LM333 3-Ampere Adjustable Negative Regulator General Description Features The LM333 is an adjustable 3-terminal negative voltage regulator capable of supplying in excess of −3.0A over an output voltage range of −1.2V to −32V. This regulator is exceptionally easy to apply, requiring only 2 external resistors to set the output voltage and 1 output capacitor for frequency compensation. The circuit design has been optimized for excellent regulation and low thermal transients. Further, the LM333 features internal current limiting, thermal shutdown and safe-area compensation, making them substantially immune to failure from overloads. The LM333 serves a wide variety of applications including local on-card regulation, programmable-output voltage regulation or precision current regulation. The LM333 is an ideal complement to the LM150/LM350 adjustable positive regulators. n n n n n n n n n n Output voltage adjustable from −1.2V to −32V 3.0A output current guaranteed, −55˚C to +150˚C Line regulation typically 0.01%/V Load regulation typically 0.2% Excellent rejection of thermal transients 50 ppm/˚C temperature coefficient Temperature-independent current limit Internal thermal overload protection Standard 3-lead transistor package Output is short circuit protected Connection Diagram TO-3 Metal Can Package DS009065-1 Bottom View Steel TO-3 Metal Can Package (K STEEL) Order Number LM333K STEEL See NS Package Number K02A Typical Application −5.2V Regulator with Electronic Shutdown DS009065-6 © 2000 National Semiconductor Corporation DS009065 www.national.com LM333 3-Ampere Adjustable Negative Regulators December 2000 LM333 Absolute Maximum Ratings (Note 1) Operating Junction Temperature Range LM333 Storage Temperature Lead Temperature (Soldering, 10 sec.) TO-3 Package ESD Susceptibility If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Power Dissipation Input-Output Voltage Differential Internally Limited 35V TMIN to TMAX −40˚C to +125˚C −65˚C to +150˚C 300˚C TBD Electrical Characteristics LM333 Specifications with standard typeface are for TJ = 25˚C, and those with boldface type apply over the full operating temperature range. (Note 3) Parameter Reference Voltage Conditions Typical Min Max (Note 2) (Note 2) IL = 10 mA −1.250 −1.225 −1.275 3V ≤ |VIN − VOUT| ≤ 35V −1.250 −1.213 −1.287 Units V 10 mA ≤ IL ≤ 3A, P ≤ PMAX Line Regulation Load Regulation 3V ≤ |VIN − VOUT| ≤ 35V 0.01 0.04 IOUT = 50 mA (Note 4) 0.02 0.07 10 mA ≤ IL ≤ 3A, P ≤ PMAX 0.2 1.0 (Notes 4, 5) 0.4 1.5 Thermal Regulation 10 ms Pulse 0.002 0.02 Temperature Stability TMIN ≤ TJ ≤ TMAX 0.5 Long Term Stability TJ = 125˚C, 1000 Hours 0.2 Adjust Pin Current Adjust Pin Current 10 mA ≤ IL ≤ 3A Change 3.0V ≤ |VIN − VOUT| ≤ 35V % /W % 65 95 70 100 2.5 8 µA mA |VIN − VOUT| ≤ 35V 2.5 10 Current |VIN − VOUT| ≤ 10V 1.5 5.0 Current Limit 3V ≤ |VIN − VOUT| ≤ 10V 3.9 3.0 (Note 5) |VIN − VOUT| = 20V 2.4 1.0 |VIN − VOUT| = 30V 0.4 0.20 10 Hz to 10 kHz % % Minimum Load Output Noise % /V µA A 0.003 % (rms) 60 dB (% of VOUT) Ripple Rejection VOUT = 10V, f = 120 Hz CADJ = 0 µF CADJ = 10 µF Thermal Resistance TO-3 Package (K STEEL) Junction to Case TO-220 Package (T) 77 Thermal Shutdown 1.2 1.8 3 4 163 ˚C/W ˚C Temperature Thermal Resistance K Package 35 Junction to Ambient T Package 50 ˚C/W (No Heatsink) Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Electrical specifications do not apply when operating the device outside of its stated operating conditions. Note 2: All limits are guaranteed at either room temperature (standard type face) or at temperature extremes (bold typeface) by production testing or correlation techniques using standard Statistical Quality Control (SQC) methods. Note 3: Unless otherwise specified: |VIN − VOUT| = 5V, IOUT = 0.5A, PDISS ≤ 30W. Note 4: Load and line regulation are measured