BQ2011K_11 Datasheet, PDF (2/22 Pages) Texas Instruments – Gas Gauge IC for High Discharge Rates

bq2011K
Pin Descriptions
LCOM LED common
Open-drain output switches VCC to source cur-
rent for the LEDs. The switch is off during ini-
tialization to allow reading of PROG1-4 pull-up
or pull-down program resistors. LCOM is high
impedance when the display is off.
SEG1–
SEG5
LED display segment outputs
Each output may activate an LED to sink
the current sourced from LCOM, the battery,
or VCC.
PROG1– Programmed full count selection inputs
PROG4 (dual function with SEG1 - SEG4)
These three-level input pins define the pro-
grammed full count (PFC) in conjunction
with SPFC pin, define the display mode and
enable or disable self-discharge.
SPFC Programmed full count selection input
This three-level input pin along with PROG1-3
define the programmed full count (PFC)
thresholds described in Table 1. The state of
the SPFC pin is only read immediately 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 and battery pack ground
(see Figure 1). VSR > VSS indicates discharge,
and VSR < VSS indicates charge. The effec-
tive voltage drop, VSRO, as seen by the
bq2011K is VSR + VOS (see Table 4).
NC
DISP
SB
RBI
DQ
REF
VCC
VSS
No connect
Display control input
DISP floating allows the LED display to
be active during certain charge and dis-
charge conditions. 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 poten-
tial to the bq2011K registers during periods
when VCC < 3V. A storage capacitor should
be connected 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