High Power Synchronous DC DC Controller

Gary

Description

1LT1339 sn1339 1339fas High Power Synchronous DC/DC Controller DESCRIPTION U FEATURES The LT®1339 is a high power synchronous current mode switching regulator controller. The IC drives dual N-channel MOSFETs to create a single IC solution for high power DC/DC converters in applications up to 60V. The LT1339 incorporates programmable average current limiting, allowing accurate limiting of DC load current independent of inductor ripple current. The IC also incor- porates user-adjustable slope compensation for minimi- zation of magnetics at duty cycles up to 90%. The LT1339 timing oscillator operating frequency is pro- grammable and can be synchronized up to 150kHz. Mini- mum off-time operation provides main switch protection. The IC also incorporates a soft start feature that is gated by both shutdown and undervoltage lockout conditions. An output phase reversal pin allows flexibility in configu- ration of converter types, including inverting and negative topologies. n High Voltage: Operation Up to 60V n High Current: Dual N-Channel Synchronous Drive Handles Up to 10,000pF Gate Capacitance n Programmable Average Load Current Limiting n 5V Reference Output with 10mA External Loading Capability n Programmable Fixed Frequency Synchronizable Current Mode Operation Up to 150kHz n Undervoltage Lockout with Hysteresis n Programmable Start Inhibit for Power Supply Sequencing and Protection n Adaptive Nonoverlapping Gate Drive Prevents Shoot-Through n 48V Telecom Power Supplies n Personal Computers and Peripherals n Distributed Power Converters n Industrial Control Systems n Lead-Acid Battery Backup Systems n Automotive and Heavy

• lockout threshold - rising


• supply current


• up pl


• bottom gate


• fall time


• operation up


• limit threshold


• voltage line


• dc standby

Sujets

• Régulation
• Linear Technology
• Fall time

Informations

• Publié par: pefav
• Nombre de lectures: 20
• Langue: English

Extrait

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FEATURES n High Voltage: Operation Up to 60V n High Current: Dual N-Channel Synchronous Drive Handles Up to 10,000pF Gate Capacitance n Programmable Average Load Current Limiting n 5V Reference Output with 10mA External Loading Capability n Programmable Fixed Frequency Synchronizable Current Mode Operation Up to 150kHz n Undervoltage Lockout with Hysteresis n Programmable Start Inhibit for Power Supply Sequencing and Protection n Adaptive Nonoverlapping Gate Drive Prevents Shoot-Through APPLICATIONS n 48V Telecom Power Supplies n Personal Computers and Peripherals n Distributed Power Converters n Industrial Control Systems n Lead-Acid Battery Backup Systems n Automotive and Heavy Equipment

TYPICAL APPLICATION 28V to 5V 20A Buck Converter DBST IN5819 SYNC V BOOST CBST 5V REF 1µF R CT TG D1 10k C 5VREF MBR0520 1µ F CT TS C CT C AVG SL/ADJ 12V IN 2200pF 2200pF  LT1339  BG I AVG D2 C SS ,  1µF SS  PGND  MBR0520  10k  PHASE C VC ,  1nF R VC , V C RUN/SHDN 1 R 0 R 0 U k N C EF SGND SENSE + R 0.1µF V FB V REF SENSE – R FB2 R FB1 1k 3k L1 = CTX02-13400-X2

, LTC and LT are registered trademarks of Linear Technology Corporation.

LT1339 High Power Synchronous DC/DC Controller DESCRIPTION The LT ® 1339 is a high power synchronous current mode switching regulator controller. The IC drives dual N-channel MOSFETs to create a single IC solution for high power DC/DC converters in applications up to 60V. The LT1339 incorporates programmable average current limiting, allowing accurate limiting of DC load current independent of inductor ripple current. The IC also incor- porates user-adjustable slope compensation for minimi- zation of magnetics at duty cycles up to 90%. The LT1339 timing oscillator operating frequency is pro- grammable and can be synchronized up to 150kHz. Mini- mum off-time operation provides main switch protection. The IC also incorporates a soft start feature that is gated by both shutdown and undervoltage lockout conditions. An output phase reversal pin allows flexibility in configu- ration of converter types, including inverting and negative topologies.

a 510 TA03 0 90 8 15 10

LT1339 ABSOLUTE AXI  U RATI GS  PACKAGE/ORDER  I FOR ATIO (Note 1) Supply Voltages TOP VIEW OR N D U E M R  B P E A R RT Power Supply Voltage (12V IN )...............–0.3V to 20V SYNC 1  20  V BOOST Topside Supply Voltage (V BOOST ) 5V REF 2 19  TG V TS  – 0.3V to V TS  + 20V (V MAX  = 75V) CT 3  18  TS LT1339CN Topside Reference Pin Voltage (TS) ......–0.3V to 60V SL/ADJ 4  17  12V IN LT1339CSW Input Voltages I AVG 5 16  BG LT1339IN Sense Amplifier Input Common Mode...–0.3V to 60V SS 6  15  PGND LT1339ISW RUN/SHDN Pin Voltage ...................... –0.3V to 12V IN V C 7 14  PHASE All Other Inputs .................................. –0.3V to 7V SGND 8 13  RUN/SHDN ..... Maximum Currents V FB 9 12  SENSE – 5V Reference Output Current............................ 65mA V REF 10 11  SENSE + Maximum Temperatures N PACKAGE SW PACKAGE Operating Ambient Temperature Range 20-LEAD PDIP 20-LEAD PLASTIC SO WIDE ∞LT1339C .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ......... . ..   . – .. 4  0 0∞ C C  t t o o     7 8 0 5 ∞ ∞ C C T J T J M M AX A   X =     = 1  1 2 2 5 5 ∞ ∞ C, C   , Κ   J Κ A J   A =     = 8  7 5 0 ∞ ∞ C C / / W W  (  ( S N W ) ) LT1339I ........ Storage Temperature Range ................. –65∞C to 150∞C Lead Temperature (Soldering, 10 sec).................. 300∞C Consult factory for Military grade parts.

ELECTRICAL CHARACTERISTICS 12V IN  = V BOOST  = 12V, V C  = 2V, TS = 0V, V FB  = V REF  = 1.25V, C TG  = C BG  = 3000pF, T A  = 25∞C unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP Supply and Protection I 12VIN DC Active Supply Current (Note 2) l 14 DC Standby Supply Current V RUN/SHDN  < 0.5V l 150 I BOOST DC Active Supply Current (Note 2) 2.2 DC Standby Supply Current V RUN/SHDN  < 0.5V 0 V RUN/SHDN Shutdown Rising Threshold l 1.15 1.25 V SSHYST Shutdown Threshold Hysteresis 25 I SS Soft Start Charge Current l 4 8 V UVLO Undervoltage Lockout Threshold - Falling l 8.20 9.00 Undervoltage Lockout Threshold - Rising l 9.35 Undervoltage Lockout Hysteresis l 200 350 5V Reference V REF5 5V Reference Voltage l 4.75 5.00 5V Reference Line Regulation l 3 I REF5 5V Reference Load Range - DC l Pulse l 5V Reference Load Regulation l –1.25 I SC 5V Reference Short-Circuit Current 45

2

Line, Load and Temperature 10Vσ 12V IN   σ 15V 0σ I REF5   σ 20mA

MAX UNITS 20 mA 250mA mA mA 1.35 V mV 14mA 9.75 V 9.95 V mV 5.25 V 5 mV/V 10 mA 20 mA – 2 V/A mA

sn1339 1339fas