LM4040/4041 Micrel LM4040/4041 Precision Micropower Shunt Voltage Reference General Description Features Ideal for space critical applications, the LM4040 and LM4041 precision voltage references are available in the subminiature (3mm x 1.3mm) SOT-23 surface-mount package. The LM4040 is the available in fixed reverse breakdown voltages of 2.500V, 4.096V and 5.000V. The LM4041 is available with a fixed 1.225V or an adjustable reverse breakdown voltage. The LM4040 and LM4041's advanced design eliminates the need for an external stabilizing capacitor while ensuring stability with any capacitive load, making them easy to use. The minimum operating current ranges from 60A for the LM4041-1.2 to 74A for the LM4040-5.0. LM4040 versions have a maximum operating current of 15mA. LM4041 versions have a maximum operating current of 12mA. The LM4040 and LM4041 utilizes zener-zap reverse breakdown voltage trim during wafer sort to ensure that the prime parts have an accuracy of better than 0.1% (A grade) at 25C. Bandgap reference temperature drift curvature correction and low dynamic impedance ensure stable reverse breakdown voltage accuracy over a wide range of operating temperatures and currents. * * * * Small SOT-23 package No output capacitor required Tolerates capacitive loads Fixed reverse breakdown voltages of 1.225, 2.500V, 4.096V and 5.000V * Adjustable reverse breakdown version * Contact Micrel for parts with extended temperature range. Key Specifications * Output voltage tolerance (A grade, 25C) .. 0.1% (max) * Low output noise (10Hz to 100Hz) LM4040 ................................................ 35VRMS (typ) LM4041 ................................................ 20VRMS (typ) * Wide operating current range LM4040 ................................................ 60A to 15mA LM4041 ................................................ 60A to 12mA * Industrial temperature range .................. -40C to +85C * Low temperature coefficient ................ 100ppm/C (max) Applications * * * * * * * * Battery-Powered Equipment Data Acquisition Systems Instrumentation Process Control Energy Management Product Testing Automotive Electronics Precision Audio Components Typical Applications VS VS RS VR LM4040 LM4041 RS I Q + IL IL VR VO R1 VO LM4041 Adjustable IQ Figure 1. LM4040, LM4041 Fixed Shunt Regulator Application VO = 1.233 (R2/R1 + 1) R2 Figure 2. LM4041 Adjustable Shunt Regulator Application Micrel, Inc. * 1849 Fortune Drive * San Jose, CA 95131 * USA * tel + 1 (408) 944-0800 * fax + 1 (408) 944-0970 * http://www.micrel.com January 2000 1 LM4040/4041 LM4040/4041 Micrel Pin Configuration + 1 FB 1 3 3- - + 2 2 Pin 3 must float or be connected to pin 2. Fixed Version SOT-23 (M3) Package Top View Adjustable Version SOT-23 (M3) Package Top View Ordering Information Part Number * Voltage Accuracy, Temp. Coefficient Part Number * Voltage Accuracy, Temp. Coefficient LM4040AIM3-2.5 2.500V 0.1%, 100ppm/C LM4041AIM3-1.2 1.225V 0.1%, 100ppm/C LM4040BIM3-2.5 2.500V 0.2%, 100ppm/C LM4041BIM3-1.2 1.225V 0.2%, 100ppm/C LM4040CIM3-2.5 2.500V 0.5%, 100ppm/C LM4041CIM3-1.2 1.225V 0.5%, 100ppm/C LM4040DIM3-2.5 2.500V 1.0%, 150ppm/C LM4041DIM3-1.2 1.225V 1.0%, 150ppm/C LM4040AIM3-4.1 4.096V 0.1%, 100ppm/C LM4041CIM3-ADJ 1.24V to 10V 0.5%, 100ppm/C LM4040BIM3-4.1 4.096V 0.2%, 100ppm/C LM4041DIM3-ADJ 1.24V to 10V 1.0%, 150ppm/C LM4040CIM3-4.1 4.096V 0.5%, 100ppm/C LM4040DIM3-4.1 4.096V 1.0%, 150ppm/C LM4040AIM3-5.0 5.000V 0.1%, 100ppm/C LM4040BIM3-5.0 5.000V 0.2%, 100ppm/C LM4040CIM3-5.0 5.000V 0.5%, 100ppm/C LM4040DIM3-5.0 5.000V 1.0%, 150ppm/C SOT-23 Package Markings Example R__ Field Code 1st Character R = Reference Example: R2C represents Reference, 2.500V, 0.5% (LM4040CIM3-2.5) LM4040/4041 Example _2_ Field Code 2nd Character 1 = 1.225V 2 = 2.500V 4 = 4.096V 5 = 5.000V A = Adjustable 2 Example __A Field 3rd Character Code A = 0.1% B = 0.2% C = 0.5% D = 1.0% Note: If 3rd character is omitted, container will indicate tolerance. January 2000 LM4040/4041 Micrel Functional Diagram LM4040, LM4041 Fixed Functional Diagram LM4041 Adjustable + + VREF FB Absolute Maximum Ratings Operating Ratings (Notes 1 and 2) Reverse Current ......................................................... 20mA Forward Current ......................................................... 10mA Maximum Output Voltage LM4041-Adjustable ................................................... 15V Power Dissipation at TA = 25C (Note 2) ................ 306mW Storage Temperature ............................... -65C to +150C Lead Temperature Vapor phase (60 seconds) .............................. +215C Infrared (15 seconds) ...................................... +220C ESD Susceptibility Human Body Model (Note 3) ................................. 2kV Machine Model (Note 3) ...................................... 200V Temperature Range (TMIN TA TMAX) .......................... -40C TA +85C Reverse Current LM4040-2.5 .......................................... 60A to 15mA LM4040-4.1 .......................................... 68A to 15mA LM4040-5.0 .......................................... 74A to 15mA LM4041-1.2 .......................................... 60A to 12mA LM4041-ADJ ........................................ 60A to 12mA Output Voltage Range LM4041-ADJ .......................................... 1.24V to 10V January 2000 3 LM4040/4041 LM4040/4041 Micrel LM4040-2.5 Electrical Characteristics Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = 25C. The grades A, B, C, and D designate initial Reverse Breakdown Voltage tolerance of 0.1%, 0.2%, 0.5%, and 1.0 respectively. LM4040AIM3 LM4040BIM3 LM4040CIM3 Symbol VR Parameter Conditions Reverse Breakdown Voltage IR = 100A Reverse Breakdown Voltage Tolerance IR = 100A Typical (Note 4) Limits (Note 5) Limits (Note 5) Limits (Note 5) 2.500 IRMIN Minimum Operating Current VR/T Average Reverse Breakdown Voltage Temperature Coefficient IR = 10mA IR = 1mA IR = 100A 20 15 15 VR/IR Reverse Breakdown Voltage Change with Operating Current Change IRMIN IR 1mA 0.3 1mA IR 15mA 2.5 IR = 1mA, f = 120Hz IAC = 0.1 IR 0.3 V 2.5 19 5.0 21 12 29 mV (max) mV (max) 60 65 60 65 60 65 A A (max) A (max) 100 100 100 0.8 1.0 0.8 1.0 0.8 1.0 mV mV (max) mV (max) 0.6 8.0 0.6 8.0 0.6 8.0 mV mV (max) mV (max) 0.8 0.8 0.9 (max) 45 ZR Reverse Dynamic Impedance eN Wideband Noise VR Reverse Breakdown Voltage Long Term Stability t = 1000hrs T = 25C 0.1C IR = 100A Symbol Parameter Conditions IR = 100A 10Hz f 10kHz Units (Limit) ppm/C ppm/C (max) ppm/C (max) 35 VRMS 120 ppm LM4040DIM3 VR Reverse Breakdown Voltage IR = 100A Reverse Breakdown Voltage Tolerance IR = 100A Typical (Note 4) 2.500 IRMIN Minimum Operating Current VR/T Average Reverse Breakdown Voltage Temperature Coefficient IR = 10mA IR = 1mA IR = 100A 20 15 15 VR/IR Reverse Breakdown Voltage Change with Operating Current Change IRMIN IR 1mA 0.3 1mA IR 15mA 2.5 IR = 1mA, f = 120Hz IAC = 0.1 IR 0.3 ZR Reverse Dynamic Impedance eN Wideband Noise VR Reverse Breakdown Voltage Long Term Stability LM4040/4041 Limits (Note 5) V 25 49 mV (max) mV (max) 65 70 A A (max) A (max) 45 IR = 100A 10Hz f 10kHz t = 1000hrs T = 25C 0.1C IR = 100A 4 Units (Limit) 150 ppm/C ppm/C (max) ppm/C (max) 1.0 1.2 mV mV (max) mV (max) 8.0 10.0 mV mV (max) mV (max) 1.1 (max) 35 VRMS 120 ppm January 2000 LM4040/4041 Micrel LM4040-4.1 Electrical Characteristics Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = 25C. The grades A, B, C, and D designate initial Reverse Breakdown Voltage tolerance of 0.1%, 0.2%, 0.5%, and 1.0% respectively. Symbol VR Parameter Conditions Reverse Breakdown Voltage IR = 100A Reverse Breakdown Voltage Tolerance IR = 100A Typical (Note 4) Minimum Operating Current VR/T Average Reverse Breakdown Voltage Temperature Coefficient IR = 10mA IR = 1mA IR = 100A 30 20 20 VR/IR Reverse Breakdown Voltage Change with Operating Current Change IRMIN IR 1mA 0.5 1mA IR 15mA 3.5 IR = 1mA, f = 120Hz IAC = 0.1 IR 0.5 Reverse Dynamic Impedance eN Wideband Noise VR Reverse Breakdown Voltage Long Term Stability t = 1000hrs T = 25C 0.1C IR = 100A Symbol Parameter Conditions IR = 100A 10Hz f 10kHz Reverse Breakdown Voltage IR = 100A Reverse Breakdown Voltage Tolerance IR = 100A Typical (Note 4) 30 20 20 VR/IR Reverse Breakdown Voltage Change with Operating Current Change IRMIN IR 1mA 0.5 1mA IR 15mA 3.0 IR = 1mA, f = 120Hz IAC = 0.1 IR 0.5 January 2000 8.2 35 mV (max) mV (max) 68 73 68 73 A A (max) A (max) 100 100 0.9 1.2 0.9 1.2 mV mV (max) mV (max) 7.0 10.0 7.0 10.0 mV mV (max) mV (max) 1.0 1.0 (max) LM4040CIM3 LM4040DIM3 Limits (Note 5) Limits (Note 5) 4.096 IR = 10mA IR = 1mA IR = 100A Reverse Breakdown Voltage Long Term Stability 4.1 31 t = 1000hrs T = 25C 0.1C IR = 100A 5 Units (Limits) V 20 47 41 81 mV (max) mV (max) 68 73 73 78 A A (max) A (max) 100 150 0.9 1.2 1.2 1.5 mV mV (max) mV (max) 7.0 10.0 9.0 13.0 mV mV (max) mV (max) 1.0 1.3 (max) 50 IR = 100A 10Hz f 10kHz ppm/C ppm/C (max) ppm/C (max) ppm Average Reverse Breakdown Voltage Temperature Coefficient VR V 120 VR/T Wideband Noise Units (Limit) VRMS Minimum Operating Current eN Limits (Note 5) 80 IRMIN Reverse Dynamic Impedance Limits (Note 5) 50 ZR ZR LM4040BIM3 4.096 IRMIN VR LM4040AIM3 ppm/C ppm/C (max) ppm/C (max) 80 VRMS 120 ppm LM4040/4041 LM4040/4041 Micrel LM4040-5.0 Electrical Characteristics Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = 25C. The grades A, B, C, and D designate initial Reverse Breakdown Voltage tolerance of 0.1%, 0.2%, 0.5%, and 1.0% respectively. Symbol VR Parameter Conditions Reverse Breakdown Voltage IR = 100A Reverse Breakdown Voltage Tolerance IR = 100A Typical (Note 4) Minimum Operating Current VR/T Average Reverse Breakdown Voltage Temperature Coefficient IR = 10mA IR = 1mA IR = 100A 30 20 20 VR/IR Reverse Breakdown Voltage Change with Operating Current Change IRMIN IR 1mA 0.5 1mA IR 15mA 3.5 IR = 1mA, f = 120Hz IAC = 0.1 IR 0.5 Reverse Dynamic Impedance eN Wideband Noise VR Reverse Breakdown Voltage Long Term Stability t = 1000hrs T = 25C 0.1C IR = 100A Symbol Parameter Conditions IR = 100A 10Hz f 10kHz Reverse Breakdown Voltage IR = 100A Reverse Breakdown Voltage Tolerance IR = 100A Typical (Note 4) 30 20 20 VR/IR Reverse Breakdown Voltage Change with Operating Current Change IRMIN IR 1mA 0.5 1mA IR 15mA 3.5 IR = 1mA, f = 120Hz IAC = 0.1 IR 0.5 LM4040/4041 43 10 mV (max) mV (max) 74 80 74 80 A A (max) A (max) 100 100 1.0 1.4 1.0 1.4 mV mV (max) mV (max) 8.0 12.0 8.0 12.0 mV mV (max) mV (max) 1.1 1.1 (max) LM4040CIM3 LM4040DIM3 Limits (Note 5) Limits (Note 5) 5.000 IR = 10mA IR = 1mA IR = 100A Reverse Breakdown Voltage Long Term Stability 5.0 38 t = 1000hrs T = 25C 0.1C IR = 100A 6 Units (Limits) V 25 58 50 99 mV (max) mV (max) 74 80 79 85 A A (max) A (max) 100 150 1.0 1.3 1.3 1.8 mV mV (max) mV (max) 8.0 12.0 10.0 15.0 mV mV (max) mV (max) 1.1 1.5 (max) 54 IR = 100A 10Hz f 10kHz ppm/C ppm/C (max) ppm/C (max) ppm Average Reverse Breakdown Voltage Temperature Coefficient VR V 120 VR/T Wideband Noise Units (Limit) VRMS Minimum Operating Current eN Limits (Note 5) 80 IRMIN Reverse Dynamic Impedance Limits (Note 5) 54 ZR ZR LM4040BIM3 5.000 IRMIN VR LM4040AIM3 ppm/C ppm/C (max) ppm/C (max) 80 VRMS 120 ppm January 2000 LM4040/4041 Micrel LM4040 Typical Characteristics Output Impedance vs. Frequency Temperature Drift for Different Average Temperature Coefficient 1k +0.5 IR = 150A +0.4 +0.3 +0.2 12ppm/C +0.1 0 -0.1 -0.2 -22ppm/C -0.3 -51ppm/C -0.4 -0.5 -40 -20 0 20 40 60 80 100 Output Impedance vs. Frequency 1k IR = IRMIN + 100 A IMPEDANCE () 100 IMPEDANCE () VR CHANGE (%) TJ = 25 C, IR = 0.1 IR CL = 0 VR = 5V 2.5V 10 CL = 1F TANTALUM 1 100 1k 10k 100k FREQUENCY (Hz) VR = 5V CL= 1F TANTALUM 2.5V 1 0.1 100 1M 80 * * ical Typ 40 100k 1M IR = 200A TJ = 25C 5.0 * 60 10k Noise Voltage vs. Frequency Noise (V/ Hz ) ed nte ara Gu uffix fix S N uf I D ,S I RM ,C ,B *A 1k FREQUENCY (Hz) 10.0 4.1V 5V 2.5V REVERSE CURRENT (A) CL= 0 10 0.1 Reverse Characteristics and Minimum Operating Current 100 100 XCL TEMPERATURE (C) 120 IR= 1mA TJ = 25 C, IR = IR TJ = 25C 2.0 5V 1.0 2.5V 0.5 0.2 20 0.1 1 0 0 2 4 6 8 10 10 REVERSE VOLTAGE (V) 100 1k 10k 100k FREQUENCY (Hz) RS VIN 1Hz rate VR LM4040 Test Circuit RS = 30k LM4040-5.0 VIN (V) VIN (V) LM4040-2.5 5 0 0 6 4 4 2 0 TJ = 25C 2 0 0 January 2000 10 6 VR (V) VR (V) IJ = 25C RS = 30k 20 40 60 RESPONSE TIME (s) 0 80 100 200 300 400 RESPONSE TIME (s) 7 LM4040/4041 LM4040/4041 Micrel LM4041-1.2 Electrical Characteristics Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = 25C. The grades A, B, C, and D designate initial Reverse Breakdown Voltage tolerance of 0.1%, 0.2%, 0.5%, and 1.0%, respectively. LM4041AIM3 LM4041BIM3 LM4041CIM3 Symbol VR Parameter Conditions Reverse Breakdown Voltage IR = 100A Reverse Breakdown Voltage Tolerance IR = 100A Typical (Note 4) Minimum Operating Current VR/T Average Reverse Breakdown Voltage Temperature Coefficient IR = 10mA IR = 1mA IR = 100A 20 15 15 VR/IR Reverse Breakdown Voltage