POWER LOSS (W) LTC7124 17V, Dual 3.5A Synchronous Step-Down Regulator with Ultralow Quiescent Current FEATURES DESCRIPTION n Wide V Range: 3.1V to 17V The LTC 7124 is a dual channel, 3.5A per output, high IN n Wide V Range: 0.6V to 99% V efficiency monolithic step-down regulator capable of OUT IN n operating from input supplies up to 17V. The program- Dual Step-Down Outputs: 3.5A Per Channel n mable switching frequency ranges from 500kHz to 4MHz Integrated 80m/40m N-Channel MOSFETs with a 25% external clock synchronization capability Provide Up to 95% Efficiency n around the programmed frequency. The regulator features No-Load I < 8A with Both Channels Enabled Q ultralow quiescent current for high efficiency over a wide I < 5.5A with Only One Channel Enabled Q V range. n OUT Programmable Frequency (500kHz to 4MHz) with 25% Frequency Synchronization Range The step-down regulator operates from an input voltage n Configurable for a 2-Phase Single Output at Up to 7A range of 3.1V to 17V and provides an adjustable output n 1.0% Output Voltage Accuracy range from 0.6V to 99% of V while delivering up to 3.5A IN n Current Mode Operation for Excellent Line and Load of output current per channel. A user selectable mode input Transient Response is provided to allow the user to trade off output ripple for n Internal or Programmable External Loop Compensation light load efficiency Burst Mode operation provides the n Available in a 3mm 5mm QFN-24 Package highest efficiency at light loads, while forced continuous operation provides the lowest output ripple. The LTC7124 APPLICATIONS includes spread spectrum modulation for low radiated and conductive noise. The LTC7124 is offered in a thermally n Battery-Powered Systems enhanced, low profile 24-lead 3mm 5mm QFN package n Point-of-Load Supplies L, LT, LTC, LTM, Burst Mode, Linear Technology, the Linear logo, LTpowerCAD and LTspice n Portable Instruments are registered trademarks of Analog Devices, Inc. All other trademarks are the property of their n respective owners. Protected by U.S. Patents, including 5481178, 6580258, 6498466, 6611131, Handheld Scanners 6177787, 5705919, 5847554. TYPICAL APPLICATION 1.8V/3.3V 1MHz Step-Down Regulator Efficiency & Power Loss vs Load Current at 1MHz V IN 10.8V TO 13.2V C IN 100 1.6 47F V V IN1 IN2 90 x2 RUN1 INTV CC C INTVCC RUN2 MODE/SYNC 80 2.2F 1.2 ITH1 70 ITH2 RT 60 LTC7124 R RT BOOST1 BOOST2 100k 50 0.8 C C BOOST1 BOOST2 0.1F 0.1F 40 L L 1 V = 12V 2 30 IN 1.2H 1.8H 0.4 V = 5.0V OUT V V OUT1 OUT2 20 SW1 SW2 V = 3.3V 1.8V AT 3.5A 3.3V AT 3.5A OUT C C FF1 R1 R3 FF2 10 V = 2.5V OUT 22pF 16pF 619k 619k V = 1.8V OUT 0 0 FB1 FB2 0 0.5 1 1.5 2 2.5 3 3.5 C C OUT1 OUT2 R2 R4 LOAD CURRENT (A) ILIM GND 100F 100F 7124 TA01a 309k 137k 7124 TA01 7124fa 1 For more information www.linear.com/LTC7124 EFFICIENCY (%)25 26 GND GND LTC7124 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW V , V (Note 2) ..................................... 0.3V to 17V IN1 IN2 RUN1, RUN2 .............................................. 0.3V to 17V MODE/SYNC ................................0.3V to INTV +0.3V CC 24 23 22 21 I , RT ........................................0.3V to INTV +0.3V LIM CC GND 1 20 SW1 ITH1, ITH2 ....................................0.3V to INTV +0.3V GND 2 19 SW1 CC V 3 18 BOOST1 PGOOD1, PGOOD2 ....................................... 0.3V to 6V IN1 I 4 17 MODE/SYNC LIM FB1, FB2 ....................................................... 0.3V to 6V RT INTV 5 16 CC Operating Junction Temperature Range V 6 15 BOOST2 IN2 (Note 3) .............................................. 40C to 125C GND 7 14 SW2 Storage Temperature Range .................. 65C to 150C GND 8 13 SW2 9 10 11 12 UDD PACKAGE VARIATION: AA 24-LEAD (3mm 5mm) PLASTIC QFN T = 150C, = 22C/W JMAX JA EXPOSED PAD (PINS 25 & 26) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION