LM285-1.2, LM385-1.2, LM385B-1.2 MICROPOWER VOLTAGE REFERENCES SLVS075C - APRIL 1989 - REVISED JULY 1999 D D D D D D Operating Current Range - LM285 . . . 10 A to 20 mA - LM385 . . . 15 A to 20 mA - LM385B . . . 15 A to 20 mA 1% and 2% Initial Voltage Tolerance Reference Impedance - LM385 . . . 1 Max at 25C - All Devices . . . 1.5 Max Over Full Temperature Range Very Low Power Consumption Applications: - Portable Meter References - Portable Test Instruments - Battery-Operated Systems - Current-Loop Instrumentation - Panel Meters Designed to be Interchangeable With National LM285-1.2 and LM385-1.2 D PACKAGE (TOP VIEW) NC NC NC ANODE 1 8 2 7 3 6 4 5 CATHODE NC NC NC LP PACKAGE (TOP VIEW) ANODE CATHODE NC NC-No internal connection description These micropower, two-terminal, band-gap voltage references operate over a 10-A to 20-mA current range and feature exceptionally low dynamic impedance and good temperature stability. On-chip trimming provides tight voltage tolerance. The band-gap reference for these devices has low noise and long-term stability. The design makes these devices exceptionally tolerant of capacitive loading and thus, easier to use in most reference applications. The wide dynamic operating temperature range accommodates varying current supplies with excellent regulation. The extremely low power drain of this series makes them useful for micropower circuitry. These voltage references can be used to make portable meters, regulators, or general-purpose analog circuitry, with battery life approaching shelf life. The wide operating current range allows them to replace older references with tighter-tolerance parts. The LM285-1.2 is characterized for operation from -40C to 85C. The LM385-1.2 and LM385B-1.2 are characterized for operation from 0C to 70C. AVAILABLE OPTIONS TA VZ TOLERANCE 0C to 70C -40C to 85C PACKAGED DEVICES SMALL OUTLINE (D) CHIP FORM (Y) PLASTIC (LP) 2% LM385D-1.2 LM385LP-1.2 1% LM385BD-1.2 LM385BLP-1.2 1% LM285D-1.2 LM285LP-1.2 LM385Y-1.2 The D package is available taped and reeled. Add the suffix R to the device type (e.g., LM385DR-1-2). The chip form is tested at TA = 25C. For ordering purposes, the decimal point in the part number must be replaced with a hyphen (i.e., show the -1.2 suffix as "-1-2"). Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. Copyright 1999, Texas Instruments Incorporated PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 1 LM285-1.2, LM385-1.2, LM385B-1.2 MICROPOWER VOLTAGE REFERENCES SLVS075C - APRIL 1989 - REVISED JULY 1999 symbol ANODE CATHODE schematic CATHODE Q13 7.5 k 600 k Q12 Q7 200 k Q4 Q11 50 k Q3 Q10 Q1 300 k 20 pF Q2 20 pF Q9 Q5 Q6 Q8 Q14 100 k 500 60 k ANODE NOTE A: Component values shown are nominal. absolute maximum ratings over operating free-air temperature range Reverse current, IR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 mA Forward current, IF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 mA Package thermal impedance, JA (see Notes 1 and 2): D package . . . . . . . . . . . . . . . . . . . . . . . . . . . 197C/W LP package . . . . . . . . . . . . . . . . . . . . . . . . . . 156C/W Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260C Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -65C to 150C Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. NOTES: 1. Maximum power dissipation is a function of TJ(max), JA, and TA. The maximum allowable power dissipation at any allowable ambient temperature is PD = (TJ(max) - TA)/JA. Operation at the absolute maximum TJ of 150C can impact reliability. 2. The package thermal impedance is calculated in accordance with JESD51, except for through-hole packages which use a trace length of zero. recommended operating conditions Reference current, IZ LM285-1.2 free air temperature range, range TA Operating free-air 2 LM385-1.2, LM385B-1.2 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 MIN MAX 0.01 20 -40 85 0 70 UNIT mA C LM285-1.2, LM385-1.2, LM385B-1.2 MICROPOWER VOLTAGE REFERENCES SLVS075C - APRIL 1989 - REVISED JULY 1999 electrical characteristics at specified free-air temperature PARAMETER LM285-1.2 LM385-1.2 LM385B-1.2 TEST CONDITIONS TA MIN TYP MAX MIN TYP MAX MIN TYP MAX 1.223 1.235 1.247 1.21 1.235 1.26 1.223 1.235 1.247 VZ Reference voltage