Change with Operating Current Change IRMIN IR 1mA 0.7 1mA IR 15mA 4.0 IR = 1mA, f = 120Hz IAC = 0.1 IR 0.5 Reverse Dynamic Impedance eN Wideband Noise VR Reverse Breakdown Voltage Long Term Stability t = 1000hrs T = 25C 0.1C IR = 100A Symbol Parameter Conditions IR = 100A 10Hz f 10kHz Reverse Breakdown Voltage IR = 100A Reverse Breakdown Voltage Tolerance IR = 100A Typical (Note 4) 20 15 15 VR/IR Reverse Breakdown Voltage Change with Operating Current Change IRMIN IR 1mA 0.3 1mA IR 15mA 2.5 IR = 1mA, f = 120Hz IAC = 0.1 IR 0.3 LM4040/4041 2.4 14 6 mV (max) mV (max) 60 65 60 65 60 65 A A (max) A (max) 100 100 100 1.5 2.0 1.5 2.0 1.5 2.0 mV mV (max) mV (max) 6.0 8.0 6.0 8.0 6.0 8.0 mV mV (max) mV (max) 1.5 1.5 1.5 (max) LM4041DIM3 LM4041EIM3 Limits (Note 5) Limits (Note 5) 1.225 IR = 10mA IR = 1mA IR = 100A Reverse Breakdown Voltage Long Term Stability 10.4 t = 1000hrs T = 25C 0.1C IR = 100A 8 Units (Limit) V 12 24 25 36 mV (max) mV (max) 65 70 65 70 A A (max) A (max) 150 150 2.0 2.5 2.0 2.5 mV mV (max) mV (max) 8.0 10.0 8.0 10.0 mV mV (max) mV (max) 2.0 2.0 (max) 45 IR = 100A 10Hz f 10kHz ppm/C ppm/C (max) ppm/C (max) ppm Average Reverse Breakdown Voltage Temperature Coefficient VR 1.2 9.2 120 VR/T Wideband Noise V VRMS Minimum Operating Current eN Units (Limit) 20 IRMIN Reverse Dynamic Impedance Limits (Note 5) 45 ZR ZR Limits (Note 5) 1.225 IRMIN VR Limits (Note 5) ppm/C ppm/C (max) ppm/C (max) 35 VRMS 120 ppm January 2000 LM4040/4041 Micrel LM4041-Adjustable Electrical Characteristics Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TJ = 25C unless otherwise specified (SOT-23, see Note 7), IRMIN IR < 12mA, VREF VOUT 10V. The grades C and D designate initial Reverse Breakdown Voltage tolerance of 0.5% and 1%, respectively for VOUT = 5V. Symbol VREF Parameter Conditions Reference Breakdown Voltage IR = 100A VOUT = 5V Reference Breakdown Voltage Tolerance (Note 8) IR = 100A IRMIN Minimum Operating Current VREF /IR Reference Voltage Change with Operating Current Change Typical (Note 4) LM4041CIM3 LM4041DIM3 Limits (Note 5) Limits (Note 5) 1.233 V 6.2 14 24 12 mV (max) mV (max) 60 65 65 70 A A (max) A (max) 1.5 2.0 2.0 2.5 mV mV (max) mV (max) 4 6 6 8 mV mV (max) mV (max) -2.0 -2.5 -2.5 -3.0 mV/V mV/V (max) mV/V (max) 100 120 150 200 nA nA (max) nA (max) 100 150 45 IRMIN IR 1mA SOT-23: VOUT 1.6V (Note 7) 0.7 1mA IR 15mA SOT-23: VOUT 1.6V (Note 7) 2 Units (Limit) VREF /VO Reference Voltage Change with Output Voltage Change IFB Feedback Current VREF /T Average Reference Voltage Temperature Coefficient (Note 8) VOUT = 5V IR = 10mA IR = 1mA IR = 100A 20 15 15 ZOUT Dynamic Output Impedance IR = 1mA, f = 120Hz IAC = 0.1 IR VOUT = VREF VOUT = 10V 0.3 2 (max) IR = 100A 10Hz f 10kHz 20 VRMS 120 ppm eN Wideband Noise VREF Reference Voltage Long Term Stability January 2000 IR = 1mA -1.3 60 t = 1000hrs T = 25C 0.1C IR = 100A 9 ppm/C ppm/C (max) ppm/C (max) LM4040/4041 LM4040/4041 Micrel LM4040 and LM4041 Electrical Characteristic Notes Note 1. Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is functional, but do not guarantee specific performance limits. For guaranteed specification and test conditions, see the Electrical Characteristics. The guaranteed specifications apply only for the test conditions listed. Some performance characteristics may degrade when the device is not operated under the listed test conditions. Note 2. The maximum power dissipation must be derated at elevated temperatures and is dictated by TJMAX (maximum junction temperature), JA (junction to ambient thermal resistance), and TA (ambient temperature). The maximum allowable power dissipation at any temperature is PDMAX = (TJMAX - TA)/JA or the number given in the Absolute Maximum Ratings, whichever is lower. For the LM4040 and LM4041, TJMAX = 125C, and the typical thermal resistance (JA), when board mounted, is 326C/W for the SOT-23 package. Note 3. The human body model is a 100pF capacitor discharged through a 1.5k resistor into each pin. The machine model is a 200pF capacitor discharged directly into each pin. Note 4. Typicals are at TJ = 25C and represent most likely parametric norm. Note 5. Limits are 100% production tested at 25C. Limits over temperature are guaranteed through correlation using Statistical Quality Control (SQL) methods. Note 6. The boldface (over temperature limit for Reverse Breakdown Voltage Tolerance is defined as the room temperature Reverse Breakdown Voltage Tolerance [(VR/T)(65C)(VR)]. VR/T is the VR temperature coefficient, 65C is the temperature range from -40C to the reference point of 25C, and VR is the reverse breakdown voltage. The total over temperature tolerance for the different grades follows: A-grade: 0.75% = 0.1% 100ppm/C x 65C B-grade: 0.85% = 0.2% 100ppm/C x 65C C-grade: 1.15% = 0.5% 100ppm/C x 65C D-grade: 1.98% = 1.0% 150ppm/C x 65C Example: The A-grade LM4040-2.5 has an over temperature Reverse Breakdown Voltage tolerance of 2.5 x 0.75% = 19mV. Note 7. When VOUT 1.6V, the LM4041-ADJ must operate at reduced IR. This is caused by the series resistance of the die attach between the die (-) output and the package (-) output pin. See the Output Saturation curve in the Typical Performance Characteristics section. Note 8. Reference voltage and temperature coefficient will change with output voltage. See Typical Performance Characteristics curves. LM4041 Typical Characteristics 1k IMPEDANCE () VR CHANGE (%) +0.5 IR = 150A +0.4 LM4041-1.2 +0.3 +0.2 12ppm/C +0.1 0 -0.1 -0.2 -22ppm/C -0.3 -51ppm/C -0.4 -0.5 -40 -20 0 20 40 60 80 100 Output Impedence vs. Frequency 10 1000 CL= 0 CL= 1F IR = 150A TANTALUM 1 I = 1mA R 800 IR = 200A TJ = 25C LM4041-1.2 LM4041-ADJ: VOUT = VREF 600 400 200 XC 100 TEMPERATURE (C) 1k 10k 100k FREQUENCY (Hz) Reverse Characteristics and Minimum Operating Current Reverse Characteristics and Minimum Operating Current 1M 0 1 10 100 1k 10k 100k FREQUENCY (Hz) 100 80 60 40 Typical TJ = 25C LM4041-1.2 20 0 0.4 0.8 1.2 1.6 REVERSE VOLTAGE (V) LM4040/4041 2.0 REVERSE CURRENT (A) REVERSE CURRENT (A) 100 0.1 100 0 TJ = 25 C IR = 0.1IR LM4041-1.2 Voltage Impedance NOISE (nV/ Hz ) Temperature Drift for Different Average Temperature Coefficient RS 30k 80 VIN 1Hz rate 60 V R LM4041-1.2 40 Typical TJ = 25C LM4041-1.2 20 0 0 0.4 0.8 1.2 1.6 Test Circuit 2.0 REVERSE VOLTAGE (V) 10 January 2000 LM4040/4041 Micrel LM4041 Typical Characteristics Reference Voltage vs. Output Voltage and Temperature 85C 1.240 1.240 1.232 1.232 -40C VOUT = 5V 1.228 1.228 85C 1.224 