Datasheet LTC3614 (Analog Devices)

LTC3614 4A, 4MHz Monolithic Synchronous Step-Down DC/DC Converter
FeaTures DescripTion
n
4A Output Current
The LTC®3614 is a low quiescent current monolithic syn- n
2.25V to 5.5V Input Voltage Range
chronous buck regulator using a current mode, constant n
Low Output Ripple Burst Mode
®
Operation: IQ = 75µA
frequency architecture. The no-load DC supply current n
±1% Output Voltage Accuracy
in sleep mode is only 75µA while maintaining the output n
Output Voltage Down to 0.6V
voltage (Burst Mode operation) at no load, dropping to n
High Efficiency: Up to 95%
zero current in shutdown. The 2.25V to 5.5V input supply n Low Dropout Operation: 100% Duty Cycle voltage range makes the LTC3614 ideally suited for single n Programmable Slew Rate on SW Node Reduces Li-Ion as well as fixed low voltage input applications. 100% Noise and EMI duty cycle capability provides low dropout operation, n Adjustable Switching Frequency: Up to 4MHz extending the operating time in battery-powered systems. n Optional Active Voltage Positioning (AVP) with The operating frequency is externally programmable up to Internal Compensation 4MHz, allowing the use of small surface mount inductors. n Selectable Pulse-Skipping/Forced Continuous/Burst For switching-noise-sensitive applications, the LTC3614 Mode Operation with Adjustable Burst Clamp can be synchronized to an external clock at up to 4MHz. n Programmable Soft-Start n Inputs for Start-Up Tracking or External Reference Forced continuous mode operation in the LTC3614 reduces n DDR Memory Mode, I noise and RF interference. Adjustable compensation allows OUT = ±3A n Available in a 24-Pin 3mm × 5mm QFN the transient response to be optimized over a wide range Thermally Enhanced Package of loads and output capacitors.
applicaTions
The internal synchronous switch increases efficiency and eliminates the need for an external catch diode, saving n Point-of-Load Supplies external components and board space. The LTC3614 n Distributed Power Supplies is offered in a leadless 24-pin 3mm × 5mm thermally n Portable Computer Systems enhanced QFN package. n DDR Memory Termination L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks n Handheld Devices of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 6580258, 5481178, 5994885, 6304066, 6498466, 6611131.
Typical applicaTion Efficiency and Power Loss vs Load Current
100 VIN 2.7V TO 5.5V 10µF 90 SV ×4 IN PVIN 80 1 RUN SRLIM/DDR 70 POWER LOSS (W) TRACK/SS 60 0.1 RT/SYNC 330nH VOUT LTC3614 SW 2.5V 50 PGOOD SGND 4A 47µF 40 0.01 ITH PGND EFFICIENCY (%) MODE V ×2 30 FB 665k 3614 TA01a 20 0 VIN = 2.8V 210k 10 VIN = 3.3V V V 0 OUT = 2.5V IN = 5V 1 10 100 1000 10000 OUTPUT CURRENT (mA) 3614 TA01b 3614fc For more information www.linear.com/LTC3614 1 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Block Diagram Operation Applications Information Package Description Typical Application Related Parts