LTC3416 4A, 4MHz, Monolithic Synchronous Step-Down Regulator with Tracking UFEATURESDESCRIPTIO ■ High Efficiency: Up to 95% The LTC®3416 is a high efficiency monolithic synchro- ■ 4A Output Current nous, step-down DC/DC converter utilizing a constant ■ Low RDS(ON) Internal Switch: 67m Ω frequency, current mode architecture. It operates from an ■ Tracking Input to Provide Easy Supply Sequencing input voltage range of 2.25V to 5.5V and provides a ■ Programmable Frequency: 300kHz to 4MHz regulated output voltage from 0.8V to 5V while delivering ■ 2.25V to 5.5V Input Voltage Range up to 4A of output current. The internal synchronous ■ ±2% Output Voltage Accuracy power switch with 67mΩ of on-resistance increases effi- ■ 0.8V Reference Allows Low Output Voltage ciency and eliminates the need for an external Schottky ■ Low Dropout Operation: 100% Duty Cycle diode. Switching frequency is set by an external resistor. ■ Power Good Output Voltage Monitor 100% duty cycle provides low dropout operation extend- ■ Overtemperature Protected ing battery life in portable systems. OPTI-LOOP® compen- ■ Available in a 20-Lead Thermally Enhanced sation allows the transient response to be optimized over TSSOP Package a wide range of loads and output capacitors. The LTC3416 operates in forced continuous operation and U provides tracking of another power supply rail. Forced APPLICATIO S continuous operation reduces noise and RF interference and ■ Portable Instruments provides excellent transient response. Fault protection is ■ Notebook Computers provided by an overcurrent comparator, and adjustable ■ Distributed Power Systems compensation allows the transient response to be optimized ■ Battery-Powered Equipment over a wide range of loads and output capacitors. ■ POL Board Power , LTC and LT are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. OPTI-LOOP is a registered trade- mark of Linear Technology Corporation. Protected by U.S. Patents including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131, 6724174. UTYPICAL APPLICATIO VOUT2 I/O VOLTAGE 2.5V 100 VIN 90 2.5V TO 5.5V 22µF VIN = 2.5V 80 SVIN PVIN 70 R PGOOD T 0.2µH VOUT1 VIN = 3.3V 127k SW 1.8V 60 4A LTC3416 100µF 50 RUN/SS PGND ×2 40 I SGND TH EFFICIENCY (%) 30 TRACK V 7.5k FB 20 820pF 10 VOUT = 1.8V 255k 255k f = 2MHz 0 0.01 0.10 1 10 3416 F01a 200k 200k LOAD CURRENT (A) 3416 G09 Figure 1a. 2.5V/4A Step-Down Regulator with TrackingFigure 1b. Efficiency vs Load Current 3416fa 1