POWER LOSS (W) LTC3807 Low I , Synchronous Q Step-Down Controller with 24V Output Voltage Capability FEATURES DESCRIPTION n Wide V Range: 4V to 38V (40V Abs Max) The LTC 3807 is a high performance step-down switching IN n Low Operating I : 50A regulator DC/DC controller that drives an all N-channel Q n Wide Output Voltage Range: 0.8V V 24V synchronous power MOSFET stage. A constant fre- OUT n R or DCR Current Sensing quency current mode architecture allows a phase-lockable SENSE n Phase-Lockable Frequency (75kHz to 750kHz) frequency of up to 750kHz. n Programmable Fixed Frequency (50kHz to 900kHz) The 50A no-load quiescent current extends operating run n Selectable Continuous, Pulse-Skipping or Low Ripple time in battery-powered systems. OPTI-LOOP compensa- Burst Mode Operation at Light Load tion allows the transient response to be optimized over n Selectable Current Limit a wide range of output capacitance and ESR values. The n Very Low Dropout Operation: 99% Duty Cycle LTC3807 features a precision 0.8V reference and power n Adjustable Output Voltage Soft-Start or Tracking good output indicator. A wide 4V to 38V input supply range n Power Good Output Voltage Monitor encompasses a wide range of intermediate bus voltages n Output Overvoltage Protection and battery chemistries. The output voltage of the LTC3807 n Low Shutdown I : 14A Q can be programmed between 0.8V to 24V. n Internal LDO Powers Gate Drive from V or EXTV IN CC n The TRACK/SS pin ramps the output voltages during No Current Foldback During Start-Up n start-up. Current foldback limits MOSFET heat dissipation Small 20-Pin 3mm 4mm QFN and TSSOP Packages during short-circuit conditions. The PLLIN/MODE pin se- lects among Burst Mode operation, pulse-skipping mode, APPLICATIONS or continuous conduction mode at light loads. n Automotive Always-On Systems L, LT, LTC, LTM, OPTI-LOOP, Burst Mode, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their n Battery Powered Digital Devices respective owners. Patents, including 5481178, 5705919, 6611131, 6498466, 6580258, n 7230497. Distributed DC Power Systems TYPICAL APPLICATION Efficiency and Power Loss vs High Efficiency 12V/10A Step-Down Converter Output Current V IN 100 10 12.5V TO 38V V = 24V IN 22F V = 12V 90 OUT V INTV IN CC EFFICIENCY 2.2F 80 1 LTC3807 70 TG 60.4k 60 FREQ 0.1F 0.1 4.7nF BOOST 50 POWER LOSS 10H 15.4k 4m V OUT ITH 40 SW 12V 47pF 10A 30 150F BG 0.01 20 0.1F PGND TRACK/SS 10 + SENSE 0 0.001 V EXTV OUT CC 100k 0.0001 0.001 0.01 0.1 1 10 SENSE I (A) SGND OUT 3807 TA01b V FB FIGURE 13 CIRCUIT 100k Burst Mode OPERATION PGOOD INTV CC 6.98k 3807 TA01a 3807fa 1 For more information www.linear.com/LTC3807 EFFICIENCY (%)LTC3807 ABSOLUTE MAXIMUM RATINGS (Note 1) ITH, V Voltages ......................................... 0.3V to 6V Input Supply Voltage (V ) ......................... 0.3V to 40V IN FB PGOOD Voltage ............................................ 0.3V to 6V Topside Driver Voltage (BOOST) ................ 0.3V to 46V TRACK/SS Voltage ....................................... 0.3V to 6V Switch Voltage (SW) ..................................... 5V to 40V Operating Junction Temperature Range (Notes 2, 3) (BOOST-SW) ................................................ 0.3V to 6V LTC3807E, LTC3807I ......................... 40C to 125C RUN ............................................................. 0.3V to 8V LTC3807H .......................................... 40C to 150C Maximum Current Sourced into Pin from LTC3807MP ....................................... 55C to 150C Source > 8V ......................................................100A + Maximum Junction Temperature (Notes 2, 3) SENSE , SENSE Voltages ......................... 0.3V to 28V LTC3807E, LTC3807I ........................................ 125C PLLIN/MODE, INTV Voltages ................... 0.3V to 6V CC LTC3807H, LTC3807MP ................................... 150C I , FREQ Voltages ..............................0.3V to INTV LIM CC Storage Temperature Range .................. 65C to 150C EXTV ...................................................... 0.3V to 14V CC PIN CONFIGURATION TOP VIEW TOP VIEW TRACK/SS 1 20 I LIM 20 19 18 17 FREQ 2 19 V IN PLLIN/MODE 3 18 PGND PLLIN/MODE 1 16 PGND SGND 4 17 EXTV SGND 2 15 EXTV CC CC SGND 3 14 INTV SGND 5 21 16 INTV 21 CC CC SGND SGND RUN 4 13 BG RUN 6 15 BG BOOST SENSE 5 12 SENSE 7 14 BOOST + SENSE 6 11 SW + SENSE 8 13 SW 7 8 9 10 V 9 TG 12 FB ITH 10 11 PGOOD FE PACKAGE 20-LEAD PLASTIC TSSOP UDC PACKAGE 20-LEAD (3mm 4mm) PLASTIC QFN T = 150C, = 38C/W JMAX JA EXPOSED PAD (PIN 21) IS SGND, MUST BE SOLDERED TO PCB T = 150C, = 43C/W JMAX JA EXPOSED PAD (PIN 21) IS SGND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3807EUDC PBF LTC3807EUDC TRPBF LGSG 20-Lead (3mm 4mm) Plastic QFN 40C to 125C LTC3807IUDC PBF LTC3807IUDC TRPBF LGSG 20-Lead (3mm 4mm) Plastic QFN 40C to 125C LTC3807HUDC PBF LTC3807HUDC TRPBF LGSG 20-Lead (3mm 4mm) Plastic QFN 40C to 150C LTC3807MPUDC PBF LTC3807MPUDC TRPBF LGSG 20-Lead (3mm 4mm) Plastic QFN 55C to 150C LTC3807EFE PBF LTC3807EFE TRPBF LTC3807FE 20-Lead Plastic TSSOP 40C to 125C LTC3807IFE PBF LTC3807IFE TRPBF LTC3807FE 20-Lead Plastic TSSOP 40C to 125C 3807fa 2 For more information www.linear.com/LTC3807 V FREQ FB TRACK/SS ITH PGOOD I LIM TG V IN