LTC3867 Synchronous Step-Down DC/DC Controller with Differential Remote Sense and Nonlinear Control FEATURESDESCRIPTION n VIN Range: 4V to 38V The LTC®3867 is a current mode synchronous step-down n VOUT Range: 0.6V to 14V switching regulator controller that drives all N-channel n Nonlinear Control Architecture Minimizes Output power MOSFET stages. Output voltage transient excursions Transient Excursions (Optional) are minimized by use of a nonlinear control architecture n Programmable DCR Temperature Compensation to eliminate clock latency issues. n ±0.75% 0.6V Voltage Reference The maximum current sense voltage is programmable n Fixed Frequency Range of 200kHz to 1.2MHz from 30mV to 75mV, allowing the use of either a discrete n PLL Frequency Synchronization sense resistor or the inductor DCR as the sensing element. n RSENSE or DCR Current Sensing Programmable DCR temperature compensation allows n Differential Remote Output Voltage Sense constant current limit regardless of inductor tempera- n Supports Smooth Start-Up into Pre-Biased Outputs ture. Programmable inductor temperature-based thermal n Programmable Soft-Start or VOUT Tracking shutdown protects the power components from thermal n Hiccup Mode/Soft Recovery from Output Overcurrent stress. Soft recovery from output shorts or overcurrent n 24-Lead (4mm × 4mm) QFN Package minimizes output overshoot. APPLICATIONS The LTC3867 features a precision 0.6V reference and n can regulate output voltages up to 14V from a wide Automotive Systems n 4V to 38V input supply range. The LTC3867 includes Telecom Systems n a high speed differential remote sense amplifier. Burst Industrial Equipment n Mode® operation, continuous and pulse-skipping modes Distributed DC Power Systems are supported. The LTC3867 is available in a 24-lead L, LT, LTC, LTM, Burst Mode, OPTI-LOOP, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their (4mm × 4mm) QFN package. respective owners. Protected by U.S. Patents, including 5481178, 5705919, 5929620, 6177787, 6580258, 6498466, 6611131. TYPICAL APPLICATIONHigh Efficiency Synchronous Step-Down Controller DIFF+ ITEMP Efficiency and Power Loss DIFF– ITSD SGND DIFFOUT PGOOD INTVCC 100 4.0 0.1µF ILIM RUN 90 TK/SS EXTV 3.5 CC V FREQ V IN 80 IN 5V TO 18V 37.4k 22µF 3.0 MODE/PLLIN TG 70 POWER LOSS (W) 50V INTVCC IFAST 0.1µF 60 2.5 LTC3867 ITH BOOST 0.4µH 50 2.0 330pF VOUT SW 1.5V 40 100pF 1.5 49.9k D 10A EFFICIENCY (%) B 330µF ×2 30 SGND INTV 1.0 CC 3.3k +100µF 20 49.9k + 0.22µF 0.5 4.7µF 10 VFB 0 0 75k SENSE– BG 0.01 0.1 1 10 100 SENSE+ PGND LOAD CURRENT (A) 3867 TA01b 3867 TA01a 3867f 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Package Description Typical Application Related Parts
