Rainbow-electronics DS2781 Bedienungsanleitung Seite 1

1 of 30 REV: 010906 Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisi

DS2781: Two-Cell Standalone Fuel Gauge IC 10 of 30 ACR register update period). A write to the ACR forces the ADC to perform an offset correction con

DS2781: Two-Cell Standalone Fuel Gauge IC 11 of 30 ACCUMULATION BIAS The Accumulation Bias register (AB) allows an arbitrary bias to be introduced in

DS2781: Two-Cell Standalone Fuel Gauge IC 12 of 30 Figure 11. Top Level Algorithm Diagram Capacity Look-upAvailable Capacity CalculationACR Housekeep

DS2781: Two-Cell Standalone Fuel Gauge IC 13 of 30 MODELING CELL STACK CHARACTERISTICS In order to achieve reasonable accuracy in estimating remainin

DS2781: Two-Cell Standalone Fuel Gauge IC 14 of 30 ((1031mAh – 1009mAh) / (1051mAh / 1M)) / (18ºC - 0ºC) = 1163 ppm/ºC 1 LSB of the slope registers

DS2781: Two-Cell Standalone Fuel Gauge IC 15 of 30 Figure 13. Lookup Function Diagram APPLICATION PARAMETERS In addition to cell model characterist

DS2781: Two-Cell Standalone Fuel Gauge IC 16 of 30 not overwritten with an incorrect value. Usually, writing AS by the host is not necessary because

DS2781: Two-Cell Standalone Fuel Gauge IC 17 of 30 between 100% and 50% with a resolution of 61ppm (precisely 2-14). Though the register format permi

DS2781: Two-Cell Standalone Fuel Gauge IC 18 of 30 STATUS REGISTER The STATUS register contains bits that report the device status. The bits can be s

DS2781: Two-Cell Standalone Fuel Gauge IC 19 of 30 CONTROL REGISTER All CONTROL register bits are read and write accessible. The CONTROL register is

DS2781: Two-Cell Standalone Fuel Gauge IC 2 of 30 ABSOLUTE MAXIMUM RATINGS Voltage on VPLS, VIN Relative to VSS -0.3V to +12VVoltage Range on Any Pi

DS2781: Two-Cell Standalone Fuel Gauge IC 20 of 30 EEPROM REGISTER The EEPROM register provides access control of the EEPROM blocks. EEPROM blocks ca

DS2781: Two-Cell Standalone Fuel Gauge IC 21 of 30 USER EEPROM A 16 byte User EEPROM memory (block 0, addresses 20h - 2Fh) provides non-volatile memo

DS2781: Two-Cell Standalone Fuel Gauge IC 22 of 30 Table 2. MEMORY MAP ADDRESS (HEX) DESCRIPTION READ/WRITE 00 Reserved R 01 STATUS - Status Re

DS2781: Two-Cell Standalone Fuel Gauge IC 23 of 30 Table 3. PARAMETER EEPROM MEMORY BLOCK 1 ADDRESS (HEX) DESCRIPTION ADDRESS (HEX) DESCRIPTION 60 C

DS2781: Two-Cell Standalone Fuel Gauge IC 24 of 30 Application Note 27, Understanding and Using Cyclic Redundancy Checks with Dallas Semiconductor To

DS2781: Two-Cell Standalone Fuel Gauge IC 25 of 30 TRANSACTION SEQUENCE The protocol for accessing the DS2781 through the 1-Wire port is as follows:

DS2781: Two-Cell Standalone Fuel Gauge IC 26 of 30 FUNCTION COMMANDS After successfully completing one of the net address commands, the bus master ca

DS2781: Two-Cell Standalone Fuel Gauge IC 27 of 30 Table 4. Function Commands COMMAND DESCRIPTION COMMAND PROTOCOL BUS STATE AFTER COMMAND PROTO

DS2781: Two-Cell Standalone Fuel Gauge IC 28 of 30 Figure 21. Net Address Command Flow Chart MASTER TX

DS2781: Two-Cell Standalone Fuel Gauge IC 29 of 30 1-WIRE SIGNALING The 1-Wire bus requires strict signaling protocols to ensure data integrity. The

DS2781: Two-Cell Standalone Fuel Gauge IC 3 of 30 PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Voltage Full-Scale VFS 0 9.9902 V Voltage Error

DS2781: Two-Cell Standalone Fuel Gauge IC 30 of 30 Figure 23. 1-Wire Write- And Read-Time Slots LINE TYP

DS2781: Two-Cell Standalone Fuel Gauge IC 4 of 30 EEPROM RELIABILITY SPECIFICATION (VPLS = 2.5V to 10V, TA = -20°C to +70°C, unless otherwise noted.

DS2781: Two-Cell Standalone Fuel Gauge IC 5 of 30 Figure 1. Block Diagram VPORDQ1-WireInterfaceBIAS/VREF TimebaseTemp&VoltageADCCurrent ADC15

DS2781: Two-Cell Standalone Fuel Gauge IC 6 of 30 Figure 2: Typical Operating Circuit DQ SNS VDD VSSRSNSPACK+PACK-DATAProtectionCircuitDS278

DS2781: Two-Cell Standalone Fuel Gauge IC 7 of 30 VOLTAGE MEASUREMENT Battery voltage is measured at the VIN input with respect to VSS over a range o

DS2781: Two-Cell Standalone Fuel Gauge IC 8 of 30 Figure 5. Current Register Format CURRENT Read Only MSB—Address 0Eh LSB—Address 0Fh S 214

DS2781: Two-Cell Standalone Fuel Gauge IC 9 of 30 CURRENT MEASUREMENT CALIBRATION The DS2781’s current measurement gain can be adjusted through the R