LTC3704 TM Wide Input Range, No R SENSE Positive-to-Negative DC/DC Controller FEATURES DESCRIPTIO High Efficiency Operation (No Sense The LTC 3704 is a wide input range, current mode, Resistor Required) positive-to-negative DC/DC controller that drives an Wide Input Voltage Range: 2.5V to 36V N-channel power MOSFET and requires very few external Current Mode Control Provides Excellent Transient components. Intended for low to high power applications, Response it eliminates the need for a current sense resistor by High Maximum Duty Cycle (Typ 92%) utilizing the power MOSFETs on-resistance, thereby maxi- 1% Internal Voltage Reference mizing efficiency. 2% RUN Pin Threshold with 100mV Hysteresis The ICs operating frequency can be set with an external Micropower Shutdown: I = 10A Q resistor over a 50kHz to 1MHz range, and can be synchro- Programmable Switching Frequency nized to an external clock using the MODE/SYNC pin. (50kHz to 1MHz) with One External Resistor Burst Mode operation at light loads, a low minimum Synchronizable to an External Clock Up to 1.3 f OSC operating supply voltage of 2.5V and a low shutdown User-Controlled Pulse Skip or Burst Mode Operation quiescent current of 10 A make the LTC3704 ideally Internal 5.2V Low Dropout Voltage Regulator suited for battery-operated systems. Capable of Operating with a Sense Resistor for High For applications requiring constant frequency operation, Output Voltage Applications (V >36V) DS the Burst Mode operation feature can be defeated using Small 10-Lead MSOP Package the MODE/SYNC pin. Higher than 36V switch voltage U APPLICATIO S applications are possible with the LTC3704 by connecting the SENSE pin to a resistor in the source of the power SLIC Power Supplies MOSFET. Telecom Power Supplies The LTC3704 is available in the 10-lead MSOP package. Portable Electronic Equipment , LTC, LT and LTM are registered trademarks of Linear Technology Corporation. Burst Cable and DSL Modems Mode is a registered trademark of Linear Technology Corporation. No R is a SENSE registered trademark of Linear Technology Corporation. All other trademarks are the Router Supplies property of their respective owners. Protected by U.S. Patents including 5847554, 5731694. TYPICAL APPLICATIO V IN 5V to 15V Conversion Efficiency R1 L1* V OUT 100 1M 5.0V 3A to 5A 90 RUN SENSE L2* C DC V = 5V IN I V 80 TH IN 47F LTC3704 V = 15V IN 70 R C C NFB INTV OUT CC 3k 100F 60 FREQ GATE M1 (X2) V = 10V IN 50 MODE/SYNC GND D1 C C1 4.7nF 40 R T C C VCC IN 80.6k 4.7F 47F 30 1% GND R R FB2 FB1 3704 TA01 20 1.21k 3.65k 0.001 0.01 0.1 1.0 10 1% 1% OUTPUT CURRENT (A) C , C : TDK C5750X5R1C476M D1: MBRD835L (ON SEMICONDUCTOR) 3704 TA01b IN DC C : TDK C5750X5R0J107M L1, L2: BH ELECTRONICS BH510-1009 OUT C : TAIYO YUDEN LMK316BJ475ML M1: Si4884 (SILICONIX/VISHAY) VCC Figure 1. High Efficiency Positive to Negative Supply 3704fb 1 EFFICIENCY (%) U ULTC3704 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) V Voltage ............................................... 0.3V to 36V TOP VIEW IN RUN 1 10 SENSE INTV Voltage ........................................... 0.3V to 7V CC I 2 9 V TH IN INTV Output Current ........................................ 50mA NFB 3 8 INTV CC CC FREQ 4 7 GATE GATE Voltage ........................... 0.3V to V + 0.3V INTVCC MODE/ 5 6 GND SYNC I Voltage ............................................... 0.3V to 2.7V TH MS PACKAGE 10-LEAD PLASTIC MSOP NFB Voltage .............................................. 2.7V to 2.7V T = 125C, = 120C/ W JMAX JA RUN, MODE/SYNC Voltages ....................... 0.3V to 7V FREQ Voltage ............................................0.3V to 1.5V ORDER PART MS PART MARKING SENSE Pin Voltage ................................... 0.3V to 36V NUMBER Operating Temperature Range (Note 2) .. 40C to 85C LTC3704EMS LTYT LTC3704E ............................................ 40C to 85C LTC3704IMS LTCFW LTC3704I........................................... 40C to 125C Order Options Tape and Reel: Add TR Junction Temperature (Note 3)............................ 125C Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Storage Temperature Range ................. 65C to 150C Lead Free Part Marking: