BQ2011_15 Datasheet, PDF (2/26 Pages) Texas Instruments – Gas Gauge IC for High Discharge Rates

bq2011
Pin Descriptions
MODE Display mode output
When left floating, this output selects rela-
tive mode for capacity display. If connected
to the anode of the LEDs to source current,
absolute mode is selected for capacity dis-
play. See Table 1.
SEG1–
SEG5
LED display segment outputs
Each output may activate an LED to sink
the current sourced from MODE, the bat-
tery, or VCC.
PFC
Programmed full count selection input
This three-level input pin defines the pro-
grammed full count (PFC) thresholds and
scale selections described in Table 1. The
state of the PFC pin is only read immediate-
ly after a reset condition.
SR
Sense resistor input
The voltage drop (VSR) across the sense re-
sistor RS is monitored and integrated over
time to interpret charge and discharge activ-
ity. The SR input is tied to the low side of
the sense resistor. VSR > VSS indicates dis-
charge, and VSR < VSS indicates charge. The
effective voltage drop, VSRO, as seen by the
bq2011 is VSR + VOS (see Table 3).
NC
No connect
DISP
SB
RBI
DQ
REF
VCC
VSS
Display control input
DISP floating allows the LED display to
be active during charge and discharge if
VSRO < -1mV (charge) or VSRO > 2mV (dis-
charge). Transitioning DISP low activates
the display for 4 ± 0.5 seconds.
Secondary battery input
This input monitors the single-cell voltage
potential through a high-impedance resis-
tive divider network for the end-of-discharge
voltage (EDV) threshold and maximum cell
voltage (MCV).
Register backup input
This input is used to provide backup potential
to the bq2011 registers during periods when
VCC ≤ 3V. A storage capacitor should be con-
nected to RBI.
Serial I/O pin
This is an open-drain bidirectional pin.
Voltage reference output for regulator
REF provides a voltage reference output for
an optional micro-regulator.
Supply voltage input
Ground
2