AS3431 Micropower SOT-23, 2.5V Precision Adjustable Shunt Regulator FEATURES APPLICATIONS • • • • • • • • • • • • • Voltage Tolerance ..................................0.5% & 1.0% Wide Operating Current ................... 1ma To 100mA Extended Temperature Range .......................... 105°°C Low Temperature Coefficient ........................30 ppm/°C Offered in SOT-23, TO-92 & SOT 89 Low Output Noise Battery Operating Equipment Adjustable Supplies Switching Power Supplies Error Amplifiers Single Supply Amplifier Monitors / VCR / TV Personal Computers PRODUCT DESCRIPTION The AS3431 is a 3-terminal Adjustable Shunt Voltage Regulator providing a highly accurate 0.5% bandgap reference. AS3431 acts as an open-loop error amplifier with a 2.5V temperature compensation reference. The AS3431 thermal stability, wide operating current (100mA) and temperature range (0°C to 105°C) makes it suitable for all variety of applications that are looking for a low cost solution with high performance. AS3431 tolerance of 0.5% is proven to be sufficient to overcome all the other errors in the system to virtually eliminate the need for trimming in the power supply manufactures assembly line and contribute a big Cost Savings. In the standard shunt configuration, the combination of low temperature coefficient (T.C.), sharp turn-on characteristics, low output impedance and programmable output voltage make this precision reference an excellent error amplifier. The AS3431 is a direct replacement for the AS431 and TL431 in low voltage, low current applications. AS3431 is also available in SOT-89 and TO-92. ORDERING INFORMATION TO-92 AS3431AN AS3431N SOT-23- 3-PIN AS3431AM AS3431M SOT-89- 3-PIN AS3431AM1 AS3431M1 TEMP RANGE 0°C to 105°C 0°C to 105°C Output Accuracy 0.5% 1% The AS3431AM is 0.5% tolerance and the marking on the pin should be “3431” The AS3431M is 1% tolerance and the marking on the pin should be “3432” SOT-23 Marking & pinout for the 0.5% device TO-92 (N) 1 2 ANODE PIN CONNECTIONS SOT-23 Marking & pinout for the 1% device ANODE SOT-89 Marking & pinout for all devices 3 3431 3431 3432 1 CATHODE REF ANODE Top View CATHODE REF Top View CATHODE REF Top View CATHODE 2 ANODE 3 REF Top View Rev. 10/11/00 AS3431 CATHODE (K) REFERENCE (R) + - 2.5V ANODE (A) ABSOLUTE MAXIMUM RATINGS Parameter Cathode-Anode Reverse Breakdown Anode-Cathode Forward Current Operating Cathode Current Reference Input Current Continuous Power Dissipation at 25°C SOT-23 Junction Temperature Storage Temperature Lead Temperature (Soldering 10 sec.) Symbol VKA IAK IKA IREF PD TJ TSTG TL Rating 18 1 100 1 Units V A mA mA 300 150 - 65 to 150 300 mW °C °C °C Stresses greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability. RECOMMENDED CONDITIONS Parameter Cathode Voltage Cathode Current Symbol VKA 1K Rating VREF to 18 10 TYPICAL THERMAL RESISTANCES Unit V mA Package SOT-23 SOT-89 TO-92 0JA 575° C/W 575° C/W 575° C/W 0JC 150° C/W 80° C/W 80° C/W Typical Derating 1.7 mW/°C 9.1 mW/°C 6.3 mW/°C Rev. 10/11/00 AS3431 ELECTRICAL CHARACTERISTICS are guaranteed over full junction temperature range (0°C to 105°C). Ambient temperature must be derated based on power dissipation and package thermal characteristics. The conditions are: VKA = VREF and IK = 10mA, unless otherwise specified. AS3431A AS3431 Parameter Symbol Test Condition Min Typ Max Min Typ Max Unit Circuit Reference Voltage VREF 2.490 2.503 2.515 2.475 2.500 2.525 V 1 TA = 25° C Over Temp. 2.480 2.530 2.450 2.550 V 1 TC 0.07 0.20 0.07 0.02 1 ∆VREF with Temp* mV/°C Ratio of Change in VREF -2.7 -1.01 -2.7 -1.01 VREF to 10 V ∆VREF MV/V 2 to Cathode Voltage 10 V 10 18 V -2 -0.4 0.3 -2 -0.4 0.3 ∆VK Reference Input Current IREF 0.7 4 0.7 4 2 µA IREF Temp Deviation 0.4 1.2 0.4 1.2 2 ∆IREF µA Min IK for Regulation VREF = 0V IK (MIN) 0.4 1 0.4 1 mA 1 VKA = 18V Off State Leakage IK (OFF) 0.04 500 0.04 500 nA 3 Dynamic Output f < 1 kHz IK = ZKA 0.15 0.5 0.15 0.5 1 Ω Impedance 1 to 100mA mV % 0 ∆Τ 2000 0.2 TC in %/°C = -5 -10 0 15 30 45 60 ∆VREF (mV) TC in mV/°C = ∆VREF 75 90 105 ∆TA TC in ppm/°C = ∆VREF VREF at 25°C ) 0 ) 0 ppm Calculating Average Temperature Coefficient (TC) ) x 100 ∆TA ∆VREF VREF at 25°C ) x 106 ∆TA Temperature (°C) 0.019 mV/°C 0.001 %/°C 7.6 ppm/°C Rev. 10/11/00 AS3431 Test Circuits VIN VKA = VREF IREF IK VIN VKA R1 IK VIN VKA IK (OFF) (VREF) R2 Figure 1a. Test Circuit 1 Figure 1b. Test Circuit 2 Figure 1c. Test Circuit 3 Rev. 10/11/00