at constant junction temperature, using low duty cycle pulse testing (output voltage changes due to heating effects are covered by the Thermal Regulation specification). For the TO-3 package, load regulation is measured on the output pin, 1⁄8" below the base of the package. Note 5: The output current of the LM333 is guaranteed to be ≥ 3A in the range 3V ≤ |VIN − VOUT| ≤ 10V. For the range 10V ≤ |VIN − VOUT| ≤ 15V, the guaranteed minimum output current is equal to: 30/ (VIN − VOUT). Refer to graphs for guaranteed output currents at other voltages. www.national.com 2 LM333 Guaranteed Performance Characteristics LM133 Guaranteed Output Current LM333 Guaranteed Output Current DS009065-4 DS009065-5 Typical Applications −5.2V Regulator with Electronic Shutdown DS009065-6 Negative Regulator with Protection Diodes DS009065-7 *When CL is larger than 20 µF, D1 protects the LM333 in case the input supply is shorted. **When C2 is larger than 10 µF and −VOUT is larger than −25V, D2 protects the LM333 in case the output is shorted. ***In case VOUT is shorted to a positive supply, D3 protects the LM333 from overvoltage, and protects the load from reversed voltage. 3 www.national.com LM333 Typical Applications (Continued) High-Performance 9-Ampere Adjustable Regulator DS009065-8 *Wire R1 and R4 to the regulator that provides the highest VOUT with a 3A load. **Full output current requires 5V≤|VIN–VOUT|≤10V. At higher input-output voltages, load current will be less (see guaranteed curves) Current Regulator High Stability 10V Regulator DS009065-9 *0.4Ω ≤ R1 ≤ 120Ω DS009065-10 www.national.com 4 LM333 Typical Applications (Continued) High-Current Adjustable Regulator DS009065-11 *Control regulator must have the largest VREF **Full output current requires 5V≤|VIN–VOUT| ≤10V. At higher input-output voltages, load current will be less (see guaranteed curves) 5 www.national.com LM333 Typical Applications (Continued) Adjustable Current Regulator Adjustable Lab Voltage Regulator DS009065-13 *0.5Ω ≤ R1 ≤ 24Ω DS009065-12 *The 10 µF capacitors are optional to improve ripple rejection. 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 the 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 50ms 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 VOUT, per watt, within the first 10 ms after a step of power is applied. The LM333’s specification is 0.01%/W, max. In Figure 1, a typical LM333’s output drifts only 2mV (or 0.02% of VOUT = −10V) when a 20W pulse is applied for 10 ms. This performance is thus well inside the specification limit of 0.01%/Wx20W = 0.2% max. When the 20W pulse is ended, the thermal regulation again shows a 2 mV step as the LM333 chip cools off. Note that the load regulation error of about 1 mV (0.01%) is additional to the thermal regulation error. In Figure 2, when the 20W pulse is applied for 100 ms, the output drifts only slightly beyond the drift in the first 10ms, and the thermal error stays well within 0.1% (10mV). www.national.com DS009065-14 FIGURE 1. 6 LM333 Typical Applications (Continued) DS009065-15 FIGURE 2. Adjustable Negative Voltage Regulator DS009065-3 † C1 = 1 µF solid tantalum or 10 µF aluminum electrolytic required for stability. *C2 = 1 µF solid tantalum is required only if regulator is more than 4" from power supply filter capacitor. Output capacitors in the range of 1 µF to 1000 µF of aluminum or tantalum electrolytic are commonly used to provide lower output impedance and improved transient response. 7 www.national.com LM333 3-Ampere Adjustable Negative Regulators Physical Dimensions inches (millimeters) unless otherwise noted Steel TO-3 Metal Can Package (K STEEL) Order Numbe LM333K STEEL NS Package Number K02A LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 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