LTC4150_15 Datasheet, PDF (1/14 Pages) Linear Technology – Coulomb Counter/ Battery Gas Gauge

FEATURES
n _{Indicates Charge Quantity and Polarity}
n _{±50mV Sense Voltage Range}
n _{Precision Timer Capacitor or Crystal Not Required}
n _{2.7V to 8.5V Operation}
n _{High Side Sense}
n _{32.55Hz/V Charge Count Frequency}
n _{1.5μA Shutdown Current}
n _{10-Pin MSOP Package}
APPLICATIONS
n _{Battery Chargers}
n _{Palmtop Computers and PDAs}
n _{Cellular Telephones and Wireless Modems}
TYPICAL APPLICATION
LTC4150
Coulomb Counter/
Battery Gas Gauge
DESCRIPTION
The LTC^®4150 measures battery depletion and charging
in handheld PC and portable product applications. The
device monitors current through an external sense resistor
between the battery’s positive terminal and the battery’s
load or charger. A voltage-to-frequency converter trans-
forms the current sense voltage into a series of output
pulses at the interrupt pin. These pulses correspond to a
fixed quantity of charge flowing into or out of the battery.
The part also indicates charge polarity as the battery is
depleted or charged.
The LTC4150 is intended for 1-cell or 2-cell Li-Ion and
3-cell to 6-cell NiCd or NiMH applications.
L, LT, LTC, LTM, Linear Technology, the Linear logo, Burst Mode are registered trademarks and
ThinSOT and PowerPath are trademarks of Linear Technology Corporation. All other trademarks
are the property of their respective owners.
R_SENSE
+
CHARGER
LOAD
4.7μF
4.7μF
SENSE^– SENSE⁺ V_DD
C_F+
INT
C_F–
LTC4150 CLR CHG
POL
GND ^SHDN
R_L R_L
μP
DISCHG
4150 TA01a
Integral Nonlinearity, % of Full Scale
0.5
0.4
0.3
0.2
0.1
0
–0.1
–0.2
–0.3
–0.4
–0.5
–50
–25
0
25
50
CURRENT SENSE VOLTAGE (mV)
4150 TA01b
4150fc
1