Features
c228 Complete and compact lithium-ion pack supervisor
c228 Provides overvoltage, undervoltage, and
overcurrent protection for two series Li-Ion cells
c228 Combines bq2058T with charge/discharge control
FETs
c228 Low side low on-resistance FETs
c228 Designed for battery pack integration
– Direct connection for series battery terminals
– Measures 1.70 X 0.70 inches
c228 Low standby and operating currents
General Description
The bq2158T provides a complete solution for the super-
vision of two series Li-Ion cells. Designed for battery
pack integration, the bq2158T incorporates a bq2058T
Pack Supervisor, two FETs, and all other components re-
quired to monitor overvoltage, undervoltage, and over-
current conditions. The board provides direct
connections for the negative and positive terminals of
each cell. See Figure 1. Please refer to the bq2058T
data sheet for specific information on the operation of
the bq2058T.
Unitrode configures the bq2158T based on the informa-
tion in Table 1.
Pin Descriptions
B1P Battery 1 positive input
B1N Battery 1 negative input
B2N Battery 2 negative input
POS Pack positive
NEG Pack negative
1
Two Series Cell
Li-Ion Pack Supervisor Module
Preliminary bq2158T
4/99