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盲
盲
Small size
Incl ud e s bq204 0 a nd b q 2 0 5 8 I C s, a n d
configuration EEPROM
On-board charge and discharge control FETs
Low operating current for minimal battery
drain
Unitrode configures the bq2168 based on the information
requested in Table 1. The configuration defines all the
EEPROM parameters and the protection threshold. Fig-
ure 1 shows how the module connects to the cells.
The bq2148L includes four LEDs to display remaining capac-
ity in 25% increments of the learned capacity. The LEDs are
activated with the onboard push-button switch.
A module development kit is also available for the
bq2148. The bq2148B-KT or the bq2148LB-KT includes
one configured module and the following:
1)
An EV2200-40 interface board that allows connec-
tion to the serial port of any AT-compatible com-
puter.
Menu driven software to display charge/discharge
activity and to allow user interface to the bq2040
from any standard Windows 3.1x or 95 PC.
Critical battery information available over two-wire
serial port
"L鈥?version includes 4 push-button activated LEDs
to display state-of-charge information
General Description
The bq2148 Smaart Battery Module provides a complete
and compact battery management solution for Li-Ion bat-
tery packs. Designed for battery pack integration, the
bq2168 combines the bq2040H Gas Gauge IC with the
bq2058 Supervisor IC on a small printed circuit board. The
board includes all the necessary components to accurately
monitor battery capacity and protect the cells from
overvoltage, undervoltage, and overcurrent conditions. The
board works with three or four Li-Ion series cells.
The Gas Gauge IC uses the on-board sense resistor to
track charge and discharge activity of the battery pack.
Critical battery information can be accessed through the
serial communications port at SMBC/SMBD. The
bq2148 uses the SMBus communications protocol and
supports the Smart Battery Data Commands in the SBD
specification. The supervisor circuit consists of the
bq2058 and two FETs. The bq2058 controls the FETs to
protect the batteries during charge/discharge cycles and
short circuit conditions. The bq2168 provides contacts
for the positive and negative terminals of each battery in
the stack. Please refer to the bq2040 and bq2058 data
sheets for the specifics on the operation of the power
gauge and supervisor ICs.
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2)
Pin Descriptions
POS
NEG
SMBC
SMBD
ITEST
B1P
B1N
B2N
B3N
B4N
PACK+/Pack positive
PACK-/Pack negative
Communications clock
Serial data
Overcurrent test input
Battery 1 positive input
Battery 1 negative input
Battery 2 negative input
Battery 3 negative input
Battery 4 negative input
1
1
2
3
4
5
6
7
8
