SPX2431 ® Precision Adjustable Shunt Regulator FEATURES ■ Trimmed Bandgap to 0.5% and 1.0% ■ Wide Operating Current 1mA to 100mA ■ Extended Temp. Range: 0°C to 105°C ■ Low Temperature Coefficient 30 ppm/°C ■ Offered in 3 Pin SOT-23 (M) ■ Replacement for TL431, AS2431 ■ Low Noise Output APPLICATIONS ■ Battery Operating Equipment ■ Adjustable Supplies ■ Switching Power Supplies ■ Error Amplifiers ■ Single Supply Amplifier ■ Monitors / VCRs / TVs ■ Personal Computers DESCRIPTION The SPX2431 is a 3-terminal adjustable shunt voltage regulator providing a highly accurate bandgap reference. The SPX2431 acts as an open-loop error amplifier with a 2.5V temperature compensation reference. The SPX2431’s thermal stability, wide operating current (100mA) and temperature range (0°C to 105°C) makes it suitable for a variety of applications that require a low cost, high performance solution. SPX2431A 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 manufacturer's assembly line and contribute a significant cost savings. The output voltage may be adjusted to any value between VREF and 20 volts with two external resistors. In the standard shunt configuration, the combination of a low temperature coefficient, sharp turn on characteristics, low output impedance, and programmable output voltage makes this precision reference an excellent error amplifier. The SPX2431 is available in SOT-23-3 package. FUNCTIONAL DIAGRAM Cathode (K) Reference (R) + 2.5V Anode (A) Date: 05/25/04 SPX2431 Precision Adjustable Shunt Regulator 1 © Copyright 2003 Sipex Corporation ABSOLUTE MAXIMUM RATINGS Cathode-Anode Reverse Breakdown VKA ....................................... 20V Anode-Cathode Forward Current, (<10ms) IAK ................................. 1A Operating Cathode Current IKA .................................................. 100mA Reference Input Current IREF ....................................................... 1.0mA Continuos Power Dissipation at 25°C PD SOT-23 .................................................................. 200 mW Junction Temperature TJ ........................................................... 150 °C Storage Temperature TSTG .............................................. -65 to 150 °C Lead Temperature (Soldering 10 sec.) TL .................................. 300°C NOTE: 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 TYPICAL THERMAL RESISTANCES PARAMETER SYMBOL RATING UNIT Cathode Voltage VKA VREF to 20 V Cathode Current IK 10 mA PACKAGE SOT-23 0JA 0JC TYPICAL DERATING 575°C/W 150°C/W 1.7 mW/°C Typical deratings of the thermal resistances are given for ambient temperature >25°. ELECTRICAL CHARACTERISTICS Electrical characteristics at 25°C IK = 10mA VK = VREF, unless otherwise specified. PARAMETER SYMBOL FIGURE CONDITIONS MIN TYP MAX MIN SPX2431A Reference Voltage ∆VREF withTemp.