BQ2052_15 Datasheet, PDF (2/20 Pages) Texas Instruments – Gas Gauge IC

Not Recommended For New Designs
bq2052 Preliminary
Pin Descriptions
SR
LCOM LED common output
This open-drain output switches VCC to
source current for the LEDs. The switch is
off during initialization to allow reading of
the soft pull-up or pull-down program resis-
tors. LCOM is also high impedance when the
display is off.
SEG1–
SEG5
LED display segment outputs (dual func-
tion with PROG₁–PROG₅)
Each output may activate an LED to sink
the current sourced from LCOM.
PROG1–
PROG2
Programmed full count selections
These three-level input pins define the pro-
grammed full count.
PROG3 Power gauge scale selection inputs (dual
function with SEG₃–SEG₄)
This three-level input pin defines the scale
factor.
PROG4
Programmed compensation factors
This three-level input pin defines the bat-
tery discharge compensation factors.
PROG5
Programmed display mode
This three-level input pin defines the capac-
ity indication display mode.
PROG6
Programmed initial capacity state
This input defines the initial battery capac-
ity indication state. When tied to VCC, the
bq2052 sets the available capacity to full on
reset. When tied to V_SS, the bq2052 sets the
available capacity to zero on reset.
VSS
Ground
DISP
SB
RBI
HDQ
CP
REF
VCC
Sense resistor input
The voltage drop (VSR) across the sense resis-
tor RS is monitored and integrated over time
to interpret discharge activity. V_SR > V_SS in-
dicates discharge. The effective voltage drop,
V_SRO, as seen by the bq2052 is V_SR + V_OS .
Display control input
DISP high disables the LED display. DISP
tied to V_CC (no display LEDs in the circuit)
allows PROG_X to connect directly to V_CC or
V_SS instead of through a pull-up or
pull-down resistor. DISP low activates the
display.
Secondary battery input
This input monitors the battery cell voltage
potential through a high-impedance resis-
tive divider network for the end-of-discharge
voltage (EDV) thresholds.
Register backup input
This pin is used to provide backup potential to
the bq2052 registers during periods when VCC
≤ 3V. A storage capacitor or a battery can be
connected to RBI.
Serial communication input/output
This is the open-drain bidirectional commu-
nications port.
Control port
This open drain output may be controlled by
serial port commands and its state is re-
flected in the CPIN bit in FLGS1.
Voltage reference output for regulator
REF provides a voltage reference output for
an optional micro-regulator.
Supply voltage input
2