LTC1922-1 Synchronous Phase Modulated Full-Bridge Controller FEATURES DESCRIPTIO TM n Adaptive DirectSense Zero Voltage Switching The LTC 1922-1 phase shift PWM controller provides all n Integrated Synchronous Rectification Control for of the control and protection functions necessary to imple- Highest Efficiency ment a high performance, zero voltage switched, phase n Output Power Levels from 50W to Kilowatts shift, full-bridge power converter with synchronous recti- n Very Low Start-Up and Quiescent Currents fication. The part is ideal for developing isolated, low n Compatible with Voltage Mode and Current Mode voltage, high current outputs from a high voltage input Topologies source. The LTC1922-1 combines the benefits of the full- n Programmable Slope Compensation bridge topology with fixed frequency, zero voltage switch- n Undervoltage Lockout Circuitry with 4.2V Hysteresis ing operation (ZVS). Adaptive ZVS circuity controls the and Integrated 10.3V Shunt Regulator turn-on signals for each MOSFET independent of internal n Fixed Frequency Operation to 1MHz and external component tolerances for optimal perfor- n 50mA Outputs for Bridge Drive and Secondary Side mance. Synchronous Rectifiers The LTC1922-1 also provides secondary side synchro- n Soft-Start, Cycle-by-Cycle Current Limiting and nous rectifier control. The device uses peak current mode Hiccup Mode Short-Circuit Protection control with programmable slope comp and leading edge n 5V, 15mA Low Dropout Regulator blanking. n 20-Pin PDIP and SSOP Packages The LTC1922-1 features extremely low operating and U APPLICATIO S start-up currents to simplify off-line start-up and bias circuitry. The LTC1922-1 also includes a full range of n Telecommunications, Infrastructure Power Systems protection features and is available in 20-pin through hole n Distributed Power Architectures (N) and surface mount (G) packages. n Server Power Supplies , LTC and LT are registered trademarks of Linear Technology Corporation. n DirectSense is a trademark of Linear Technology Corporation. High Density Power Modules TYPICAL APPLICATIO V IN 48V BIAS Efficiency SUPPLY 100 V OUT 3.3V 90 V = 48V IN V = 36V IN 80 LTC1922-1 70 ISOLATED 60 FEEDBACK 0 10 20 30 40 LOAD CURRENT (A) 1922 TA01b 1922 TA01a 1 EFFICIENCY (%) U ULTC1922-1 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) TOP VIEW ORDER PART V to GND CC SYNC 1 20 C T NUMBER Low Impedance Source ......................... 0.3V to 10V RAMP 2 19 GND (Chip Self Regulates at 10.3V) CS 3 18 OUTA LTC1922EG-1 All Other Pins to GND COMP 4 17 OUTB LTC1922IG-1 (Low Impedance Source) ..................... 0.3V to 5.5V R 5 16 OUTC LEB LTC1922EN-1 V (Current Fed).................................................. 25mA FB 6 15 V CC CC LTC1922IN-1 V Output Current ................................ Self Regulated SS 7 14 OUTD REF 8 13 OUTE Outputs (A, B, C, D, E, F) Current ..................... 100mA PDLY 9 12 OUTF SBUS Operating Temperature Range (Note 5) 10 11 V ADLY REF LTC1922E ........................................... 40 C to 85 C LTC1922I............................................ 40 C to 85 C G PACKAGE N PACKAGE 20-LEAD PLASTIC SSOP 20-LEAD PDIP Storage Temperature Range ................. 65 C to 125 C T = 125 C, q = 110 C/W (G) JMAX JA Lead Temperature (Soldering, 10 sec).................. 300 C T = 125 C,q = 62 C/W (N) JMAX JA Consult factory for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at V = 9.5V, C = 180pF, T = T to T unless other wise noted. CC T A MIN MAX SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Input Supply UVLO Undervoltage Lockout Measured on V 10.25 10.7 V CC UVHY UVLO Hysteresis Measured on V 3.8 4.2 V CC I Start-Up Current V = V 0.3V l 145 250 m A CCST CC UVLO I Operating Current 47 mA CCRN V Shunt Regulator Voltage Current Into V = 10mA 10.2 10.8 V SHUNT CC R Shunt Resistance Current Into V = 7mA to 17mA 1.5 2 W SHUNT CC Delay Blocks DTHR Delay Pin Threshold SBUS = 1.5V 1.38 1.50 1.62 V ADLY and PDLY SBUS = 2.25V 2.08 2.25 2.42 V DHYS Delay Hysteresis Current SBUS = 1.5V, ADLY/PDLY = 1.6V 1.1 1.3 1.45 mA ADLY and PDLY DTMO Delay Time-Out SBUS = 1.5V 600 ns SBUS = 2.25V 900 ns DZRT Zero Delay Threshold Measured on SBUS 3 4.15 5 V Phase Modulator ROS RAMP Offset Voltage Measured on COMP, RAMP = 0V 0.4 V I RAMP Discharge Current RAMP = 1V, COMP = 0V 30 50 mA RMP I Slope Compensation Current Measured on CS, C = 1.5V 35 55 75 m A SLP T C = 3V 70 110 150 m A T DCMX Maximum Phase Shift COMP = 4V l 95 99.5 % DCMN Minimum Phase Shift COMP = 0V l 0.1 0.6 % 2 U WWW