IR3725 Data Sheet INPUT POWER MONITOR WITH DIGITAL INTERFACE FEATURES DESCRIPTION Accurate power, current, or voltage reporting The IR3725 is a highly configurable power monitor IC 1.5 % maximum power error that uses proprietary digital technology to measure a 1.0 % maximum current error 12V rail current, its voltage, or its average power over a Serial digital interface user specified time interval. Configuration and result 2 SMBus and I C compatible reporting are managed through a serial digital interface. Programmable averaging interval The current is measured as a voltage across a shunt Flexible current sensing resistance, an input inductor, or a copper trace Resistive or Inductor DCR resistance. Applications Synchronous rectified buck converters The real time voltage and current signals are multiplied, Multiphase converters digitized, and averaged over a user selectable 12pin 3x4 DFN lead free averaging interval providing TruePower measurement RoHS Compliant of highly dynamic loads. TYPICAL APPLICATION CIRCUIT Input 3.3V +12V Buck Regulators Capacitors L DCR To system VDD Controller IR3725 C CS1 2 I C 2 ALERT VO C CS2 VT VCS2 ADDR VCS1 R T 0.1 uF GND +12V Return ORDERING INFORMATION Device Package Order Quantity IR3725MTRPBF 12 lead DFN (4x3 mm body) 3000 piece reel IR3725MPBF 12 lead DFN (4x3 mm body) Sample Quantity Page 1 of 19 www.irf.com 2013 12 09 IR3725 Data Sheet ABSOLUTE MAXIMUM RATINGS o All voltages referenced to GND Operating Junction Temperature .... -10C to 150 C o o VDD: ................................................................ 3.9V Storage Temperature Range .......... -65 C to 150 C ALERT : ........................................................... 3.9V Thermal Impedance ( ) .......................... 1.6 C/W JC ALERT ............................................. < VDD + 0.3V Thermal Impedance ( ) ........................... 30 C/W JA VCS1, VCS2, VO ........................................... 25.0V ESD Rating ......... HBM Class 1C JEDEC Standard All other Analog and Digital pins ...................... 3.9V MSL Rating .................................................. Level 2 Reflow Temperature ..................................... 260C Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications are not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL SPECIFICATIONS Unless otherwise specified, these specifications apply: o o VDD = 3.3V 5%, 0 C T 125 C, 8V VO 23.5V, and operation in the typical application circuit. See notes J following table. PARAMETER TEST CONDITION NOTEMIN TYP MAX UNIT BIAS SUPPLY VDD Turn-on Threshold, VDD 3.1 V UP VDD Turn-off Threshold, VDD 2.4 V DN VDD UVLO Hysteresis 75 mV VDD Operating Current R = 25.5 k 700 1000 A T VDD Shutdown Current Config Reg enable bit d4=1 18 100 A VOLTAGE REFERENCE V Voltage R = 25.5 k 1.40 1.50 1.60 V T T Reference load, R 1 20 25.5 45.3 k T VOLTAGE SENSOR Voltage, full scale, V 23.5 V FS CURRENT SENSOR Voltage, Current Gain, V R = 25.5 k 1.48 V IG T DIGITIZER Internal Sampling frequency Driven from internal clock 512 kHz External Sampling frequency Driven from external clock 922 1024 1126 kHz POWER INFORMATION Minimum Averaging Interval Config Reg d3..d0 = b0000 1 0.85 1 1.15 ms Maximum Averaging Interval Config Reg d3..d0 = b1000 1 217 256 295 ms Page 2 of 19 www.irf.com 2013 12 09