LM285-2.5, LM385-2.5, LM385B-2.5 MICROPOWER VOLTAGE REFERENCES SLVS023E – JANUARY 1989 – REVISED JULY 1999 D D D D D D Operating Current Range . . . 20 µA to 20 mA 1.5% and 3% Initial Voltage Tolerance Reference Impedance – LM385 . . . 1 Ω Max at 25°C – All Devices . . . 1.5 Ω 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 LM285-2.5 and LM385-2.5 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 20-µA 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 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 LM285-2.5 is characterized for operation from –40°C to 85°C. The LM385-2.5 and LM385B-2.5 are characterized for operation from 0°C to 70°C. AVAILABLE OPTIONS TA 0°C to 70°C –40°C to 85°C VZ TOLERANCE PACKAGED DEVICES CHIP FORM (Y) SMALL OUTLINE (D) PLASTIC (LP) LM385D-2.5 LM385LP-2.5 1.5% LM385BD-2.5 LM385BLP-2.5 1.5% LM285D-2.5 LM285LP-2.5 3% LM385Y-2.5 The D package is available taped and reeled. Add the suffix R to the device type (e.g., LM385DR-2-5). Chip forms are tested at 25°C. For ordering purposes, the decimal point in the part number must be replaced with a hyphen (i.e., show the -2.5 suffix as “-2-5”). 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 Powered by ICminer.com Electronic-Library Service CopyRight 2003 • DALLAS, TEXAS 75265 1 LM285-2.5, LM385-2.5, LM385B-2.5 MICROPOWER VOLTAGE REFERENCES SLVS023E – JANUARY 1989 – REVISED JULY 1999 logic symbol ANODE CATHODE schematic CATHODE Q13 600 kΩ 7.5 kΩ Q12 Q4 Q7 200 kΩ Q11 Q3 50 kΩ Q10 Q1 20 pF 300 kΩ 20 pF 500 Ω Q9 Q2 Q5 Q6 100 kΩ 500 Ω Q8 Q14 500 Ω 60 kΩ ANODE NOTE A: All 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, θJA (see Notes 1 and 2): D package . . . . . . . . . . . . . . . . . . . . . . . . . . . 97°C/W LP package . . . . . . . . . . . . . . . . . . . . . . . . . 156°C/W Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260°C Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –65°C to 150°C † 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), θJA, and TA. The maximum allowable power dissipation at any allowable ambient temperature is PD = (TJ(max) – TA)/θJA. Operation at the absolute maximum TJ of 150°C can impact reliability. 2. The package thermal impedance is calculated in accordance with JESD 51, except for through-hole packages which use a trace length of zero. recommended operating conditions Reference current, IZ free air temperature range, range TA Operating free-air 2 POST OFFICE BOX 655303 Powered by ICminer.com Electronic-Library Service CopyRight 2003 LM285-2.5 LM385-2.5, LM385B-2.5 • DALLAS, TEXAS 75265 MIN MAX 0.02 20 –40 85 0 70 UNIT mA °C LM285-2.5, LM385-2.5, LM385B-2.5 MICROPOWER VOLTAGE REFERENCES SLVS023E – JANUARY 1989 – REVISED JULY 1999 electrical characteristics at specified free-air temperature PARAMETER LM285-2.5 LM385-2.5 LM385B-2.5 TEST CONDITIONS TA† MIN TYP MAX MIN TYP MAX MIN TYP MAX 2.462 2.5 2.538 2.425 2.5 2.575 2.462 2.5 2.538 VZ Reference voltage IZ = 20 µA to 20 mA 25°C αVZ Average temperature coefficient of reference voltage‡ IZ = 20 µA to 20 mA 25°C ∆VZ Change in reference voltage with currentt IZ = 20 µA µ to 1 mA µ IZ = 1 µA to 20 mA ∆VZ/∆t Long-term change in reference voltage IZ(min) Minimum reference current zz Reference impedance IZ = 100 µA Vn Broadband noise voltage IZ = 100 µA, f = 10 Hz to 10 kHz IZ = 100 µA ±20 25°C ±20 ±20 1 2 2 1.5 2 2 25°C 10 20 20 Full range 30 30 30 Full range 25°C ±20 20 8 0.2 0.6 0.4 Full range 25°C ±20 8 1.5 ±20 20 8 1 0.4 20 1 1.5 120 mV ppm/khr 1.5 120 V ppm/°C Full range 25°C UNIT µA Ω µV 120 † Full range is 0°C to 70°C for the LM385-2.5 and LM385B-2.5, and –40°C to 85°C for the LM285-2.5. ‡ The average temperature coefficient of reference voltage is defined as the total change in reference voltage divided by the specified temperature range. electrical characteristics at TA = 25°C PARAMETER TEST CONDITIONS VZ αVZ Reference voltage ∆VZ/∆t zz Long-term change in reference voltage Vn Broadband noise voltage Average temperature coefficient of reference voltage‡ Reference impedance IZ = 20 µA to 20 mA IZ = 20 µA to 20 mA IZ = 100 µA IZ = 100 µA IZ = 100 µA, f = 10 Hz to 10 kHz LM385Y-2.5 MIN TYP MAX 2.462 2.5 2.575 UNIT V ±20 ppm/°C ±20 ppm/khr 0.4 120 1 Ω µV ‡ 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 Powered