LTC6802IG-2 LINER [Linear Technology], LTC6802IG-2 Datasheet - Page 11

• Manufacturer Part Number: LTC6802IG-2
• Description: Multicell Addressable Battery Stack Monitor
• Manufacturer: LINER [Linear Technology]

operaTion
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between C2 and C4 after several cycles of measuring cells
B3 and B4. Thus the measurements for B3 and B4 may
indicate a valid cell voltage when in fact the exact state of
B3 and B4 is unknown.
To reliably detect an open connection, the command
STOWAD is provided. With this command, two 100µA
current sources are connected to the ADC inputs and
Figure 1. 96-Cell Battery Stack, Isolated Interface. In this Diagram the Battery Negative is Isolated from Module Ground.
Opto-Couplers or Digital Isolators Allow Each IC to be Addressed Individually. This is a Simplified Schematic Showing
the Basic Multi-IC Architecture
V
C12
S12
C11
S11
C10
S10
C9
S9
C8
S8
C7
S7
C6
S6
C5
S5
C4
S4
C3
S3
C2
V
C12
S12
C11
S11
C10
S10
C9
S9
C8
S8
C7
S7
C6
S6
C5
S5
C4
S4
C3
S3
C2
+
+
LTC6802-2
LTC6802-2
IC #2
IC #1
V
V
V
V
GPIO2
GPIO1
WDTB
GPIO2
GPIO1
WDTB
TEMP2
TEMP1
TEMP2
TEMP1
MMB
V
MMB
V
CSBI
SCKI
CSBI
SCKI
V
V
SDO
SDO
TOS
TOS
REG
REG
SDI
SDI
REF
REF
NC
NC
A3
A2
A1
A0
S1
C1
S2
A3
A2
A1
A0
S1
C1
S2
V
V
–
–
ADDRESS 1
ADDRESS 0
68022 F01
V2
OE2
V2
V2
V2
OE2
V2
V2
ISOLATOR
ISOLATOR
–
–
+
DIGITAL
–
–
+
DIGITAL
OE1
OE1
V1
V1
V1
V1
V1
V1
IC #3 TO IC #7
–
–
+
–
–
+
3V
3V
POSITIVE
BATTERY
350V
+
+
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turned on during all cell conversions. Referring again to
Figure 3, with the STOWAD command, the C3 pin will be
pulled down by the 100µA current source during the B3
cell measurement AND during the B4 cell measurement.
This will tend to decrease the B3 measurement result and
increase the B4 measurement result relative to the normal
STCVAD command. The biggest change is observed in the
MISO
CS
MOSI
CLK
MPU
3V
V
C12
S12
C11
S11
C10
S10
C9
S9
C8
S8
C7
S7
C6
S6
C5
S5
C4
S4
C3
S3
C2
+
LTC6802-2
IC #8
MODULE
IO
V
V
GPIO2
GPIO1
WDTB
TEMP2
TEMP1
MMB
V
CSBI
SCKI
V
SDO
TOS
SDI
REG
REF
NC
A3
A2
A1
A0
S1
C1
S2
V
–
ADDRESS 15
LTC6802-2
V2
OE2
V2
V2
ISOLATOR
DIGITAL
–
–
+
OE1
V1
V1
V1
–
–
+
3V

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