LTC7124 17V, Dual 3.5A Synchronous Step-Down Regulator with Ultralow Quiescent Current FEATURESDESCRIPTION n Wide VIN Range: 3.1V to 17V The LTC®7124 is a dual channel, 3.5A per output, high n Wide VOUT Range: 0.6V to 99% VIN efficiency monolithic step-down regulator capable of n Dual Step-Down Outputs: 3.5A Per Channel operating from input supplies up to 17V. The program- n Integrated 80mΩ/40mΩ N-Channel MOSFETs mable switching frequency ranges from 500kHz to 4MHz Provide Up to 95% Efficiency with a ±25% external clock synchronization capability n No-Load I around the programmed frequency. The regulator features Q < 8μA with Both Channels Enabled;I ultralow quiescent current for high efficiency over a wide Q < 5.5μA with Only One Channel Enabled n Programmable Frequency (500kHz to 4MHz) with VOUT range. ±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 VIN while delivering up to 3.5A 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 n conductive noise. The LTC7124 is offered in a thermally Battery-Powered Systems n enhanced, low profile 24-lead 3mm × 5mm QFN package Point-of-Load Supplies n Portable Instruments L, LT, LTC, LTM, Burst Mode, Linear Technology, the Linear logo, LTpowerCAD and LTspice are registered trademarks of Analog Devices, Inc. All other trademarks are the property of their n Handheld Scanners respective owners. Protected by U.S. Patents, including 5481178, 6580258, 6498466, 6611131, 6177787, 5705919, 5847554. TYPICAL APPLICATION1.8V/3.3V 1MHz Step-Down RegulatorEfficiency & Power Lossvs Load Current at 1MHz VIN 10.8V TO 13.2V CIN 100 1.6 47µF VIN1 VIN2 x2 RUN1 90 INTVCC C RUN2 INTVCC MODE/SYNC 80 2.2µF ITH1 1.2 ITH2 70 POWER LOSS (W) RT LTC7124 R 60 RT BOOST1 BOOST2 100k C 50 0.8 BOOST1 CBOOST2 0.1µF 0.1µF 40 L EFFICIENCY (%) 1 L2 30 VIN = 12V 1.2µH 1.8µH 0.4 V V OUT1 SW1 SW2 VOUT2 OUT = 5.0V 20 1.8V AT 3.5A V C 3.3V AT 3.5A OUT = 3.3V FF1 R1 R3 CFF2 10 V 22pF OUT = 2.5V 619k 619k 16pF VOUT = 1.8V FB1 FB2 0 0 C 0 0.5 1 1.5 2 2.5 3 3.5 OUT1 COUT2 R2 ILIM GND R4 100µF 100µF LOAD CURRENT (A) 309k 7124 TA01a 7124 TA01 137k 7124fa For more information www.linear.com/LTC7124 1