LT8609S 42V, 2A/3A Peak Synchronous Step-Down Regulator with 2.5µA Quiescent Current FEATURESDESCRIPTION n Silent Switcher ® 2 Architecture The LT®8609S is a compact, high efficiency, high speed n Ultralow EMI Emissions on Any PCB synchronous monolithic step-down switching regulator n Eliminates PCB Layout Sensitivity that consumes only 1.7µA of non-switching quiescent n Internal Bypass Capacitors Reduce Radiated EMI current. The LT8609S can deliver 2A of continuous cur- n Optional Spread Spectrum Modulation rent with peak loads of 3A (<1sec) to support applications n Wide Input Voltage Range: 3.0V to 42V such as GSM transceivers which require high transient n Ultralow Quiescent Current Burst Mode ® Operation: loads. Top and bottom power switches are included with n <2.5µA IQ Regulating 12VIN to 3.3VOUT all necessary circuitry to minimize the need for external n Output Ripple <10mVP-P components. Low ripple Burst Mode operation enables n High Efficiency 2MHz Synchronous Operation: high efficiency down to very low output currents while n >93% Efficiency at 1A, 12VIN to 5VOUT keeping the output ripple below 10mVP-P. A SYNC pin n 2A Maximum Continuous Output, 3A Peak Transient allows synchronization to an external clock, or spread Output spectrum modulation of switching frequencies for low n Fast Minimum Switch-On Time: 45ns EMI operation. Internal compensation with peak current n Adjustable and Synchronizable: 200kHz to 2.2MHz mode topology allows the use of small inductors and n Allows Use of Small Inductors results in fast transient response and good loop stability. n Low Dropout The EN/UV pin has an accurate 1V threshold and can be n Peak Current Mode Operation used to program VIN undervoltage lockout or to shut down n Internal Compensation the LT8609S reducing the input supply current to 1µA. A n Output Soft-Start and Tracking capacitor on the TR/SS pin programs the output voltage n Small 16-Lead 3mm × 3mm LQFN Package ramp rate during start-up while the PG flag signals when n AEC-Q100 Qualified for Automotive Applications VOUT is within ±8.5% of the programmed output voltage as well as fault conditions. The LT8609S is available in a APPLICATIONS small 16-lead 3mm × 3mm LQFN package. n General Purpose Step Down All registered trademarks and trademarks are the property of their respective owners. n Low EMI Step Down TYPICAL APPLICATION12VIN to 5VOUT Efficiency 100 5V, 2MHz Step Down 95 V 90 IN VIN 5.5V TO 40V 4.7µF ON OFF 85 EN/UV 2.2µH VOUT SYNC SW 5V 80 10pF 2A LT8609S 75 INTVCC 70 TR/SS PG 1M EFFICIENCY (%) RT FB 65 1µF 18.2k 182k 22µF GND 60 55 8609S TA01a fSW = 2MHz 50 0 0.50 1.00 1.50 2.00 2.50 IOUT (A) 8609S TA01b Rev. D Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
