BQ2058T Datasheet, PDF (7/18 Pages) Texas Instruments – Lithium Ion Pack Supervisor For 2-Cell Packs

bq2058T
01
Cell Voltage
23
VOV
4 5 6 7 8 9 10
VCE
11 12
VUV
CSL
BAT2N + 160mV (VOCL)
BAT2N - 70mV (VCD)
DSG
CHG
CTL
tOVD
tOCD
tUVD
TD2058T1.eps
Figure 3. Protector Event Diagram
Event Definition:
0:
The bq2058T is in the low-power sleep mode because one or more of the cell voltages are below VUV.
1:
A charger is applied to the pack, causing the difference between CSL and BAT2N to become greater
than 70mV. This awakens the bq2058T, and the discharge pin DSG goes high.
2:
One or more cells charge to a voltage equal to VOV, initiating the overvoltage delay timer.
3:
The overvoltage delay time expires, causing CHG to go to high impedance (pulled low externally).
4:
All cell voltages fall below VCE, causing CHG to go high.
5:
Stop charging, apply a load.
6:
An overcurrent condition is detected, initiating the overcurrent delay timer.
7:
The overcurrent delay time expires, causing DSG to go low.
8:
The overcurrent condition is no longer present. DSG is driven high.
9:
Pin CTL is driven high; both DSG and CHG go inactive.
10:
Pin CTL is driven low; both DSG and CHG go active resuming their normal function.
11:
One or more cells fall below VUV, initiating the overdischarge delay timer.
12:
Once the overdischarge delay timer expires, if any of the cells is below VUV, the bq2058T drives
DSG low and enters the low-power sleep mode.
July 15, 1997
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