BQ2084DBTR-V150 Datasheet, PDF (7/69 Pages) Texas Instruments – SBS v1.1-COMPLIANT GAS GAUGE WITH LED DELAY

bq2084-V150
www.ti.com
SLUS758 – JUNE 2007
Terminal Functions
TERMINAL
NAME
NO.
TSSOP
I/O
DESCRIPTION
DISP
17
I
Display control for the LED drivers LED1 through LED5
CLKOUT
35
O
32.768-kHz output to the bq29312A
FILT
32
I
Analog input connected to the external PLL filter
EVENT
25
I
Input from bq29312A XALERT output
LED1
24
O
LED2
23
O
LED3
22
O
LED display segments that each may drive an external LED
LED4
21
O
LED5
20
O
MRST
26
I
Master reset input that forces the device into reset when held high
NC
7, 13, 14, 36, 37
–
No connection
PFIN
18
I
Active low input to detect secondary protector output status
PRES
5
I
Active low input to sense system insertion
PU
4
O
Output to pull up the PRES pin for detection
RBI
9
I
Register backup that provides backup potential to the bq2084-V150 data registers during
periods of low operating voltage. RBI accepts a storage capacitor or a battery input.
SAFE
12
O
Active low output for additional level of safety protection; e.g., fuse blow.
SCLK
6
O
Communication clock to the bq29312A
SDATA
10
I/O
Data transfer to and from bq29312A
SMBC
15
I/O
SMBus clock open-drain bidirectional pin used to clock the data transfer to and from the
bq2084-V150
SMBD
16
I/O
SMBus data open-drain bidirectional pin used to transfer address and data to and from
the bq2084-V150
SR1
28
I
Connections for a small-value sense resistor to monitor the battery charge- and
SR2
27
I
discharge-current flow
TS
2
I
Thermistor voltage input connection to monitor temperature
VDDA
31
I
Positive supply for analog circuitry
VDDD
8
I
Positive supply for digital circuitry and I/O pins
VIN
1
I
Single-cell voltage input from the bq29312A
VSSA
3, 29, 30
I
Negative supply for analog circuitry
VSSD
11, 19, 38
I
Negative supply for digital circuitry
XCK1/VSSA
34
I
32.768-kHz crystal oscillator input pin or connected to VSSA if the internal oscillator is
used
XCK2/ROSC
33
O
32.768-kHz crystal oscillator output pin or connected to a 100-kΩ, 50 ppm or better
resistor if the internal oscillator is used
FUNCTIONAL DESCRIPTION
OSCILLATOR FUNCTION
The oscillator of the bq2084-V150 can be set up for an internal or external operation. As the bq2084-V150
powers up it automatically attempts to start the internal oscillator, but if a 100-kΩ resistor is not connected to
ROSC (pin 33), then it attempts to start the oscillator using an external 32.768-kHz crystal. Either the 100-kΩ
ROSC resistor OR the 12 pF 32.768-kHz crystal should be mounted, NOT both.
The performance of the internal oscillator depends on the tolerance of the 100-kΩ resistor connected between
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