LT1085CK-5

LT1083/LT1084/LT1085 Fixed 3A, 5A, 7.5A Low Dropout Positive Fixed Regulators FEATURES ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO Three-Terminal 3.3V, 3.6V, 5V and 12V Output Current of 3A, 5A or 7.5A Operates Down to 1V Dropout Guaranteed Dropout Voltage at Multiple Current Levels Line Regulation: 0.015% Load Regulation: 0.1% 100% Thermal Limit Functional Test Adjustable Versions Available APPLICATIO S ■ ■ ■ ■ High Efficiency Linear Regulators Post Regulators for Switching Supplies Constant Current Regulators Battery Chargers DEVICE LT1083 LT1084 LT1085 OUTPUT CURRENT* 7.5 Amps 5.0 Amps 3.0 Amps The LT®1083 series of positive adjustable regulators are designed to provide 3A, 5A and 7.5A with higher efficiency than currently available devices. All internal circuitry is designed to operate down to 1V input to output differential and the dropout voltage is fully specified as a function of load current. Dropout is guaranteed at a maximum of 1.5V at maximum output current, decreasing at lower load currents. On-chip trimming adjusts the output voltage to 1%. Current limit is also trimmed, minimizing the stress on both the regulator and power source circuitry under overload conditions. The LT1083 series devices are pin compatible with older three-terminal regulators. A 10μF output capacitor is required on these new devices; however, this is usually included in most regulator designs. Unlike PNP regulators, where up to 10% of the output current is wasted as quiescent current, the LT1083 quiescent current flows into the load, increasing efficiency. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. *For a 1.5A low dropout regulator see the LT1086 data sheet. TYPICAL APPLICATIO 5V, 7.5A Regulator INPUT/OUTPUT VOLTAGE DIFFERENTIAL (V) 2 Dropout Voltage vs Output Current VIN ≥ 6.5V LT1083-5 5V AT 7.5A + 10μF + 22μF* TANTALUM LT1083/4/5 TA01 *REQUIRED FOR STABILITY 1 0 0 U IFULLLOAD/2 OUTPUT CURRENT (A) IFULLLOAD 1083/4/5 TA02 U U 1083ffd 1 LT1083/LT1084/LT1085 Fixed ABSOLUTE AXI U RATI GS PRECO DITIO I G 100% Thermal Limit Functional Test. PACKAGE/ORDER I FOR ATIO VIN 2 CASE IS OUTPUT ORDER PART NUMBER LT1083CK-5 LT1083CK-12 LT1083MK-5 LT1083MK-12 LT1084CK-5 LT1084CK-12 LT1084MK-5 LT1084MK-12 LT1085CK-5 LT1085CK-12 LT1085MK-5 LT1085MK-12 TAB IS OUTPUT FRONT VIEW 1 GND K PACKAGE 2-LEAD TO-3 METAL CAN 3 2 1 P PACKAGE 3-LEAD TO-3P PLASTIC θJA = 35°C/W OBSOLETE NOT RECOMMENDED FOR NEW DESIGNS TAB IS OUTPUT FRONT VIEW θJA = 45°C/W 3 2 1 T PACKAGE 3-LEAD PLASTIC TO-220 VIN VOUT GND LT1084CT-3.3 LT1084CT-5 LT1084CT-12 LT1085CT-3.3 LT1085CT-3.6 LT1085CT-5 LT1085CT-12 FRONT VIEW 3 TAB IS OUTPUT 2 1 M PACKAGE 3-LEAD PLASTIC DD VIN VOUT GND θJA = 30°C/W* *WITH PACKAGE SOLDERED TO 0.52IN2 COPPER AREA OVER BACKSIDE GROUND PLANE OR INTERNAL POWER PLANE. θJA CAN VARY FROM 20°C/W TO > 40°C/W DEPENDING ON MOUNTING TECHNIQUE. θJA = 50°C/W Consult factory for parts specified with wider operating temperature ranges. 2 UU U Power Dissipation .............................. Internally Limited Input Voltage* ........................................................ 30V Operating Input Voltage 3.3V, 3.6V Devices ........................................... 20V 5V Devices ....................................................... 20V 12V Devices ..................................................... 25V Operating Junction Temperature Range “C” Grades Control Section .............................. 0°C to 125°C Power Transistor ............................ 0°C to 150°C “M” Grades Control Section .......................... –55°C to 150°C Power Transistor ........................ –55°C to 200°C U U W WW U W (Note 1) Storage Temperature Range ................ – 65°C to 150°C Lead Temperature (Soldering, 10 sec)................. 300°C *Although the devices maximum operating voltage is limited, (20V for a 3V, 5V device, and 25V for a 12V device) the devices are guaranteed to withstand transient input voltages up to 30V. For input voltages greater than the maximum operating input voltage some degradation of specifications will occur. For input/output voltage differentials greater than 15V, a minimum external load of 5mA is required to maintain regulation. ORDER PART NUMBER LT1083CP-5 LT1083CP-12 LT1084CP-5 LT1084CP-12 VIN VOUT GND LT1085CM-3.3 LT1085CM-3.6 LT1085IM-3.6 1083ffd LT1083/LT1084/LT1085 Fixed ELECTRICAL CHARACTERISTICS PARAMETER Output Voltage CONDITIONS LT1084-3.3 LT1085-3.3 LT1085-3.6 The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. MIN IOUT = 0mA, TJ = 25°C, VIN = 8V (K Package Only) 4.8V ≤ VIN ≤ 15V, 0 ≤ IOUT ≤ IFULLOAD (Notes 3, 4, 9) VIN = 5V, IOUT = 0mA, TJ = 25°C (K Package Only) 4.8V ≤ VIN ≤ 15V, 0 ≤ IOUT ≤ IFULLOAD (Notes 3, 4, 9) VIN = 5V, IOUT = 0mA, TJ = 25°C (K Package Only) 5V ≤ VIN ≤ 15V, 0 ≤ IOUT ≤ IFULLOAD (Note 9) 5V ≤ VIN ≤ 15V, 0 ≤ IOUT ≤ IFULLOAD, TJ ≥ 0°C (Notes 3, 4, 9) 5V ≤ VIN ≤ 15V, 0 ≤ IOUT ≤ 2.5A (Notes 3, 4, 9) VIN = 4.75V, IOUT = 3A, TJ ≥ 0°C VIN = 4.75V, IOUT = 2.5A, TJ ≥ 0°C VIN = 4.75V, IOUT = 1.5A, TJ > 0°C IOUT = 0mA, TJ = 25°C, VIN = 8V (K Package Only) 0 ≤ IOUT ≤ IFULLOAD, 6.5V ≤ VIN ≤ 20V (Notes 4, 6, 7, 9) ● ● ● ● TYP 3.300 3.300 3.300 3.300 3.600 MAX 3.330 3.365 3.330 3.365 3.636 3.672 3.672 3.672 3.672 3.672 3.672 UNITS V V V V V V V V V V V V V V V mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV mV V V V V A A A A A A A A 1083ffd 3.270 3.235 3.270 3.235 3.564 3.500 3.528 3.528 3.350 3.450 3.528 4.950 4.900 11.880 11.760 LT1085-3.6 LT1083/4/5-5 5.000 5.000 12.000 12.000 0.5 1.0 0.5 1.0 0.5 1.0 0.5 1.0 1.0 2.0 3 7 3 7 3 7 5 10 12 24 1.3 1.3 1.3 1.3 5.050 5.100 12.120 12.240 6 6 6 6 6 6 10 10 25 25 15 20 15 20 15 20 20 35 36 72 1.5 1.5 1.5 1.5 LT1083/4/5-12 IOUT = 0mA, TJ = 25°C, VIN = 15V (K Package Only) 0 ≤ IOUT ≤ IFULLOAD, 13.5V ≤ VIN ≤ 25V (Notes 4, 6, 7, 9) Line Regulation LT1084-3.3 LT1085-3.3 LT1085-3.6 LT1083/4/5-5 IOUT = 0mA, TJ = 25°C, 4.8V ≤ VIN ≤ 15V 4.8V ≤ VIN ≤ 15V, IOUT = 0mA, TJ= 25°C 4.8V ≤ VIN ≤ 15V, IOUT = 0mA, TJ= 25°C IOUT = 0mA, TJ = 25°C, 6.5V ≤ VIN ≤ 20V (Notes 2, 3) ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● LT1083/4/5-12 IOUT = 0mA, TJ = 25°C, 13.5V ≤ VIN ≤ 25V (Notes 2, 3) Load Regulation LT1084-3.3 LT1085-3.3 LT1085-3.6 LT1083/4/5-5 VIN = 5V, 0 ≤ IOUT ≤ 5A, TJ = 25°C VIN = 5V, 0 ≤ IOUT ≤ 3A, TJ = 25°C VIN = 5.25V, 0 ≤ IOUT ≤ 3A, TJ = 25°C VIN = 8V, 0 ≤ IOUT ≤ IFULLLOAD, TJ = 25°C (Notes 2, 3, 4, 6) LT1083/4/5-12 VIN = 15V, 0 ≤ IOUT ≤ IFULLLOAD, TJ = 25°C (Notes 2, 3, 4, 6) Dropout Voltage LT1084/5-3.3 LT1085-3.6 LT1083/4/5-5 Current Limit ΔVOUT = 33mV, IOUT = IFULL LOAD (Notes 5, 6) ΔVOUT = 36mV, IOUT = IFULL LOAD (Notes 5, 6) ΔVOUT = 50mV, IOUT = IFULL LOAD (Notes 5, 6) LT1083/4/5-12 ΔVOUT = 120mV, IOUT = IFULL LOAD (Notes 5, 6) LT1083-5 VIN = 10V LT1083-12 LT1084-3.3 LT1084-5 LT1084-12 VIN = 17V VIN = 8V VIN = 10V VIN = 17V 8.0 8.0 5.5 5.5 5.5 3.2 3.2 3.2 9.5 9.5 6.5 6.5 6.5 4.0 4.0 4.0 LT1085-3.3/3.6 VIN = 8V LT1085-5 VIN = 10V LT1085-12 VIN = 17V 3 LT1083/LT1084/LT1085 Fixed ELECTRICAL CHARACTERISTICS PARAMETER Quiescient Current CONDITIONS LT1084-3.3 LT1085-3.3 LT1085-3.6 LT1083/4/5-5 LT1083/4/5-12 Thermal Regulation VIN = 18V VIN = 18V VIN = 18V VIN ≤ 20V VIN ≤ 25V The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. MIN ● ● ● ● ● TYP 5.0 5.0 5.0 5.0 5.0 0.002 0.003 0.004 MAX 10.0 10.0 10.0 10.0 10.0 0.010 0.015 0.020 UNITS mA mA mA mA mA %/W %/W %/W dB dB dB dB dB % LT1083-5/12 TA = 25°C, 30ms pulse LT1084-3.3/5/12 LT1085-3.3/3.6/5/12 f = 120Hz, COUT = 25μF Tantalum, IOUT = IFULLLOAD (Note 4) LT1084-3.3 f = 120Hz, COUT = 25μF Tantalum, IOUT = 5A, VIN = 6.3V LT1085-3.3 f = 120Hz, COUT = 25μF Tantalum, VIN = 6.3V, IOUT = 3A LT1085-3.6 f = 120Hz, COUT = 25μF Tantalum, VIN = 6.6V, IOUT = 3A LT1083/4/5-5 VIN = 8V (Note 6) LT1083/4/5-12 VIN = 15V (Note 6) TA = 125°C, 1000 Hrs. TA = 25°C, 10Hz = ≤ f ≤ 10kHz Control Circuitry/Power Transistor (See Applications Information) LT1083 K Package P Package LT1084 K Package P Package T Package K Package T Package DD Package ● ● ● ● ● ● Ripple Rejection 60 60 60 60 54 72 72 72 68 60 0.5 0.03 0.003 0.6/1.6 0.5/1.6 0.75/2.3 0.65/2.3 0.65/2.7 0.9/3.0 0.7/3.0 0.7/3.0 1.0 Temperature Stability Long Term Stability RMS Output Noise (% of VOUT) Thermal Resistance Junctrion-to-Case % % °C/W °C/W °C/W °C/W °C/W °C/W °C/W °C/W LT1085 Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: 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. Note 3: Line and load regulation are guaranteed up to the maximum power dissipation (60W for the LT1083, 45W for the LT1084 (K, P), 30W for the LT1084 (T) and 30W for the LT1085). Power dissipation is determined by the input/output differential and the output current. Guaranteed maximum power dissipation will not be available over the full input/output range. Note 4: IFULL LOAD is defined in the current limit curves. The IFULLLOAD curve is defined as the minimum value of current limit as a function of input to output voltage. Note that the 60W power dissipation for the LT1083 (45W for the LT1084 (K, P), 30W for the LT1084 (T), 30W for the LT1085) is only achievable over a limited range of input to output voltage. Note 5: Dropout voltage is specified over the full output current range of the device. Test points and limits are shown on the Dropout Voltage curve. Note 6: For LT1083 IFULL LOAD is 5A for – 55°C ≤ TJ ≤ – 40°C and 7.5A for TJ ≥ – 40°C. Note 7: 1.7V ≤ (VIN – VOUT) ≤ 25V for LT1084 at – 55°C ≤ TJ ≤ – 40°C. Note 8: Dropout voltage 1.7V maximum for LT1084 at – 55°C ≤ TJ ≤ – 40°C. Note 9: Full load current is not available at all input-output voltages. See Notes 3, 4, 6. 1083ffd 4 LT1083/LT1084/LT1085 Fixed TYPICAL PERFOR A CE CHARACTERISTICS LT1083 Dropout Voltage MINIMUM INPUT/OUTPUT DIFFERENTIAL (V) 2 INDICATES GUARANTEED TEST POINT –40°C ≤ TJ ≤ 150°C 0°C ≤ TJ ≤ 125°C 12 10 8 6 4 2 0 0 1 2 345678 OUTPUT CURRENT (A) 9 10 0 20 30 15 25 5 10 INPUT/OUTPUT DIFFERENTIAL (V) 35 –55°C 25°C 150°C OUTPUT VOLTAGE DEVIATION (%) SHORT-CIRCUIT CURRENT (A) 1 TJ = 150°C TJ = 25°C TJ = – 55°C 0 LT1083/4/5 FIXED G01 LT1084 Dropout Voltage MINIMUN INPUT/OUTPUT DIFFERENTIAL (V) 2 INDICATES GUARANTEED TEST POINT –55°C ≤ TJ ≤ 150°C 0°C ≤ TJ ≤ 125°C 10 9 OUTPUT VOLTAGE DEVIATION (%) SHORT-CIRCUIT CURRENT (A) 1 TJ = 25°C TJ = – 55°C TJ = 150°C 0 0 1 3 4 2 OUTPUT CURRENT (A) 5 6 LT1083/4/5 FIXEDG04 LT1085 Dropout Voltage MINIMUM INPUT/OUTPUT DIFFERENTIAL (V) 2 INDICATES GUARANTEED TEST POINT OUTPUT VOLTAGE DEVIATION (%) 0°C ≤ TJ ≤ 125°C SHORT-CIRCUIT CURRENT (A) –55°C ≤ TJ ≤ 150°C 1 TJ = 150°C TJ = 25°C TJ = – 55°C 0 0 3 2 1 OUTPUT CURRENT (A) 4 LT1083/4/5 FIXED G07 UW LT1083 Short-Circuit Current 0.10 0.05 0 –0.05 –0.10 –0.15 LT1083 Load Regulation ΔI = 7.5A IFULL LOAD GUARANTEED –0.20 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) LT1083/4/5 FIXED G03 LT1083/4/5 FIXED G02 LT1084 Short Circuit Current 0.10 0.05 0 –0.05 –0.10 –0.15 LT1084 Load Regulation ΔI = 5A 8 7 6 5 4 3 2 1 0 0 20 15 10 25 30 5 INPUT/OUTPUT DIFFERENTIAL (V) 35 IFULL LOAD GUARANTEED 150°C 25°C –55°C –0.20 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) LT1083/4/5 FIXED G06 LT1083/4/5 FIXED G05 LT1085 Short-Circuit Current 6 5 4 3 –55°C 2 1 0 0 20 30 15 25 5 10 INPUT/OUTPUT DIFFERENTIAL (V) 35 IFULL LOAD GUARANTEED 25°C 150°C 0.10 0.05 0 –0.05 –0.10 –0.15 LT1085 Load Regulation ΔI = 3A –0.20 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) LT1083/4/5 FIXED G09 LT1083/4/5 FIXED G08 1083ffd 5 LT1083/LT1084/LT1085 Fixed TYPICAL PERFOR A CE CHARACTERISTICS LT1083/4/5-5 Ripple Rejection 80 70 RIPPLE REJECTION (dB) 60 50 40 30 20 10 IOUT = IFULLLOAD 0 10 100 1k 10k FREQUENCY (Hz) 100k VRIPPLE ≤ 3VP-P VRIPPLE ≤ 0.5VP-P RIPPLE REJECTION (dB) (VIN – VOUT) ≥ 3V (VIN – VOUT) ≥ VDROPOUT 80 70 60 50 40 30 20 10 0 0 fR = 20kHz VRIPPLE ≤ 0.5VP-P fR = 120Hz VRIPPLE ≤ 3VP-P OUTPUT VOLTAGE CHANGE (%) LT1083/4/5-12 Ripple Rejection 80 70 VRIPPLE ≤ 3VP-P VRIPPLE ≤ 0.5VP-P RIPPLE REJECTION (dB) RIPPLE REJECTION (dB) 60 50 40 30 20 10 IOUT = IFULLLOAD 0 10 100 1k 10k FREQUENCY (Hz) 100k (VIN – VOUT) ≥ 3V 60 50 40 30 20 10 0 0 0.8 0.2 0.6 0.4 OUTPUT CURRENT (0 TO IFULLLOAD) 1.0 fR = 20kHz VRIPPLE ≤ 0.5VP-P POWER (W) (VIN – VOUT) ≥ VDROPOUT LT1084 Maximum Power Dissipation* 60 50 LT1084MK 40 50 POWER (W) POWER (W) 30 LT1084CT 20 10 0 LT1084CK LT1084CP 50 60 70 80 90 100 110 120 130 140 150 CASE TEMPERATURE (°C) * AS LIMITED BY MAXIMUM JUNCTION TEMPERATURE LT1083/4/5 FIXED G16 6 UW 1083/4/5 FIXED G10 1083/4/5 FIXED G13 LT1083/4/5-5 Ripple Rejection vs Current 100 90 1.0 2.0 Temperature Stability 0 –1.0 0.8 0.2 0.6 0.4 OUTPUT CURRENT (0 TO IFULLLOAD) 1.0 –2.0 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) LT1183/4/5 FIXED G12 1083/4/5 FIXED G11 LT1083/4/5-12 Ripple Rejection vs Current 100 90 80 70 fR = 120Hz VRIPPLE ≤ 3VP-P 100 90 80 70 60 50 40 30 20 10 0 LT1083 Maximum Power Dissipation* LT1083MK LT1083CP LT1083CK 1083/4/5 FIXED G14 50 60 70 80 90 100 110 120 130 140 150 CASE TEMPERATURE (°C) * AS LIMITED BY MAXIMUM JUNCTION TEMPERATURE LT1083/4/5 FIXED G15 LT1085 Maximum Power Dissipation* 40 LT1085MK 30 20 LT1085CT 10 LT1085CK 0 50 60 70 80 90 100 110 120 130 140 150 CASE TEMPERATURE (°C) * AS LIMITED BY MAXIMUM JUNCTION TEMPERATURE LT1083/4/5 FIXED G17 1083ffd LT1083/LT1084/LT1085 Fixed BLOCK DIAGRA APPLICATIO S I FOR ATIO The LT1083 family of three-terminal regulators are easy to use and have all the protection features that are expected in high performance voltage regulators. They are short circuit protected, have safe area protection as well as thermal shutdown to turn off the regulator should the temperature exceed about 165°C. These regulators offer lower dropout voltage and more precise reference tolerance. Further, the reference stability with temperature is improved over older types of regulators. The only circuit difference between using the LT1083 family and older regulators is that they require an output capacitor for stability. Stability The circuit design used in the LT1083 family requires the use of an output capacitor as part of the device frequency compensation. For all operating conditions, the addition of 150μF aluminum electrolytic or a 22μF solid tantalum on the output will ensure stability. Normally capacitors much smaller than this can be used with the LT1083. Many different types of capacitors with widely varying charac- U W W THERMAL LIMIT VIN + – VOUT GND LT1083/4/5 BD UU teristics are available. These capacitors differ in capacitor tolerance (sometimes ranging up to ±100%), equivalent series resistance, and capacitance temperature coefficient. The 150μF or 22μF values given will ensure stability. Normally, capacitor values on the order of 100μF are used in the output of many regulators to ensure good transient response with heavy load current changes. Output capacitance can be increased without limit and larger values of output capacitance further improve stability and transient response of the LT1083 regulators. Another possible stability problem that can occur in monolithic IC regulators is current limit oscillations. These can occur because in current limit the safe area protection exhibits a negative impedance. The safe area protection decreases the current limit as the input-tooutput voltage increases.That is the equivalent of having a negitive resistance since increasing voltage causes current to decrease. Negitive resistance during current limit is not unique to the LT1083 series and has been present on all power IC regulators. The value of negative resistance is a function of how fast the current limit is 1083ffd 7 LT1083/LT1084/LT1085 Fixed APPLICATIO S I FOR ATIO folded back as input-to-output voltage increases. This negative resistance can react with capacitors or inductors on the input to cause oscillations during current limiting. Depending on the value of series resistance, the overall circuitry may end up unstable. Since this is a system problem, it is not necessarily easy to solve; however it does not cause any problems with the IC regulator and can usually be ignored. Protection Diodes In normal operation the LT1083 family does not need any protection diodes, The internal diode between the input and the output pins of the LT1083 family can handle microsecond surge currents of 50A to 100A. Even with large output capacitances it is very difficult to get those values of surge current in normal operation. Only with high value output capacitors, such as 1000μF to 5000μF and with the input pin instantaneously shorted to ground, can damage occur. A crowbar circuit at the input of the LT1083 can generate those kinds of currents and a diode from output-to-input is then recommended. Normal power supply cycling or even plugging and unplugging in the system will not generate currents large enough to do any damage. D1 1N4002 (OPTIONAL) VIN IN LT1083 ADJ OUT VOUT + COUT 150μF 1083/4/5 AI01 Overload Recovery Like any of the IC power regulators, the LT1083 has safe area protection. The safe area protection decreases the current limit as input-to-output voltage increases and keeps the power transistor inside a safe operating region for all values of input-to-output voltage. The LT1083 protection is designed to provide some output current at all values of input-to-output voltage up to the device breakdown. When power is first turned on, as the input voltage rises, the output follows the input, allowing the regulator to start 8 U up into very heavy loads. During the start-up, as the input voltage is rising, the input-to-output voltage differential remains small allowing the regulator to supply large output currents. With high input voltage a problem can occur wherein removal of an output short will not allow the output voltage to recover. Older regulators such as the 7800 series, also exhibited this phenomenon so it is not unique to the LT1083. The problem occurs with a heavy output load when the input voltage is high and the output voltage is low, such as immediately after a removal of a short. The load line for such a load may intersect the output current curve at two points. If this happens there are two stable output operating points for the regulator. With this double intersection the power supply may need to be cycled down to zero and brought up again to make the output recover. Ripple Rejection In applications that require improved ripple rejection the LT1083 series adjustable regulators should be used. With LT1083 series adjustable regulators the addition of a bypass capacitor from the adjust pin to ground will reduce output ripple by the ratio of VOUT/1.25V. See LT1083 series adjustable regulator data sheet. Load Regulation Because the LT1083 is a three-terminal device, it is not possible to provide true remote load sensing. Load regulation will not be limited by the resistance of the wire connecting the regulator to the load. The data sheet specification for the load regulation is measured at the bottom of the package. Negative side sensing is a true Kelvin connection, with the ground pin of the device returned to the negative side of the load. Thermal Considerations The LT1083 series of regulators have internal power and thermal limiting circuitry designed to protect the device under overload conditions. For continuous normal load conditions however, maximum junction temperature ratings must not be exceeded. It is important to give careful consideration to all sources of thermal resistance from junction to ambient. This includes junction-to-case, 1083ffd W UU LT1083/LT1084/LT1085 Fixed APPLICATIO S I FOR ATIO case- to-heat sink interface, and heat sink resistance itself. New thermal resistance specifications have been developed to more accurately reflect device temperature and ensure safe operating temperatures. The data section for these new regulators provides a separate thermal resistance and maximum junction temperature for both the Control Section and the Power Section. Previous regulators, with a single junction-to-case thermal resistance specification, used an average of the two values provided here and therefore could allow excessive junction temperatures under certain conditions of ambient temperature and heat sink resistance. To avoid this possibility, calculations should be made for both sections to ensure that both thermal limits are met. Junction-to-case thermal resistance is specified from the IC junction to the bottom of the case directly below the die. This is the lowest resistance path for heat flow. Proper mounting is required to ensure the best possible thermal flow from this area of the package to the heat sink. Thermal compound at the case-to-heat sink interface is strongly recommended. If the case of the device must be electronically isolated, a thermally conductive spacer can be used as long as its added contribution to thermal resistance is considered. Note that the case of all devices in this series is electronically connected to the ouput. TYPICAL APPLICATIO S High Efficiency Regulator 1mH IN 10,000μF 10k MR1122 28V LT1083-5 OUT GND 470Ω 1N914 OUTPUT 28V INPUT + 1k 1M 4N28 + LT1011 10k – 1N914 10k 28V U For example, using a LT1083-5CP (TO-3P, Commercial) and assuming: VIN(max continuous) = 9V, VOUT = 5V, IOUT = 6A, TA = 75°C, θHEAT SINK = 1°C/W, θCASE-TO-HEAT SINK = 0.2°C/W for P package with thermal compound. Power dissipation under these conditions is equal to: PD = (VIN – VOUT) (IOUT) = 24W Junction temperature will be equal to: TJ = TA + PD (θHEAT SINK + θCASE-TO-HEAT SINK + θJC) For the Control Section: TJ = 75°C + 24W (1°C/W + 0.2°C/W + 0.5°C/W) = 118°C 118°C < 125°C = TJMAX (Control Section Commercial Range) For the Power Transistor: TJ = 75°C + 24W (1°C/W + 0.2°C/W + 1.6°C/W) = 142°C 142°C < 150°C = TJMAX (Power Transistor Commercial Range) In both cases the junction temperature is below the maximum rating for the respective sections, ensuring reliable operation. Paralleling Regulators 2 FEET #18 WIRE* VIN IN LT1083-5 OUT GND VOUT = 5V IOUT = 0A TO 15A 0.015Ω IN LT1083-5 OUT GND *THE #18 WIRE ACTS AS BALLAST RESISTANCE INSURING CURRENT SHARING BETWEEN BOTH DEVICES LT1083/4/5 TA04 LT1083/4/5 TA03 W U UU 1083ffd 9 LT1083/LT1084/LT1085 Fixed TYPICAL APPLICATIO S 7.5A Regulator T1 TRIAD F-269U C30B 20Ω 110VAC 20Ω C30B 1N4003 1N4003 1μF 560Ω 1N914 16k* 15V 16k* L 1MH IN 3 T2 4 2 LT1004-1.2 1N4003 LT1083-12 OUT GND 12V 0A TO 7.5A 82k 10k 1N4148 * 1% FILM RESISTOR L-DALE TO-5 TYPE T2-STANCOR 11Z-2003 REGULATOR WITH SCR PREREGULATOR TO LOWER POWER DISSIPATION. ABOUT 1.7V DIFFERENTIAL IS MAINTAINED ACROSS THE LT1083 INDEPENDENT OF LOAD CURRENT. PACKAGE DESCRIPTIO K Package 2-Lead TO-3 Metal Can (LTC DWG # 05-08-1310) .320 – .350 (8.13 – 8.89) .760 – .775 (19.30 – 19.69) .060 – .135 (1.524 – 3.429) .420 – .480 (10.67 – 12.19) .038 – .043 (0.965 – 1.09) 1.177 – 1.197 (29.90 – 30.40) .655 – .675 (16.64 – 17.15) .210 – .220 (5.33 – 5.59) .151 – .161 (3.86 – 4.09) DIA, 2PLCS .167 – .177 (4.24 – 4.49) R .067 – .077 (1.70 – 1.96) .490 – .510 (12.45 – 12.95) R .425 – .435 (10.80 – 11.05) OBSOLETE PACKAGE 1083ffd 10 U U + C1 50,000μF + 100μF 1 15k 8 2 + – –15V 4 7 200k 11k* LT1011 3 1 15V –15V 4 7 8 0.1μF NC 100pF 2N3904 – + 1 3 8 2 10k 6 1 LT1011 + – 4 –15V 3 LM301A 2 11k* LT1083/4/5 TA05 15k 15V 7 15V 1μF T Package 3-Lead Plastic TO-220 (LTC DWG # 05-08-1420) .390 – .415 (9.906 – 10.541) .147 – .155 (3.734 – 3.937) DIA .230 – .270 (5.842 – 6.858) .460 – .500 (11.684 – 12.700) .570 – .620 (14.478 – 15.748) .330 – .370 (8.382 – 9.398) .165 – .180 (4.191 – 4.572) .045 – .055 (1.143 – 1.397) .980 – 1.070 (24.892 – 27.178) .520 – .570 (13.208 – 14.478) .218 – .252 (5.537 – 6.401) .013 – .023 (0.330 – 0.584) .100 (2.540) BSC .028 – .038 (0.711 – 0.965) .050 (1.270) TYP .095 – .115 (2.413 – 2.921) T3 (TO-220) 0801 K2 (TO-3) 0801 LT1083/LT1084/LT1085 Fixed PACKAGE DESCRIPTIO .256 (6.502) .060 (1.524) .060 (1.524) .183 (4.648) .075 (1.905) .300 (7.620) BOTTOM VIEW OF DD PAK HATCHED AREA IS SOLDER PLATED COPPER HEAT SINK .420 +.012 .143 –.020 +0.305 3.632 –0.508 .100 (2.54) BSC .013 – .023 (0.330 – 0.584) .090 .100 .070 RECOMMENDED SOLDER PAD LAYOUT .560 (14.224) .325 (8.255) .275 (6.985) .580 (14.732) .700 (17.780) .098 (2.489) .124 (3.149) BOTTOM VIEW OF TO-3P HATCHED AREA IS SOLDER PLATED COPPER HEAT SINK 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. U M Package 3-Lead Plastic DD Pak (LTC DWG # 05-08-1460) .060 (1.524) TYP .390 – .415 (9.906 – 10.541) 15° .165 – .180 (4.191 – 4.572) .045 – .055 (1.143 – 1.397) .330 – .370 (8.382 – 9.398) .059 (1.499) ( +.008 .004 –.004 +0.203 0.102 –0.102 ) .095 – .115 (2.413 – 2.921) .050 ± .012 (1.270 ± 0.305) ( ) .050 (1.270) .420 .080 .276 .350 .205 .565 .325 .565 .320 NOTE: 1. DIMENSIONS IN INCH/(MILLIMETER) 2. DRAWING NOT TO SCALE .100 .070 .090 M (DD3) 0204 RECOMMENDED SOLDER PAD LAYOUT FOR THICKER SOLDER PASTE APPLICATIONS P Package 3-Lead Plastic TO-3P (Similar to TO-247) (LTC DWG # 05-08-1450) .620 – .64O (15.75 – 16.26) .187 – .207 (4.75 – 5.26) MOUNTING HOLE 18° – 22° .115 – .145 (2.92 – 3.68) DIA .060 – .080 (1.52 – 2.03) .830 – .870 (21.08 – 22.10) .580 – .6OO (14.73 – 15.24) .170 – .2OO (4.32 – 5.08) EJECTOR PIN MARKS .105 – .125 (2.67 – 3.18) DIA 3° – 7° .170 (4.32) MAX .780 – .800 (19.81 – 20.32) .042 – .052 (1.07 – 1.32) .074 – .084 (1.88 – 2.13) .215 (5.46) BSC .113 – .123 (2.87 – 3.12) .087 – .102 (2.21 – 2.59) .020 – .040 (0.51 – 1.02) P3 0801 1083ffd 11 LT1083/LT1084/LT1085 Fixed TYPICAL APPLICATIO S Adjusting Output Voltage Regulator with Reference VIN > 12V LT1085-5 + 10μF + 10μF* 1k LT1083/4/5 TA06 *OPTIONAL IMPROVES RIPPLE REJECTION Low Dropout Negative Supply VIN IN + 10,000μF FLOATING INPUT RELATED PARTS PART NUMBER LT1129 LT1175 LT1374 LT1529 LT1573 LT1575 LT1580 LT1581 LT1584/85/87 LT1735 LT1761 Series LT1762 Series LT1763 Series LT1764 LT1962 LT1963 DESCRIPTION 700mA Micropower Low Dropout Regulator 500mA Negative Low Dropout Micropower Regulator 4.5A, 500kHz Step-Down Converter 3A Low Dropout Regulator with 50μA IQ UltraFastTM Transient Response Low Dropout Regulator UltraFast Transient Response Low Dropout Regulator 7A, Very Low Dropout Regulator 10A, Very Low Dropout Regulator 7A/4.6A/3A Fast Response LDOs Synchronous Step-Down Converter 150mA, Low Noise, LDO Micropower Regulators 500mA, Low Noise LDO Micropower Regulators 3A Low Noise Fast Transient Response LDO 300mA, Low Noise LDO Micropower Regulator 1.5A, Low Noise, Fast Transient Response LDO COMMENTS 50μA Quiescent Current 45μA IQ, 0.26V Dropout Voltage, SOT-223 Package 4.5A, 0.07Ω Internal Switch, SO-8 Package 500mV Dropout Voltage Drives External PNP Drives External N-Channel MOSFET 0.54V Dropout at 7A, Fixed 2.5VOUT and Adjustable 0.63V Dropout at 10A, Fixed 2.5VOUT and Adjustable Fast Transient Response for Microprocessor Applications High Efficiency, OPTI-LOOPTM Compensation 25μA Quiescent Current, 20μVRMS Noise, MSOP Package 30μA Quiescent Current, 20μVRMS Noise, SO-8 Package 40μVRMS Noise, 5-Lead DD Package 20μVRMS Noise, MSOP Package 40μVRMS Noise, SOT-223 Package 1083ffd 100mA, Low Noise, Low Dropout Micropower Regulators in SOT-23 20μA Quiescent Current, 20μVRMS Noise, SOT-23 Package UltraFast and OPTI-LOOP are trademarks of Linear Technology Corporation. 12 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● U 5V to 10V VIN > 11.5V LT1085-5 10V + 100μF + 10μF 5VOUT LT1029 LT1083/4/5 TA07 + 100μF Battery Backed Up Regulated Supply VIN LT1084-12 OUT GND LT1084-5 5.2V LINE 5.0V BATTERY + + SELECT FOR CHARGE RATE 10μF 50 Ω 100μF VOUT = –12V LT1083/4/5 TA08 LT1084-5 6.5V + 10μF + 100μF LT1083/4/5 TA09 LT 1007 REV D • PRINTED IN USA www.linear.com © LINEAR TECHNOLOGY CORPORATION 1994