MAX1665S Datasheet, PDF (6/12 Pages) Maxim Integrated Products – Lithium-Ion Battery Pack Protector

Lithium-Ion Battery Pack Protector
Table 2. Functionality Truth Table for V_BN > V_PKN + 0.018V (Charge Mode)
CHARGE
DISCHARGE
OVERCURRENT OVERCURRENT
OVERVOLTAGE
UNDERVOLTAGE
CHG
0
0
0
0
0
0
0
0
1
0
0
1
1
0
0
1
0
0
1
0
1
1
0
1
*Assuming no load on CHG or DSG.
0
High
1
High
0
Low
1
Low
0
Gated
1
Gated
0
Low
1
Low
DSG
High
High
High
High
Gated
Gated
High
High
GATE
CLOCKED
No
No
No
No
Yes
Yes
No
No
MAX
SUPPLY
CURRENT*
(µA)
25
25
25
25
25
25
25
25
POWER ^POWER
ON
ON
SLEEP _{CHARGE = 1}
DSG = 0
CHG = 0
SUPPLIES
ON ^{RDY = 1}
DSG = 0
CHG = 0
START
COUNTER ^{∆T =}
DSG = 0 2.4ms
CHG = 0
START-UP
ZCHK
DSG = 0
CHG = 0
∆T =
160µs
START-UP
MEASURE
DSG = 0
CHG = 0
∆T =
640µs
WAIT FOR
BLANK = 0
DSG = 0
CHG = 0
∆T =
2.4ms
UV = 0
OV = 0
NORMAL ∆T =
DSG = 1 _2.4ms
CHG = 1
NORMAL
PULSE OFF ^{∆T =}
DSG = * 96ms
CHG = *
NORMAL
PULSE ON
DSG = 1
CHG = 1
∆T =
6.4ms
NORMAL
ZCHK
DSG = 1
CHG = 1
∆T =
160µs
NORMAL
MEASURE
DSG = 1
CHG = 1
∆T =
640µs
UV = 0
OV = 1
OV
DSG = 1
CHG = 0
∆T =
2.4ms
OV
PULSE OFF ^{∆T =}
DSG = 1 96ms
CHG = 0
OV
PULSE ON
DSG = 1
CHG = 0
∆T =
6.4ms
OV
ZCHK
DSG = 1
CHG = 0
∆T =
160µs
OV
MEASURE
DSG = 1
CHG = 0
∆T =
640µs
UV = 1
OV = 0
UV
∆T =
DSG = 1
CHG = 1 ^2.4ms
CHARGE = 0
UV
PULSE OFF ^{∆T =}
DSG = * _96ms
CHG = *
CHARGE = 0
UV
PULSE ON
DSG = 1
CHG = 1
∆T =
6.4ms
CHARGE = 0
UV
ZCHK
DSG = 1
CHG = 1
∆T =
160µs
CHARGE = 0
UV = 1
OV = 1
OV & UV _{∆T =}
DSG = 1
CHG = 0
2.4ms
OV & UV
PULSE OFF ^{∆T =}
DSG = 1 96ms
CHG = 0
OV & UV
PULSE ON
DSG = 1
CHG = 0
∆T =
6.4ms
OV & UV
ZCHK
DSG = 1
CHG = 0
∆T = 160µs
UV
MEASURE
DSG = 1
CHG = 1
∆T =
640µs
OV & UV
MEASURE
DSG = 1
CHG = 0
∆T =
640µs
* = 0 FOR OVERCURRENT FAULT; 1 OTHERWISE
Figure 1. State Diagram
_______________Detailed Description
The MAX1665S, MAX1665V, and MAX1665X supervise
the charging and discharging processes on Li+ cells.
Designed for 2, 3, and 4-cell applications, these devices
monitor the voltage across each cell to provide protec-
tion against overcurrent, overvoltage, and undervoltage.
Figure 1 shows the MAX1665 state diagram. Two con-
trol pins, CHG and DSG, drive the gates of two series-
connected external N-channel MOSFETs, enabling/
disabling the charging/discharging process as neces-
sary (see Typical Operating Circuit). The voltages at
B1P, B2P, B3P, and B4P are measured differentially
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