DS2746_07 Datasheet, PDF (1/16 Pages) Dallas Semiconductor – Low-Cost 2-Wire Battery Monitor with Ratiometric A/D Inputs

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GENERAL DESCRIPTION
The DS2746 provides system-side battery capacity
monitoring in cost-sensitive applications. Voltage,
bidirectional current, and accumulated current
measurement data is provided to the host processor
over a 2-wire interface. Offset bias and offset
blanking features greatly enhance the accuracy of
the coulomb counter. In addition, the DS2746 has
two auxiliary A/D inputs to sample the pack
identification resistor, thermistor, or other voltage
source. The results are reported as a ratiometric
fraction of the supply voltage eliminating error related
to the supply. The DS2746 reduces the total power
consumption of the measurement circuit by enabling
the resistor dividers, through the V_OUT pin, only while
measurements are made. When the system is
inactive, a low power sleep mode reduces current
consumption while maintaining the coulomb count.
The tiny 3mm × 3mm TDFN package consumes only
9mm² of PCB space.
APPLICATIONS
2.5G/3G Wireless Handsets
PDA/Smartphones
Digital Still and Video Cameras
Handheld Computers and Terminals
DS2746
Low-Cost 2-Wire Battery Monitor
with Ratiometric A/D Inputs
FEATURES
ƒ 14-Bit Bidirectional Current Measurement
- 6.25μV LSB, ±51.2mV Dynamic Range
- 416.7μA LSB, ±3.4A Range (R_SNS = 15mΩ)
ƒ Current Accumulation Register Resolution
- 6.25μVhr LSB, 409.6mVh Range
- 417μAhr LSB, 27.31Ah Range
ƒ 11-Bit Battery Voltage Measurement
- 2.44mV LSB, 0V to 4.997V Input Range
- ±10mV Accuracy at 3.6V Input
ƒ Two 11-Bit Aux Input Voltage Measurements
- Ratiometric Inputs Eliminate Supply Error
- VOUT drives Dividers, Reduces Power
- ±8 LSB Accuracy
ƒ Low Power Consumption:
- Active Current: 70μA typical, 100μA max
- Sleep Current: 1μA typical, 3μA max
ORDERING INFORMATION
PART
TEMP RANGE PIN-PACKAGE
DS2746G+
-20ºC to +70ºC
10-Pin 3mm×3mm
TDFN
DS2746G+T&R
-20ºC to +70ºC
DS2746G+ in Tape-
and-Reel
+ Denotes lead-free package.
TYPICAL OPERATING CIRCUIT
PIN CONFIGURATION
TOP VIEW
3mm × 3mm TDFN
Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device
may be simultaneously available through various sales channels. For information about device errata, click here: www.maxim-ic.com/errata.
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REV: 080107