texas Instruments Incorporated