Datasheet LTC3623 (Analog Devices)

LTC3623 15V, ±5A Rail-to-Rail Synchronous Buck Regulator
FeaTures DescripTion
n Single Resistor Programmable VOUT: 0V to VIN – 0.5V The LTC®3623 is a high efficiency, monolithic synchro- n Silent Switcher® Architecture nous buck regulator in which the output voltage is pro- n IISET Accuracy: ±1% grammed with a single external resistor. The accurate n Tight VOUT Regulation Across VOUT Range internally generated 50µA current source on the ISET pin n Output Current Monitor Accuracy: ±5% allows the user to program an output voltage from 0V n Programmable Wire Drop Compensation to 0.5V below VIN. The user can also directly drive the n Easy to Parallel for Higher Current and Heat Spreading ISET pin with an external voltage supply to program the n Input Supply Voltage Regulation Loop converter’s VOUT. The VOUT voltage is fed directly back n High Efficiency: Up to 96% to the error amplifier to be regulated to the ISET voltage. n Output Current: ±5A The operating supply voltage range for the SVIN pin is from n Integrated N-MOSFETs (60mΩ Top & 30mΩ Bottom) 15V down to 4V, while the PVIN pin’s voltage range is 15V n Adjustable Switching Frequency: 400kHz to 4MHz down to 1.5V, making it suitable for dual Li-Ion batteries n VIN Range: 4V to 15V and for taking power from a 12V or 5V rail. n Current Mode Operation for Excellent Line and Load The operating frequency is programmable from 400kHz Transient Response to 4MHz with an external RT resistor. Higher switching fre- n Shutdown Mode Draws Less Than 1µA Supply Current quency allows the use of smaller surface mount inductors n Low Profile 24-Lead 3mm × 5mm QFN Package while lower frequency allows for higher power efficiency. The unique constant-frequency/controlled on-time
applicaTions
architecture is ideal for high step-down ratio applications n Tracking Supply or DDR Memory Supply that are operating at high frequency while demanding fast n ASIC Substrate Biasing transient response. n Point-of-Load (POL) Power Supply L, LT, LTC, LTM, OPTI-LOOP, Silent Switcher, Linear Technology and the Linear logo are n Portable Instruments, Battery-Powered Equipment registered trademarks of Analog Devices, Inc. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 5481178, 5705919, 5847554, 6580258. n Thermo Electric Cooler (TEC) Systems
Typical applicaTion Efficiency and Power Loss
VIN
vs Load Current
(5.5V TO 15V) PV BOOST IN 100 3.0 SV V IN LTC3623EUD IN = 12V 90 V 0.1µF OUT = 5V 80 2.4 RUN 50µA PWM DCM 70 POWER LOSS (W) CONTROL 22µF 1µH V AND OUT SW POWER 5V 60 LOSS 1.8 ERROR SWITCH 5A AMP DRIVER 50 47µF CCM 40 1.2 PGND EFFICIENCY (%) LOAD 30 VOUT 20 0.6 I CCM OUT/50k 10 VIN_REG V CC DCM 0 0 ISET IMON MODE/ SYNC INT RT PGFB ITH PGOOD 0.001 0.01 0.1 1 10 3623 TA01 LOAD CURRENT (A) 3623 TA01a 100k 10k 1µF 0.1µF 10nF 3623fa For more information www.linear.com/LTC3623 1