LT1038MK

LT1038 OBSOLETE PRODUCT DATA SHEET FOR REFERENCE ONLY Consult www.linear.com for possible alternate source. 10A Positive Adjustable Voltage Regulator DESCRIPTIO U Load Regulation 0.2 OUTPUT VOLTAGE DEVIATION (%) FEATURES s s s s s s s Guaranteed 0.8% Initial Tolerance Guaranteed 0.4% Load Regulation Guaranteed 10A Output Current 100% Thermal Limit Burn-In 24A Transient Output Current Standard Adjustable Pinout Operates to 35V The LT®1038 is a three terminal regulator which is capable of providing in excess of 10A output current over 1.2V to 32V range. The device is packaged in a standard T0-3 power package and is plug-in compatible with industry standard adjustable regulators, such as the LM117 and LM138. Also, the LT1038 is a functional replacement for the LM396. In addition to excellent load and line regulations, the LT1038 is fully protected by current limiting, safe area protection and thermal shutdown. New current limiting circuitry allows transient load currents up to 24A to be supplied for 500µs without causing the regulator to current limit and drop out of regulation during the transient. On-chip trimming of initial reference voltage to ±0.8% combined with 0.4% load regulation minimize errors in all high current applications. Further, the LT1038 is manufactured with standard bipolar processing and has Linear Technology’s high reliability. , LTC and LT are registered trademarks of Linear Technology Corporation. APPLICATIO S s s s s s System Power Supplies High Power Linear Regulator Battery Chargers Power Driver Constant Current Regulator TYPICAL APPLICATIONS 5V, 10A Regulator VIN = 15V VOUT = 10V PRELOAD = 100mA VIN ≥ 8V LT1038 VIN VOUT 1µF + ADJ U U 0.1 0 – 0.1 – 0.2 – 0.3 121Ω 1% 365Ω 1% 5V AT 10A IOUT = 6A IOUT = 10A + 10µF 1038 TA01 – 0.4 – 75 – 50 – 25 0 25 50 75 100 125 150 TEMPERATURE (°C) 1038 TA02 1 LT1038 ABSOLUTE (Note 1) AXI U RATI GS PACKAGE/ORDER I FOR ATIO BOTTOM VIEW VIN 2 Power Dissipation ............................... Internally Limited Input to Output Voltage Differential ......................... 35V Operating Junction Temperature Range LT1038M Control Circuitry ................ –55°C to 150°C LT1038M Power Transistor ............... –55°C to 200°C LT1038C Control Circuitry ..................... 0°C to 125°C LT1038C Power Transistor .................... 0°C to 175°C Storage Temperature Range ................. – 65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C ORDER PART NUMBER LT1038MK LT1038CK 1 ADJ K PACKAGE 2-LEAD TO-3 METAL CAN CASE IS OUTPUT TJMAX = 3°C, θJA = 35°C/W OBSOLETE PACKAGE PRECO DITIO I G 100% Thermal Limit Burn-in The q denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. (Note 2) SYMBOL VREF PARAMETER Reference Voltage CONDITIONS IOUT = 20mA, Tj = 25°C 