1.220 0 2 4 6 8 OUTPUT VOLTAGE (V) VOUT = 10V 1.224 10 1.220 -40 -20 Output Saturation 1.7 1K 1.5 100 IMPEDANCE () LM4041-ADJ 1.6 VADJ = VREF + 5V -40C 1.4 85C 1.3 1.2 25C 0 20 40 TEMPERATURE (C) 2 4 6 8 OUTPUT VOLTAGE (V) Output Impedence vs. Frequency * Output Impedence vs. Frequency * CL = 0 VOUT = 10V CL=1F 5V 2.5V 1.23V 0 2 4 6 8 10 12 0 100 OUTPUT CURRENT (mA) 1k 10k 0 1K 100k LM4041-ADJ TJ = 25 C IR = 1mA IR = 0.1 IR 100 10 CL = 0 VOUT = 10V 10 5V 2.5V 1.23V CL=1F 1 XC XC 1.0 TJ = 25C, -40C 40 0 60 80 100 10 1.1 TJ = 85C 60 20 LM4041-ADJ TJ = 25 C IR = 1mA IR = 0.1IR 1 LM4041-ADJ 80 VOUT = VREF 1.236 1.236 -40C OUTPUT SATURATION (V) 100 LM4041-ADJ IR = 1mA FEEDBACK (nA) LM4041-ADJ REFERENCE VOLTAGE (V) REFERENCE VOLTAGE (V) 25C IMPEDANCE () 1.244 1.244 Feedback Current vs. Output Voltage and Temperature Reference Voltage vs. Temperature and Output Voltage 1M FREQUENCY (Hz) 0 100 1k 10k 100k 1M FREQUENCY (Hz) Reverse Characteristics FB STEPS (V) 2 4 6 0 IR 8 REVERSE CURRENT (A) 100 80 (+) 60 40 V 20 0 TJ = 25C LM4041-ADJ 0 2 4 6 8 10 OUTPUT VOLTAGE (V) Reverse Characteristics Test Circuit Large Signal Response -40C VOLTAGE (V) 10 8 LM4041-ADJ TJ = -40C OUTPUT 25C 85C INPUT -40C IR FB V OUT ( - ) 2V / step LM4041-ADJ + CL 120k FB - * Output Impedance vs. Freq. Test Circuit + 15V 5.1k INPUT 6 (+) FB LM4041 - ADJ VOUT (-) 100k 4 2 0 0 January 2000 10 20 30 40 RESPONSE TIME (s) Large Signal Response Test Circuit 11 LM4040/4041 LM4040/4041 Micrel Adjustable Regulator The LM4041-ADJ's output voltage can be adjusted to any value in the range of 1.24V through 10V. It is a function of the internal reference voltage (VREF) and the ratio of the external feedback resistors as shown in Figure 2. The output is found using the equation (1) VO = VREF [ (R2/R1) + 1 ] where VO is the desired output voltage. The actual value of the internal VREF is a function of VO. The "corrected" VREF is determined by (2) VREF = VO (VREF / VO) + VY where VO is the desired output voltage. VREF / VO is found in the Electrical Characteristics and is typically -1.3mV/V and VY is equal to 1.233V. Replace the value of VREF in equation (1) with the value found using equation (2). Note that actual output voltage can deviate from that predicted using the typical VREF / VO in equation (2); for Cgrade parts, the worst-case VREF / VO is -2.5mV/V and VY = 1.248V. The following example shows the difference in output voltage resulting from the typical and worst case values of VREF / VO: Let VO = +9V. Using the typical values of VREF /VO , VREF is 1.223V. Choosing a value of R1 = 10k, R2 = 63.272k. Using the worst case VREF / VO for the C-grade and Dgrade parts, the output voltage is actually 8.965V and 8.946V respectively. This results in possible errors as large as 0.39% for the C-grade parts and 0.59% for the D-grade parts. Once again, resistor values found using the typical value of VREF / VO will work in most cases, requiring no further adjustment. Applications Information The LM4040 and LM4041 have been designed for stable operation without the need of an external capacitor connected between the (+) and (-) pins. If a bypass capacitor is used, the references remain stable. Schottky Diode LM4040-x.x and LM4041-1.2 in