LTC3836 Datasheet | Linear Technology

Dual 2-Phase, No RSENSETM Low VIN Synchronous Controller Features n No Current Sense Resistors Required n Out-of-Phase Controllers Reduce Required Input Capacitance n All N-Channel Synchronous Drive n VIN Range: 2.75V to 4.5V n Constant-Frequency Current Mode Operation n 0.6V ±1.5% Voltage Reference n Low Dropout Operation: 97% Duty Cycle n True PLL for Frequency Locking or Adjustment n Selectable Pulse-Skipping/Continuous Operation n Tracking Function n Internal Soft-Start Circuitry n Power Good Output Voltage Monitor n Output Overvoltage Protection n Micropower Shutdown: IQ = 6.5μA n Tiny Low Profile (4mm × 5mm) QFN and Narrow SSOP Packages APPLICATIONS n General Purpose 3.3V to 1.X Supplies n Single Lithium-Ion Powered Devices n Distributed DC Power Systems L, LT, LTC, LTM, Linear Technology, Burst Mode, OPTI-LOOP and the Linear logo are registered trademarks and No RSENSE is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 5929620, 6144194, 6304066, 6498466, 6580258, 6611131. DESCRIPTION The LTC®3836 is a 2-phase dual output synchronous step-down switching regulator controller with tracking that drives external N-channel power MOSFETs using few external ponents. The constant-frequency current mode architecture with MOSFET VDS sensing eliminates the need for sense resistors and improves efficiency. The power loss and noise due to the ESR of the input capacitance are minimized by operating the two controllers out-of-phase. Pulse-skipping operation provides high efficiency at light loads. The 97% duty cycle capability provides low dropout operation, extending operating time in battery-powered systems. The operating frequency is selectable from 300k Hz to 750k Hz, allowing the use of small surface mount inductors and capacitors. For noise sensitive applications, the LTC3836 operating frequency can be externally synchronized from 250k Hz to 850k Hz. The...