POWER LOSS (W) LTC3822-1 TM No R , Low Input SENSE Voltage, Synchronous Step-Down DC/DC Controller FEATURES DESCRIPTION Dual N-Channel MOSFET Synchronous Drive The LTC 3822-1 is a synchronous step-down switching No Current Sense Resistor Required regulator controller that drives external N-channel power Optimized for 3.3V and Li-Ion Applications MOSFETs using few external components. The constant IN Constant Frequency Current Mode Operation for frequency current mode architecture with MOSFET V DS Excellent Line and Load Transient Response sensing eliminates the need for sense resistors and im- 1% 0.6V Reference proves ef ciency. Low Dropout Operation: 99% Duty Cycle Burst Mode operation provides high ef ciency at light Phase-Lockable or Adjustable Frequency: loads. The 99% maximum duty cycle provides low dropout 250kHz to 750kHz operation, extending operating time in battery-powered Internal Soft-Start Circuitry systems. Tracking and Adjustable Soft-Start Input The operating frequency can be programmed up to 750kHz, Selectable Maximum Peak Current Sense Threshold allowing the use of small surface mount inductors and ca- Selectable Burst Mode / Forced Continuous/Pulse pacitors. For noise sensitive applications, the LTC3822-1 Skipping Mode at Light Load can be synchronized to an external clock from 250kHz to Digital RUN Control Pin 750kHz. Output Overvoltage Protection Micropower Shutdown: I = 7.5A Q The LTC3822-1 is available in the tiny footprint thermally Tiny Thermally Enhanced 12-Pin (3mm 3mm) DFN enhanced 12-pin DFN package or 16-pin narrow SSOP or 16-Pin Narrow SSOP Packages package. LTC3822-1 LTC3822 APPLICATIONS Light Load Continuous, Discontinuous Discontinuous Mode Operation or Burst Mode Operation Single Cell Li-Ion Powered Systems Package DD12 (3mm 3mm), GN16 DD10 (3mm 3mm), 3.3V Systems IN MS10E , LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology Tracking/Soft-Start Yes Internal Soft-Start Only Corporation. No R is a trademark of Linear Technology Corporation. SENSE External Sync Yes No All other trademarks are the property of their respective owners. Protected by Patents, including 5481178, 5929620, 6580258, 6304066, 5847554, PGOOD Pin GN16 Only No 6611131, 6498466, 5705919. Ef ciency/Power Loss vs Load Current TYPICAL APPLICATION 100 10 90 V Burst Mode IN IPRG V IN 80 3.3V EFFICIENCY 47F 1 RUN 2 70 PLLLPF TG 60 LTC3822-1 0.47H V I SW OUT TH 50 0.1 1.8V BOOST 47F Burst Mode 8A 10.2k 40 2 POWER LOSS SYNC/MODE 0.1F 30 1nF TRACK/SS 0.01 20 GND BG V = 3.3V IN 10 V = 1.8V V GND OUT FB FIGURE 10 CIRCUIT 0 0.001 38221 TA01 10 100 1000 10000 59k 118k LOAD CURRENT (mA) 38221 TA01b 38221f 1 EFFICIENCY (%)LTC3822-1 ABSOLUTE MAXIMUM RATINGS (Note 1) Input Supply Voltage (V ) ........................ 0.3V to 4.5V Storage Ambient Temperature Range IN BOOST Voltage .......................................... 0.3V to 10V DD ..................................................... 65C to 125C PLLLPF, RUN, IPRG, SYNC/MODE, GN ..................................................... 65C to 150C TRACK/SS Voltages .......................0.3V to (V + 0.3V) Junction Temperature (Note 3) ............................. 125C IN V , I Voltages ....................................... 0.3V to 2.4V Lead Temperature (Soldering, 10 sec) FB TH SW Voltage ............................................ 2V to V + 1V GN Only ............................................................300C IN Operating Temperature Range (Note 2) ... 40C to 85C PACKAGE/ORDER INFORMATION TOP VIEW TOP VIEW GND 1 16 SW 1 12 SW PLLLPF 2 15 SENSE PLLLPF 2 V SYNC/MODE 11 IN SYNC/MODE 3 14 V IN 3 BOOST TRACK/SS 10 PGOOD 4 13 BOOST 13 4 TG V 9 FB TRACK/SS 5 12 TG I 5 8 BG TH V 6 11 BG FB 6 RUN 7 IPRG I 7 10 IPRG TH DD PACKAGE RUN 8 9 GND 12-LEAD (3mm 3mm) PLASTIC DFN T = 125C, = 43C/W JMAX JA GN PACKAGE EXPOSED PAD (PIN 13) IS GND, MUST BE SOLDERED TO PCB 16-LEAD PLASTIC SSOP T = 125C, = 110C/W JMAX JA ORDER PART NUMBER DD PART MARKING ORDER PART NUMBER GN PART MARKING LTC3822EDD-1 LCMS LTC3822EGN-1 38221 Order Options Tape and Reel: Add TR Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Lead Free Part Marking: