LTC4150 Datasheet, PDF (1/12 Pages) Linear Technology – Coulomb Counter/ Battery Gas Gauge

LTC4150
Coulomb Counter/
Battery Gas Gauge
FEATURES
■ _{Indicates Charge Quantity and Polarity}
■ _{±50mV Sense Voltage Range}
■ _{Precision Timer Capacitor or Crystal Not Required}
■ _{2.7V to 8.5V Operation}
■ _{High Side Sense}
■ _{32.55Hz/V Charge Count Frequency}
■ _{1.5µA Shutdown Current}
■ _{10-Pin MSOP Package}
U
APPLICATIO S
■ _{Battery Chargers}
■ _{Palmtop Computers and PDAs}
■ _{Cellular Telephones and Wireless Modems}
DESCRIPTIO
The LTC^®4150 measures battery depletion and charging in
handheld PC and portable product applications. The de-
vice 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.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
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
4150fa
1