Advanced Monolithic Systems AMS3431 PRECISION ADJUSTABLE SHUNT REGULATOR RoHS compliant FEATURES APPLICATIONS • Trimmed 0.25% Reference • Wide Operating Current Range 250µA to 150mA • Low Dynamic Output Impedance • Low Output Noise • Nominal Temperature Range to 85°C • Temperature-Compensated: 60ppm/°C • Internal Amplifier with 150mA Capability • Battery Powered Systems • Switching Power Supplies • Adjustable Power Supplies • Linear Regulators • Error Amplifiers • Notebook/Personal Computer • Monitors/ VCR/ TV • Pagers GENERAL DESCRIPTION The AMS3431 is a three-terminal adjustable shunt regulator with guaranteed temperature stability over the entire range of operation. The output voltage can be set to any value between 2.5V (VREF) and 36V by adding two external resistors. Due to the sharp turn-on characteristics this device is an excellent replacement for zener diodes in many applications. AMS3431 is available in the space saving SOT-23 package and in the TO-92 package. ORDERING INFORMATION: TOL. ±0.25% ±0.5% ±1.0% PACKAGE TYPE TO-92 AMS3431AN AMS3431BN AMS3431CN 3 LEAD SOT-23 AMS3431AM AMS3431BM AMS3431CM OPERATING TEMPERATURE RANGE -40 to +85° C -40 to +85° C -40 to +85° C PIN CONNECTIONS TO-92 Plastic Package (N) 3L SOT-23 (M) ANODE 1 2 CATHODE ANODE 3 REF Bottom View Advanced Monolithic Systems, Inc. CATHODE REF Top View www.advanced-monolithic.com Phone (925) 443-0722 Fax (925) 443-0723 AMS3431 ABSOLUTE MAXIMUM RATINGS (Note 1) Cathode Voltage (VZ) Continuous Cathode Current (IZ) Reference Input Current (IREF) Junction Temperature (TJ) Storage Temperature Lead Temperature (Soldering, 25sec.) 37V -10mA to +150mA 10mA -40°C to +125°C -65°C to +150°C 265°C Internal Power Dissipation (PD) TO-92 Package SOT-23 Package Thermal Resistance (ϕJA) TO-92 Package SOT-23 Package 0.78W 0.28W 160°C/W 410°C/W Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is intended to be functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics. The guaranteed specifications apply only for the test conditions listed. ELECTRICAL CHARACTERISTICS Electrical Characteristics at IZ =10 mA and TA = +25°C unless otherwise specified. Parameter Conditions Min Reference Voltage 2.489 AMS3431A Typ Max 2.495 2.501 8.0 8.0 Min 2.483 AMS3431B Typ Max 2.495 2.507 15 8.0 15 8.0 Min 2.470 AMS3431C Typ Max Units 2.495 2.520 V 15 8.0 15 mV 15 8.0 15 mV Deviation of Reference Input Voltage over Temperature VZ = VREF (circuit 1) TA = +25°C to +85°C TA = -40°C to +25°C Ratio of Change in Reference Voltage to Cathode Voltage VZ from VREF to 10V -0.5 -2.7 -0.5 -2.7 -0.5 -2.7 mV/V VZ from VREF to 36V -1.0 -2.0 -1.0 -2.0 -1.0 -2.0 mV/V R1 =10kΩ, R2 = ∞Ω 0.5 4.0 0.5 4.0 0.5 4.0 µA 0.4 1.2 0.4 1.2 0.4 1.2 µA 0.04 0.5 0.04 0.5 0.04 0.5 µA 0.25 0.5 0.25 0.5 0.25 0.5 Ω 100 250 100 250 100 250 µA Reference Input Current Reference Input Current Deviation over Temperature (test circuit 2) R1 =10kΩ, R2 = ∞Ω TA = Full Range (test circuit 2) Off State Cathode Current VZ = 36V, VREF = 0V Dynamic Output Impedance f < 1KHz, VZ = VREF ( test circuit 3) Minimum Operating Current IZ =100µA to 100mA (test circuit 1) VZ = VREF (test circuit 1) RECOMMENDED OPERATING CONDITIONS: Cathode Voltage, (VZ) Cathode Current, (IZ) Min VREF 0.25mA Advanced Monolithic Systems, Inc. Max 36 V 120mA www.advanced-monolithic.com Phone (925) 443-0722 Fax (925) 443-0723 AMS3431 TEST CIRCUITS VZ = VREF VIN VZ VIN IREF R1 IZ VZ VIN IZ OFF IREF IZ VREF R2 Figure 1. Test Circuit for VZ=VREF VREF Figure 2. Test Circuit for VREF vs IZ Test circuit for IREF. Figure 3. Test Circuit for Off-State Current TYPICAL APPLICATIONS Single Supply Comparator with Temperature Compensated Threshold Shunt Regulator VO V+ V+ R1 VREF OUT R2 VON ≈ 2V VOFF = V+ IN VTH ≈ 2.5V VO ≈ (1+R1/R2)VREF GND Series Regulator Higher Current Shunt Regulator V+ V+ VO 30Ω R1 0.01µF R1 R1 VO R2 VO ≈ (1+R1/R2)VREF Advanced Monolithic Systems, Inc. VO ≈ (1+R1/R2)VREF www.advanced-monolithic.com Phone (925) 443-0722 Fax (925) 443-0723 AMS3431 TYPICAL APPLICATIONS (Continued) Over Voltage/Under Voltage Protection Circuit Voltage Monitor V+ V+ OUT ON WHEN LOW < V+ < HIGH LIMIT LIMIT R1B R1A R1B R1A R2A R2B R2A R2B LOW LIMIT ≈ VREF( 1+R1B/R2B)+VBE LOW LIMIT ≈ VREF( 1+R1A/R2A) LIMIT LOW LIMIT ≈ VREF( 1+R1B/R2B)+VBE LOW LIMIT ≈ VREF( 1+R1A/R2A) Delay Timer LED ON WHEN LOW LIMIT < V+ < HIGH Current Limiter or Current Source V+ IO V+ RCL R OFF ON C IO =VREF/RCL DELAY = R*C*ln*V+/(V+)-VREF Constant Current Sink V+ IO RS IO = VREF/RS Advanced Monolithic Systems, Inc. www.advanced-monolithic.com Phone (925) 443-0722 Fax (925) 443-0723 AMS3431 TYPICAL PERFORMANCE CHARACTERISTICS Input Current vs VZ 150 500 IZ MIN 400 300 200 100 0 1.0 2.0 CATHODE VOLTAGE (V) 3.0 500 INPUTT CURRENT ( mA) REFERENCE VOLTAGE (V) INPUTT CURRENT ( µA) Τ Α = 25°C VZ = VREF 0 Input Current vs VZ Thermal Information 1000 TO-92 SOT-23 100 ΤΑ = 25°C VZ = VREF 100 50 0 25 70 85 TEMPERATURE (° C) 125 0 1.0 2.0 CATHODE VOLTAGE (V) 3.0 PACKAGE DIMENSIONS inches (millimeters) unless otherwise noted. 3L TO-92 PLASTIC PACKAGE (N) 0.060±0.005 (1.524±0.127) DIA 0.180±0.005 (4.572±0.127) 0.180±0.005 (4.572±0.127) 0.060±0.010 (1.524±0.254) 0.90 (2.286) NOM 0.140±0.010 (3.556±0.127) 5° NOM 0.500 (12.70) MIN 0.050±0.005 (1.270±0.127) Advanced Monolithic Systems, Inc. 0.050 (1.270) MAX 10° NOM UNCONTROLLED LEAD DIMENSIONS 0.016±0.003 (0.406±0.076) 0.015±0.002 (0.381±0.051) www.advanced-monolithic.com N (TO-92 ) AMS DRW# 042391 Phone (925) 443-0722 Fax (925) 443-0723 AMS3431 PACKAGE DIMENSIONS inches (millimeters) unless otherwise noted (Continued). 3 LEAD SOT-23 PLASTIC PACKAGE (M) 0.110-0.120 (2.794-3.048) 0.015-0.017 (0.381-0.432) 0.083-0.098 (2.108-2.489) 0.047-0.055 (1.194-1.397) 0.035-0.040 (0.889-1.016) 0.018-0.024 (0.457-0.610) 10° NOM 0.035-0.041 (0.089-1.041) 0.0034-0.0050 (0.086-0.127) 0.0005-0.0040 (0.013-0.102) 0.070-0.080 (1.778-2.032) 10° NOM 0.018-0.024 (0.457-0.610) (SOT-23 ) AMS DRW# 051991 Advanced Monolithic Systems, Inc. www.advanced-monolithic.com Phone (925) 443-0722 Fax (925) 443-0723