IR3721 DATA SHEET Power Monitor IC with Analog Output FEATURES DESCRIPTION TM Accurate TruePower monitor The IR3721 is a versatile power or current monitor IC for low-voltage DC-DC converters. The IR3721 2.5% static accuracy monitors the inductor current in buck or multiphase Minimizes dynamic errors converters using either a current sensing resistor or the Minimizes power dissipation inductors winding resistance (DCR). The output (DI) is 5mV - 150mV full scale current range a pulse code modulated signal whose duty ratio is Versatile proportional to the inductor current. An analog voltage Monitors power or current that is proportional to power is realized by connecting Single buck or multiphase converters V to V and connecting an RC filter to DI. K O Inductor DCR or resistive shunt sensing TM Simple add-on to existing converters The IR3721 uses Patent Pending TruePower 10 pin 3x3 DFN lead free package technology to accurately capture highly dynamic power RoHS compliant waveforms typical of microprocessor loads. TYPICAL APPLICATION CIRCUIT ORDERING INFORMATION Device Package Order Quantity IR3721MTRPBF 10 lead DFN (3x3 mm body) 3000 piece reel * IR3721MPBF 10 lead DFN (3x3 mm body) 121 piece tube * Samples only Page 1 of 16 www.irf.com 09/15/08 IR3721 DATA SHEET ABSOLUTE MAXIMUM RATINGS Absolute Maximum Ratings (Referenced to GND) Operating Junction Temperature....-10C to 150C VDD:.................................................................3.9V Storage Temperature Range..........-65C to 150C All other Analog and Digital pins......................3.9V ESD Rating ............HBM Class 2 JEDEC Standard 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 o o Unless otherwise specified, these specifications apply: VDD = 3.3V 5%, 0 C T 125 C, 0.5 Vo 1.8 V, and J operation in the typical application circuit. See notes following table. PARAMETER TEST CONDITION MIN TYP MAX UNIT BIAS SUPPLY VDD Turn-on Threshold, VDD 3.10 V UP VDD Turn-off Threshold, VDD 2.4 V DN VDD UVLO Hysteresis DI output low when off 75 mV VDD Operating Current, ICC 350 450 A VOLTAGE REFERENCE V Voltage R = 25.5k 1.452 1.493 1.535 V RT T R resistance range Note 1 25.5 k T CONVERTER Vo common mode range 0.5 1.8 V Duty Ratio Accuracy V =20 mV, V =1V, 2.5 % DCR O R =25.5k, R +R =600 T CS1 CS2 T =65C, Note 1 j Duty Ratio Accuracy V =20 mV, V =1V, 4 % DCR O R =25.5k, R +R =600 , T CS1 CS2 Note 1 Sampling frequency, f 435 512 589 kHz CLK Comparator Offset -0.5 +0.5 mV CS pin input current, I DI output low -250 +250 nA CS DIGITAL OUTPUT VK pin voltage range 0.5 1.8 V DI source resistance 1250 2000 3000 NOTES: 1. Guaranteed by design Page 2 of 16 www.irf.com 09/15/08