3V ≤ (VIN – VOUT) ≤ 35V 20mA ≤ IOUT ≤ 10A, P ≤ 75W ∆VOUT ∆VIN ∆VOUT ∆IOUT Line Regulation Load Regulation 3V ≤ (VIN – VOUT) ≤ 35V, IOUT = 20mA (Note 3) 20mA ≤ IOUT ≤ 10A (Note 3) 3V ≤ (VIN – VOUT) ≤ 35V 3V ≤ (VIN – VOUT) ≤ 35V 20ms Pulse VOUT = 10V, f = 120Hz CADJ = 0µF CADJ = 10µF 20mA ≤ IOUT ≤ 10A 3V ≤ (VIN – VOUT) ≤ 35V (VIN – VOUT) = 35V (VIN – VOUT) ≤ 20V (VIN – VOUT) ≤ 10V DC Transient (0.5ms) (VIN – VOUT) = 30V, Tj = 25°C ∆VOUT ∆Temp ∆VOUT ∆Time en θJC Temperature Stability Long Term Stability RMS Output Noise (% of VOUT) Thermal Resistance Junction to Case TA = 125°C, 1000 Hours 10Hz ≤ f ≤ 10kHz Power Transistor Control Circuity q q q q q q q q q q ELECTRICAL CHARACTERISTICS MIN 1.24 1.22 LT1038M TYP 1.25 1.25 0.005 0.02 0.1 0.3 0.002 60 75 50 0.2 7 MAX 1.26 1.285 0.01 0.03 0.4 0.8 0.005 MIN 1.23 1.22 LT1038C TYP 1.25 1.25 0.005 0.02 0.1 0.3 0.002 60 75 50 0.2 7 MAX 1.275 1.285 0.02 0.03 0.6 1.0 0.01 UNITS V V %/V %/V % % %/W dB dB q q Thermal Regulation Ripple Rejection 60 60 100 3 20 10 10 12 1 2 1 IADJ ∆IADJ Adjust Pin Current Adjust Pin Current Change Minimum Load Current 100 3 20 10 ISC Current Limit 10 14 1 14 22 2 1 0.3 0.001 1 0.5 14 22 2 1 0.3 0.001 1 0.5 1 °C/W °C/W 2 U µA µA mA mA A A A % % % W U U WW UU W U LT1038 ELECTRICAL CHARACTERISTICS Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: Unless otherwise specified, these specifications apply: VIN – VOUT = 5V and IOUT = 5A. These specifications are applicable for power dissipations up to 75W. At input-output voltage differentials greater than 10V, achievable output current and power dissipation decrease due to protection circuitry. Note 3: See thermal regulation specifications for changes in output voltage due to heating effects. Load and line regulation are measured at a constant junction temperature by low duty cycle pulse testing. TYPICAL PERFOR A CE CHARACTERISTICS Dropout Voltage 4 ∆VOUT = 100mV 65 60 INPUT-OUTPUT DIFFERENTIAL (V) ADJUSTMENT CURRENT (µA) REFERENCE VOLTAGE (V) 3 IOUT = 10A IOUT = 6A 2 IOUT = 2A 1 – 75 – 50 – 25 0 25 50 75 100 125 150 TEMPERATURE (°C) 1038 TA02 Output Impedance 10 10 VIN = 15V VOUT = 10V IOUT = 1A CADJ = 0µF COUT = 0µF CADJ = 10µF COUT = 10µF QUIESCENT CURRENT (mA) OUTPUT IMPEDANCE (Ω) 1 RIPPLE REJECTION (dB) 0.1 0.01 0.001 0.0001 10 100 10k 1k FREQUENCY (Hz) 100k 1M 1038 G04 UW Adjustment Current 1.27 Temperature Stability 55 50 45 40 35 30 – 75 – 50 – 25 1.26 1.25 1.24 0 25 50 75 100 125 150 TEMPERATURE (°C) 1038 G02 1.23 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) 1038 G03 Minimum Operating Current 100 Ripple Rejection CADJ = 10µF 8 Tj = 150°C 6 Tj = 25°C Tj = – 55°C 80 CADJ = 0µF 60 4 40 VIN – VOUT = 5V IOUT = 1A f = 120Hz Tj = 25°C 0 5 20 15 10 25 OUTPUT VOLTAGE (V) 30 35 2 20 0 0 25 30 35 5 10 15 20 INPUT-OUTPUT DIFFERENTIAL (V) 40 0 1038 G05 1038 G06 3 LT1038 TYPICAL PERFOR A CE CHARACTERISTICS Ripple Rejection 100 CADJ = 10µF 80 RIPPLE REJECTION (dB) VIN = 15V VOUT = 10V IOUT = 1A RIPPLE REJECTION (dB) 60 CADJ = 0µF OUTPUT CURRENT (A) 40 20 0 10 100 10k 1k FREQUENCY (Hz) 100k Current Limit 28 24 OUTPUT CURRENT (A) OUTPUT VOLTAGE DEVIATION (V) VIN = 10V VOUT = 5V TCASE = 25°C OUTPUT CURRENT (A) 20 16 12 8 4 0 0.1 1 TIME (ms) LTXXX GXX PRELOAD = 10A PRELOAD = 0A INPUT VOLTAGE CHANGE (V) 10 OUTPUT VOLTAGE DEVIATION (V) LOAD CURRENT (A) 4 UW 1M 1038 G07 Ripple Rejection 80 CADJ = 10µF 70 24 32 Current Limit PEAK CURRENT LIMIT DC CURRENT LIMIT TCASE = 25°C PRELOAD = 0A PRELOAD = 10A 16 60 CADJ = 0µF PRELOAD = 2A 8 50 40 VIN = 15V VOUT = 10V f = 120Hz TCASE = 25°C 0.1 1 OUTPUT CURRENT (A) 10 1038 G08 0 0 20 10 30 INPUT-OUTPUT DIFFERENTIAL (V) 40 1195 G20 Current Limit 28 24 20 VIN – VOUT = 10V 16 12 8 4 0 VIN – VOUT = 15V VIN – VOUT = 20V VIN – VOUT = 30V PRELOAD CURRENT = 0A TCASE = 25°C 1.5 1.0 0.5 0 – 0.5 –1.0 –1.5 1.0 0.5 0 Line Transient Response VOUT = 10V IOUT = 100mA Tj = 25°C CL = 1µF; CL = 10µF COUT = 0A CADJ = 0A 100 0.1 1 TIME (ms) 10 100 1038 G11 0 10 20 TIME (µs) 30 40 1038 G12 Load Transient Response 3 2 1 0 –1 –2 –3 6 4 2 0 0 10 20 TIME (µs) 30 40 1038 G13 VIN = 15V VOUT = 10V TCASE = 25°C PRELOAD = 200mA CL = 0µF; CADJ = 0µF CL = 1µF; CADJ = 10µF LT1038 APPLICATIO S I FOR ATIO General The LT1038 develops a 1.25V reference voltage between the output and the adjustment terminal (see Figure 1). By placing a resistor, R1, between these two terminals, a constant current is caused to flow through R1 and down through R2 to set the overall output voltage. Normally this current is the specified minimum load current of 10mA or 20mA. Because IADJ is very small and constant when compared with the current through R1, it represents a small error and can usually be ignored. Bypass Capacitors Input bypassing using a 1µF tantalum or 25µF electrolytic is recommended when the input filter capacitors are more than 5 inches from the device. Improved ripple rejection (80dB) can be accomplished by adding a 10µF capacitor from the ADJ pin to ground. Increasing the size of the capacitor to 20µF will help ripple rejection at low output voltage since the reactance of this capacitor should be small compared to the voltage setting resistor, R2. For improved AC transient response and to prevent the possibility of oscillation due to unknown reactive load, a 1µF capacitor is also recommended at the output. Because of their low impedance at high frequencies, the best type of capacitor to use is solid tantalum. Protection Diodes The LT1038 does not require a protection diode from the adjustment terminal to the output (see Figure 2). Improved internal circuitry eliminates the need for this diode when the adjustment pin is bypassed with a capacitor to improve ripple rejection. D1 1N4002 VIN VIN LT1038 VOUT ADJ VREF VOUT VIN R1 IADJ 50µA R2 VOUT = VREF (1 + R2 ) + IADJ R2 R1 1038 F01 Figure 1. Basic Adjustable Regulator U If a very large output capacitor is used, such as a 100µF shown in Figure 2, the regulator could be damaged or destroyed if the input is accidentally shorted to ground or crowbarred, due to the output capacitor discharging into the output terminal of the regulator. To prevent this, a diode, D1 as shown, is recommended to safely discharge the capacitor. Load Regulation Because the LT1038 is a three-terminal device, it is not possible to provide true remote load sensing. Load regulation will be limited by the resistance of the wire connecting the regulator to the load. The data sheet specification for load regulation is measured at the bottom of the package. Negative side sensing can be a true Kelvin connection if the bottom of resistor R2 is returned to the negative side of the load. Although it may not be immediately obvious, best load regulation is obtained when the top of the resistor divider, R1, is connected directly to the case, not to the load. This is illustrated in Figure 3. If R1 were connected to the load, the effective resistance between the regulator and the load would be:  R2 + R1 Rp •   R = Parasitic Line Resistance  R1  p W U U Connected as shown, Rp is not multiplied by the divider ratio. Rp is about 0.004Ω per foot using 16 gauge wire. This translates to 4mV/ft at 1A load current, so it is important to keep the lead between the regulator and the load as short as possible, and use large wire or PC board traces. Rp PARASITIC LINE RESISTANCE CONNECT R1 TO CASE R1 R2 RL LT1038 VIN VOUT ADJ R1 * VIN VIN LT1038 VOUT ADJ + VOUT COUT 100µF CADJ 10µF + R2 *NOT NEEDED 1038 F02 CONNECT R2 TO LOAD 1038 F03 Figure 2 Figure 3. Connections for Best Load Regulation 5 LT1038 TYPICAL APPLICATIO S Paralleling Regulators T1 TRIAD F-269U C30B 20Ω 110V AC 20Ω C30B 3 1 1N4003 1N4003 1µF 82k 10k 1N4148 *1% FILM RESISTOR L-DALE TO-5 TYPE T2-STANCOR 11Z-2003 GENERAL PURPOSE REGULATOR WITH SCR PREREGULATOR TO LOWER POWER DISSIPATION. ABOUT 4V DIFFERENTIAL IS MAINTAINED ACROSS THE LT1038 INDEPENDENT OF OUTPUT VOLTAGE AND LOAD CURRENT. 6 U VIN VIN LT1038 VOUT ADJ 2 FEET #18 WIRE* VOUT = 1.25 (1 + 0.015Ω IOUT = 0A TO 20A R2 ) R1 LT1038 VIN ADJ VOUT * THE #18 WIRE ACTS AS BALLAST RESISTANCE R1 INSURING CURRENT SHARING 120Ω BETWEEN BOTH DEVICES R2 1038 TA03 10A Variable Regulator* L 1MHz VIN 1N4003 T2 4 2 LT1004-1.2 LT1004-2.5 560Ω 15V 16k* 20k OUTPUT ADJUST LT1038 VOUT ADJ 750Ω* 1.5k + C1 50,000µF + 0V TO 35V 0A TO 10A 100µF 15k 2 LT1004-1.2 8 –15V 4 LT1011 3 7 0.1µF 15V 8 –15V 4 7 LT1011 1 NC 100pF 3 2N3904 8 6 7 15k 15V 15V 4 1µF –15V LM301A 1 200k + – 1 11k* 16k* 2.7k –15V – + 2 10k + – 3 2 11k* 1038 TA04 LT1038 TYPICAL APPLICATIO S Improving Ripple Rejection VIN VIN LT1038 VOUT ADJ 5V R1 121Ω 1% 1µF + R2 365Ω 1% + C1* 10µF *C1 IMPROVES RIPPLE REJECTION. XC SHOULD BE SMALL COMPARED TO R2. 