* Ratio of Change in VREF to Cathode Voltage VREF TC 2 2 3 Reference Input Current IREF 3 IREF Temp Deviation ∆IREF 3 Min IK for Regulation IK(MIN) 2 Off State Leakage IK(OFF) 4 Date: 05/25/04 ZKA 2.487 2.480 2.500 2.513 2.520 0.07 0.20 -2.7 -2.0 -1.01 -0.4 2 ∆ VREF ∆VK Dynamic Output Impedance TJ = 0°C to 105°C 2 VREF to 10V 10V to 20V TJ = 0°C to 105°C MAX UNITS 0.3 2.474 2.460 2.500 2.526 2.540 V V 0.07 0.20 mV/°C -2.7 -2.0 -1.01 -0.4 0.3 mV/V 0.7 4.0 0.7 4.0 µA 0.4 1.2 0.4 1.2 µA 0.4 1.0 0.4 1.0 mA 0.04 500 nA 0.15 0.5 Ω VREF = 0V, VKA = 20V 0.04 ƒz ≤ 1kHz IK = 1 to 100mA 0.15 SPX2431 Precision Adjustable Shunt Regulator 2 TYP SPX2431 0.5 © Copyright 2004 Sipex Corporation CALCULATING AVERAGE TEMPERATURE COEFFICIENT (TC) ppm 0 % mV 0 0 ∆VREF(mV) ∆TA • TC in mV / °C = ∆VREF ∆T • TC in % / °C = -5 5000 ( ∆VREF ∆VREF at 25°C 0 15 30 45 60 75 90 105 x 100 ∆ TA 0.5 • TC in ppm / °C = ) ( ∆VREF ∆VREF at 25°C ) x 106 ∆TA Junction Temperature (°C) 0.0033mV /°C 0.0027% / °C 27ppm/°C Figure 1. VREF VS Temperature TEST CIRCUITS VIN VKA = VREF VIN VKA VIN VKA IK (OFF) IREF IK R1 IREF IK (VREF) R2 Figure 2. Test Circuit for VKA = VREF Date: 05/25/04 Figure 3. Test Circuit for VKA > VREF SPX2431 Precision Adjustable Shunt Regulator 3 Figure 4. Test Circuit for IKOFF © Copyright 2003 Sipex Corporation TYPICAL PERFORMANCE CHARACTERISTICS 2.53 150 125 VREF Reference Voltage (V) IK Cathode Current (mA) 75 50 25 0 -25 -50 2.51 2.50 2.49 2.48 2.47 2.46 -75 -100 -2 -1 0 1 2 VKA Cathode Voltage (V) 2.45 -60 3 -30 0 30 60 90 120 TA Ambient Temperature (°C) Figure 6. Reference Voltage VS Ambient Tempetature Figure 5. High Current Operating Characteristics 900 3.0 800 IREF Reference Input Current (µA) VKA = VREF 0° to 105°C 700 IK Cathode Current (µA) VKA = VREF IK = 10mA 2.52 VKA = VREF 0°C to 105°C 100 600 500 400 105°C 300 25°C 200 -0°C 100 0 -100 -200 -1.0 0 1.0 2.0 VKA Cathode Voltage (V) R1 = 10kΩ R2 = ∞ IK = 10mA 2.5 2.0 1.5 1.0 0.5 0 -60 3.0 -30 0 30 60 90 120 TA Ambient Temperature (°C) Figure 8. Reference Input Current VS Ambient Temperature Figure 7. Low Current Operating Characteristics 70 0 60 Noise Voltage n/√Hz -10 ∆VREF (mV) 0°C -20 25°C 75°C -30 125°C IKA = 10mA -40 -50 0 50 40 30 20 10 3 6 9 12 15 18 21 24 0 10 27 30 100 1K 10K 100K f Frequency (Hz) VKA Cathode Voltage (V) Figure 10. Noise Voltage VS Frequency Figure 9. Reference Voltage Line Regulation VS Cathode Voltage and TAMBIENT Date: 05/25/04 VKA = VREF IK = 10mA TA = 25°C SPX2431 Precision Adjustable Shunt Regulator 4 © Copyright 2004 Sipex Corporation TYPICAL PERFORMANCE CHARACTERISTICS: Continued ZKA Dynamic Impedance (Ω) 0.125 /DIV 10.000dB 45.000deg REF LEVEL 60.000dB 0.0deg 0.150 VKA = VREF IK = 1 to 100mA f≤1kHz MARKER 25 297 698.000 Hz MAG (A/R) -0.025 dB MARKER 25 297 698.000 Hz PHASE (A/R) 93.320 deg 60dB 215° 180° 50dB PHASE 0.100 0.075 40dB 135° 30dB 90° 20dB 45° 0° 10dB GAIN 0.050 0.025 -45° -10dB -90° -20dB -135° -30dB 0.0 -60 0dB -30 0 30 60 90 120 -180° -40dB 10 TA Free Air Temperature 100 1K 10K 100K START 10.000Hz 1M -215° 10M STOP 50 000 000.000Hz Figure 12. Small Signal Gain and Phase VS Frequency; IK = 10mA, TA = 25°C Figure 11. Low Frequency Dynamic Output Impedance VS TAMBIENT VOUT VIN 230Ω 9µF 15kΩ IK VOUT VIN 8.25kΩ GND Figure 13. Test Circuit for Gain and Phase Frequency Response Figure 14. Frequency = 100kHz, IK = 10mA, TA = 25°C 100 VIN 90 250Ω 80 IK Cathode Current (mA) VOUT IK fp = 100kHz 50Ω A: VKA = VREF B: VKA= 5V at IK=10mA C: VKA=10V at IK=10mA D: VKA=15V at IK=10mA 70 