NA LT1084CT-3.3 3-Lead Plastic TO-220 Control: 0C to 125C Power: 0C to 150C LT1084CT-5#PBF NA LT1084CT-5 3-Lead Plastic TO-220 Control: 0C to 125C Power: 0C to 150C LT1084CT-12#PBF NA LT1084CT-12 3-Lead Plastic TO-220 Control: 0C to 125C Power: 0C to 150C LT1085CT-3.3#PBF NA LT1085CT-3.3 3-Lead Plastic TO-220 Control: 0C to 125C Power: 0C to 150C LT1085CT-3.6#PBF NA LT1085CT-3.6 3-Lead Plastic TO-220 Control: 0C to 125C Power: 0C to 150C LT1085CT-5#PBF NA LT1085CT-5 3-Lead Plastic TO-220 Control: 0C to 125C Power: 0C to 150C LT1085CT-12#PBF NA LT1085-12 3-Lead Plastic TO-220 Control: 0C to 125C Power: 0C to 150C LT1085CM-3.3#PBF LT1085CM-3.3#TRPBF LT1085CM-3.3 3-Lead Plastic DD Control: 0C to 125C Power: 0C to 150C LT1085CM-3.6#PBF LT1085CM-3.6#TRPBF LT1085CM-3.6 3-Lead Plastic DD Control: 0C to 125C Power: 0C to 150C LT1085IM-3.6#PBF LT1085IM-3.6#TRPBF LT1085IM-3.6 3-Lead Plastic DD Control: -40C to 125C Power: -40C to
imum junction temperature specifications for both the control and power sections, as shown in Table 2. Two Examples Showing Thermal Resistance of Control and Power Sections of LTC Regulators CONTROL POWER JC TJMAX JC TJMAX LT1083MK 0.6C/W 150C 1.6C/W 200C LT1085CT 0.7C/W 125C 3.0C/W 150C DEVICE As an example, let's calculate the junction temperature for the same application shown before, using an LT1085CT instead of the LT1129CT. Once again, we are operating in a 50C enclosure; the input voltage is 8VDC, the output voltage is 5VDC and the load current is 1A. The power dissipated by the LT1085CT is the same as before, 3W. We will assume we have selected a heat sink with a thermal resistance, SA of 10C/W. First calculate the control section of the LT1085CT: P = (VIN - VOUT)(ILOAD) = (6V - 5V)1A = 1W AN66-99 Application Note 66 JC = 0.7C/W (LT1085CT data sheet) CA = 0.2C/W (typical) SA = 10C/W TOTAL = JC + CA + SA = 0.7C/W + 0.2C/W + 10C/W = 10.9C/
LT1083CP#TRPBF PART MARKING* LT1083CP PACKAGE DESCRIPTION 3-Lead Plastic TO-3P LT1084CP#PBF LT1084CP#TRPBF LT1084CP 3-Lead Plastic TO-3P LT1084CT#PBF LT1084CT#TRPBF LT1084CT 3-Lead Plastic TO-220 LT1084IT#PBF LT1084IT#TRPBF LT1084IT 3-Lead Plastic TO-220 LT1085CT#PBF LT1085CT#TRPBF LT1085CT 3-Lead Plastic TO-220 LT1085IT#PBF LT1085IT#TRPBF LT1085IT 3-Lead Plastic TO-220 LT1085CM#PBF LT1085CM#TRPBF LT1085CM 3-Lead Plastic DD LT1085IM#PBF LT1085IM#TRPBF LT1085IM 3-Lead Plastic DD LEAD BASED FINISH LT1083CP TAPE AND REEL LT1083CP#TR PART MARKING* LT1083CP PACKAGE DESCRIPTION 3-Lead Plastic TO-3P LT1084CP LT1084CP#TR LT1084CP 3-Lead Plastic TO-3P LT1084CT LT1084CT#TR LT1084CT 3-Lead Plastic TO-220 LT1084IT LT1084IT#TR LT1084IT 3-Lead Plastic TO-220 LT1085CT LT1085CT#TR LT1085CT 3-Lead Plastic TO-220 LT1085IT LT1085IT#TR LT1085IT 3-Lead Plastic TO-220 LT1085CM LT1085CM#TR LT1085CM 3-Lead Plastic DD LT1085IM LT1085IM#TR LT1085IM 3-Lead P
nction to ambient, JA= 50C/watt for the LT1129CT. TJ = P x JA + TA = 1 watt x 50C/watt + 50C = 50C + 50C = 100C Table 2. Two examples showing thermal resistance of control and power sections of LTC regulators. Control Device JC TJ MAX LT1083MK 0.6C/W 150C LT1085CT 0.7C/W 125C 24 Power JC TJ MAX 1.6C/W 200C 3.0C/W 150C The junction temperature, TJ that we just calculated is now less than the LT1129CT's maximum junction temperature specification of 125C. Therefore this circuit does not need a heat sink. This illustrates the advantage of a low dropout regulator like the LT1129CT. To determine the control section junction temperature: TJ = P x TOTAL + TA = 3 watts x 10.9C/watt + 50C = 82.7C (TJ MAX = 125C) To calculate the power section of the LT1085CT: JC = 3C/watt (LT1085CT data sheet) TOTAL = JC + CA + SA = 3C/W + 0.2C/watt + 10C/watt = 13.2C/watt An Alternative Method for Specifying Thermal Parameters Linear Technology Corp. has introduced an alternative method to specif
GND LT1083CP-5 LT1083CP-12 LT1084CP-5 LT1084CP-12 P PACKAGE 3-LEAD TO-3P PLASTIC JA = 45C/W JA = 35C/W FRONT VIEW TAB IS OUTPUT ORDER PART NUMBER FRONT VIEW 3 VIN 2 VOUT 1 GND T PACKAGE 3-LEAD PLASTIC TO-220 JA = 50C/W LT1084CT-3.3 LT1084CT-5 LT1084CT-12 LT1085CT-3.3 LT1085CT-3.6 LT1085CT-5 LT1085CT-12 FRONT VIEW TAB IS OUTPUT 3 VIN 2 VOUT 1 GND LT1085CM-3.3 LT1085CM-3.6 M PACKAGE 3-LEAD PLASTIC DD JA = 30C/W* * WITH PACKAGE SOLDERED TO 0.52IN2 COPPER AREA OVER BACKSIDE GROUND PLANE OR INTERNAL POWER PLANE. JA CAN VARY FROM 20C/W TO > 40C/W DEPENDING ON MOUNTING TECHNIQUE. Consult factory for Industrial grade parts. ELECTRICAL CHARACTERISTICS PARAMETER Output Voltage CONDITIONS LT1084-3.3 LT1085-3.3 LT1085-3.6 2 IOUT = 0mA, TJ = 25C, VIN = 8V (K Package Only) 0 IOUT 5A, 4.8V VIN 15V (Note 8) VIN = 5V, IOUT = 0mA, TJ = 25C (K Package Only) 4.8V VIN 15V, 0 IOUT 3A (Note 8) VIN = 5V, IOUT = 0mA, TJ = 25C (K Package Only) 5V VIN 15V, 0 IOUT 3A (Note 8) 5V VIN 1
ND LT1082CN8-ND LT1082CT-ND LT1083CK-ND LT1083CP-ND LT1084CP-ND LT1084CT-ND LT1084CT-3.3-ND LT1084IT-ND 9176B-ND 9175B-ND 9175B-ND 9175B-ND 9210B-ND 9210B-ND 9210B-ND 9210B-ND 9210B-ND 9210B-ND 9210B-ND 9210B-ND LT1085CM-ND LT1085CM-3.3-ND LT1085CM-3.6-ND LT1085CT-ND 9210B-ND 9210B-ND 9210B-ND 9210B-ND LT1085CT-3.3-ND LT1085CT-3.6-ND LT1085CT-5-ND LT1085CT-12-ND LT1086CM-ND 9210B-ND 9210B-ND 9210B-ND 9210B-ND 9210B-ND LT1086CM-3.3-ND LT1086CT-ND 9210B-ND 9210B-ND LT1086CT-2.85-ND LT1086CT-3.3-ND LT1086CT-3.6-ND LT1086CT-5-ND LT1086CT-12-ND LT1097CN8-ND LT1097S8-ND LT1101ACN8-ND LT1101CN8-ND LT1101SW-ND LT1102ACN8-ND 9210B-ND 9210B-ND 9210B-ND 9210B-ND 9210B-ND 9176B-ND 9176B-ND 9176B-ND 9176B-ND 9176B-ND 9176B-ND LT1102CN8-ND 9176B-ND LT1105CN-ND LT1105CN8-ND LT1108CS8-5-ND LT1109ACN8-12-ND LT1109ACS8-12-ND LT1109CS8-ND LT1109CS8-12-ND LT1110CN8-ND LT1110CN8-5-ND LT1110CN8-12-ND LT1110CS8-ND LT1110CS8-5-ND LT1110CS8-12-ND 9210B-ND 9210B-ND 9210B
1084CP#PBF NA LT1084CP 3-Lead Plastic TO-3P Control: 0C to 125C Power: 0C to 150C LT1084CT#PBF NA LT1084CT 3-Lead Plastic TO-220 Control: 0C to 125C Power: 0C to 150C LT1084IT#PBF NA LT1084IT 3-Lead Plastic TO-220 Control: -40C to 125C Power: -40C to 150C LT1085CT#PBF NA LT1085CT 3-Lead Plastic TO-220 Control: 0C to 125C Power: 0C to 150C LT1085IT#PBF NA LT1085IT 3-Lead Plastic TO-220 Control: -40C to 125C Power: -40C to 150C LT1085CM#PBF LT1085CM#TRPBF LT1085CM 3-Lead Plastic DD Control: 0C to 125C Power: 0C to 150C LT1085IM#PBF LT1085IM#TRPBF LT1085IM 3-Lead Plastic DD Control: -40C to 125C Power: -40C to 150C OBSOLETE PACKAGE LEAD BASED FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LT1083CP NA LT1083CP 3-Lead Plastic TO-3P Control: 0C to 125C Power: 0C to 150C LT1084CP NA LT1084CP 3-Lead Plastic TO-3P Control: 0C to 125C Power: 0C to 150C OBSOLETE PACKAGE LT1084CT NA LT1084CT 3-Lead Plastic TO-220 Control: 0C to 125C Power: 0C to 150C LT1084IT NA LT1084IT
ND LT1083CP-5 LT1083CP-12 LT1084CP-5 LT1084CP-12 JA = 45C/W FRONT VIEW 3 3 P PACKAGE 3-LEAD TO-3P PLASTIC JA = 35C/W TAB IS OUTPUT ORDER PART NUMBER FRONT VIEW VIN 2 VOUT 1 GND T PACKAGE 3-LEAD PLASTIC TO-220 JA = 50C/W LT1084CT-3.3 LT1084CT-5 LT1084CT-12 LT1085CT-3.3 LT1085CT-3.6 LT1085CT-5 LT1085CT-12 FRONT VIEW TAB IS OUTPUT 3 VIN 2 VOUT 1 GND LT1085CM-3.3 LT1085CM-3.6 M PACKAGE 3-LEAD PLASTIC DD JA = 30C/W* * WITH PACKAGE SOLDERED TO 0.52IN2 COPPER AREA OVER BACKSIDE GROUND PLANE OR INTERNAL POWER PLANE. JA CAN VARY FROM 20C/W TO > 40C/W DEPENDING ON MOUNTING TECHNIQUE. Consult factory for Industrial grade parts. ELECTRICAL CHARACTERISTICS PARAMETER Output Voltage CONDITIONS LT1084-3.3 LT1085-3.3 LT1085-3.6 2 IOUT = 0mA, TJ = 25C, VIN = 8V (K Package Only) 0 IOUT 5A, 4.8V VIN 15V (Note 8) VIN = 5V, IOUT = 0mA, TJ = 25C (K Package Only) 4.8V VIN 15V, 0 IOUT 3A (Note 8) VIN = 5V, IOUT = 0mA, TJ = 25C (K Package Only) 5V VIN 15V, 0 IOUT 3A (Note 8) 5V VIN 1
