CATHODE REF R F ATHODE - Diodes Incorporated

1 AS431 Document number: DS36599 Rev. 4 - 2 1 of 20 May 2018 Diodes Incorporated AS431 ADJUSTABLE precision SHUNT REGULATORS Description The AS431 is a three-terminal adjustable shunt regulator with guaranteed thermal stability over a full operation range. It features sharp turn-on characteristics, low temperature coefficient and low output impedance, which make it ideal substitute for Zener diode in applications such as switching power supply, charger and other adjustable regulators. The output voltage of AS431 can be set to any value between VREF ( ) and the corresponding maximum CATHODE voltage (36V).

2 The AS431 precision reference is offered in two voltage tolerance: and This IC is available in 4 packages: TO92 (Ammo Packing), SOT23, SOT25 and SOT89. Features Programmable Precise Output voltage from to 36V High Stability under Capacitive Load Low Temperature Deviation: Typical Low Equivalent Full-range Temperature Coefficient with 20 PPM/ C Typical Sink Current Capacity from 1mA to 100mA Low Output Noise Wide Operating Range of -40 to +125 C Lead-Free Packages: SOT23, SOT25, TO92 (Ammo Packing), SOT89 Totally Lead-Free; RoHS Compliant (Notes 1 & 2) Lead-Free Packages, Available in Green Molding Compound: SOT23, SOT25, TO92 (Ammo Packing), SOT89 Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free.

3 Green Device (Note 3) Applications Charger voltage Adapter Switching Power Supply Graphic Card precision voltage reference Pin Assignments (Top View) (Top View) SOT23 SOT25 Note 4: * Pin 2 is attached to substrate and must be connected to ANODE or open. (Top View) (Top View) SOT89 (Option 1) SOT89 (Option 2) (Top View) TO92 (Ammo Packing) Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS), 2011/65/EU (RoHS 2) & 2015/863/EU (RoHS 3) compliant.

4 2. See for more information about Diodes Incorporated s definitions of Halogen- and Antimony-free, "Green" and Lead-free. 3. Halogen- and Antimony-free "Green products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and <1000ppm antimony compounds. ANODECATHODEREF321123 REFCATHODEANODE123 REFCATHODEANODEREFCATHODEANODE12345NC(No te 4)*REFCATHODEANODE123 AS431 Document number: DS36599 Rev. 4 - 2 2 of 20 May 2018 Diodes Incorporated AS431 Typical Applications Circuit Shunt Regulator High Current Shunt Regulator Current Source or Current Limit AS431 Document number: DS36599 Rev.

5 4 - 2 3 of 20 May 2018 Diodes Incorporated AS431 Typical Applications Circuit (Cont.) precision 5V 1A Regulator PWM Converter with reference AS431 Document number: DS36599 Rev. 4 - 2 4 of 20 May 2018 Diodes Incorporated AS431 Functional Block Diagram Absolute Maximum Ratings (Note 5) Symbol Parameter Rating Unit VKA CATHODE voltage 40 V IKA CATHODE Current Range (Continuous) -100 to 150 mA IREF reference Input Current Range 10 mA PD Power Dissipation Z, R Package 770 mW N, K Package 370 TJ Junction Temperature +150 C TSTG Storage Temperature Range -65 to +150 C ESD ESD (Human Body Model) 2000 V Note 5: Stresses greater than those listed under Absolute Maximum Ratings may cause permanent damage to the device.

6 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 Ratings for extended periods may affect device reliability. Recommended Operating Conditions Symbol Parameter Min Max Unit VKA CATHODE voltage VREF 36 V IKA CATHODE Current 100 mA TA Operating Ambient Temperature Range -40 +125 C AS431 Document number: DS36599 Rev. 4 - 2 5 of 20 May 2018 Diodes Incorporated AS431 Electrical Characteristics (Operating Conditions: TA = +25 C, unless otherwise specified.)

7 Symbol Parameter Test Circuit Conditions Min Typ Max Unit VREF reference voltage 4 VKA = VREF, IKA = 10mA V VREF Deviation of reference voltage Over Full Temperature Range 4 VKA = VREF, IKA = 10mA 0 to +70 C 8 mV -40 to +85 C 10 -40 to +125 C 16 VREF VKA Ratio of Change in reference voltage to the Change in CATHODE voltage 5 IKA = 10mA VKA = 10V to VREF mV/V VKA = 36V to 10V IREF reference Current 5 IKA = 10mA, R1 = 10k , R2 = 4 A IREF Deviation of reference Current Over Full Temperature Range 5 IKA = 10mA, R1 = 10k , R2 = , TA = -40 to +125 C A IKA (Min) Minimum CATHODE Current for Regulation 4 VKA = VREF mA IKA (Off) Off-state CATHODE Current 6 VKA = 36V, VREF = 0 A ZKA Dynamic Impedance 4 VKA = VREF, IKA = 1 to 100mA, f JC Thermal Resistance SOT23 C/W SOT25 TO92 (Ammo Packing) SOT89 AS431 Document number: DS36599 Rev.

8 4 - 2 6 of 20 May 2018 Diodes Incorporated AS431 Electrical Characteristics (Cont.) Test Circuit 4 for VKA = VREF Test Circuit 5 for VKA > VREF Test Circuit 6 for IOFF AS431 Document number: DS36599 Rev. 4 - 2 7 of 20 May 2018 Diodes Incorporated AS431 Performance Characteristics reference voltage vs. Ambient Temperature reference Current vs. Ambient Temperature CATHODE Current vs. CATHODE voltage CATHODE Current vs. CATHODE voltage Off-State CATHODE Current Ratio of Delta reference voltage to the vs.

9 Ambient Temperature Ratio of Delta CATHODE voltage voltage (V)Ambient Temperature (oC)VKA = VREFIKA = R1=10K,R2=Infinite IKA=10mAReference Current ( A)Ambient Temperature (0C)-2-10123-100-50050100150 CATHODE Current (mA) CATHODE voltage (V)VKA=VREFTA= Current ( A) CATHODE voltage (V)VKA=VREFTA= CATHODE Current ( A)Ambient Temperature (oC)VKA=36 VVREF=0 to 36V VREF / VKA (mV/V)Ambient Temperature (oC) AS431 Document number: DS36599 Rev. 4 - 2 8 of 20 May 2018 Diodes Incorporated AS431 Performance Characteristics (Cont.)

10 Small Signal voltage Gain vs. Frequency reference Impedance vs. Frequency Stability Boundary Conditions vs. Load Capacitance 1k10k100k1M-10010203040506070 voltage Gain (dB)Small Signal Frequency (Hz)TA=250 CIKA=10mA1K10K100K1, Impedance ( )Frequency (Hz)IKA=10mATA= Current (mA)Load Capacitance ( F)TA=25oCVKA=VREF VKA= 5V:No oscillation VKA=10V:No oscillation VKA=15V:No oscillation AS431 Document number: DS36599 Rev.