LM137 LM337 Three-terminal adjustable negative voltage regulators Features ■ Output voltage adjustable down to VREF ■ 1.5 A guaranteed output current ■ 0.3 %/V typical load regulation ■ 0.01 %/V typical line regulation ■ Current limit constant with temperature ■ Ripple rejection: 77 dB ■ Standard 3-lead transistor packages ■ Excellent thermal regulation: 0.002 %/V ■ 50 ppm/°C temperature coefficient TO-220 Description The LM137 series are adjustable 3-terminal negative voltage regulators capable of supplying in excess -1.5 A over a -1.2 to -37 V output voltage range. They are exceptionally easy to use and require only two external resistors to set the output voltage. Further, both line and load regulation are better than standard fixed regulators. Also, LM137 regulators are supplied in standard transistor packages which are easily mounted and handled. In addition to higher performance than fixed regulators, the LM137 series offer full overload protection available only in integrated circuits. Table 1. July 2008 TO-3 Included on the chip are current limit, thermal overload protection and safe area protection. All overload protection circuitry remains fully functional even if the adjustment terminal is disconnected. Device summary Part numbers Order codes Temperature range LM137 LM137K -55 °C to 150 °C LM337 LM337K 0 °C to 125 °C Rev 3 1/18 www.st.com 18 Contents LM137 - LM337 Contents 1 Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 5 Typical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 6 Thermal regulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7 Typical application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 8 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 2/18 LM137 - LM337 1 Diagram Figure 1. Schematic diagram Diagram 3/18 Pin configuration LM137 - LM337 2 Pin configuration Figure 2. Pin connections (top view) TO-220 4/18 TO-3 LM137 - LM337 Maximum ratings 3 Maximum ratings Table 2. Absolute maximum ratings Symbol Value Unit Input output voltage differential 40 V IO Output current 1.5 A PD Power dissipation VI - VO Parameter Internally limited TSTG Storage temperature range TOP Operating junction temperature range - 65 to 150 LM137 - 55 to 150 LM337 0 to 125 °C °C Note: Absolute maximum ratings are those values beyond which damage to the device may occur. Functional operation under these condition is not implied. Table 3. Thermal data Symbol Parameter TO-220 TO-3 Unit RthJC Thermal resistance junction-case max. 3 4 °C/W RthJA Thermal resistance junction-ambient max. 70 35 °C/W 5/18 Electrical characteristics LM137 - LM337 4 Electrical characteristics Table 4. Electrical characteristics of LM137 (TJ = -55 to 150 °C, VI - VO = 5 V, IO = 0.5 A unless otherwise specified) (1) Symbol Parameter Test conditions Min. Typ. Max. -1.225 -1.25 -1.275 -1.2 -1.25 -1.3 IO = 0.1 A 0.01 0.02 IO = 20 mA 0.01 0.02 |VO| ≤ 5 V 15 25 mV |VO| ≥ 5 V 0.3 0.5 % 0.002 0.02 %/W 65 100 µA 2 5 µA 0.02 0.05 %/V |VO| ≤ 5 V 20 50 mV |VO| ≥ 5 V 0.3 1 % |VI - VO| ≤ 40 V 2.5 5 |VI - VO| ≤ 10 V 1.2 3 Ta = 25°C VREF Reference voltage KVI Line regulation (2) KVO Load regulation (2) Thermal regulation |VI - VO| = 3 to 40 V, TJ = Tmin to Tmax |IO| = 10mA to |IO(max)| P ≤ Pmax Ta = 25°C |VI - VO| = 3 to 40 V Ta = 25°C |IO| = 10mA to |IO(max)| Adjustment pin current ΔIADJ Adjustment pin current change Ta = 25°C, |IO| = 10 mA to |IO(max)| |VI - VO| = 3 to 40 V KVI Line regulation (2) |VI - VO| = 3 to 40 V KVO Load regulation (2) |IO| = 10mA to |IO(max)| |IO(min)| Minimum load current IOS Short circuit output current VNO RMS output noise (% of VO) RVF Ripple rejection ratio KVT Temperature stability KVH Long term stability V %/V Ta = 25°C, pulse 10 ms IADJ mA |VI - VO| ≤ 15 V 1.5 2.2 |VI - VO| = 40 V, TJ =25°C 0.24 0.4 A Ta = 25°C, f = 10 Hz to 10 kHz 0.003 VO = -10 V, f = 120 Hz CADJ = 10 µF % 60 dB 66 77 0.6 Ta = 125°C, 1000 H 0.3 % 1 1. Although power dissipation is internally limited, these specifications are applicable for power dissipation of: 15 W for TO-220 and 20 W for TO-3 Package; IO(max) is 1.5 A 2. 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. 6/18 Unit % LM137 - LM337 Table 5. Symbol Electrical characteristics Electrical characteristics of LM337 (TJ = 0 to 150 °C unless otherwise specified). (1) Parameter Test conditions Min. Typ. Max. -1.213 -1.25 -1.287 -1.2 -1.25 -1.3 IO = 0.1 A 0.01 0.04 IO = 20 mA 0.01 0.04 |VO| ≤ 5 V 15 50 mV |VO| ≥ 5 V 0.3 1 % 0.003 0.04 %/W 65 100 µA 2 5 µA 0.02 0.07 %/V |VO| ≤ 5 V 20 70 mV |VO| ≥ 5 V 0.3 1.5 % |VI - VO| ≤ 40 V 2.5 10 |VI - VO| ≤ 10 V 1.5 6 Ta = 25°C VREF Reference voltage KVI Line regulation (2) KVO Load regulation (2) Thermal regulation |VI - VO| = 3 to 40 V, TJ = Tmin to Tmax |IO| = 10mA to |IO(max)|, P ≤ Pmax Ta = 25°C |VI - VO| = 3 to 40 V Ta = 25°C |IO| = 10mA to |IO(max)| Adjustment pin current ΔIADJ Adjustment pin current change Ta = 25°C, |IO| = 10 mA to |IO(max)| |VI - VO| = 3 to 40 V KVI Line regulation (2) |VI - VO| = 3 to 40 V KVO Load regulation (2) |IO| = 10mA to |IO(max)| |IO(min)| Minimum load current IOS Short circuit output current VNO RMS output noise (% of VO) RVF Ripple rejection ratio KVT Temperature stability KVH Long term stability V %/V Ta = 25°C, pulse 10 ms IADJ mA |VI - VO| ≤ 15 V 1.5 2.2 |VI - VO| = 40 V, TJ =2 5°C 0.15 0.4 A Ta = 25°C, f = 10 Hz to 10 kHz 0.003 VO = -10 V, f = 120 Hz CADJ = 10 µF % 60 dB 66 77 0.6 Ta = 125°C, 1000 H Unit 0.3 % 1 % 1. Although power dissipation is internally limited, these specifications are applicable for power dissipation of: 15 W for TO-220 and 20 W for TO-3 package; IO(max) is 1.5 A. 2. 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. 7/18 Typical characteristics LM137 - LM337 5 Typical characteristics Figure 3. Load regulation Figure 4. Current limit Figure 5. Adjustment current Figure 6. Dropout voltage Figure 7. Temperature stability Figure 8. Minimum operating current 8/18 LM137 - LM337 Figure 9. Ripple rejection vs output voltage Typical characteristics Figure 10. Ripple rejection vs frequency Figure 11. Ripple rejection vs output current Figure 12. Output impedance Figure 13. Line transient response Figure 14. Load transient response 9/18 Thermal regulation 6 LM137 - LM337 Thermal regulation When power is dissipated in an IC, a temperature gradient occurs across the IC chip affecting the individual IC circuit components. With an IC regulator, this gradient can be especially severe since power dissipation is large. Thermal regulation is the effect of these temperature gradients on output voltage (in percentage output change) per watt of power change in a specified time. Thermal regulation error is independent of electrical regulation or temperature coefficient, and occurs within 5 ms to 50 ms after a change in power dissipation. Thermal regulation depends on IC layout as well as electrical design. The thermal regulation of a voltage