Rainbow Electronics DS2740 - Manual (Page 2)

DS2740
2 of 15
Table 1. ORDERING INFORMATION
PART MARKING PIN-PACKAGE
DS2740U DS2740 15-Bit Current Resolution, mMAX
DS2740U/T&R DS2740 15-Bit Current Resolution, mMAX, Tape-and-Reel
DS2740BU DS2740B 13-Bit Current Resolution, mMAX
DS2740BU/T&R DS2740B 13-Bit Current Resolution, mMAX, Tape-and-Reel
DESCRIPTION
The DS2740 provides high-precision current-flow measurement data to support battery-capacity
monitoring in cost-sensitive applications. Current is measured bidirectionally over a dynamic range of 15
bits (DS2740U) or 13 bits (DS2740UB), with the net flow accumulated in a separate 16-bit register.
Through its 1-Wire interface, the DS2740 allows the host system read/write access to status and current
measurement registers. Each device has a unique factory-programmed 64-bit net address that allows it to
be individually addressed by the host system, supporting multibattery slot operation. The interface can be
operated with standard or overdrive timing.
Although the DS2740 is primarily intended for location on the host system, it is also suited for mounting
in the battery pack. The DS2740 and FuelPack™ algorithms, along with host measurements of
temperature and voltage, form a complete and accurate solution for estimating remaining capacity.
Figure 1. BLOCK DIAGRAM
1-WIRE
INTERFACE
AND
ADDRESS
DQ
PIO
TIMEBASE
CURRENT
ACCUMULATED
CURRENT
STATUS/CONTROL
CHIP
GROUND
SNS IS2 V
SS
IS1
15-Bit + Sign
ADC
R
IS
10 k W
R
IS
10 k W
V
DD
FuelPack is a trademark of Dallas Semiconductor.