LTC3896 150V Low IQ, Synchronous Inverting DC/DC Controller FeaTuresDescripTion– n Wide VIN + |VOUT | Range: 4V to 140V (150V Abs Max) The LTC®3896 is a high performance inverting DC/DC n Wide Output Voltage Range: –60V to –0.8V switching regulator controller that drives an all N-channel n Ground-Referenced Control / Interface Pins synchronous power MOSFET stage. It converts a wide- n Adjustable Gate Drive Level 5V to 10V (OPTI-DRIVE) ranging positive input voltage source to a regulated negative n Integrated Bootstrap Diode output that can be as much as 60V below ground. The n Low Operating IQ: 40μA (Shutdown = 10μA) input can operate from a voltage as low as 4V and as high n Selectable Gate Drive UVLO Thresholds as 140V – |V – OUT |. n Onboard LDO or External NMOS LDO for DRVCC The LTC3896 contains true ground-referenced RUN, PLLIN n EXTVCC LDO Powers Drivers from Output and PGOOD pins, eliminating the need for external discrete n Phase-Lockable Frequency (75kHz to 850kHz) level-shifting components to interface with the LTC3896. n Programmable Fixed Frequency (50kHz to 900kHz) n Selectable Continuous, Pulse-Skipping or Low Ripple A constant frequency current mode architecture allows a Burst Mode® Operation at Light Loads phase-lockable frequency of up to 850kHz. The low 40μA n Adjustable Burst Clamp and Current Limit no-load quiescent current extends operating run time in n Power Good Output Voltage Monitor battery-powered systems. OPTI-LOOP® compensation n Programmable Input Overvoltage Lockout allows the transient response to be optimized over a n 38-Lead TSSOP High Voltage Package wide range of output capacitance and ESR values. The LTC3896 features a precision 0.8V reference and power good output indicator. The soft-start (SS) pin ramps the applicaTions output voltage during start-up. n Automotive and Industrial Power Systems L, LT, LTC, LTM, Linear Technology, the Linear logo, Burst Mode and OPTI-LOOP are registered trademarks of Linear Technology Corporation. All other trademarks are the property n Telecommunications Power Supplies of their respective owners. Protected by U.S. Patents including 5481178, 5705919, 5929620, 6144194, 6177787, 6580258. n Distributed Power Systems Typical applicaTionHigh Efficiency 36V–72V to –48V/2A Inverting RegulatorEfficiency and Power Loss V vs Load Current IN 36V to 72V 100 100k V 47µF 0V IN RUN TG 90 EFFICIENCY PLLIN 0.1µF 80 0V 10k POWER LOSS (mW) GND BOOST 70 100k V – 5V PGOOD SW OUT 60 –48V NDRV LTC3896 2A 50 1k 0.1µF POWER LOSS DRV 47µH CC 4.7µF ×3 40 INTV EFFICIENCY (%) CC 100V 30 4.7µF SENSE+ 2220 100 0.1µF DRVSET 10mΩ ×4 20 301k V DRVUV IN = +48V V – = –48V SENSE– OUT 10 FIGURE 16 CIRCUIT SS 0 10 0.0001 0.001 0.01 0.1 1 10 ITH BG LOAD CURRENT (A) 590k 3896 TA01b 0.1µF 4.99k 100pF FREQ V – V OUT FB 15nF 10k 3896 TA01a 3896f For more information www.linear.com/LTC3896 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts
