LT1076CT-5#06PBF

LT1076-5 5V Step-Down Switching Regulator FEATURES DESCRIPTION n The LT®1076-5 is a 2A fixed 5V output monolithic bipolar switching regulator which requires only a few external parts for normal operation. The power switch, all oscillator and control circuitry, all current limit components, and an output monitor are included on the chip. The topology is a classic positive “buck” configuration but several design innovations allow this device to be used as a positive-to-negative converter, a negative boost converter, and as a flyback converter. The switch output is specified to swing 40V below ground, allowing the LT1076-5 to drive a tapped inductor in the buck mode with output currents up to 4A. n n n n n n n Fixed 5V Output 2A On-Board Switch 100kHz Switching Frequency 2% Output Voltage Tolerance Over Temperature Greatly Improved Dynamic Behavior Available in Low Cost 5- and 7-Lead Packages Only 9.5mA Quiescent Current Operates Up to 60V Input APPLICATIONS n n n 5V Output Buck Converter Tapped Inductor Buck Converter with 4A Output at 5V Positive-to-Negative Converter The LT1076-5 uses a true analog multiplier in the feedback loop. This makes the device respond nearly instantaneously to input voltage fluctuations and makes loop gain independent of input voltage. As a result, dynamic behavior of the regulator is significantly improved over previous designs. On-chip pulse by pulse current limiting makes the LT10765 nearly bust-proof for output overloads or shorts. The input voltage range as a buck converter is 8V to 60V, but a self-boot feature allows input voltages as low as 5V in the inverting and boost configurations. The LT1076-5 is available in a low cost 5- and 7-lead TO220 packages with frequency pre-set at 100kHz and current limit at 2.6A. See Application Note 44 for design details. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION Basic Positive Buck Converter 100μH** † VIN 8V TO 40V 5V ≤1.8A VSW LT1076-5 MBR340* * MBR330P MAY BE USED FOR VIN ≤ 25V SENSE GND + C3 200μF ** COILTRONICS #100-1-52 HURRICANE #HL-AG210LL VC R3 1.5k C2 0.033μF † + C1 500μF 25V VALUE MAY BE REDUCED TO 50μH FOR OUTPUT LOADS BELOW 1.5A LT1076-5 TA01 10765fc 1 LT1076-5 ABSOLUTE MAXIMUM RATINGS (Note 1) Input Voltage LT1076-5 .............................................................45V LT1076HV-5 .........................................................64V Switch Voltage with Respect to Input Voltage LT1076-5 ..............................................................64V LT1076HV-5 .........................................................75V Switch Voltage with Respect to Ground Pin (VSW Negative) LT1076-5 (Note 6) ................................................35V LT1076HV-5 (Note 6) ...........................................45V Sense Pin Voltage ............................................ –2V, 10V Maximum Operating Ambient Temperature Range LT1076C-5, LT1076HVC-5 ....................... 0°C to 70°C LT1076I-5, LT1076HVI-5 ..................... –40°C to 85°C Maximum Operating Junction Temperature Range LT1076C-5, LT1076HVC-5 ..................... 0°C to 125°C LT1076I-5, LT1076HVI-5 ................... –40°C to 125°C Maximum Storage Temperature ............ –65°C to 150°C Lead Temperature (Soldering, 10 sec) .................. 300°C PACKAGE/ORDER INFORMATION FRONT VIEW 5 VIN 4 VSW 3 GND 2 VC 1 FB/SENSE FRONT VIEW 7 6 5 4 3 2 1 TAB IS GND SHDN VC SENSE GND ILIM VSW VIN LT1076CQ-5 LT1076CR-5 θJC = 4°C/W, θJA = 30°C/W θJC = 4°C/W, θJA = 30°C/W FRONT VIEW TAB IS GND ORDER PART NUMBER R PACKAGE 7-LEAD PLASTIC DD Q PACKAGE 5-LEAD PLASTIC DD 5 4 3 2 1 ORDER PART NUMBER FRONT VIEW VIN 7 6 5 4 3 2 1 VSW GND VC SENSE TAB IS GND T PACKAGE 5-LEAD PLASTIC TO-220 T7 PACKAGE 7-LEAD PLASTIC TO-220 LEADS ARE FORMED STANDARD FOR STRAIGHT LEADS, ORDER FLOW 06 θJC = 4°C/W, θJA = 50°C/W θJC = 4°C/W, θJA = 50°C/W SHDN VC SENSE GND ILIM VSW VIN ORDER PART NUMBER ORDER PART NUMBER LT1076CT-5 LT1076HVCT-5 LT1076IT-5 LT1076HVIT-5 LT1076CT7-5 Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: http://www.linear.com/leadfree/ Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TJ = 25°C. VIN = 25V, unless otherwise noted. SYMBOL CONDITIONS Switch “On” Voltage (Note 2) ISW = 0.5A ISW = 2A Switch “Off” Leakage VIN = 25V, VSW = 0 VIN = 25V, VSW = 0 MIN l l TYP MAX UNITS 1.2 1.7 V V 150 250 μA μA 10765fc 2 LT1076-5 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TJ = 25°C. VIN = 25V, unless otherwise noted. SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Current (Note 3) VOUT = 5.5V, VIN ≤ 40V 40V < VIN < 60V VSHDN = 0.1V (Device Shutdown) (Note 9) l l 8.5 9.0 140 11 12 300 mA mA μA Minimum Supply Voltage Normal Mode Start-Up Mode (Note 4) l l 7.3 3.5 8.0 4.8 V V Switch Current Limit (Note 5) ILIM = Open RLIM = 10k (Note 10) RLIM = 7k (Note 10) l 2 2.6 1.8 1.2 3.2 A A A l 85 90 l 90 85 100 Maximum Duty Cycle Switching Frequency TJ ≤ 125°C VOUT = VSENSE = 0V (Note 5) 110 120 kHz kHz kHz 0.1 %/V 20 l Switching Frequency Line Regulation 8V ≤ VIN ≤ VMAX (Note 8) 0.03 Error Amplifier Voltage Gain (Note 8) 1V ≤ VC ≤ 4V 2000 Error Amplifier Transconductance (Note 8) Error Amplifier Source and Sink Current % Source (VSENSE = 4.5V) Sink (VSENSE = 5.5V) Sense Pin Divider Resistance V/V 3700 5000 8000 μmho 100 0.7 140 1.0 225 1.6 μA mA 3 5 8 kΩ 4.85 5 5.15 V % % Sense Voltage VC = 2V l Output Voltage Tolerance VOUT (Nominal) = 5V All Conditions of Input Voltage, Output Voltage, Temperature and Load Current l ±0.5 ±1.0 ±2 ±3 Output Voltage Line Regulation 8V ≤ VIN ≤ VMAX (Note 7) l 0.005 0.02 l 1.5 –4.0 VC Voltage at 0% Duty Cycle Over Temperature Multiplier Reference Voltage V mV/°C 24 Shutdown Pin Current VSHDN = 5V VSHDN ≤ VTHRESHOLD (≅ 2.5V) Shutdown Thresholds Switch Duty Cycle = 0 Fully Shut Down Thermal Resistance Junction to Case 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: To calculate maximum switch “on” voltage at currents between low and high conditions, a linear interpolation may be used. Note 3: A sense pin voltage (VSENSE) of 5.5V forces the VC pin to its low clamp level and the switch duty cycle to zero. This approximates the zero load condition where duty cycle approaches zero. Note 4: Total voltage from VIN pin to ground pin must be ≥ 8V after startup for proper regulation. For TA < 25°C, limit = 5V. Note 5: Switch frequency is internally scaled down when the sense pin voltage is less than 2.6V to avoid extremely short switch on times. During %/V V 5 10 20 50 μA μA 2.2 0.1 2.45 0.30 2.7 0.5 V V 4 °C/W current limit testing, VSENSE is adjusted to give a minimum switch on time of 1ms. Note 6: Switch to input voltage limitation must also be observed. Note 7: VMAX = 40V for the LT1076-5 and 60V for the LT1076HV-5. Note 8: Error amplifier voltage gain and transconductance are specified relative to the internal feedback node. To calculate gain and transconductance from the Sense pin (Output) to the VC pin, multiply by 0.44. Note 9: Does not include switch leakage. Note 10: ILIM ≈ RLIM − 1k 5k 10765fc 3 LT1076-5 PACKAGE DESCRIPTION Q Package 5-Lead Plastic DD Pak (Reference LTC DWG # 05-08-1461) .256 (6.502) .060 (1.524) TYP .060 (1.524) .390 – .415 (9.906 – 10.541) .165 – .180 (4.191 – 4.572) .045 – .055 (1.143 – 1.397) 15° TYP .060 (1.524) .183 (4.648) +.008 .004 –.004 +0.203 0.102 –0.102 .059 (1.499) TYP .330 – .370 (8.382 – 9.398) ( ) .095 – .115 (2.413 – 2.921) .075 (1.905) .300 (7.620) +.012 .143 –.020 +0.305 3.632 –0.508 ( BOTTOM VIEW OF DD PAK HATCHED AREA IS SOLDER PLATED COPPER HEAT SINK .067 (1.702) .028 – .038 BSC (0.711 – 0.965) TYP ) Q(DD5) 0502 .420 .276 .080 .420 .050 ± .012 (1.270 ± 0.305) .013 – .023 (0.330 – 0.584) .325 .350 .205 .565 .565 .320 .090 .090 .067 .042 RECOMMENDED SOLDER PAD LAYOUT NOTE: 1. DIMENSIONS IN INCH/(MILLIMETER) 2. DRAWING NOT TO SCALE .067 .042 RECOMMENDED SOLDER PAD LAYOUT FOR THICKER SOLDER PASTE APPLICATIONS 10765fc 4 LT1076-5 R Package 7-Lead Plastic DD Pak (Reference LTC DWG # 05-08-1462) .256 (6.502) .060 (1.524) TYP .060 (1.524) .390 – .415 (9.906 – 10.541) .165 – .180 (4.191 – 4.572) .045 – .055 (1.143 – 1.397) 15° TYP .060 (1.524) .183 (4.648) +.008 .004 –.004 +0.203 0.102 –0.102 .059 (1.499) TYP .330 – .370 (8.382 – 9.398) ( ) .095 – .115 (2.413 – 2.921) .075 (1.905) .300 (7.620) +.012 .143 –.020 +0.305 3.632 –0.508 ( BOTTOM VIEW OF DD PAK HATCHED AREA IS SOLDER PLATED COPPER HEAT SINK ) .026 – .035 (0.660 – 0.889) TYP .050 (1.27) BSC .013 – .023 (0.330 – 0.584) .050 ± .012 (1.270 ± 0.305) R (DD7) 0502 .420 .080 .420 .276 .350 .325 .205 .565 .565 .320 .090 .050 .035 RECOMMENDED SOLDER PAD LAYOUT NOTE: 1. DIMENSIONS IN INCH/(MILLIMETER) 2. DRAWING NOT TO SCALE .090 .050 .035 RECOMMENDED SOLDER PAD LAYOUT FOR THICKER SOLDER PASTE APPLICATIONS 10765fc 5 LT1076-5 PACKAGE DESCRIPTION T Package 5-Lead Plastic TO-220 (Standard) (Reference LTC DWG # 05-08-1421) .390 – .415 (9.906 – 10.541) .165 – .180 (4.191 – 4.572) .147 – .155 (3.734 – 3.937) DIA .045 – .055 (1.143 – 1.397) .230 – .270 (5.842 – 6.858) .460 – .500 (11.684 – 12.700) .570 – .620 (14.478 – 15.748) .330 – .370 (8.382 – 9.398) .620 (15.75) TYP .700 – .728 (17.78 – 18.491) SEATING PLANE .152 – .202 .260 – .320 (3.861 – 5.131) (6.60 – 8.13) .095 – .115 (2.413 – 2.921) .155 – .195* (3.937 – 4.953) .013 – .023 (0.330 – 0.584) BSC .067 (1.70) .028 – .038 (0.711 – 0.965) .135 – .165 (3.429 – 4.191) * MEASURED AT THE SEATING PLANE T5 (TO-220) 0801 10765fc 6 LT1076-5 PACKAGE DESCRIPTION T7 Package 7-Lead Plastic TO-220 (Standard) (Reference LTC DWG # 05-08-1422) .390 – .415 (9.906 – 10.541) .165 – .180 (4.191 – 4.572) .147 – .155 (3.734 – 3.937) DIA .045 – .055 (1.143 – 1.397) .230 – .270 (5.842 – 6.858) .460 – .500 (11.684 – 12.700) .570 – .620 (14.478 – 15.748) .330 – .370 (8.382 – 9.398) .620 (15.75) TYP .700 – .728 (17.780 – 18.491) .095 – .115 (2.413 – 2.921) .155 – .195* (3.937 – 4.953) SEATING PLANE .152 – .202 .260 – .320 (3.860 – 5.130) (6.604 – 8.128) BSC .050 (1.27) .026 – .036 (0.660 – 0.914) .135 – .165 (3.429 – 4.191) .013 – .023 (0.330 – 0.584) *MEASURED AT THE SEATING PLANE T7 (TO-220) 0801 10765fc 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. 7 LT1076-5 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1074/HV 4.4A (IOUT), 100kHz High Efficiency Step-Down DC/DC Converter VIN: 7.3V to 45V/64V, VOUT(MIN): 2.21V, IQ: 8.5mA, ISHDN: 10μA, DD5/7, TO-2205/7 LT3430 60V, 2.75A (IOUT), 200kHz High Efficiency Step-Down DC/DC Converter VIN: 5.5V to 60V, VOUT(MIN): 1.20V, IQ: 2.5mA, ISHDN: 25μA, TSSOP16E LT1956 60V, 1.2A (IOUT), 500kHz High Efficiency Step-Down DC/DC Converter VIN: 5.5V to 60V, VOUT(MIN): 1.20V, IQ: 2.5mA, ISHDN: 25μA, TSSOP16E 10765fc 8 Linear Technology Corporation LT 0407 REV C • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 1994