19-4631 Rev 5/09 DS2745 2 Low-Cost I C Battery Monitor www.maxim-ic.com PIN CONFIGURATION FEATURES 16-Bit Bidirectional Current Measurement 1.56V LSB, 51.2mV Dynamic Range 1 8 VDD SCL 104 A LSB, 3.4A Dynamic Range (RSNS = SDA 2 7 VIN 15m) 3 6 PIO CTG Current Accumulation Register Resolution 4 5 6.25Vhr LSB, 204.8mVh Range SNS VSS 0.417mAhr LSB, 13.65Ah Range MAX (R = 15m) SNS 11-Bit Voltage Measurement See Table 1 for Ordering Information. 4.88mV LSB, 0V to 4.5V Input Range 11-Bit Temperature Measurement 0.125C Resolution, -20C to +70C DESCRIPTION 2 Industry Standard I C Interface The DS2745 provides current-flow, voltage, and Low Power Consumption: temperature measurement data to support battery- Active Current: capacity monitoring in cost-sensitive applications. The DS2745 can be mounted on either the host side or 70 A typical, 100A max pack side of the application. Current measurement Sleep Current: and coulomb counting is accomplished by monitoring 1 A typical, 3 A max the voltage drop across an external sense resistor, voltage measurement is accomplished through a separate voltage-sense input, and temperature BLOCK DIAGRAM 2 measurement takes place on-chip. A standard I C interface with software programmable address gives the controlling microprocessor access to all data and status registers inside the DS2745. A low-power sleep mode state conserves energy when the cell pack is in storage. APPLICATIONS Cellular GPS PDAs Handheld Products Table 1. ORDERING INFORMATION PART MARKING PIN-PACKAGE DS2745U+ 2745 MAX package DS2745U+T&R 2745 DS2745U+ in Tape-and-Reel +Denotes a lead(Pb)-free/RoHS-compliant package. 1 of 15 2 DS2745 Low-Cost I C Battery Monitor ABSOLUTE MAXIMUM RATINGS* Voltage on All Pins Relative to V -0.3V to +6V SS Operating Temperature Range -40C to +85C Storage Temperature Range -55C to +125C Soldering Temperature See IPC/JEDECJ-STD-020A * This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. RECOMMENDED DC OPERATING CONDITIONS (2.5V V 4.5V T = 0C to +70 C.) DD A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Voltage V (Note 1) +2.5 +4.5 V DD Serial Data I/O Pin SDA (Note 1) -0.3 +5.5 V Serial Clock Pin SCL (Note 1) -0.3 +5.5 V Programmable I/O Pin PIO (Note 1) -0.3 +5.5 V VIN Pin V (Note 1) -0.3 V +0.3 V IN DD DC ELECTRICAL CHARACTERISTICS (2.5V V 4.5V T = 0C to +70 C, unless otherwise noted.) DD A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 70 100 Active Current I A ACTIVE V = 4.5V 105 DD SCL = SDA = V , SS Sleep-Mode Current I 1 3 A SLEEP PIO = V SS Current Resolution I 1.56 V/R LSB Current Full-Scale I (Note 1) 51.2 mV/R FS Magnitude Current Offset I (Note 2) -7.82 +12.5 V/R OERR % of Current Gain Error I -1.0 +1.0 GERR reading Accumulated Current q 6.25 Vh/R CA Resolution Accumulated Current Vh/R q V = V , (Notes 4, 5) -188 +0 OERR SNS SS Offset per day Voltage Resolution V 4.88 mV LSB Voltage Full-Scale V 0 4.992 V FS Voltage Error V (Note 12) -25 +25 mV GERR Temperature Resolution T 0.125 C LSB Temperature Error T -3 +3 C ERR Current Sample Clock f 18.6 kHz SAMP Frequency Timebase Accuracy t V = 3.8V, T = +25C 1 % ERR DD A 2 of 15