the SOT-23 package have a parasitic Schottky diode between pin 2 (-) and pin 3 (die attach interface connect). Pin 3 of the SOT-23 package must float or be connected to pin 1. LM4041-ADJs use pin 3 as the (-) output. Conventional Shunt Regulator In a conventional shunt regulator application (see Figure 1), an external series resistor (RS) is connected between the supply voltage and the LM4040-x.x or LM4041-1.2 reference. RS determines the current that flows through the load (IL) and the reference (IQ). Since load current and supply voltage may vary, RS should be small enough to supply at least the minimum acceptable IQ to the reference even when the supply voltage is at its minimum and the load current is at its maximum value. When the supply voltage is at its maximum and IL is at its minimum, RS should be large enough so that the current flowing through the LM4040-x.x is less than 15mA, and the current flowing through the LM4041-1.2 or LM4041-ADJ is less than 12mA. RS is determined by the supply voltage (VS), the load and operating current, (IL and IQ), and the reference's reverse breakdown voltage (VR). Rs = (Vs - VR) / (IL + IQ) R1 + FB 120k LM4041-ADJ D1 FB D1 - R2 1M LM4041- ADJ < -12V R3 LED ON 200 R1 120k R2 1M > -12V R3 LED ON 330 -5V -5V Figure 3. Voltage Level Detector LM4040/4041 + Figure 4. Voltage Level Detector 12 January 2000 LM4040/4041 Micrel VIN R1 I VOUT D1 1N914 R2 50A VIN I R1 D2 1N914 + LM4041-ADJ FB R3 240k - D1 1N457 + R3 510k + LM4041-ADJ - FB R2 510k - FB R4 240k Figure 5. Fast Positive Clamp 2.4V + VD1 LM4041-ADJ Figure 6. Bidirectional Clamp 2.4V VIN I VOUT D2 1N457 VIN R1 I R1 VOUT R2 390k + LM4041-ADJ R3 500k VOUT D2 1N457 FB - + LM4041-ADJ LM4041-ADJ + R2 330k D2 1N457 FB - FB R3 1M FB - - D1 1N457 R4 390k D1 1N457 Figure 7. Bidirectional Adjustable Clamp 18V to 2.4V R4 330k LM4041-ADJ + Figure 8. Bidirectional Adjustable Clamp 2.4 to 6V 0 to 20mA + 5V 1N4002 D2 R1 390 2% D1* + FB LM4041-ADJ N.C. I THRESHOLD = R2 470k - 1 6 2 5 3 4N28 N.C. CMOS 4 1.24V 5A + = 3.2mA R1 4N28 GAIN Figure 9. Floating Current Detector January 2000 13 LM4040/4041 LM4040/4041 Micrel +15V R1 + LM4041-ADJ FB - 2N2905 2N 3964 R2 120k 1A < IOUT = 100mA 1.24V I OUT = R1 Figure 10. Current Source 0 to 20 mA R1 332 1% D2 1N4002 +5V + FB LM4041-ADJ - 1N914 R3 100k 2N2222 R2 22k D1* 1 6 2 5 3 N.C. 1.24V I THRESHOLD = = 3.7mA 2% R1 4 4N28 CMOS R4 10M Figure 11. Precision Floating Current Detector * D1 can be any LED, VF = 1.5V to 2.2V at 3mA. D1 may act as an indicator. D1 will be on if ITHRESHOLD falls below the threshold current, except with I = O. LM4040/4041 14 January 2000 LM4040/4041 Micrel Package Information 1.40 (0.055) 2.50 (0.098) 1.19 (0.047) 2.10 (0.083) C L 2.36 (0.093) 2.28 (0.090) C L 3.05 (0.120) 2.67 (0.105) 0.445 (0.0175) TYP 3 PLACES DIMENSIONS: MM (INCH) 1.15 (0.045) 0.76 (0.030) 0.10 (0.004) 0.013 (0.0005) 8 0 0.15 (0.006) 0.076 (0.0030) 0.41 (0.016) 0.13 (0.005) SOT-23 (M3) January 2000 15 LM4040/4041 LM4040/4041 Micrel MICREL INC. TEL 1849 FORTUNE DRIVE SAN JOSE, CA 95131 + 1 (408) 944-0800 FAX + 1 (408) 944-0970 WEB USA http://www.micrel.com This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel Inc. (c) 2000 Micrel Incorporated LM4040/4041 16 January 2000