AS2431 Micropower SOT-23, 2.5V Precision Adjustable Shunt Regulator FEATURES APPLICATIONS • • • • • • • • • • • • • Voltage Tolerance ............................................... 0.5% Wide Operating Current ..................... 1ma to 100mA Extended Temperature Range ...............0°°C to 105°°C Low Temperature Coefficient ........................30 ppm/°C Offered In Small Low Power SOT-23 Package Low Output Noise Battery Operating Equipment Adjustable Supplies Switching Power Supplies Error Amplifiers Single Supply Amplifier Monitors / VCR / TV Personal Computers PRODUCT DESCRIPTION The AS2431 is a 3-terminal Adjustable Shunt Voltage Regulator providing a highly accurate 0.5% bandgap reference. AS2431 acts as an open-loop error amplifier with a 2.5V temperature compensation reference. The AS2431 thermal stability, wide operating current (100mA) and temperature range (105°C) makes it suitable for all variety of applications that are looking for a low cost solution with high performance. AS2431 tolerance of 0.5% is proven to be sufficient to overcome all of the other errors in the system to virtually eliminate the need for trimming in the power supply manufactures assembly line and contribute a significant 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 AS2431 is a direct replacement for the AS431 and TL431 in low voltage, low current applications. ORDERING INFORMATION SOT-23 5-PIN AS2431YM5 SOT-23 3-PIN AS2431YM TEMP OPER RANGE 0°C to 105°C Y = Output Accuracy (Y= A or Blank) PIN CONNECTIONS SOT-23-5 SOT-23-5 N/C N/C N/C N/C 5 4 5 4 3 1 AS2431 1 REF 2 ANODE AS2432 CATHODE Top View 0.5% Device REF 2 SOT-23 SOT-23 ANODE ANODE AS2431 AS2432 3 ANODE Top View 1% Device CATHODE REF CATHODE Top View 0.5% Device REF CATHODE Top View 1% Device Rev. 10/11/00 AS2431 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 1 300 150 - 65 to 150 300 Units V A mA mA 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 Current Voltage Cathode Current Symbol VKA IK Rating VREF to 18 10 TYPICAL THERMAL RESISTANCES Unit V mA Package SOT-23 0JA 575° C/W 0JC 150° C/W Typical Derating 1.7 mW/°C Rev. 10/11/00 AS2431 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. AS2431A AS2431 Test Parameter Symbol Test Condition Min Typ Max Min Typ Max Unit Circuit Reference Voltage VREF 2.487 2.500 2.513 2.474 2.500 2.526 V 1 TA = 25° C Over Temp. 2.480 2.520 2.460 2.540 V 1 TC 0.07 0.20 0.07 0.20 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 to 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 IK (MIN) 0.4 1 0.4 1 mA 1 Off State Leakage IK (OFF) VREF = 0V 0.04 500 0.04 500 nA 3 VKA = 18V Dynamic Output f < 1 kHz IK = ZKA 0.15 0.5 0.15 0.5 1 Ω Impedance 1 to 100mA mV % 0 ∆VREF ∆Τ -10 5000 TC in %/°C = 0.5 -20 ∆VREF (mV) TC in mV/°C = -55 -25 0 25 50 75 100 125 ∆TA TC in ppm/°C = ∆VREF VREF at 25°C ) x 100 ∆TA ) 0 ) 0 ppm Calculating Average Temperature Coefficient (TC) ∆VREF VREF at 25°C ) x 106 ∆TA Temperature (°C) 0.06 mV/°C 0.002 %/°C 24 ppm/°C Rev. 10/11/00 AS2431 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 AS2431 TYPICAL PERFORMANCE CURVES High Current Operating Characteristics Low Current Operating Characteristics 900 150 VKA = VREF Temperature Range: - 0 to 105 °C 800 700 100 600 500 400 105 °C 300 25 °C 200 75 IK - Cathode Current (mA) µA) IK - Cathode Current (µ VKA = V REF Temperature Range: - 0 to 105 °C 125 50 25 0 -25 -0°C 100 -50 0 -75 -100 -100 -200 -1.0 0 1.0 2.0 -2 3.0 -1 0 2 3 Figure 3 Figure 2 Off State Leakage Reference Voltage vs. Ambient Temperature 100 2.53 VKA = 18V VREF = 0V V KA= V REF IK = 10 mA 2.52 VREF - Reference Voltage (V) IZ off - Off State Cathode Current (nA) 1 VKA - Cathode Voltage (V) VKA - Cathode Voltage (V) 10 1 0.1 2.51 2.50 VREF = 2.500 V at 25 °C 2.49 2.48 2.47 2.46 0.01 -60 -30 0 30 60 TA - Ambient Temperature ( °C) Figure 4 90 120 2.45 -60 -30 0 30 60 90 120 TA - Ambient Temperature ( °C) Figure 5 Rev. 10/11/00 AS2431 TYPICAL PERFORMANCE CURVES Reference Input Current VREF - Change in Reference Voltage (mV) IREF - Reference Input Currentµ(A) R1 = 10 k Ω R2 = ∞ IK = 10 mA 2.5 Reference Voltage Line Regulation 0 3.0 2.0 1.5 1.0 0.5 -10 0 °C -20 25 °C 75 °C -30 105 °C -40 -50 0 -60 -30 0 30 60 90 120 0 3 6 9 12 15 TA - Ambient Temperature ( °C) VKA - Cathode Voltage (V) Figure 6 Figure 7 18 Low Frequency Dynamic Output Impedance Noise Voltage 0.150 70 VKA = VREF IKA = 1 to 100 mA f < 1 kHz 60 ZKA - Dynamic Impedance (Ω ) 0.125 Noise Voltage nV/√Hz 50 40 30 20 0.100 0.075 0.050 0.025 10 V KA = V REF IK = 10 mA TA = 25°C 0.0 0 -60 10 100 1k f - Frequency (Hz) Figure 8 10 k 100 k -30 0 30 60 90 120 TA - Free Air Temperature Figure 9 Rev. 10/11/00 AS2431 TYPICAL PERFORMANCE CURVE Dynamic Output Impedance 100 ZKA - Dynamic Impedance TA = 25 °C IK = 1 to 100 mA 10 1.0 0.1 0.01 1k 10 k 100 k 10 M 1M f - Frequency (Hz) Figure 10 Small Signal Voltage Gain vs. Frequency 70 AV - Small Signal Voltage Gain (dB) Temperature Range: -0 to 105 °C 60 IK = 10 mA 50 OUT 40 15 k IK 230 Ω 9 µF 30 8.25 k 20 GND 10 0 1k 10 k 100 k f - Frequency (Hz) 1M 10 M Figure 11 Rev. 10/11/00 AS2431 TYPICAL PERFORMANCE CURVES Pulse Response 6 INPUT Input and Output Voltages (V) 5 INPUT MONITOR 220 Ω OUT 4 3 OUTPUT 50 Ω fP = 100 kHz 2 1 GND 0 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 t - Time ( µs) Figure 12 Stability Boundary Conditions 100 A: B: C: D: 90 V KA = V REF V KA = 5V at I K = 10 mA V KA = 10V at I K = 10 mA V KA= 15V at I K = 10 mA 80 IK - Cathode Current (mA) 70 C 60 150 Ω IK 50 40 STABILITY REGION CL 30 A 20 TA = 25 °C 10 10 k B D 0 100 101 102 103 104 105 CL - Load Capacitance (pF) 106 107 Figure 13 Rev. 10/11/00