rent) Ultra Low Dropout (0.5V at 3A) LT129CT-3.3 5-Lead T0-220 3.4V LT1529CT-5 5-Lead TO-220 5V LT1529C0 5-Lead DD 15 Adjustable LT1529CQ-3.3 5-Lead DD 4.3 LT1529CT-5 5-Lead OD 5V LT323AK LM323K Steel TO-3 20 5 M |LT323A Has 1% Vout Tol LT323AT 0-220 20 5 LT1085CT-3.3 TO-220 30 3.3 Low Dropout (1.2V}, 1% Voyr Tol LT1085CM-3.3 Plastic OD 30 3.3 Low Dropout (1.2V), 1% Vour Tol 3-Pin Surface Mount Package LT1085CM-3.6 Plastic OD 30 3.6 LT1085CT-3.6 TO-220 30 3.6 Low Dropout (1.2), 1% Vour Tol LT1085CK-5 Steal TO-3 30 5 M, | LT1085CT-5 TO-220 30 5 I LT1085CK-12 Stee! T0-3 30 42 M, | LT1085CT-12 70-220 30 12 | Pos Adj LT1587CM Plastic DD ? Adjustable Low Dropout, Fast Transient Response for Microprocessor Applications LT1587CT TO-220 7 Adjustable LT350AK LM350K Steel TO-3 35 1.2 to33 M |LT350A Has 1% Vage Tol LT350AT LM350T 0-220 35 1,2 to 33 LT350AP_ LM350P Plastic T0-9P 35 4.21033 LT1085CK Steel TO-3 30 1.2 to 29 M, | | Low Dropout (1.2), Pin Compatible with 31
3A NPN LDO Voltage Regulator 3 TO-263 Pin to Pin Linear Technology LT1085CM-3.3 SPX1587AT-3.3 3A NPN LDO Voltage Regulator 3 TO-263 Pin to Pin Linear Technology LT1085CM-5.0 SPX1587AT-5.0 3A NPN LDO Voltage Regulator 3 TO-263 Pin to Pin Linear Technology LT1085CT SPX1587AU 3A NPN LDO Voltage Regulator 3 TO-220 Pin to Pin Linear Technology LT1085CT-3.3 SPX1587AU-3.3 3A NPN LDO Voltage Regulator 3 TO-220 Pin to Pin Linear Technology LT1085CT-5.0 SPX1587AU-5.0 3A NPN LDO Voltage Regulator 3 TO-220 Pin to Pin Linear Technology LT1086CM SPX2815AT 1.5A NPN LDO Voltage Regulator 3 TO-263 Pin to Pin Linear Technology LT1086CM-5.0 SPX2815AT-5.0 1.5A NPN LDO Voltage Regulator 3 TO-263 Pin to Pin Linear Technology LT1086CT SPX2815AU 1.5A NPN LDO Voltage Regulator 3 TO-220 Pin to Pin Linear Technology LT1086CT-3.3 SPX2815AU-3.3 1.5A NPN LDO Voltage Regulator 3 TO-220 Pin to Pin Linear Technology LT1086CT-5.0 SPX2815AU-5.0 1.5A NPN LDO Voltage Regulator 3 TO-220 Pin to Pin Linear Te