by ICminer.com Electronic-Library Service CopyRight 2003 • DALLAS, TEXAS 75265 3 LM285-2.5, LM385-2.5, LM385B-2.5 MICROPOWER VOLTAGE REFERENCES SLVS023E – JANUARY 1989 – REVISED JULY 1999 TYPICAL CHARACTERISTICS† REVERSE CURRENT vs REVERSE VOLTAGE REFERENCE VOLTAGE CHANGE vs REVERSE CURRENT 100 16 TA = –55°C to 125°C ∆V Z – Reference Voltage Change – mV I R – Reverse Current – µ A TA = –55°C to 125°C 10 1 0.1 0 0.5 1 2 1.5 2.5 12 8 4 0 –4 0.01 3 VR – Reverse Voltage – V 0.1 1 Figure 1 REFERENCE VOLTAGE vs FREE-AIR TEMPERATURE 2.525 1.6 IZ = 20 µA to 20 mA TA = 25°C 1.4 2.52 1.2 2.515 VZ – Reference Voltage – V V F – Forward Voltage – V 100 Figure 2 FORWARD VOLTAGE vs FORWARD CURRENT 1 0.8 0.6 0.4 2.51 2.505 2.5 2.495 2.49 0.2 0 0.01 10 IR – Reverse Current – mA 2.485 0.1 1 10 100 2.48 – 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 Powered by ICminer.com Electronic-Library Service CopyRight 2003 • DALLAS, TEXAS 75265 LM285-2.5, LM385-2.5, LM385B-2.5 MICROPOWER VOLTAGE REFERENCES SLVS023E – JANUARY 1989 – REVISED JULY 1999 TYPICAL CHARACTERISTICS† REFERENCE IMPEDANCE vs REFERENCE CURRENT REFERENCE IMPEDANCE vs FREQUENCY 1000 10 k IZ = 100 µA TA = 25°C z z – Reference Impedance – Ω z z – Reference Impedance – Ω f = 25 Hz TA = MIN to MAX‡ 100 10 1 0.1 0.01 0.1 1 10 1k 100 10 1 0.1 0.01 100 0.1 1 Iz – Reference Current – mA Figure 5 TA = 25°C 100 µA Filtered RMS Output Noise Voltage – µV Vn – Noise Voltage – nV/ Hz 120 IZ = 100 µA TA = 25°C 1000 800 600 400 200 100 1000 FILTERED RMS OUTPUT NOISE VOLTAGE vs FREQUENCY 1400 0 10 100 Figure 6 NOISE VOLTAGE vs FREQUENCY 1200 10 f – Frequency – kHz 1k 10 k 100 k 100 RC Low Pass R C 80 60 40 20 0 0.1 f – Frequency – Hz 1 10 100 f – Frequency – kHz Figure 7 Figure 8 † Data at high and low temperatures are applicable only within the rated operating free-air temperature ranges of the various devices. ‡ For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions. POST OFFICE BOX 655303 Powered by ICminer.com Electronic-Library Service CopyRight 2003 • DALLAS, TEXAS 75265 5 LM285-2.5, LM385-2.5, LM385B-2.5 MICROPOWER VOLTAGE REFERENCES SLVS023E – JANUARY 1989 – REVISED JULY 1999 TYPICAL CHARACTERISTICS† TRANSIENT RESPONSE Input and Output Voltages – V 4 ÎÎÎ ÎÎÎ 3 Output 2 24 kΩ VI VO 1 0 5 ÎÎ ÎÎ Input 0 0 100 t – Time – µs 500 600 Figure 9 † Data at high and low temperatures are applicable only within the rated operating free-air temperature ranges of the various devices. 6 POST OFFICE BOX 655303 Powered by ICminer.com Electronic-Library Service CopyRight 2003 • DALLAS, TEXAS 75265 LM285-2.5, LM385-2.5, LM385B-2.5 MICROPOWER VOLTAGE REFERENCES SLVS023E – JANUARY 1989 – REVISED JULY 1999 APPLICATION INFORMATION IO ≈ 60 µA + Two Mercury Cells 2.6 V – V+ 3.3 kΩ 200 kΩ ±1% LM334 cw 2.00 kΩ ±1% cw V– 20 kΩ 500 Ω 412 Ω† ±1% 953 Ω ±1% LM385-2.5 R + Type K – Meter †Adjust for 12.17 mV at 25°C across 412 Ω Figure 10. Thermocouple Cold-Junction Compensator 3.7 V ≤ V+ ≤ 30 V V+ LM334 R V– 2.74 kΩ 2.5 V LM385-2.5 Figure 11. Operation Over a Wide Supply Range 9V 221 kΩ LM385-2.5 Figure 12. Reference From a 9-V Battery POST OFFICE BOX 655303 Powered by ICminer.com Electronic-Library Service CopyRight 2003 • DALLAS, TEXAS 75265 7 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. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed, except those mandated by government requirements. CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL APPLICATIONS”). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, AUTHORIZED, OR WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT DEVICES OR SYSTEMS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF TI PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE FULLY AT THE CUSTOMER’S RISK. In order to minimize risks associated with the customer’s applications, adequate design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right of TI covering or relating to any combination, machine, or process in which such semiconductor products or services might be or are used. TI’s publication of information regarding any third party’s products or services does not constitute TI’s approval, warranty or endorsement thereof. Copyright 1999, Texas Instruments Incorporated Powered by ICminer.com Electronic-Library Service CopyRight 2003