●The LM21305SQ/NOPB is a current mode Synchronous Buck Regulator with adjustable frequency. It is optimized for solution size, flexibility and high conversion efficiency. High-power density LM21305 design is easily achieved by virtue of monolithic integration of high-side and low-side power MOSFETs, high switching frequency, peak current-mode control and optimized thermal design. The efficiency of the LM21305 is maximized at light loads with diode emulation mode operation and at heavy loads by optimal design of the MOSFET adaptive gate drivers to minimize switch dead-times and body-diode conduction losses. The LM21305 offers flexible system configuration with programmable switching frequency from 300kHz to 1.5MHz using one resistor or by external clock synchronization for beat-frequency-sensitive and multi-regulator applications. On-chip bias supply low-dropout sub-regulators eliminate the need for an external bias power and simplify circuit board layout.
● High-efficiency
● External frequency synchronization
● Ultra-fast line and load transient response
● Peak current-mode control
● Internal slope compensation
● High-bandwidth error amplifier
● Ultra-low shutdown quiescent current
● Diode emulation mode at light loads
● Integrated bias supply LDO sub-regulators
● Internal soft-start function - Monotonic startup into pre-biased loads
● Precision enable input with hysteresis
● Open-drain PGOOD indicator
● Internal input undervoltage lockout
● Cycle-by-cycle overcurrent protection
● Output overvoltage protection
● Thermal shutdown protection with hysteresis
● Accurate 0.598V feedback voltage reference