regulator is defined as the percentage change of VO, per watt, within the first 10ms after a step of power, is applied. The LM137 specification is 0.02 %/W max. In Figure 1, a typical LM337’s output drifts only 3 mV for 0.03% of VO = – 10 V) when a 10 W pulse is applied for 10 ms. This performance is thus well inside the specification limit of 0.02 %/W x 10 W = 0.2% max. When the 10 W pulse is ended the thermal regulation again shows a 3 mV step as the LM137 chip cools off. Note that the load regulation error of about 8 mV (0.08 %) is additional to the thermal regulation error. In Figure 2, when the 10 W pulse is applied for 100 ms, the output drifts only slightly beyond the drift in the first 10 ms and the thermal error stays well within 0.1% (10 mV). 10/18 LM137 - LM337 7 Typical application Typical application Figure 15. Adjustable negative voltage regulator * C1 = 1 µF solid tantalum or 10µF aluminium electrolytic required for stability. ** C2 = 1 µF solid tantalum is required only if regulator is more than 10 cm from power supply filter capacitors Figure 16. Adjustable lab voltage regulator * The 10 µF capacitors are optimal to improve ripple rejection. 11/18 Typical application LM137 - LM337 Figure 17. Current regulator Figure 18. Negative regulator with protection diodes * When CL is larger than 20 µF, D1 protects the LM137 in case the input supply is shorted. ** When C2 is larger than 10 µF and VO is larger than - 25 V, D2 protects the LM137 in case the output is shorted. 12/18 LM137 - LM337 Typical application Figure 19. - 5.2 V regulator with electronic shutdown (1) 1. Minimum output = - 1.3 V when control input is low. Figure 20. Current regulator 13/18 Package mechanical data 8 LM137 - LM337 Package mechanical data In order to meet environmental requirements, ST offers these devices in ECOPACK® packages. These packages have a lead-free second level interconnect. The category of second Level Interconnect is marked on the package and on the inner box label, in compliance with JEDEC Standard JESD97. The maximum ratings related to soldering conditions are also marked on the inner box label. ECOPACK is an ST trademark. ECOPACK specifications are available at: www.st.com. 14/18 LM137 - LM337 Package mechanical data TO-220 mechanical data Dim. mm. Min. Typ. inch. Max. Min. Typ. Max. A 4.40 4.60 0.173 0.181 C 1.23 1.32 0.048 0.051 D 2.40 2.72 0.094 0.107 0.70 0.019 0.027 D1 E 1.27 0.49 0.050 F 0.61 0.88 0.024 0.034 F1 1.14 1.70 0.044 0.067 F2 1.14 1.70 0.044 0.067 G 4.95 5.15 0.194 0.203 G1 2.4 2.7 0.094 0.106 H2 10.0 10.40 0.393 0.409 L2 16.4 0.645 L4 13.0 14.0 0.511 0.551 L5 2.65 2.95 0.104 0.116 L6 15.25 15.75 0.600 0.620 L7 6.2 6.6 0.244 0.260 L9 3.5 3.93 0.137 0.154 DIA. 3.75 3.85 0.147 0.151 P011C 15/18 Package mechanical data LM137 - LM337 TO-3 mechanical data mm. Dim. Min. A inch. Typ. Max. Min. Typ. 11.85 B 0.96 Max. 0.466 1.05 1.10 0.037 0.041 0.043 C 1.70 0.066 D 8.7 0.342 E 20.0 0.787 G 10.9 0.429 N 16.9 0.665 P 26.2 R 3.88 1.031 4.09 U 0.152 39.5 V 1.555 30.10 1.185 A P D C O N B V E G U 0.161 R P003C/C 16/18 LM137 - LM337 Revision history 9 Revision history Table 6. Document revision history Date Revision Changes 19-Jul-2004 1 First issue. 10-Jan-2005 2 Modified pin connection for TO-3. 17-Jul-2008 3 Added: Table 1 on page 1. 17/18 LM137 - LM337 Please Read Carefully: Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale. 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