LM336—2.5

LM136-2.5/LM236-2.5/LM336-2.5V Reference Diode General Description The LM136-2.5/LM236-2.5 and LM336-2.5 integrated cir- cuits are precision 2.5V shunt regulator diodes. These monolithic IC voltage references operate as a low- temperature-coefficient 2.5V zener with 0.2Ω dynamic im- pedance. A third terminal on the LM136-2.5 allows the refer- ence voltage and temperature coefficient to be trimmed easily. The LM136-2.5 series is useful as a precision 2.5V low voltage reference for digital voltmeters, power supplies or op amp circuitry. The 2.5V make it convenient to obtain a stable reference from 5V logic supplies. Further, since the LM136- 2.5 operates as a shunt regulator, it can be used as either a positive or negative voltage reference. The LM136-2.5 is rated for operation over −55˚C to +125˚C while the LM236-2.5 is rated over a −25˚C to +85˚C tem- perature range. The LM336-2.5 is rated for operation over a 0˚C to +70˚C temperature range. See the connection diagrams for avail- able packages. Features n Low temperature coefficient n Wide operating current of 400 µA to 10 mA n 0.2Ω dynamic impedance n ±1% initial tolerance available n Guaranteed temperature stability n Easily trimmed for minimum temperature drift n Fast turn-on Connection Diagrams TO-92 Plastic Package 00571508 Bottom View Order Number LM336Z-2.5 or LM336BZ-2.5 See NS Package Number Z03A TO-46 Metal Can Package 00571520 Bottom View Order Number LM136H-2.5, LM136H-2.5/883, LM236H-2.5, or LM236AH-2.5 See NS Package Number H03H SO Package 00571512 Top View Order Number LM236M-2.5, LM236AM-2.5, LM336M-2.5 or LM336BM-2.5 See NS Package Number M08A June 2005 LM 136-2.5/LM 236-2.5/LM 336-2.5V Reference Diode © 2005 National Semiconductor Corporation DS005715 www.national.com Typical Applications 2.5V Reference 00571509 2.5V Reference with Minimum Temperature Coefficient 00571510 †Adjust to 2.490V *Any silicon signal diode Wide Input Range Reference 00571511 LM 13 6- 2. 5/ LM 23 6- 2. 5/ LM 33 6- 2. 5V www.national.com 2 Absolute Maximum Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Reverse Current 15 mA Forward Current 10 mA Storage Temperature −60˚C to +150˚C Operating Temperature Range (Note 2) LM136 −55˚C to +150˚C LM236 −25˚C to +85˚C LM336 0˚C to +70˚C Soldering Information TO-92 Package (10 sec.) 260˚C TO-46 Package (10 sec.) 300˚C SO Package Vapor Phase (60 sec.) 215˚C Infrared (15 sec.) 220˚C See AN-450 “Surface Mounting Methods and Their Effect on Product Reliability” (Appendix D) for other methods of soldering surface mount devices. Electrical Characteristics (Note 3) LM136A-2.5/LM236A-2.5 LM336B-2.5 Parameter Conditions LM136-2.5/LM236-2.5 LM336-2.5 Units Min Typ Max Min Typ Max Reverse Breakdown Voltage TA=25˚C, IR=1 mA LM136, LM236, LM336 2.440 2.490 2.540 2.390 2.490 2.590 V LM136A, LM236A, LM336B 2.465 2.490 2.515 2.440 2.490 2.540 V Reverse Breakdown Change TA=25˚C, 2.6 6 2.6 10 mV With Current 400 µA≤IR≤10 mA Reverse Dynamic Impedance TA=25˚C, IR=1 mA, f = 100 Hz 0.2 0.6 0.2 1 Ω Temperature Stability VR Adjusted to 2.490V (Note 4) IR=1 mA, Figure 2 0˚C≤TA≤70˚C (LM336) 1.8 6 mV −25˚C≤TA≤+85˚C 3.5 9 mV (LM236H, LM236Z) −25˚C ≤ TA ≤ +85˚C (LM236M) 7.5 18 mV −55˚C≤TA≤+125˚C (LM136) 12 18 mV Reverse Breakdown Change 400 µA≤IR≤10 mA 3 10 3 12 mV With Current Reverse Dynamic Impedance IR=1 mA 0.4 1 0.4 1.4 Ω Long Term Stability TA=25˚C ±0.1˚C, IR=1 mA, 20 20 ppm t = 1000 hrs Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Electrical specifications do not apply when operating the device beyond its specified operating conditions. Note 2: For elevated temperature operation, Tj max is: LM136 150˚C LM236 125˚C LM336 100˚C Thermal Resistance TO-92 TO-46 SO-8 θja (Junction to Ambient) 180˚C/W (0.4" leads) 440˚C/W 165˚C/W 170˚C/W (0.125" lead) θja (Junction to Case) n/a 80˚C/W n/a LM 136-2.5/LM 236-2.5/LM 336-2.5V www.national.com3 Electrical Characteristics (Note 3) (Continued) Note 3: Unless otherwise specified, the LM136-2.5 is specified from −55˚C ≤ TA ≤ +125˚C, the LM236-2.5 from −25˚C ≤ TA ≤ +85˚C and the LM336-2.5 from 0˚C ≤ TA ≤ +70˚C. Note 4: Temperature stability for the LM336 and LM236 family is guaranteed by design. 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. Stability is defined as the maximum change in Vref from 25˚C to TA (min) or TA (max). LM 13 6- 2. 5/ LM 23 6- 2. 5/ LM 33 6- 2. 