IZ = I(min) to 20 mA 25C VZ Average temperature coefficient of reference voltage IZ = I(min) to 20 mA 25C VZ Change in reference voltage with currentt VZ/t Long-term change in reference voltage IZ(min) Minimum reference current zz Reference impedance Vn IZ = 100 A, Broadband f = 10 Hz to noise voltage 10 kHz IZ = I(min) ( ) to 1 mA IZ = 1 mA to 20 mA 20 25C 20 1 1 1 1.5 1.5 1.5 25C 12 20 20 Full range 30 30 30 25C 20 Full range 25C 20 10 8 15 8 15 0.2 0.6 0.4 1 0.4 1 1.5 1.5 60 1.5 60 mV ppm/khr 8 Full range 25C 20 V ppm/C Full range IZ = 100 A IZ = 100 A, , f = 25 Hz 20 UNIT A V 60 Full range is -40C to 85C for the LM285-1.2, and 0C to 70C for the LM385-1.2 and LM385B-1.2. I(min) = 10 A for the LM285-1.2 and 15 A for the LM385-1.2 and LM385B-1.2. The average temperature coefficient of reference voltage is defined as the total change in reference voltage divided by the specified temperature range. electrical characteristics, TA = 25C PARAMETER TEST CONDITIONS VZ Reference voltage IZ = 15 A to 20 mA VZ Average temperature coefficient of reference voltage IZ = 15 A to 20 mA VZ Change in reference voltage with current IZ = 15 A to 1 mA IZ = 1 mA to 20 mA VZ/t IZ(min) Long-term change in reference voltage IZ = 100 A zz Reference impedance Vn Broadband noise voltage Minimum reference current IZ = 100 A IZ = 100 A, f = 10 Hz to 10 kHz LM385Y-1.2 MIN TYP MAX 1.21 1.235 1.26 20 UNIT V ppm/C 1 20 20 mV ppm/khr 8 15 A 0.4 1 60 V The average temperature coefficient of reference voltage is defined as the total change in reference voltage divided by the specified temperature range. POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 3 LM285-1.2, LM385-1.2, LM385B-1.2 MICROPOWER VOLTAGE REFERENCES SLVS075C - APRIL 1989 - REVISED JULY 1999 TYPICAL CHARACTERISTICS REVERSE CURRENT vs REVERSE VOLTAGE 100 REFERENCE VOLTAGE CHANGE vs REVERSE CURRENT IIIIII IIIIII V Z - Reference Voltage Change - mV I R - Reverse Current - A TA = -55C to 125C 10 1 0.1 0 0.2 0.4 IIIIIII 16 TA = -55C to 125C 0.6 0.8 1 1.2 12 8 4 0 -4 0.01 1.4 VR - Reverse Voltage - V 0.1 1 10 100 IR - Reverse Current - mA Figure 1 Figure 2 REFERENCE VOLTAGE vs FREE-AIR TEMPERATURE FORWARD VOLTAGE vs FORWARD CURRENT IIII IIII 1.2 1.245 V Z - Reference Voltage - V V F - Forward Voltage - V TA = 25C 0.8 0.4 1.24 1.235 1.23 1.225 0 0.01 0.1 1 10 100 1.220 -55 -35 -15 5 25 45 65 85 105 125 TA - Free-Air Temperature - C IF - Forward Current - mA Figure 3 Figure 4 Data at high and low temperatures are applicable only within the rated operating free-air temperature ranges of the various devices. 4 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 LM285-1.2, LM385-1.2, LM385B-1.2 MICROPOWER VOLTAGE REFERENCES SLVS075C - APRIL 1989 - REVISED JULY 1999 TYPICAL CHARACTERISTICS NOISE VOLTAGE vs FREQUENCY REFERENCE IMPEDANCE vs REFERENCE CURRENT 700 100 600 Vn - Noise Voltage - nV/ Hz Vn zz - Reference Impedance - f = 25 Hz TA = -55C to 125C 10 1 IZ = 100 A TA = 25C 500 400 300 200 100 0.1 0.01 0.1 1 10 0 10 100 100 1k Figure 6 Figure 5 OUTPUT NOISE VOLTAGE vs CUTOFF FREQUENCY 50 40 TRANSIENT RESPONSE IIIII IIIII IZ = 100 A TA = 25C IIII IIII 100 A R C 30 20 Output 1.5 36 k 1 VI VO 0.5 0 5 10 0 0.1 III III RC Low Pass Input and Output Voltages - V Output Noise Voltage - V 60 100 k f - Frequency - Hz IZ - Reference Current - mA 70 10 k Input 1 10 f - Cutoff Frequency - kHz 100 0 Figure 7 0 100 t - Time - s 500 600 Figure 8 Data at high and low temperatures are applicable only within the rated operating free-air temperature ranges of the various devices. POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 5 LM285-1.2, LM385-1.2, LM385B-1.2 MICROPOWER VOLTAGE REFERENCES SLVS075C - APRIL 1989 - REVISED JULY 1999 APPLICATION INFORMATION IO 58 A + V+ 5.1 k 100 k 1% Mercury Cell 1.345 V LM334 cw - R 2.00 k 1% cw V- 10 k 500 412 1% 953 1% LM385-1.2 + Type K - Meter Adjust for 11.15 mV at 25C across 953 Adjust for 12.17 mV at 25C across 412 Figure 9. Thermocouple Cold-Junction Compensator 2.3 V V+ 30 V V+ LM334 R V- 2.74 k 1.2 V LM385-1.2 Figure 10. Operation Over a Wide Supply Range 9V 499 k 1.2 V LM385-1.2 Figure 11. Reference From a 9-V Battery 6 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. 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