LT8301 - 42VIN Micropower No-Opto Isolated …

1 LT830118301fFor more information APPLICATION FEATURESDESCRIPTION42 VIN Micropower No-Opto Isolated Flyback Converter with 65 SwitchThe LT 8301 is a Micropower Isolated flyback converter. By sampling the Isolated output voltage directly from the primary-side flyback waveform, the part requires no third winding or opto -isolator for regulation. The output voltage is programmed with a single external resistor. In-ternal compensation and soft-start further reduce external component count. Boundary mode operation provides a small magnetic solution with excellent load regulation.

2 Low ripple Burst Mode operation maintains high efficiency at light load while minimizing the output voltage ripple. A , 65V DMOS power switch is integrated along with all high voltage circuitry and control logic into a 5-lead ThinSOT LT8301 operates from an input voltage range of to 42V and can deliver up to 6W of Isolated output power. The high level of integration and the use of boundary and low ripple burst modes result in a simple to use, low component count, and high efficiency application solution for Isolated power delivery.

3 L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by Patents, including 5438499, 7463497, and to 36 VIN/5 VOUT Micropower Isolated Flyback ConverterAPPLICATIONSn to 42V Input Voltage Rangen , 65V Internal DMOS Power Switchn Low Quiescent Current: 100 A in Sleep Mode 350 A in Active Moden Boundary Mode Operation at Heavy Loadn Low-Ripple Burst Mode Operation at Light Loadn Minimum Load < (Typ)

4 Of Full Outputn VOUT Set with a Single External Resistorn No Transformer Third Winding or opto -Isolator Required for Regulationn Accurate EN/UVLO Threshold and Hysteresisn Internal Compensation and Soft-Startn Output Short-Circuit Protectionn 5-Lead TSOT-23 Packagen Isolated Telecom, Automotive, Industrial, Medical Power Suppliesn Isolated Auxiliary/Housekeeping Power SuppliesEfficiency vs Load CurrentLT83013:1 RFBSW40 HEN/UVLO10 TO 36 VVOUT+5V6mA TO (VIN = 5V)6mA TO (VIN = 12V)6mA TO (VIN = 24V)6mA TO (VIN = 36V)VOUT GND154k 100 F8301 TA01aLOAD CURRENT (A)060 EFFICIENCY (%) = 5 VVIN = 12 VVIN = 24 VVIN = 36 VLT830128301fFor more information CONFIGURATIONABSOLUTE MAXIMUM RATINGSSW (Note 2).

5 65 VVIN .. 42 VEN/UVLO .. VINRFB .. VIN to VINC urrent into RFB .. 200 AOperating Junction Temperature Range (Notes 3, 4)LT8 301E, LT8 301I .. 40 C to 125 C LT8 301H .. 40 C to 150 C LT8 301MP .. 55 C to 150 CStorage Temperature Range .. 65 C to 150 C (Note 1)EN/UVLO 1 GND 2 TOP VIEWS5 PACKAGE5-LEAD PLASTIC TSOT-23 RFB 35 VIN4 SW JA = 150 C/WORDER INFORMATIONLEAD FREE FINISHTAPE AND REELPART MARKING*PACKAGE DESCRIPTIONTEMPERATURE RANGELT8301ES5#PBFLT8301ES5#TRPBFLTGMF5- Lead Plastic TSOT-23 40 C to 125 CLT8301IS5#PBFLT8301IS5#TRPBFLTGMF5-Lead Plastic TSOT-23 40 C to 125 CLT8301HS5#PBFLT8301HS5#TRPBFLTGMF5-Lead Plastic TSOT-23 40 C to 150 CLT8301 MPS5#PBFLT8301 MPS5#TRPBFLTGMF5-Lead Plastic TSOT-23 55 C to 150 CConsult LTC Marketing for parts specified with wider operating

6 Temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based finish more information on lead free part marking, go to: For more information on tape and reel specifications, go to: more information CHARACTERISTICSNote 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 2: The SW pin is rated to 65V for transients.

7 Depending on the leakage inductance voltage spike, operating waveforms of the SW pin should be derated to keep the flyback voltage spike below 65V as shown in Figure 3: The LT8301E is guaranteed to meet performance specifications from 0 C to 125 C operating junction temperature. Specifications over the 40 C to 125 C operating junction temperature range are assured by design, characterization and correlation with statistical process controls. The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25 C.

8 VIN = 5V, VEN/UVLO = VIN unless otherwise Voltage UVLO ThresholdRising VIQVIN Quiescent CurrentVEN/UVLO = VEN/UVLO = Sleep Mode (Switch Off) Active Mode (Switch On) 215 100 3502 A A A AEN/UVLO Shutdown Threshold For Lowest Off Enable ThresholdFalling VIHYSEN/UVLO Hysteresis CurrentVEN/UVLO = VEN/UVLO = VEN/UVLO = A A AfMINM inimum Switching (MIN)Minimum Switch-On Time170nstOFF(MAX)Maximum Switch-Off TimeBackup Timer190 sISW(MAX)Maximum SW Current (MIN)Minimum SW Current (ON)Switch On-ResistanceISW = ILKGS witch Leakage CurrentVIN = 42V, VSW = AIRFBRFB Regulation ARFB Regulation Current Line VIN LT8301I is guaranteed over the full 40 C to 125 C operating junction temperature range.

9 The LT8301H is guaranteed over the full 40 C to 150 C operating junction temperature range. The LT8301MP is guaranteed over the full 55 C to 150 C operating junction temperature range. High junction temperatures degrade operating lifetimes. Operating lifetime is derated at junction temperature greater than 125 4: The LT8301 includes overtemperature protection that is intended to protect the device during momentary overload conditions. Junction temperature will exceed 150 C when overtemperature protection is active. Continuous operation above the specified maximum operating junction temperature may impair device more information PERFORMANCE CHARACTERISTICSB oundary Mode WaveformsDiscontinuous Mode WaveformsBurst Mode WaveformsVIN Shutdown CurrentVIN Quiescent Current, Sleep ModeVIN Quiescent Current, Active ModeOutput Load and Line RegulationOutput Short-Circuit ProtectionSwitching Frequency vs Load CurrentTA = 25 C, unless otherwise CURRENT (A) FREQUENCY (kHz)

10 VIN = 5 VVIN = 12 VVIN = 24 VVIN = 36 VFRONT PAGE APPLICATIONVIN (V)00IQ ( A)26810102025458301 G074515303540TJ = 150 CTJ = 25 CTJ = 55 CVIN (V)0IQ ( A)100110120408301 G0890806010203054515253570140130TJ = 150 CTJ = 25 CTJ = 55 CVIN (V)0IQ ( A)320340360408301 G09300280102030545152535400380TJ = 150 CTJ = 25 CTJ = 55 CLOAD CURRENT (A)0 OUTPUT VOLTAGE (V) PAGE = 5 VVIN = 12 VVIN = 24 VVIN = 36 VLOAD CURRENT (A)00 OUTPUT VOLTAGE (V) = 5 VVIN = 12 VVIN = 24 VVIN = 36 VFRONT PAGE APPLICATIONVOUT50mV/DIVVSW20V/DIV5 s/DIVFRONT PAGE APPLICATIONVIN = 12 VILOAD = 600mA8301 G04 VOUT50mV/DIVVSW20V/DIV5 s/DIVFRONT PAGE APPLICATIONVIN = 12 VILOAD = 200mA8301 G05 VOUT50mV/DIVVSW20V/DIV20 s/DIVFRONT PAGE APPLICATIONVIN = 12 VILOAD = 6mA8301 G06LT830158301fFor more information PERFORMANCE CHARACTERISTICSRDS(ON)