5V www.national.com 4 Typical Performance Characteristics Reverse Voltage Change Zener Noise Voltage 00571521 00571522 Dynamic Impedance Response Time 00571523 00571524 Reverse Characteristics Forward Characteristics 00571525 00571526 LM 136-2.5/LM 236-2.5/LM 336-2.5V www.national.com5 Typical Performance Characteristics (Continued) Temperature Drift 00571527 Application Hints The LM136 series voltage references are much easier to use than ordinary zener diodes. Their low impedance and wide operating current range simplify biasing in almost any circuit. Further, either the breakdown voltage or the temperature coefficient can be adjusted to optimize circuit performance. Figure 1 shows an LM136 with a 10k potentiometer for adjusting the reverse breakdown voltage. With the addition of R1 the breakdown voltage can be adjusted without affect- ing the temperature coefficient of the device. The adjustment range is usually sufficient to adjust for both the initial device tolerance and inaccuracies in buffer circuitry. If minimum temperature coefficient is desired, two diodes can be added in series with the adjustment potentiometer as shown in Figure 2. When the device is adjusted to 2.490V the temperature coefficient is minimized. Almost any silicon signal diode can be used for this purpose such as a 1N914, 1N4148 or a 1N457. For proper temperature compensation the diodes should be in the same thermal environment as the LM136. It is usually sufficient to mount the diodes near the LM136 on the printed circuit board. The absolute resis- tance of R1 is not critical and any value from 2k to 20k will work. 00571528 FIGURE 1. LM136 With Pot for Adjustment of Breakdown Voltage (Trim Range = ±120 mV typical) 00571529 FIGURE 2. Temperature Coefficient Adjustment (Trim Range = ±70 mV typical) LM 13 6- 2. 5/ LM 23 6- 2. 5/ LM 33 6- 2. 5V www.national.com 6 Application Hints (Continued) Low Cost 2 Amp Switching Regulator† 00571505 *L1 60 turns #16 wire on Arnold Core A-254168-2 †Efficiency ≈ 80% Precision Power Regulator with Low Temperature Coefficient 00571513 5V Crowbar 00571514 Trimmed 2.5V Reference with Temperature Coefficient Independent of Breakdown Voltage 00571515 *Does not affect temperature coefficient LM 136-2.5/LM 236-2.5/LM 336-2.5V www.national.com7 Application Hints (Continued) Adjustable Shunt Regulator 00571506 Linear Ohmmeter 00571516 LM 13 6- 2. 5/ LM 23 6- 2. 5/ LM 33 6- 2. 5V www.national.com 8 Application Hints (Continued) Op Amp with Output Clamped 00571517 Bipolar Output Reference 00571518 2.5V Square Wave Calibrator 00571519 5V Buffered Reference 00571530 Low Noise Buffered Reference 00571531 LM 136-2.5/LM 236-2.5/LM 336-2.5V www.national.com9 Schematic Diagram 00571501 LM 13 6- 2. 5/ LM 23 6- 2. 5/ LM 33 6- 2. 5V www.national.com 10 Physical Dimensions inches (millimeters) unless otherwise noted Order Number LM136H-2.5, LM136H-2.5/883, LM236H-2.5, LM136AH-2.5, LM136AH-2.5/883 or LM236AH-2.5 NS Package Number H03H Small Outline (SO) Package (M) Order Number LM236M-2.5, LM236AM-2.5, LM336M-2.5 or LM336BM-2.5 NS Package Number M08A LM 136-2.5/LM 236-2.5/LM 336-2.5V www.national.com11 Physical Dimensions inches (millimeters) unless otherwise noted (Continued) TO-92 Plastic Package (Z) Order Number LM336Z-2.5 or LM336BZ-2.5 NS Package Number Z03A National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications. 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National Semiconductor Americas Customer Support Center Email: new.feedback@nsc.com Tel: 1-800-272-9959 National Semiconductor Europe Customer Support Center Fax: +49 (0) 180-530 85 86 Email: europe.support@nsc.com Deutsch Tel: +49 (0) 69 9508 6208 English Tel: +44 (0) 870 24 0 2171 Français Tel: +33 (0) 1 41 91 8790 National Semiconductor Asia Pacific Customer Support Center Email: ap.support@nsc.com National Semiconductor Japan Customer Support Center Fax: 81-3-5639-7507 Email: jpn.feedback@nsc.com Tel: 81-3-5639-7560 www.national.com LM 13 6- 2. 5/ LM 23 6- 2. 5/ LM 33 6- 2. 5V Re fe re nc e Di od e LM136-2.5/LM236-2.5/LM336-2.5V General Description Features Connection Diagrams Typical Applications Absolute Maximum Ratings Electrical Characteristics Typical Performance Characteristics Application Hints FIGURE 1. LM136 With Pot for Adjustment of Breakdown Voltage (Trim Range = 120 mV typical) FIGURE 2. Temperature Coefficient Adjustment (Trim Range = 70 mV typical) Schematic Diagram Physical Dimensions