LTC3833 Fast Accurate Step-Down DC/DC Controller with Differential Output Sensing FEATURESDESCRIPTION n Wide VIN Range: 4.5V to 38V The LTC®3833 is a synchronous step-down DC/DC n VOUT Range: 0.6V to 5.5V switching regulator controller targeted for high power n Output Accuracy: ±0.25% at 25°C and ±0.67% applications. It drives all N-channel power MOSFETs. The over Temperature controlled on-time valley current mode architecture allows n Differential Output Sensing Allowing Up to 500mV for both fast transient response and constant frequency Line Loss switching in steady-state operation, independent of VIN, n Fast Load Transient Response VOUT and load current. n tON(MIN) = 20ns, tOFF(MIN) = 90ns Differential output voltage sensing along with a precision n Controlled On-Time Valley Current Mode internal reference combine to offer ±0.67% output regula- Architecture tion and the ability to correct for up to ±500mV variations n Frequency Programmable from 200kHz to 2MHz in the output terminals due to line losses. The operating and Synchronizable to External Clock frequency can be programmed from 200kHz to 2MHz with n RSENSE or Inductor DCR Current Sensing an external resistor and can be synchronized to an external n Overvoltage Protection and Current Limit Foldback clock for noise and EMI sensitive applications. n Power Good Output Voltage Monitor n Output Tracking or Adjustable Soft-Start Very low tON and tOFF times allow for near 0% and near n External V 100% duty cycles, respectively. Programmable soft-start or CC Input for Bypassing Internal LDO n 20-Pin QFN (3mm × 4mm) and TSSOP Packages output voltage tracking is available. Safety features include output overvoltage protection, programmable current limit APPLICATIONS with foldback, and a power good output signal. n L, LT, LTC, LTM, OPTI-LOOP, PolyPhase, µModule, Linear Technology and the Linear logo Distributed Power Systems are registered trademarks and Hot Swap, No RSENSE and UltraFast are trademarks of Linear n Point-of-Load Converters Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 5481178, 5487554, 6580258, 6304066, 6476589, n Computing Systems 6774611. n Datacomm Systems TYPICAL APPLICATION1.5V, 20A, 300kHz High Current Step-Down Converter INTVCC Efficiency V V RNG VIN IN 4.5V TO 14V 100 VOUT 180µF PULSE-SKIPPING 100k SENSE– MODE PGOOD 90 SENSE+ 0.1µF RUN TG 3.24k LTC3833 80 FORCED 0.1µF SW CONTINUOUS 0.47µH VOUT MODE TRACK/SS BOOST 1.5V 70 470pF 20A 10k 0.1µF 15k ITH INTVCC INTVCC 330µF EFFICIENCY (%) 60 137k 4.7µF ×2 RT 10k EXTV 50 CC BG VIN = 12V SGND PGND VOUT = 1.5V 40 300kHz MODE/PLLIN 0.1 1 10 100 V + OSNS LOAD CURRENT (A) – 3833 TA01a VOSNS 3833 TA01b 3833f 1