Datasheet LTC3418 (Analog Devices)

LTC3418 8A, 4MHz, Monolithic Synchronous Step-Down Regulator
FeaTures DescripTion
n
High Efficiency: Up to 95%
The LTC®3418 is a high efficiency, monolithic synchronous n
8A Output Current
step-down DC/DC converter utilizing a constant frequency, n
2.25V to 5.5V Input Voltage Range
current mode architecture. It operates from an input voltage n
Low RDS(ON) Internal Switch: 35mΩ
range of 2.25V to 5.5V and provides a regulated output n
Tracking Input to Provide Easy Supply Sequencing
voltage from 0.8V to 5V while delivering up to 8A of output n Programmable Frequency: 300kHz to 4MHz current. The internal synchronous power switch increases n 0.8V ±1% Reference Allows Low Output Voltage efficiency and eliminates the need for an external Schottky n Quiescent Current: 380µA diode. Switching frequency is set by an external resistor n Selectable Forced Continuous/Burst Mode® Operation or can be synchronized to an external clock. OPTI-LOOP® with Adjustable Burst Clamp compensation allows the transient response to be optimized n Synchronizable Switching Frequency over a wide range of loads and output capacitors. n Low Dropout Operation: 100% Duty Cycle The LTC3418 can be configured for either Burst Mode n Power Good Output Voltage Monitor operation or forced continuous operation. Forced con- n Overtemperature Protected tinuous operation reduces noise and RF interference n 38-Lead Low Profile (0.75mm) Thermally Enhanced QFN (5mm while Burst Mode operation provides high efficiency by × 7mm) Package reducing gate charge losses at light loads. In Burst Mode operation, external control of the burst clamp level allows
applicaTions
the output voltage ripple to be adjusted according to the requirements of the application. A tracking input in the n Microprocessor, DSP and Memory Supplies LTC3418 allows for proper sequencing with respect to n Distributed 2.5V, 3.3V and 5V Power Systems another power supply. n Automotive Applications n Point of Load Regulation L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. n Notebook Computers Burst Mode and OPTI-LOOP are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131, 6724174.
Typical applicaTion 2.5V/8A Step-Down Regulator Efficiency and Power Loss vs Load Current
100 100000 VIN CIN 2.8V TO 5.5V 47µF 90 EFFICIENCY SV 10000 IN TRACK PV ×4 IN 0.2µH VOUT 80 POWER LOSS (mW) RT SW 2.5V 2.2M 70 30.1k LTC3418 COUT 8A 1000 100µF PGOOD ×2 60 RUN/SS PGND POWER LOSS 100 1000pF I 50 TH SGND EFFICIENCY (%) 4.99k SYNC/MODE VFB 40 10 820pF 332Ω 4.32k 30 VIN = 3.3V 3418 TA01a VOUT = 2.5V 20 1 1.69k 0.01 0.1 1 10 LOAD CURRENT (A) 3418 TA01b 3418fc For more information www.linear.com/LTC3418 1 Document Outline Description Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Typical Application Related Parts