A A MICROELECTRONICS Adjustable Shunt Regulator GM1431 ADJUSTABLE SHUNT REGULATOR Features Description Sink Current Capability 1 mA to 100mA The GM1431 is a three terminal adjustable shunt regulator with thermal stability guaranteed over temperature. Output Low dynamic output impedance, 0.2W typ. 0.5%, 1% or 2% reference voltage tolerance voltage can be adjusted to any value between 2.5V (Vref) Alternate for TL431, TL431, LM431 & AS431 and 36V by using two external resistors. The GM1431 has Temperature range 0°C to+ 70 °C a typical dynamic output impedance of 0.2W. Active output Available in SOT-23, TO-92, SOT-89 and circuitry provides a very unique turn on characteristic, mak- SOP- 8 packages ing the GM1431 an excellent tum on replacement for zener diodes in many applications such as onboard regulation and adjustable power supplies. The GM1431 is an ideal voltage reference for 3.0 to 3.3V switching power supplies. The GM1431 shunt regulator is available with 3 voltage tolerances, 0.5%, 1.0% and 2.0% over TA= 0°C to + 70°C, and four package options (SOT-23, TO-92, SOT-89 and SOP-8). Whatever your application is, the GM1431 offers the optimum combination of performance, reliability, and economy. Application Switching power supplies Battery-operated computers Linear regulators Computer disk drives Adjustable supplies Instrumentation LOGIC SYMBOL BLOCK DIAGRAM (POSITIVE LOGIC) REFERENCE REFERENCE GM1431 V0.11 CATHODE + _ ANODE CATHODE V ref ANODE www.gammamicro.com PRELIMINARY 1 A Adjustable Shunt Regulator GM1431 A MICROELECTRONICS ADJUSTABLE SHUNT REGULATOR MARKING INFORMATION & PIN CONFIGURATIONS (TOP VIEW) TO- 92 SOP- 8 SOT-23 ANODE REF Anode GM 1431G AYWW 3 1 2 1 REF ANODE NC 8 7 6 5 XXXYW 1. REF 2. Anode 3. Cathode SOT - 89 GM1431G AYWW GM1431G AYWW 2 Cathode 1 2 3 4 CATHODE ANODE 3 REF 1 2 3 CATHODE ANODE NC ANODE XXX = Marking Code G** = Grade A = Assembly Location Y = Year WW, W= Weekly ORDERING INFORMATION GM1431 Ordering Number 2 Precision Device code Grade Package Shipping GM1431AT92B 0.5% A TO-92 1,000 Units/ ESD Bag GM1431AT92RL 0.5% A TO-92 2,000 Units/ Ammo Pack(Tape) GM1431AST23R 0.5% SOT-23 3,000 Units / Tape &Reel GM1431AS8T 0.5% A SOP-8 100 Units / Tube GM1431AS8R 0.5% A SOP-8 2,500 Units / Tape & Reel GM1431AST89R 0.5% A SOT-89 1,000 Units / Tape & Reel GM1431BT92B 1% B TO-92 1,000 Units/ ESD Bag GM1431BT92RL 1% B TO-92 2,000 Units/ Ammo Pack(Tape) GM1431BST23R 1% SOT-23 3,000 Units / Tape &Reel GM1431BS8T 1% B SOP-8 100 Units / Tube GM1431BS8R 1% B SOP-8 2,500 Units / Tape & Reel GM1431BST89R 1% B SOT-89 1,000 Units / Tape & Reel GM1431CT92B 2% C TO-92 1,000 Units/ ESD Bag GM1431CT92RL 2% C TO-92 2,000 Units/ Ammo Pack(Tape) GM1431CST23R 2% SOT-23 3,000 Units / Tape &Reel GM1431CS8T 2% C SOP-8 100 Units / Tube GM1431CS8R 2% C SOP-8 2,500 Units / Tape & Reel GM1431CST89R 2% C SOT-89 1,000 Units / Tape & Reel NAA NAB NAC * For detail Ordering Number identification, please see last page. **Grade A: indicates Precision of 0.5%, B: indicates Precision of 1%, C: indicates Precision of 2% A Adjustable Shunt Regulator GM1431 A MICROELECTRONICS ADJUSTABLE SHUNT REGULATOR EQUIVALENT SCHEMATIC CATHODE 800W 800W 20pF REF 150W 3.28KW 4KW 10kW 2.4KW 20pF 7.2KW 1kW 800W ANODE GM1431 * All component values are nominal. Pin numbers shown are for the D package. 3 A A MICROELECTRONICS Adjustable Shunt Regulator GM1431 ADJUSTABLE SHUNT REGULATOR ABSOLUTE MAXIMUM RATINGS (over free-air temperature range except as noted) SYMBOL VALUE UNIT VKA 37 V Continuous cathode current IK -100 to 150 mA Reference input current range Iref -50µA to 10mA mA Power dissipation at TA = 25°C SOT-23 SOP-8 TO-92 SOT-89 PD Package thermal impedance (2, 3) SOT-23 TO-92 SOP-8 SOT-89 qJA 336 132 163 132 Operating ambient temperature range TA 0 to 70 °C TLEAD TJ 260 °C PARAMETER Cathode Voltage (1) Lead temperature (soldering) 10 seconds 0.23 0.60 0.78 0.80 W °C/W These are stress ratings only. Functional operation of the device at these or any conditions beyond the "recommended operating conditions" is not implied. Exposure to absolute maximum rated conditions may affect device reliability. NOTES: 1. Voltage values are with respect to the anode except as noted. 2. Maximum power dissipation is a function of TJ(max), qJA and TA. Maximum allowable power dissipation at any allowable ambient temperature is PD = (TJ(max) 3. Package thermal impedance is calculated per JESD 51. RECOMMENDED OPERATING CONDITIONS SYMBOL MINIMUM MAXIMUM UNIT Cathode Voltage VKA Vref 36 V Cathode Current IK 1.0 100 mA GM1431 PARAMETER 4 A A MICROELECTRONICS Adjustable Shunt Regulator GM1431 ADJUSTABLE SHUNT REGULATOR ELECTRICAL CHARACTERISTICS (TA = 25°C unless otherwise noted) GM1431A (0.5%) PARAMETER CONDITION Reference Input Voltage Vref Vref temp deviation Vdev Ratio of change in Vref to change in VKA DVref DVKA Reference input current Iref VKA = Vref, IK = 10 mA, TA = 25°C (1) VKA=Vref,IK=10 mA,TA= 0 to 70°C(1) MIN TYP MAX UNIT 2.487 2.500 2.512 V 4 17 mV VKA = Vref, IK = 10 mA (1), TA = full range IK = 10mA DVKA = 10V to Vref DVKA = 36V to 10V IK = 10mA, R1 = 10KW, R2 = (2) Deviation of reference input current over full temperature range I = 10mA, R1 = 10KW, R2 = Iref(dev) K TA = full range (2) Minimum operating current IK(min) VKA = Vref (1) VKA = 36V, Vref = 0V -2.7 -2.0 -1.0 -0.4 mV/V 1.3 4.0 mA 0.4 1.2 mA 0.4 1.0 mA 0.1 1 mA 0.2 0.50 W MIN TYP MAX UNIT 2.474 2.500 2.525 V 4 17 mV (3) Off-state cathode current IK(off) Dynamic impedance | ZKA | f 1kHz,VKA=Vref, IK=100mA to 100mA (1) VKA = 16V, Vref = 0V (3) GM1431B (1.0%) CONDITION Reference Input Voltage Vref Vref temp deviation Vdev Ratio of change in Vref to change in VKA DVref DVKA Reference input current Iref VKA = Vref, IK = 10 mA, TA = 25°C (1) VKA=Vref,IK=10 mA,TA= 0 to 70°C(1) VKA = Vref, IK = 10 mA (1), TA = full range IK = 10mA DVKA = 10V to Vref DVKA = 36V to 10V IK = 10mA, R1 = 10KW, R2 = (2) Deviation of reference input current over full temperature range I = 10mA, R1 = 10KW, R2 = Iref(dev) K TA = full range (2) Minimum operating current IK(min) VKA = Vref (1) Off-state cathode current IK(off) Dynamic impedance | ZKA | f 1kHz,VKA=Vref, IK=100mA to 100mA (1) NOTES: (1) See test circuit 1 on page 5. (2) See test circuit 2 on page 5. (3) See test circuit 3 on page 5. VKA = 36V, Vref = 0V -2.7 -2.0 -1.0 -0.4 mV/V 1.3 4.0 mA 0.4 1.2 mA 0.4 1.0 mA 0.1 1 mA 0.2 0.50 W (3) VKA = 16V, Vref = 0V (3) GM1431 PARAMETER 5 A Adjustable Shunt Regulator GM1431 A MICROELECTRONICS ADJUSTABLE SHUNT REGULATOR ELECTRICAL CHARACTERISTICS (TA = 25°C unless otherwise noted) GM1431C (2.0%) PARAMETER CONDITION Reference Input Voltage Vref Vref temp deviation Vdev Ratio of change in Vref to change in VKA DVref DVKA Reference input current Iref VKA = Vref, IK = 10 mA, TA = 25°C (1) VKA=Vref,IK=10 mA,TA= 0 to 70°C(1) MIN TYP MAX UNIT 2.45 2.500 2.55 V 4 17 mV VKA = Vref, IK = 10 mA (1), TA = full range IK = 10mA DVKA = 10V to Vref DVKA = 36V to 10V IK = 10mA, R1 = 10KW, R2 = (2) Deviation of reference input current over full temperature range I = 10mA, R1 = 10KW, R2 = Iref(dev) K TA = full range (2) Minimum operating current IK(min) VKA = Vref (1) Off-state cathode current IK(off) Dynamic impedance | ZKA | f 1kHz,VKA=Vref, IK=100mA to 100mA (1) -2.7 -2.0 VKA = 36V, Vref = 0V (3) VKA = 16V, Vref = 0V (3) -1.0 -0.4 mV/V 1.3 4.0 mA 0.4 1.2 mA 0.4 1.0 mA 0.1 1 mA 0.2 0.50 W NOTES: (1) See test circuit 1. (2) See test circuit 2. (3) See test circuit 3. TEST CIRCUITS VIN VKA VIN VKA lref lk VIN VKA lk(off) R1 V ref R2 lref Vref GM1431 Vref 6 Test Circuit 1 V KA = V ref Test Circuit 2 V KA > V ref Test Circuit 3 Off-State A Adjustable Shunt Regulator GM1431 A MICROELECTRONICS ADJUSTABLE SHUNT REGULATOR TYPICAL APPLICATIONS GM1431A, GM1431B Vout Vin Vout Vin R1 R1 R2 R2 R1 Vout=( 1+ R2 ) Vref Vout=( 1+ Figure 1. Shunt Regulator Vin R1 ) Vref R2 Figure 2. High Current Shunt Regulator Vout Vin GM 7805 In Out Common Vout R1 R1 R2 R2 Vout=(1+ R1 )Vref R2 Vout=(1+ Vout(min) = Vref+ 5.0V Vout(min) = Vref+ Vbe Figure 3. Output Control for a Three Terminal Fixed Regulator RCL Vin Iout R1 ) Vref R2 2.0V Figure 4. Series Pass Regulator Vin Isink Vout V Isink= ref RS Vref RS RCL Figure 6. Constant Current Sink Figure 5. Constant Current Source Vout Vin Vout Vin R1 R1 R2 R2 Vout(trip)=(1 + R1 ) Vref R2 Figure 7. TRIAC Crowbar Vout(trip)=(1 + R1 ) Vref R2 Figure 8. SCR Crowbar GM1431 Iout= 7 A Adjustable Shunt Regulator GM1431 A MICROELECTRONICS ADJUSTABLE SHUNT REGULATOR Typical Performance Characteristics 800 150 Cathode current (mA) 200 Cathode current (mA) 1000 600 400 200 0 -200 50 0 -50 -100 -400 -1 -0.5 0 0.5 1 1.5 2 2.5 -150 -2 3 -1 0 1 2 3 Cathode Voltage (V) Cathode Voltage (V) Figure 9. Cathode Current vs. Cathode Voltage Figure 10. Cathode Current vs. Cathode Voltage 0.6 2.5 0.5 2 Impedance (W) Iref, REFERENCE INPUT CURRENT (mA) 100 0.4 0.3 0.2 1.5 1 0.5 0.1 0 0 0 20 40 60 80 0 100K 200K 300K 400K 500K 600K Frequency (Hz) T A , AMBIENT TEMPERATURE (°C) Avol, OPEN LOOP VOLTAGE GAIN (dB) Vref, REFERENCE INPUT VOLTAGE (V) 2.5 2.498 2.496 2.494 2.492 2.49 2.488 2.486 0 20 40 60 80 1k 10k 100k 1M f, FREQUENCY (HZ) Figure 13. Reference Input Voltage versus Figure 14. Open-Loop Voltage Gain vs. Frequency IK- Cathode Current (mA) GM1431 0° I KA =10mA 36° T A =25°C 72° 108° 144° 180° T A , AMBIENT TEMPERATURE (°C) Ambient Temperature 8 80 70 60 50 40 30 20 10 0 -10 -20 100 100 A: VKA = VREF 90 B: VKA = 5V 80 C: VKA = 10V 70 D: VKA = 15V 60 50 Stability A 40 Region 30 20 TA = 25° 10 B 0 0 1 2 3 4 5 6 7 10 10 10 10 10 10 10 10 CL-Load Capacitance(pF) Figure 15. Stability Boundary Conditions (No Oscillation at VKA=10V and VKA=15V) Phase Shift Figure 12. Dynamic Impedance Frequency Figure 11. Reference Input Current versus Ambient Temperature A Adjustable Shunt Regulator GM1431 A MICROELECTRONICS ADJUSTABLE SHUNT REGULATOR Design Guide for AC-DCSMPS (Switching Mode Power Supply) Use of Shunt Regulator in Transformer Secondary Side Control This example is applicable to both forward transformers and flyback transformers. A shunt regulator is used on the secondary side as an error amplifier, and feedback to the primary side is provided via a photocoupler. Transformer R1 SBD R3 GM384X GM38C4X (+) Output IF VF Phototransistor Photocoupler IB Light emitting diode VO R2 (-) Vref VK R5 C1 R4 REF GM1431 GND Figure 16. Typical Shunt Regulator/ Error Amplifier Determination of External Costants for the Shunt Regulator R1 = VO - VF - VK I F +I B , R2 = VF IB VK Is the GM1431 operating voltage, and is set at around 3V, taking into account a margin for fluctuation. R2 is the current shunt resistance for the light emitting diode, in which a bias current IB of around 1/5 IF flows. Next, the output voltage can be determined by R3 and R4, and the following formula is obtained: VO = R3 +R4 X V ref , V erf =2 .5 V Typ R4 The absolute values of R3 and R4 are determined by the GM1431 reference input current Iref and the AC characteristics described in the next section. The Iref value is around 1.3µA Typ. GM1431 Dc characteristic determination: In figure 16, R1 and R2 are protection resistor for the light emitting diode in the photocoupler, and R2 is a bypass resistor to feed IK Minimum, and these are determined as shown below. The photocoupler specification should be obtained separately from the manufacturer. Using the parameters in figure 16, the following formulas are obtained: 9 A Adjustable Shunt Regulator GM1431 A MICROELECTRONICS ADJUSTABLE SHUNT REGULATOR AC Characteristic Determination: This refers to the determination of the gain frequency characteristic of the shunt regulator as an error amplifier. Taking the configuration in figure 16, the error amplifier characteristic is as shown in figure 17. G1 Gain G (dB) * fosc: PWM switching frequency G2 When R5= 0 When R5= 0 f1 fAC f2 fosc Frequency f (Hz) Figure 17. GM1431 Error Amplification Characteristic In Figure 17, the following formulas are obtained: Gain G1 = G0 50 dB to 60 dB (determined by shunt regulator) G2 = R5 R3 Corner frequencies f1 = 1/(2p C1 G0 R3) f2 = 1/(2p C1 R5) G0 is the shunt regulator open-loop gain; this is given by the reciprocal of the reference voltage fluctuation DVref/DVKA, and is approximately 50 dB. Practical Example GM1431 Consider the example of a photocoupler, with an internal light emitting diode VF = 1.05 V and IF = 2.5 mA, power supply output voltage V2 = 5 V, and bias resistance R2 current of approximately 1/5 IF at 0.5 mA. If the shunt regulator VK = 3 V, the following values are found. 10 R1= 5V - 1.05V - 3V =316W 2.5mA + 0.54mA R 2= 1.05V =2.1 kW 0.54mA Next, assume that R3 = R4 = 10 kW. This gives a 5 V output. If R5 = 3.3 kW and C1 = 0.022 µF, the following values are found. G2 = 3.3 kW / 10 kW = 0.33 times (–10 dB) f1 = 1 / (2 x p x 0.022 µF x 316 x 10 kW) = 2.3 (Hz) f2 = 1 / (2 x p x 0.022 µF x 3.3 kW) = 2.2 (kHz) A Adjustable Shunt Regulator GM1431 A MICROELECTRONICS ADJUSTABLE SHUNT REGULATOR SOT-89 PACKAGE OUTLINE DIMENSIONS 4.50 ± 0.05 1.650 REF 2 NO DRAFT~2 R 0.13~3X G 3 R 0.13~4X 4.20 ± 0.05 2.5 ± 0.05 45° 6° 1.00 ± 0.07 Units: mm Pad Layout 1.50 ± 0.05 1.400 REF R 0.1 MAX 0.7 0.46 ± 0.025 1.50 3.00 ± 0.025 6°~2X 0.38 ± 0.01 1.5 1.50 1.5 1 R 0.13~2X R 0.13~2X Unit: mm 6°~2X SOT-23 PACKAGE OUTLINE DIMENSIONS 2.90 ± 0.1 0.13 0.4 ± 0.1 F 0~0.1 Pad Layout 1.5 ± 0.05 2.8 ± 0.1 0.031 0.8 0.035 0.9 0.65 ± 0.05 1.9 ± 0.05 5° 0.079 2.0 0.8 ± 0.05 0.037 0.95 0.037 0.95 Inches ( mm ) 1.10 ± 0.1 Unit: mm GM1431 0.95 ± 0.038 11 A Adjustable Shunt Regulator GM1431 A MICROELECTRONICS ADJUSTABLE SHUNT REGULATOR SOP-8 PACKAGE OUTLINE DIMENSIONS 0.008 +0.0018 -0.0005 (0.20 +0.05 -0.01 8° 0.028 +0.022 -0.013 (0.71 +0.56 -0.33 ) Pad Layout ) 0.060 1.52 0.236 ± 0.008 (5.99 +0.21 -0.20 ) R 0.154 +0.003 -0.004 0.275 0.155 7.0 4.0 PIN INDENT (3.91 ± 0.1) 0.024 0.050 0.6 1.270 Inches ( mm ) 0.191 +0.004 -0.002 (4.85 +0.10 -0.05 ) 0.057 (1.45) 0.063 ± 0.005 (1.60 ± 0.13) Inches ( mm ) 0.0025 ± 0.0015 (0.175 ± 0.075) 0.050 (1.270) 0.016 +0.004 -0.003 (0.41 +0.10 -0.08 ) TO-92 PACKAGE OUTLINE DIMENSIONS 4.6 ± 0.1 3.6 ± 0.15 2° 2° 4.6 ± 0.1 D 2.3 1.45 ± 0.1 GM1431 14.5 ± 0.5 12 2° 2° 3 - 0.46 0.38 ± 0.015 1.27 1.27 Unit: mm 3.6 ± 0.15 1.3 ± 0.1 5° 5° A Adjustable Shunt Regulator GM1431 A MICROELECTRONICS ADJUSTABLE SHUNT REGULATOR ORDERING NUMBER GM 1431 A T92 B Shipping B : ESD Bag RL: Ammo Pack R: Tape & Reel T: Tube Gamma Micro. Circuit Type (Tape) Package T92: TO-92 ST23: SOT-23 S8: SOP-8 ST89: SOT-89 GM1431 Voltage Tolerance A: 0.5% B: 1.0% C: 2.0% 13