LTC2947-65 65A+ Power/Energy Monitor with Integrated Sense Resistor FEATURES DESCRIPTION n Measures Current, Voltage, Power, Charge, Energy The LTC 2947-65 is a high precision power and energy n 65A Current Range with Low 18mA Offset monitor with an internal sense resistor supporting up * n Integrated 150 Sense Resistor to 65A . Three internal No Latency ADCs ensure n 0V to 15V Input Range Independent of Supply Voltage accurate measurement of voltage and current, while high- n Instantaneous Multiplication of Voltage and Current bandwidth analog multiplication of voltage and current n 0.5% Voltage Accuracy provides accurate power measurement in a wide range of n 1% Current and Charge Accuracy applications. Internal or external clocking options enable n 1.2% Power and Energy Accuracy precise charge and energy measurements. n Alerts When Thresholds Exceeded An internal 150, temperature-compensated sense n Stores Maximum and Minimum Values resistor minimizes efficiency loss and external compo- n Shutdown Mode with I < 10A Q nents, simplifying energy measurement applications while 2 n I C/SPI Compatible Interface enabling high accuracy current measurement over the full n Available in 38-Lead 5mm 7mm QFN Package temperature range. All measured quantities are stored in internal regis- 2 APPLICATIONS ters accessible via the selectable I C/SPI interface. The LTC2947-65 features programmable high and low thresh- n Servers olds for all measured quantities to reduce digital traffic n Telecom Infrastructure with the host. n Industrial n *For applications greater than 65A, see Figure19 or contact the factory. Electric Vehicles n Photovoltaics All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. Patents, including 8907703, 8841962. TYPICAL APPLICATION Energy Measurement Total Unadjusted 150 IP IM 0V TO 15V Error vs Current, VP VM = 12V 65A TO 65A 0.5 5V AVCC INTERNAL CLOCK 0.4 VP 1F EXTERNAL CLOCK AGND 0.3 LTC2947-65 LOAD DVCC 0.2 1F 0.1 DGND VM 0.0 CFP OVDD 5V 1F 0.1 SCL SCL CFM 2 I C SDI SDA 0.2 BYP INTERFACE 1F SDO 0.3 AD1 ALERT AD0 0.4 CLKI CLKO 0.5 0 20 40 65 I (A) SENSE 294765 TA01b 294765 TA01a Rev. 0 1 Document Feedback For more information www.analog.com TUE (%)LTC2947-65 TABLE OF CONTENTS Description......................................................................................................................... 1 Absolute Maximum Ratings ..................................................................................................... 3 Order Information ................................................................................................................. 3 Pin Configuration ................................................................................................................. 3 Electrical Characteristics ........................................................................................................ 4 Timing Diagrams ................................................................................................................. 7 Typical Performance Characteristics .......................................................................................... 8 Pin Functions .....................................................................................................................10 Block Diagram ....................................................................................................................11 Operation..........................................................................................................................12 Overview ............................................................................................................................................................... 12 Modes of Operation .............................................................................................................................................. 12 Current, Voltage and Temperature Measurement .................................................................................................. 14 Power Measurement ............................................................................................................................................. 14 Charge, Energy Measurement and Accumulated Time ......................................................................................... 14 Applications Information .......................................................................................................15 Timebase: Internal/External Clock/Crystal ........................................................................................................... 15 Configuring the GPIO Pin ...................................................................................................................................... 15 Internal Sense Resistor ......................................................................................................................................... 16 Current and Voltage Input Filtering ....................................................................................................................... 16 Layout Considerations .......................................................................................................................................... 17 Digital Interface ..................................................................................................................19 2 Selecting SPI or I C Serial Interface ..................................................................................................................... 19 SPI Mode ............................................................................................................................................................. 19 2 I C Mode .............................................................................................................................................................. 21 Register Map .....................................................................................................................24 Register Description ............................................................................................................25 Register Naming Conventions .............................................................................................................................. 25 Paging Mechanism ............................................................................................................................................... 25 PAGE Control ........................................................................................................................................................ 25 Operation Control ................................................................................................................................................. 25 Register Map PAGE0 ............................................................................................................................................. 26 Register Map PAGE1 ............................................................................................................................................. 37 Typical Applications .............................................................................................................39 Package Description ............................................................................................................41 Typical Application ..............................................................................................................42 Related Parts .....................................................................................................................42 Rev. 0 2 For more information www.analog.com