POWER LOSS (W) LTC3544 Quad Synchronous Step-Down Regulator: 2.25MHz, 300mA, 200mA, 200mA, 100mA FEATURES DESCRIPTION High Ef ciency: Up to 95% The LTC 3544 is a quad, high efficiency, monolithic Four Independent Regulators Provide Up to 300mA, synchronous buck regulator using a constant-frequency, 200mA, 200mA and 100mA Output Current current mode architecture. The four regulators operate 2.25V to 5.5V Input Voltage Range independently with separate run pins. The 2.25V to 5.5V 2.25MHz Constant-Frequency Operation input voltage range makes the LTC3544 well suited for No Schottky Diodes Required single Li-Ion/polymer battery-powered applications. Extremely Low Channel-to-Channel Transient 100% duty cycle provides low dropout operation, ex- Crosstalk tending battery runtime in portable systems. Low ripple Low Ripple (20mV ) Burst Mode Operation: Burst Mode operation increases ef ciency at light loads, P-P I = 70A (All Channels On) further extending battery runtime with typically only 20mV Q 0.8V Reference Allows Low Output Voltages of ripple. Shutdown Mode Draws <1A Supply Current Switching frequency is internally set to 2.25MHz, allowing Current Mode Operation for Excellent Line and Load the use of small surface mount inductors and capacitors. Transient Response The internal synchronous switches increase ef ciency Overtemperature Protected and eliminate the need for external Schottky diodes. Low Low Pro le (3mm 3mm) 16-Lead QFN Package output voltages are easily supported with the 0.8V feedback reference voltage. APPLICATIONS The LTC3544 is available in a low pro le (0.75mm) (3mm 3mm) QFN package. Cellular Telephones Personal Information Appliances , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Burst Mode is a registered trademark of Linear Technology Corporation. All other Wireless and DSL Modems trademarks are the property of their respective owners. Protected by U.S. Patents, including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131, 5994885. Digital Still Cameras Media Players Portable Instruments TYPICAL APPLICATION Ef ciency vs Load Current, 300mA High Ef ciency Quad Step-Down Converter Channel, All Other Channels Off 100 1 V IN 2.25V TO 5.5V 90 4.7F CER V PV EFFICIENCY CC IN 80 RUN200B RUN200A V 4.7H 3.3H V 0.1 OUT2 OUT3 70 1.5V 0.8V SW200B SW200A 93.1k LOSS 200mA 200mA 60 V V FB200B FB200A 4.7F 4.7F V = 2.5V 107k 100k 50 OUT 0.01 CER CER T = 25C A LTC3544 40 30 RUN300 RUN100 0.001 3.3H 10H V V OUT1 OUT4 20 1.2V V = 2.7V 1.8V SW300 SW100 IN 133k 59k 300mA 100mA V = 3.6V 10 IN V V FB300 FB100 V = 4.2V IN 4.7F GNDA PGND 4.7F 0 0.0001 107k 118k CER CER 0.0001 0.001 0.01 0.1 1 LOAD CURRENT (A) 3544 TA01b 3544B TA01a 3544fa 1 EFFICIENCY (%)LTC3544 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) Input Supply Voltage .....................................0.3V to 6V TOP VIEW RUNx ............................................. 0.3V to (V + 0.3V) IN V ................................................ 0.3V to (V + 0.3V) FBx IN 16 15 14 13 SWx ............................................... 0.3V to (V + 0.3V) IN V 1 12 RUN100 FB200B 300mA P-Channel Source Current (DC) (Note 8) ..450mA V 2 11 V FB200A FB100 300mA N-Channel Sink Current (DC) (Note 8) ......450mA 17 RUN200A 3 10 V FB300 200mA P-Channel Source Current (DC) (Note 8) ..300mA SW200B RUN300 4 9 200mA N-Channel Sink Current (DC) (Note 8) ......300mA 5 6 7 8 100mA P-Channel Source Current (DC) (Note 8) ..200mA 100mA N-Channel Sink Current (DC) (Note 8) ......200mA Peak 300mA SW Sink and Source Current UD PACKAGE 16-LEAD (3mm 3mm) PLASTIC QFN (Note 8) ................................................................600mA T = 125C, = 68C/W JMAX JA Peak 200mA SW Sink and Source Current EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB (Note 8) ................................................................400mA Peak 100mA SW Sink and Source Current (Note 8) ................................................................200mA Operating Temperature Range ...................40C to 85C Junction Temperature (Notes 3, 4) ........................ 125C Storage Temperature Range ....................65C to 125C ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3544EUD PBF LTC3544EUD TRPBF LCXM 16-Lead (3mm 3mm) Plastic QFN 40C to 85C LEAD BASED FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3544EUD LTC3544EUD TR LCXM 16-Lead (3mm 3mm) Plastic QFN 40C to 85C Consult LTC Marketing for parts speci ed with wider operating temperature ranges. For more information on lead free part marking, go to: