Datasheet

LTC2942
6
2942fa
pin FuncTions
block Diagram
SENSE
+
(Pin 1): Positive Current Sense Input and Power
Supply. Connect to the load/charger side of the sense
resistor. V
SENSE
+
operating range is 2.7V to 5.5V.
GND (Pin 2): Device Ground. Connect directly to the nega-
tive battery terminal.
SCL (Pin 3): Serial Bus Clock Input.
SDA (Pin 4): Serial Bus Data Input and Output.
AL/CC (Pin 5): Alert Output or Charge Complete Input.
Configured either as an SMBus alert output or charge
complete input by control register bits B[2:1]. At power-up,
the pin defaults to alert mode conforming to the SMBus
alert response protocol. It behaves as an open-drain logic
output that pulls to GND when any threshold register value
is exceeded. When configured as a charge complete input,
connect to the charge complete output from the battery
charger circuit. A high level at CC sets the value of the
accumulated charge (registers C, D) to FFFFh.
SENSE
–
(Pin 6): Negative Current Sense Input. Connect
SENSE
–
to the positive battery terminal side of the sense
resistor. The voltage between SENSE
–
and SENSE
+
must
remain within ±50mV in normal operation. SENSE
–
is also
the input for the ADC in voltage measurement mode.
Exposed Pad (Pin 7): Do Not Connect.
REF
+
REF
–
REF CLK
COULOMB COUNTER
ADC
IN
CLK
MUX
SENSE
–
REFERENCE
GENERATOR
TEMPERATURE
SENSOR
ACCUMULATED
CHARGE
REGISTER
DATA AND
CONTROL
REGISTERS
OSCILLATOR
6
SENSE
+
1
AL/CC
AL
5
GND
2
I
2
C/
SMBus
SCL
CC
LTC2942
SDA
2942 BD
3
4
V
SUPPLY