LTC3890-3 60V Low IQ, Dual, 2-Phase Synchronous Step-Down DC/DC Controller FeaTuresDescripTion n Wide VIN Range: 4V to 60V (65V Abs Max) The LTC®3890-3 is a high performance dual step-down n Low Operating IQ: 50µA (One Channel On) switching regulator DC/DC controller that drives all n Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 24V N-channel synchronous power MOSFET stages. A constant n RSENSE or DCR Current Sensing frequency current mode architecture allows a phase- n Out-of-Phase Controllers Reduce Input Capacitance lockable frequency of up to 850kHz. Power loss and supply and Power Supply Induced Noise noise are minimized by operating the two controller output n Phase-Lockable Frequency (75kHz to 850kHz) stages out-of-phase. n Programmable Fixed Frequency (50kHz to 900kHz) The 50μA no-load quiescent current extends operating life n Selectable Continuous, Pulse-Skipping or Low Ripple in battery-powered systems. OPTI-LOOP® compensation Burst Mode® Operation at Light Loads allows the transient response to be optimized over a wide n Very Low Dropout Operation: 99% Duty Cycle range of output capacitance and ESR values. A wide 4V n Adjustable Output Voltage Soft-Start or Tracking to 60V input supply range encompasses a wide range of n Power Good Output Voltage Monitor intermediate bus voltages and battery chemistries. n Low Shutdown IQ: <14µA Independent TRACK/SS pins for each controller ramp the n Internal LDO Powers Gate Drive from VIN or EXTVCC output voltages during start-up. Current mode control limits n Narrow SSOP Package the inductor current during short-circuit conditions. The applicaTions PLLIN/MODE pin selects among Burst Mode operation, pulse-skipping mode, or continuous conduction mode at n Automotive Always-On Systems light loads. n Battery Operated Digital Devices n Distributed DC Power Systems For versions with different and/or additional features, see L the LTC3890 family summary, Table 1, in the Pin Functions , LT, LTC, LTM, Linear Technology, Burst Mode, OPTI-LOOP, PolyPhase and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the section of this data sheet. property of their respective owners. Protected by U.S. Patents including 5481178, 5705919, 5929620, 6100678, 6144194, 6177787, 6304066, 6580258, 7230497. Typical applicaTionHigh Efficiency Dual 8.5V/3.3V Output Step-Down ConverterEfficiency and Power Lossvs Output Current VIN 9V TO 60V 100 10000 4.7µF 22µF VIN = 12V V 90 VOUT = 3.3V IN INTVCC TG1 TG2 80 1000 0.1µF 0.1µF POWER LOSS (mW) 4.7µH BOOST1 BOOST2 70 8µH SW1 SW2 60 100 BG1 BG2 50 LTC3890-3 PGND 40 10 EFFICIENCY (%) SENSE1+ 30 SENSE2+ 20 1 0.008Ω 0.01Ω 10 V SENSE1– SENSE2– V OUT1 OUT2 3.3V 8.5V V 0 0.1 FB1 VFB2 5A 100k 0.0001 0.001 0.01 0.1 1 10 ITH1 ITH2 100k 3A 470µF 1000pF OUTPUT CURRENT (A) 1000pF TRACK/SS1 SGND TRACK/SS2 330µF 10.5k 38903 TA01b 31.6k 34.8k 34.8k 0.1µF 0.1µF 38903 TA01a 38903f For more information www.linear.com/3890-3 1 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Typical Performance Characteristics Operation Package Description Typical Application