1038 TA05 Remote Sensing LT1038 VOUT VIN ADJ 25Ω 121Ω Rp (MAX DROP 300mV) VIN VIN 6 1 LM301A 8 4 365Ω 100pF 25Ω RETURN 1038 TA08 RETURN SCHE ATIC DIAGRA 310Ω 310Ω 190Ω Q4 Q2 30k Q5 Q6 Q9 Q15 Q14 3k 4k 12.4k Q16 Q10 Q12 Q13 C1 30pF C2 30pF Q17 2.4k Q18 Q20 Q22 16k Q25 Q19 1.6k Q21 C3 5pF 6.7k 12k Q1 130Ω Q8 Q3 160k 180Ω Q7 4.1k 6k 10k 5.1k 12k 3Ω 0.005Ω VOUT Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. – + W U 7 1.2V to 25V Adjustable Regulator VIN VIN LT1038 VOUT ADJ R1 121Ω R2 5k VOUT†† 5V Regulator with Shutdown VIN VIN LT1038 VOUT ADJ 1µF 1k TTL 1k 2N3904 365Ω 1% 5V 121Ω 1% + C2† 1µF + C1* 1µF + *NEEDED IF DEVICE IS FAR FROM FILTER CAPACITORS † OPTIONAL—IMPROVES TRANSIENT RESPONSE †† VOUT = 1.25V (1 + R2/R1) 1038 TA06 1038 TA07 Temperature Compensated Lead Acid Battery Charger 10A VIN 5V OUTPUT 2 VIN LT1038 VOUT ADJ 121Ω 1% THERMALLY COUPLED 10k* 3 1k 5µF 25k RL 50Ω 2N3906 CHARGE 2N3904 + – 2k* 50k* 12V + *LOAD ON BATTERY ≈ 200µA WHEN NOT CHARGING 1038 TA09 W VIN 50Ω Q11 Q24 5.6k 20k Q23 200Ω Q27 Q26 120Ω 400Ω 160Ω Q28 D1 6.3V 18k D2 6.3V 160Ω 300Ω ADJ 1038 SD 7 LT1038 TYPICAL APPLICATIO S Lamp Flasher 15V 1µF VIN LT1038 VOUT ADJ 10µF 12V + OFF 1k 2N3904 12k 12k + + 12k 10µF 10µF 1039 TA10 PACKAGE DESCRIPTIO 0.320 – 0.350 (8.13 – 8.89) 0.760 – 0.775 (19.30 – 19.69) 0.060 – 0.135 (1.524 – 3.429) 0.210 – 0.220 (5.33 – 5.59) 0.420 – 0.480 (10.67 – 12.19) 0.058 – 0.062 (1.47 – 1.57) RELATED PARTS PART NUMBER LT1084 LT1581 LT1584 LT1585 DESCRIPTION Low Dropout, 0.01% Load Regulation Low Dropout, 430mV at 10A Low Dropout, 0.05% Load Regulation Low Dropout, 0.05% Load Regulation COMMENTS 7.5A Max Current Output Best Replacement 7A Max Current Output 5A Max Current Output 8 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 q FAX: (408) 434-0507 q U U Automatic Light Control LT1038 VIN VOUT ADJ 1.2k Protected High Current Lamp Driver LT1038 VOUT ADJ TTL OR CMOS VIN 12V 10A 15V 10k 1039 TA11 1039 TA12 Dimensions in inches (millimeters) unless otherwise noted. K Package 2-Lead TO-3 Metal Can (60mil Diameter Leads) (LTC DWG # 05-08-1312) 1.177 – 1.197 (29.90 – 30.40) 0.655 – 0.675 (16.64 – 17.15) 0.151 – 0.161 (3.86 – 4.09) DIA, 2 PLACES 0.167 – 0.177 (4.24 – 4.49) R 0.067 – 0.077 (1.70 – 1.96) 0.490 – 0.510 (12.45 – 12.95) R 0.425 – 0.435 (10.80 – 11.05) K2(TO-3) 1098 OBSOLETE PACKAGE 1038fa LT/TP 0701 1.5K REV A • PRINTED IN USA www.linear.com © LINEAR TECHNOLOGY CORPORATION 2000