Datasheet LTC3374 (Analog Devices)

LTC3374 8-Channel Parallelable 1A Buck DC/DCs
FEATURES DESCRIPTION
n
8-Channel Independent Step-Down DC/DCs
The LTC®3374 is a high efficiency multioutput power sup- n
Master-Slave Configurable for Up to 4A per Output
ply IC. The DC/DCs consist of eight synchronous buck
Rail with a Single Inductor
converters (1A each) all powered from independent 2.25V n
Independent VIN Supplies for Each DC/DC
to 5.5V input supplies.
(2.25V to 5.5V)
The DC/DCs may be used independently or in parallel to n
All DC/DCs Have 0.8V to VIN Output Range
achieve higher currents of up to 4A per output with a shared n
Precision Enable Pin Thresholds for Autonomous
inductor. The common buck switching frequency may be
Sequencing
programmed with an external resistor, synchronized to an n 1MHz to 3MHz Programmable/Synchronizable external oscillator, or set to a default internal 2MHz clock. Oscillator Frequency (2MHz Default) The operating mode for all DC/DCs may be programmed n Die Temperature Monitor Output via the MODE pin. n Thermally-Enhanced 38-Lead QFN (5mm × 7mm) and TSSOP Packages To reduce input noise the buck converters are phased in 90° steps. Precision enable pin thresholds provide reli-
APPLICATIONS
able power-up sequencing. The LTC3374 is available in a compact 38-lead 5mm × 7mm QFN package as well as a n General Purpose Multichannel Power Supplies 38-lead TSSOP package. n Industrial/Automotive/Communications L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.
TYPICAL APPLICATION 8-Channel 1A Multioutput Buck Regulator
VIN1 2.2µH 0.8V TO VIN1 2.7V TO 5.5V VCC BUCK1 UP TO 1A 22µF
Buck Efficiency vs ILOAD
100 MASTER LTC3374 90 VIN2 2.2µH SLAVE 80 BUCK2 0.8V TO VIN2 UP TO 1A 70 22µF 60 EN1 50 EN2 MASTER 40 1A BUCK EN3 • EFFICIENCY (%) 2A BUCK EN4 • • 30 3A BUCK V EN5 IN7 2.2µH SLAVE 4A BUCK BUCK7 0.8V TO VIN7 EN6 20 UP TO 1A FORCED CONTINUOUS MODE EN7 10µF 10 VIN = 3.3V, VOUT = 1.8V EN8 fOSC = 1MHz, L = 3.3µH PGOOD_ALL MASTER 0 TEMP 0 1000 2000 3000 4000 MODE LOAD CURRENT (mA) VIN8 2.2µH SLAVE 0.8V TO V BUCK8 IN8 3374 TA01b UP TO 1A 10µF SYNC RT 3374 TA01a 3374fc For more information www.linear.com/LTC3374 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Buck Switching Regulators Buck Regulators with Combined Power Stages Power Failure Reporting Via PGOOD_ALL Pin Temperature Monitoring and Overtemperature Protection Programming the Operating Frequency Applications Information Buck Switching Regulator Output Voltage and Feedback Network Buck Regulators Combined Buck Regulators Input and Output Decoupling Capacitor Selection PCB Considerations Package Description Revision History Typical Application Related Parts