LM368-2.5 Precision Voltage Reference General Description Features The LM368-2.5 is a precision, monolithic, temperature-compensated voltage reference. The LM368-2.5 makes use of thin-film technology enhanced by the discrete laser trimming of resistors to achieve excellent Temperature coefficient (Tempco) of VOUT (as low as 11 ppm/§ C), along with tight initial tolerance, (as low as 0.02%). The trim scheme is such that individual resistors are cut open rather than being trimmed (partially cut), to avoid resistor drift caused by electromigration in the trimmed area. The LM368-2.5 also provides excellent stability vs. changes in input voltage and output current. The output is short circuit proof. A trim pin is made available for fine trimming of VOUT or for obtaining intermediate values without greatly affecting the Tempco of the device. Y Y Y Y Y Y Y Y 400 mA operating current Low output impedance Excellent line regulation (.0001%/V typical) Single-supply operation Externally trimmable Low temperature coefficient Excellent initial accuracy (0.02% typical) Best reference available for low-voltage operation (VS e 5V, VREF e 2.500V) Connection Diagram Metal Can Package (TO-5) TL/H/8446 – 1 Top View *case connected to Vb Order Number LM368H-2.5 LM368YH-2.5 See NS Package Number H08C Typical Applications Low Voltage Reference TL/H/8446 – 2 C1995 National Semiconductor Corporation TL/H/8446 RRD-B30M115/Printed in U. S. A. LM368-2.5 Precision Voltage Reference December 1994 Absolute Maximum Ratings (Note 7) Soldering Information TO-5 (H) Package (10 sec.) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/Distributors for availability and specifications. Input Voltage Power Dissipation Storage Temperature Range Operating Temperature Range a 300§ C See AN-450 ‘‘Surface Mounting Methods and Their Effect on Product Reliability’’ (Appendix D) for other methods of soldering surface mount devices. 35V 600 mW b 60§ C to a 150§ C 0§ C to a 70§ C Electrical Characteristics (Note 1) LM368-2.5 Parameter Conditions Typical VOUT Error: LM368 Tested Limit (Note 2) Design Limit (Note 3) Units (Max. unless noted) g 0.02 g 0.2 % Line Regulation 5.0V s VIN s 30V g 0.0001 g 0.0005 %/V Load Regulation (Note 8) 0 mA s ISOURCE s 10 mA g 0.0003 g 0.0025 %/mA Thermal Regulation T e 20 mS (Note 4) g 0.005 g 0.02 %/100 mW Quiescent Current 350 550 mA Change of Quiescent Current vs. VIN 5.0V s VIN s 30V 3 5 mA/V Temperature Coefficient of VOUT (see graph): LM368Y-2.5 (Note 5) LM368-2.5 0§ C s TA s 70§ C 0§ C s TA s 70§ C g 11 g 20 Short Circuit Current VOUT e 0 Noise: g 15 30 0.1 – 10 Hz 100 Hz –10 kHz VOUT Adjust Range g 30 70 100 12 420 0 s VPIN5 s VOUT 1.9 – 5.2 ppm/§ C ppm/§ C mA uVp-p nV/0Hz 2.2 – 5.0 V min. Note 1: Unless otherwise noted, these specifications apply: TA e 25§ C, 4.9V s VIN s 10.5V, 0 s ILOAD s 0.5 mA, 0 s CL s 200 pF. Note 2: Tested Limits are guaranteed and 100% tested in production. Note 3: Design Limits are guaranteed (but not 100% production tested) over the indicated temperature and supply voltage ranges. These limits are not used to calculate outgoing quality levels. Note 4: Thermal Regulation is defined as the change in the output Voltage at a time T after a step change in power dissipation of 100 mW. Note 5: Temperature Coefficient of VOUT is defined as the worst case delta-VOUT measured at Specified Temperatures divided by the total span of the Specified Temperature Range (See graphs). There is no guarantee that the Specified Temperatures are exactly at the minimum or maximum deviation. Note 6: In metal can (H), iJ-C is 75§ C/W and iJ-A is 150§ C/W. Note 7: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. DC and AC electrical specifications do not apply when operating the device beyond its Rated Operating Conditions (see Note 1 and Conditions). Note 8: Load regulation is measured on the output pin at a point (/8× below the base of the package. Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes in output voltage due to heating effects are covered under the specification for thermal regulation. 2 Typical Performance Characteristics (Note 1) Quiescent Current vs. Input Voltage and Temperature Dropout Voltage vs. Output Current Output Impedance vs. Frequency Ripple Rejection vs. Frequency Output Change vs. Output Current (1) LM368 as is. (2) with 0.01 mf Mylar, Trim to Gnd. (3) with 10X in series with 10 mf, VOUT to Gnd. (4) with Both. Temperature Coefficient: LM368-2.5 (Curve A) Output Noise vs. Frequency TL/H/8446 – 3 Typical Temperature Coefficient Calculations: LM368-2.5 (see Curve A) T.C. e 1.7 mV/(70§ c 2.5V) e 9.7 ppm/§ C 3 Typical Applications Wide Range Trimmable Regulator Narrow Range Trimmable Regulator ( g 1% min.) TL/H/8446–5 TL/H/8446 – 6 Improved Noise Performance TL/H/8446 – 7 g 2.5V, g 1.25V References e (/4 LM324A or (/2 LM358A TL/H/8446 – 8 Re Thin Film Resistor Network, g 0.05% Matching and 5 ppm Tracking (Beckman 694-3-R-10K-A), (Caddock T-914-10K-100-05) or similar. 4 Typical Applications (Continued) Multiple Output Voltages TL/H/8446 – 9 TL/H/8446 – 10 R e Thin Film Resistor Network 0.05% Matching and 5 ppm Tracking (Beckman 694-3-R-10K-A), (Caddock T-914-10K-100-05) or similar. Reference with Booster 100 mA Boosted Reference TL/H/8446 – 11 TL/H/8446 – 12 5 Typical Applications (Continued) Buffered High-Current Reference with Filter TL/H/8446 – 13 Simplified Schematic Diagram TL/H/8446 – 14 *Reg. U.S. Pat. Off. 6 7 LM368-2.5 Precision Voltage Reference Physical Dimensions inches (millimeters) Lit. Ý106560 Metal Can Package (H) Order Number LM368H-2.5 or LM368YH-2.5 NS Package Number H08C This data sheet contains preliminary limits and design specifications. Supplemental information will be published at a later date. National Semiconductor reserves the right to make changes in the products contained in this document in order to improve design or performance and to supply the best possible products. National also assumes no responsibility for the use of any circuits described herein, conveys no license under any patent or other right, and makes no representations that the circuits are free from patent infringement. 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