-5 LT1083MK-12 LT1084CK-5 LT1084CK-12 2 1 GND K PACKAGE 2-LEAD TO-3 METAL CAN LT1084MK-5 LT1084MK-12 LT1085CK-5 LT1085CK-12 LT1085MK-5 LT1085MK-12 ORDER PART NUMBER TAB IS OUTPUT JA = 35C/W FRONT VIEW 3 VIN 2 VOUT 1 GND LT1084CT-3.3 LT1084CT-5 LT1084CT-12 LT1085CT-3.3 LT1085CT-3.6 LT1085CT-5 LT1085CT-12 T PACKAGE 3-LEAD PLASTIC TO-220 JA = 50C/W Consult factory for parts specified with wider operating temperature ranges. 2 3 VIN 2 VOUT 1 GND LT1083CP-5 LT1083CP-12 LT1084CP-5 LT1084CP-12 P PACKAGE 3-LEAD TO-3P PLASTIC OBSOLETE NOT RECOMMENDED FOR NEW DESIGNS TAB IS OUTPUT FRONT VIEW JA = 45C/W FRONT VIEW TAB IS OUTPUT 3 VIN 2 VOUT 1 GND M PACKAGE 3-LEAD PLASTIC DD JA = 30C/W* *WITH PACKAGE SOLDERED TO 0.52IN2 COPPER AREA OVER BACKSIDE GROUND PLANE OR INTERNAL POWER PLANE. JA CAN VARY FROM 20C/W TO > 40C/W DEPENDING ON MOUNTING TECHNIQUE. LT1085CM-3.3 LT1085CM-3.6 LT1085IM-3.6 LT1083/LT1084/LT1085 Fixed ELECTRICAL CHARACTERISTICS The denotes the specifications
ER TAB IS OUTPUT JA = 35C/W 3 VIN 2 VOUT 1 GND LT1083CP-5 LT1083CP-12 LT1084CP-5 LT1084CP-12 P PACKAGE 3-LEAD TO-3P PLASTIC OBSOLETE NOT RECOMMENDED FOR NEW DESIGNS TAB IS OUTPUT FRONT VIEW FRONT VIEW 3 VIN 2 VOUT 1 GND LT1084CT-3.3 LT1084CT-5 LT1084CT-12 LT1085CT-3.3 LT1085CT-3.6 LT1085CT-5 LT1085CT-12 T PACKAGE 3-LEAD PLASTIC TO-220 JA = 50C/W JA = 45C/W FRONT VIEW TAB IS OUTPUT 3 VIN 2 VOUT 1 GND LT1085CM-3.3 LT1085CM-3.6 LT1085IM-3.6 M PACKAGE 3-LEAD PLASTIC DD JA = 30C/W* *WITH PACKAGE SOLDERED TO 0.52IN2 COPPER AREA OVER BACKSIDE GROUND PLANE OR INTERNAL POWER PLANE. JA CAN VARY FROM 20C/W TO > 40C/W DEPENDING ON MOUNTING TECHNIQUE. Consult factory for parts specified with wider operating temperature ranges. 1083ffd 2 LT1083/LT1084/LT1085 Fixed ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. PARAMETER CONDITIONS Output Voltage LT1084-3.3 LT1085-3.
4CZ-2.5 . . . . . . . . .SPX1004N-2.5 LT1084CT . . . . . . . . . . . . . .SPX1585AU LT1084CT-3.3 . . . . . . . . .SPX1585AU-3.3 LT1084CT-5.0 . . . . . . . . .SPX1585AU-5.0 LT1085CM-3.3 . . . . . . . .SPX1587AT-3.3 LT1085CM-5.0 . . . . . . . .SPX1587AT-5.0 LT1085CT . . . . . . . . . . . . . .SPX1587AU LT1085CT-3.3 . . . . . . . . .SPX1587AU-3.3 LT1085CT-5.0 . . . . . . . . .SPX1587AU-5.0 LT1086CM . . . . . . . . . . . . . .SPX2815AT LT1086CM-5.0 . . . . . . . .SPX2815AT-5.0 LT1086CT . . . . . . . . . . . . . .SPX2815AU LT1086CT-3.3 . . . . . . . . .SPX2815AU-3.3 LT1086CT-5.0 . . . . . . . . .SPX2815AU-5.0 LT1117CM . . . . . . . . . . . . . . .SPX1117T LT1117CM-2.5 . . . . . . . . .SPX1117T-2.5 LT1117CM-3.3 . . . . . . . . .SPX1117T-3.3 LT1117CST . . . . . . . . . . . . .SPX1117M3 LT1117CST-2.5 . . . . . . .SPX1117M3-2.5 LT1117CST-3.3 . . . . . . .SPX1117M3-3.3 LT1117CT . . . . . . . . . . . . . . . .SPX1117U LT1580CQ . . . . . . . . . . . . . . .SPX1580T5 LT1580CQ-2.5 . .
1084CP-12 PALKAGE LT1084K-5 LT{085MK-5 P PACKAGE 2-LEAD 0-3 METAL CAN LT1084CK-12 LT1085MK-12 S-LEAD TO-3P PLASTIC Oy, = 35C/W By, = 45C/W TBs FRONT VIEW LTA O84CT-3.3 FRONT VIEW LT1084CT-5 3 vin LT N- : vm LT1084CT-12 oureur| |O 23Vour THosecMae O 2 Vout LT1085CT-3.3 1 GND , ' GND LT1085CT-3.6 T PACKAGE LT1 085CT-5 ABAD PLASTIC oD 3-LEAD PLASTIC 70-290 LT1085CT-12 8yy = 30C" yn = 50C * WITH PACKAGE SOLDERED TO 0.521N2 COPPER AREA OVER BACKSIDE GROUND PLANE OR INTERNAL POWER PLANE. @j, CAN VARY FROM 20C/W TO > 40C/W DEPENDING ON MOUNTING TECHNIQUE. Consult factory for Industrial grade parts. ELECTRICAL CHARACTERISTICS PARAMETER CONDITIONS MIN TYP MAX | UNITS Output Voltage LT1084-3.3 lout = OMA, Ty = 25C, Viy = 8V (K Package Only) 3.270 3.300 3.330 V 0 < Igur < 5A, 4.8V < Vin < 15V (Note 8) e 3.235 3.300 3.365 V LT1085-3.3 Vin = 5V, loyt = OMA, Ty = 25C (K Package Only) 3.270 3.300 3.330 Vv 4.BV < Vin < 15V, 0 < lour < 3A (Note 8) @ | 3235 3300 3.365 V LT1085-3.6 Vin = 5
ver/receiver WSOIC-16 SOIC-16 0C to 70C 0C to 70C - - F LT1085CM LM1085IS-Adj 3A low-dropout regulator TO263-3 TO263-3 0C to 125C -40C to 125C Adj. Adj. S LT1085CM-3.3 LM1085IS-3.3 3A low-dropout regulator TO263-3 TO263-3 0C to 125C -40C to 125C 3.3 3.3 S LT1085CT LM1085IT-Adj 3A low-dropout regulator TO220-3 TO220-3 0C to 125C -40C to 125C Adj. Adj. S LT1085CT-12 LM1085IT-12 3A low-dropout regulator TO220-3 TO220-3 0C to 125C -40C to 125C 12 12 S LT1085CT-3.3 LM1085IT-3.3 3A low-dropout regulator TO220-3 TO220-3 0C to 125C -40C to 125C 3.3 3.3 S LT1085CT-5.0 LM1085IT-5.0 3A low-dropout regulator TO220-3 TO220-3 0C to 125C -40C to 125C 5 5 S LT1085IT LM1085IT-Adj 3A low-dropout regulator TO220-3 TO220-3 0C to 125C -40C to 125C Adj. Adj. S LT1086CM LM1086CS-Adj 1.5A low-dropout regulator TO263-3 TO263-3 0C to 125C 0C to 125C Adj. Adj. D LT1086CM-3.3 LM1086CS-3.3 1.5A low-dropout regulator TO263-3 TO263-3 0C to 125C 0C to 125C 3.3 3.3 D LT1086CT LM1086CT-Adj 1