C 60 50 40 STABLE STABLE A 30 20 TA = 25°C 10 B D 0 100 GND 102 103 104 105 106 107 CL Load Capacitance (pF) Figure 15. Test Circuit for Pulse Response Date: 05/25/04 101 Figure 16. Stability Boundary Conditions SPX2431 Precision Adjustable Shunt Regulator 5 © Copyright 2003 Sipex Corporation TYPICAL PERFORMANCE CHARACTERISTICS: Continued 100 ZKA Dynamic Impedance (Ω) 150 Ω IK R CL 10kΩ TA = 25°C IK = 1 to 100mA 10 1.0 0.1 0.01 1K 100K 1M f Frecuency (Hz) 10M Figure 18. Dynamic Output Impedance TA = 25°C, IK = 1 to 100mA Figure 17. Test Circuit for Stability 100 IKOFF Cathode Current (nA) 10K R3 VIN VOUT 10 R1 0.1% VKA = 20V VREF = 0V 1 VREF SPX2431 0.1 R2 0.1% 0.01 -50 0 50 100 150 TA Ambient Temperature (°C) Figure 19. Off State Leakage Figure 20. Shunt Regulator VOUT = (1+R1/R2)VREF VIN VOUT ISINK R3 R2 R1 0.1% Opto Isolator Q1 R3 sets feedback gain, C1 provides feedback compensation Isolated Feedback SPX2431 C1 C2 R1 0.1% + SPX2431 R2 0.1% VOUTRTN Figure 22. Reference Amplifier for Isolated Feedback in Off-Line DC-DC Converters Figure 21. Constant Current, Sink, ISINK = VREF/R1 Date: 05/25/04 SPX2431 Precision Adjustable Shunt Regulator 6 © Copyright 2004 Sipex Corporation TYPICAL PERFORMANCE CHARACTERISTICS: Continued VIN VIN VOUT R5 R1 0.1% R4 C1 R1 0.1% R3 R2 0.1% R3 VOUT SPX2431 Q1 SPX2431 R2 0.1% Figure 23. Precision High Current Series Regulator VOUT = (1+R1/R2)VREF Figure 24. High Current Shunt Regulator VOUT = (1+R1/R2)VREF VCC R2 VIN R1 * Resistor values are chosen such that the effect to IREF is negligible. VOUT SPX2431 Figure 25. Single Supply Comparator with Temperature Compensated Threshold. VIN Threshold = 2.5V Date: 05/25/04 SPX2431 Precision Adjustable Shunt Regulator 7 © Copyright 2003 Sipex Corporation PACKAGES: 3 PIN SOT-23 D b B 3 B E1 1 SEE VIEW C E VIEW A-A 2 e Gauge Plane e1 Seating Plane L Ø L1 VIEW C 3 PIN SOT-23 JEDEC TO-236 (AB) Variation Dimensions in (mm) A MIN A 0.89 A1 0.01 A2 NOM MAX - 1.12 - 0.88 0.95 1.02 0.30 - 0.50 c 0.08 - 0.20 2.80 2.90 e 0.95 BSC e1 1.90 BSC E 2.10 E1 1.20 L 0.40 C A1 SIDE VIEW b WITH PLATING - 2.64 1.40 c 0.60 0.54 REF L1 Ø A 3.04 1.30 0.50 Seating Plane 0.10 b D A2 A 0º - BASE METAL SECTION B-B 8º 3 PIN SOT-23 Date: 05/25/04 SPX2431 Precision Adjustable Shunt Regulator 8 © Copyright 2004 Sipex Corporation ORDERING INFORMATION PART NUMBER ACC SPX2431AM ...................... 0.5% SPX2431AM/TR ................ 0.5% SPX2431M ........................ 1.0% SPX2431M/TR .................. 1.0% OUTPUT VOLTAGE PACKAGES ...................... 2.5V ......................... 3 Pin SOT-23 ...................... 2.5V ......................... 3 Pin SOT-23 ...................... 2.5V ......................... 3 Pin SOT-23 ...................... 2.5V ......................... 3 Pin SOT-23 /TR = Tape and Reel Pack quantity is 2,500 for SOT-23. Corporation ANALOG EXCELLENCE Sipex Corporation Headquarters and Sales Office 22 Linnell Circle Billerica, MA 01821 TEL: (978) 667-8700 FAX: (978) 670-9001 e-mail: [email protected] Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others. Date: 05/25/04 SPX2431 Precision Adjustable Shunt Regulator 9 © Copyright 2003 Sipex Corporation