Datasheet LTC3815 (Analog Devices)

LTC3815 6A Monolithic Synchronous DC/DC Step-Down Converter with PMBus Interface
FEATURES DESCRIPTION
n
2.25V to 5.5V Input Voltage Range
The LTC®3815 is a high efficiency, 6A monolithic synchro- n
±1% Total Output Voltage Accuracy Over
nous buck regulator using a phase lockable controlled
Temperature at VIN = 3.3V or 5V
on-time, current mode architecture. The output voltage n
Single Resistor-Programmable Output Voltage
is programmable from 0.4V to 72% of VIN with a single n
PMBus Compliant Serial Interface:
external resistor or an external voltage reference through n
Programmable Output Voltage Margining:
the reference input (REF) pin. The output voltage can be
Up to ±25% VOUT Range with 0.1% Resolution
margined up or down up to ±25% with 0.1% resolution n
Read back of Average and Peak Temperature,
via a PMBus-compliant serial interface. The serial inter-
Current, and Voltage (25Hz Refresh Rate)
face can also be used to read back fault status and both n
Fault Status
time-averaged (~4ms) and peak input/output current, n
Phase-Lockable Fixed Frequency Up to 3MHz
input/output voltage and temperature. System configu- n
Less Than 1ms Power-Up Time
ration and monitoring is supported by the LTpowerPlay® n Integrated 13-Bit ADC development system. n Optional External Reference Input n The architecture provides extremely fast transient Pin Selectable Fast-Margining of the Output Voltage n response and allows operation at the very low on-times Power Good Flag with Pin Programmable Thresholds required to regulate low output voltages at high switching and Filter Delay n frequencies. The operating frequency is programmable Differential Remote Output Voltage Sensing n Master Shutdown Mode: <1μA Supply Current from 400kHz to 3MHz with an external resistor or for n Clock Out for 2-Phase Operation (12A Output Current) noise sensitive applications, it can be synchronized to an n Available in a Thermally-Enhanced 38-Lead external clock over the same range. The operating supply 4mm × 6mm QFN Package voltage range is from 2.25V to 5.5V making it suitable for operation from 2.5V, 3.3V or 5V rails or Lithium-Ion
APPLICATIONS
batteries. n Intelligent Energy Efficient Power Conversion All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 5705919, 5929620, 6144194, 6177787, 6580258, 5408150, n ASIC/FPGA/Processor Power 7420359. Licensed under U.S. Patent 7000125 and other related patents worldwide. n Distributed Power Systems n Point of Load Power Conversion
TYPICAL APPLICATION Efficiency and Power Loss vs Load Current
VIN 2.25V TO 5.5V 100 10 C V PV IN OUT = 1.8V IN VIN 90 LTC3815 80 EFFICIENCY MODE/SYNC PGLIM 70 POWER LOSS (W) RT TRACK/SS 1 RUN_MSTR RUN_STBY 60 L VOUT PMBUS SCL, SDA, ALERT SW 0.4V TO 0.72*V 50 IN VCC_SENSE 6A MARGIN 40 C EFFICIENCY (%) POWER LOSS 0.1 WP V OUT SS_SENSE 30 PGOOD RC1 20 CLKOUT DAOUT VIN = 2.8V CSLEW FB 10 VIN = 3.3V REF I VIN = 5V TH 0 0 ASEL PGFD RC2 C 10 100 1000 10000 C2 LOAD CURRENT (mA) 3815 TA01a 3815 TA01b Rev B Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information PMBus Command Details Typical Applications Package Description Revision History Typical Application Related Parts