LTC6802-1
Multicell
Battery Stack Monitor
FEATURES
n
n
n
n
n
DESCRIPTION
The LTC
®
6802-1 is a complete battery monitoring IC that
includes a 12-bit ADC, a precision voltage reference, a
high voltage input multiplexer and a serial interface. Each
LTC6802-1 can measure up to 12 series connected bat-
tery cells with an input common mode voltage up to 60V.
In addition, multiple LTC6802-1 devices can be placed in
series to monitor the voltage of each cell in a long battery
string. The unique level-shifting serial interface allows the
serial ports of these devices to be daisy-chained without
optocouplers or isolators.
When multiple LTC6802-1 devices are connected in series
they can operate simultaneously, permitting all cell voltages
in the stack to be measured within 13ms.
To minimize power, the LTC6802-1 offers a measure mode,
which simply monitors each cell for overvoltage and un-
dervoltage conditions. A standby mode is also provided.
Each cell input has an associated MOSFET switch for
discharging overcharged cells.
For large battery stack applications requiring individually
addressable serial communications, see the LTC6802-2.
n
n
n
n
n
n
n
Measures up to 12 Li-Ion Cells in Series (60V Max)
Stackable Architecture Enables >1000V Systems
0.25% Maximum Total Measurement Error
13ms to Measure All Cells in a System
Cell Balancing:
On-Chip Passive Cell Balancing Switches
Provision for Off-Chip Passive Balancing
Two Thermistor Inputs Plus On-Board
Temperature Sensor
1MHz Daisy-Chainable Serial Interface
High EMI Immunity
Delta Sigma Converter with Built-In Noise Filter
Open Wire Connection Fault Detection
Low Power Modes
44-Lead SSOP Package
APPLICATIONS
n
n
n
n
Electric and Hybrid Electric Vehicles
High Power Portable Equipment
Backup Battery Systems
High Voltage Data Acquisition Systems
L,
LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
NEXT 12-CELL
PACK ABOVE
V
+
LTC6802-1 SERIAL DATA
TO LTC6802-1
ABOVE
DIE TEMP
REGISTERS
AND
CONTROL
12-CELL
BATTERY
STRING
MUX
12-BIT
Δ∑ ADC
Measurement Error Over
Extended Temperature
0.30
0.25
MEASUREMENT ERROR (%)
0.20
0.15
0.10
0.05
0
–0.05
–0.10
–0.15
–0.20
–0.25
7 REPRESENTATIVE
UNITS
V
NEXT 12-CELL
PACK BELOW
–
EXTERNAL
TEMP
VOLTAGE
REFERENCE
68021 TA01a
SERIAL DATA
TO LTC6802-1
BELOW
–0.30
–50
–25
0
25
50
75
TEMPERATURE (°C)
100
125
68021 TA01b
100k
100k NTC
68021fa
1
LTC6802-1
ABSOLUTE MAXIMUM RATINGS
(Note 1)
PIN CONFIGURATION
TOP VIEW
CSBO
SDOI
SCKO
V
+
C12
S12
C11
S11
C10
1
2
3
4
5
6
7
8
9
44 CSBI
43 SDO
42 SDI
41 SCKI
40 V
MODE
39 GPIO2
38 GPIO1
37 WDTB
36 MMB
35 TOS
34 V
REG
33 V
REF
32 V
TEMP2
31 V
TEMP1
30 NC
29 V
–
28 S1
27 C1
26 S2
25 C2
24 S3
23 C3
Total Supply Voltage (V
+
to V
–
) .................................60V
Input Voltage (Relative to V
–
)
C1 ............................................................ –0.3V to 9V
C12 .......................................... V
+
– 0.6V to V
+
+ 0.3V
Cn (Note 5) ......................... –0.3V to min (9 • n, 60V)
Sn (Note 5) ......................... –0.3V to min (9 • n, 60V)
CSBO, SCKO, SDOI .................. V
+
– 0.6V to V
+
+ 0.3V
All other pins ........................................... –0.3V to 7V
Voltage Between Inputs
Cn to Cn-1 ................................................ –0.3V to 9V
Sn to Cn-1 ................................................ –0.3V to 9V
C12 to C8 ............................................... –0.3V to 25V
C8 to C4 ................................................. –0.3V to 25V
C4 to V
–
................................................. –0.3V to 25V
Operating Temperature Range .................–40°C to 85°C
Specified Temperature Range ..................–40°C to 85°C
Junction Temperature ........................................... 150°C
Storage Temperature Range .................. –65°C to 150°C
*n = 1 to 12
S10 10
C9 11
S9 12
C8 13
S8 14
C7 15
S7 16
C6 17
S6 18
C5 19
S5 20
C4 21
S4 22
G PACKAGE
44-LEAD PLASTIC SSOP
T
JMAX
= 150°C,
θ
JA
= 70°C/W
ORDER INFORMATION
LEAD FREE FINISH
LTC6802IG-1#PBF
TAPE AND REEL
LTC6802IG-1#TRPBF
PART MARKING
LTC6802G-1
PACKAGE DESCRIPTION
44-Lead Plastic SSOP
TEMPERATURE RANGE
–40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/
68021fa
2
LTC6802-1
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
DC Specifications
V
ACC
Measurement Resolution
ADC Offset Voltage
ADC Gain Error
V
ERR
Total Measurement Error
Quantization of the ADC
(Note 2)
(Note 2)
(Note 4)
V
CELL
= 0V
V
CELL
= 2.3V
V
CELL
= 2.3V
V
CELL
= 3.6V
V
CELL
= 3.6V
V
CELL
= 4.2V
V
CELL
= 4.2V
V
CELL
= 4.6V
V
TEMP
= 2.3V
V
TEMP
= 3.6V
V
TEMP
= 4.2V
Full Scale Voltage Range
Range of Inputs CN for <0.25% Gain Error, N = 3 to 11
Range of Input C3 for <1% Gain Error
Range of Input C2 for <0.25% Gain Error
Range of Input C1 for <0.25% Gain Error
Programmed for 4.2V
Programmed for 2.3V
Error in Measurement at 125°C
R
LOAD
= 100k to V
–
l
l
l
l
l
l
l
l
l
l
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
+
= 43.2V, V
–
= 0V, unless otherwise noted.
CONDITIONS
MIN
TYP
1.5
–0.5
–0.12
–0.22
0.8
l
l
l
l
l
l
MAX
UNITS
mV/Bit
0.5
0.12
0.22
mV
%
%
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
V
V
V
V
V
V
V
°C
V
V
ppm/°C
ppm
ppm/√khr
–2.8
–5.1
–4.3
–7.9
–5
–9.2
±8
–5.1
–7.9
–9.2
5
3.7
1.8
1.2
0
4.182
2.290
3.020
3.015
4.200
2.300
3
3.065
3.065
8
100
60
2.8
5.1
4.3
7.9
5
9.2
5.1
7.9
9.2
5•N
15
10
5
4.218
2.310
3.110
3.115
V
CELL
V
CM
Cell Voltage Range
Common Mode Voltage Range Measured
Relative to V
–
Overvoltage (OV) Detection Level
Undervoltage (UV) Detection Level
Die Temperature Measurement Error
V
REF
Reference Pin Voltage
Reference Voltage Temperature Coefficient
Reference Voltage Thermal Hysteresis
Reference Voltage Long Term Drift
V
REG
Regulator Pin Voltage
Regulator Pin Short Circuit Current Limit
V
S
I
B
Supply Voltage, V
+
Relative to V
–
Input Bias Current
25°C to 85°C and 25°C to –40°C
10 < V
+
< 50, No Load
I
LOAD
= 4mA
V
ERR
Specifications Met
Timing Specifications Met
In/Out of Pins C1 Thru C12
When Measuring Cells
When Not Measuring Cells
Current Into the V
+
Pin when Measuring Voltages
with the ADC
Average Current Into the V
+
Pin While Monitoring
for UV and OV Conditions
Continuous Monitoring (CDC = 2)
Monitor Every 130ms (CDC = 5)
Monitor Every 500ms (CDC = 6)
Monitor Every 2s (CDC = 7)
Current into the V
+
Pin When Idle
All Serial Port Pins at Logic ‘1’
All Serial Port Pins at Logic ‘0’ V
MODE
= 0, This
Current is Added to I
S
or I
QS
l
l
l
l
l
l
l
l
4.5
4.1
5
10
4
–10
5.0
4.8
8
5.5
V
V
mA
V
V
μA
nA
mA
mA
50
50
10
1
0.8
1.1
1.2
I
S
I
M
Supply Current, Active
Supply Current, Monitor Mode
l
800
225
150
100
35
30
3
60
80
85
4.5
μA
μA
μA
μA
μA
μA
mA
I
QS
I
CS
Supply Current, Idle
Supply Current, Serial I/O
68021fa
3
LTC6802-1
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
Discharge Switch On-Resistance
Temperature Range
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
Voltage Mode Timing Specifications
t
CYCLE
Measurement Cycle Time
Time Required to Measure 11 or 12 Cells
Time Required to Measure Up to 10 Cells
Time Required to Measure 1 Cell
l
l
l
l
l
l
l
l
l
l
l
l
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
+
= 43.2V, V
–
= 0V, unless otherwise noted.
CONDITIONS
V
CELL
> 3V (Note 3)
l
l
MIN
–40
TYP
10
145
5
MAX
20
85
UNITS
Ω
°C
°C
°C
11
9.2
1
10
250
400
400
400
100
100
13
11
1.2
16
13.5
1.5
ms
ms
ms
ns
ns
ns
ns
ns
ns
ns
t
1
t
2
t
3
t
4
t
5
t
6
t
7
t
8
SDI Valid to SCKI Rising Setup
SDI Valid to SCKI Rising Hold
SCKI Low
SCKI High
CSBI Pulse Width
SCKI Rising to CSBI Rising
CSBI Falling to SCKI Rising
SCKI Falling to SDO Valid
Clock Frequency
Watchdog Timer Time Out Period
250
1
1
2.5
600
300
300
300
2
0.8
0.3
10
1000
–1000
–10
3
1000
–1650
–10
1200
–1200
–3
10
1650
–1000
0
ns
MHz
s
ns
ns
ns
ns
V
V
V
μA
μA
μA
μA
μA
μA
μA
μA
Timing Specifications
t
PD1
t
PD2
t
PD3
t
PD4
V
IH
V
IL
V
OL
I
IH1
I
IL1
I
IH2
I
IL2
I
OH1
I
OL1
I
OH2
I
OL2
CSBI to CSBO
SCKI to SCKO
SDI to SDOI Write Delay
SDOI to SDI Read Delay
Digital Input Voltage High
Digital Input Voltage Low
Digital Output Voltage Low
Digital Input Current High
Digital Input Current Low
Digital Input Current High
Digital Input Current Low
Digital Output Current High
Digital Output Current Low
Digital Output Current High
Digital Output Current Low
C
CSBO
= 150pF
C
SCKO
= 150pF
C
SDOI
= 150pF
C
SDO
= 150pF
Pins SCKI, SDI, and CSBI
Pins SCKI, SDI, and CSBI
Pin SDO; Sinking 500μA
Pins CSBI, SCKI, and SDI (Write)
Pins CSBI, SCKI, and SDI (Write)
Pin SDOI (Read)
Pin SDOI (Read)
Pins CSBO, SCKO, and SDOI (Write)
Pins CSBO, SCKO, and SDOI (Write)
Pin SDI (Read)
Pin SDI (Read)
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
Voltage Mode Digital I/O Specifications
Current Mode Digital I/O Specifications
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2:
The ADC specifications are guaranteed by the Total Measurement
Error (V
ERR
) specification.
Note 3:
Due to the contact resistance of the production tester, this
specification is tested to relaxed limits. The 20Ω limit is guaranteed by
design.
Note 4:
V
CELL
refers to the voltage applied across the following pin
combinations: Cn to Cn-1 for n = 2 to 12, C1 to V
–
. V
TEMP
refers to the
voltage applied from V
TEMP1
or V
TEMP2
to V
–
.
Note 5:
These absolute maximum ratings apply provided that the voltage
between inputs do not exceed their absolute maximum ratings.
68021fa
4
LTC6802-1
TYPICAL PERFORMANCE CHARACTERISTICS
Cell Measurement Total
Unadjusted Error
10
TOTAL UNADJUSTED ERROR (mV)
8
6
4
2
0
–2
–4
–6
–8
–10
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
CELL VOLTAGE (V)
68021 G01
Cell Measurement Total
Unadjusted Error
vs Input Resistance
10
TOTAL UNADJUSTED ERROR (mV)
0
–10
–20
–30
–40
R
S
= 1k
R
S
= 2k
–50
R
S
= 5k
R
S
= 10k
–60
R
S
IN SERIES WITH CN AND CN-1
–70 NO EXTERNAL CAPACITANCE ON
CN AND CN-1
–80
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
CELL VOLTAGE (V)
68021 G02
Measurement Gain Error
Hysteresis
25
T
A
= 85°C TO 25°C
T
A
= –40°C
T
A
= 25°C
T
A
= 85°C
T
A
= 125°C
20
NUMBER OF UNITS
15
10
5
0
–250 –200 –150 –100 –50 0 50 100 150 200
CHANGE IN GAIN ERROR (ppm)
68021 G03
Measurement Gain Error
Hysteresis
20
18
16
NUMBER OF UNITS
REJECTION (db)
14
12
10
8
6
4
2
0
–250 –200 –150 –100 –50 0 50 100 150 200
CHANGE IN GAIN ERROR (ppm)
68021 G04
Cell Measurement Common Mode
Rejection
V
CM(IN)
= 5V
P-P
72dB REJECTION
–10 CORRESPONDS TO
LESS THAN 1 BIT
–20 AT ADC OUTPUT
–30
–40
–50
–60
–70
REJECTION (db)
10
100
1k
10k 100k
FREQUENCY (Hz)
1M
10M
68021 G05
ADC Normal Mode Rejection
vs Frequency
0
–10
–20
–30
–40
–50
–60
–70
T
A
= –45°C TO 25°C
0
10
100
1k
10k
FREQUENCY (Hz)
100k
68021 G06
ADC INL
2.0
1.5
1.0
DNL (BITS)
INL (BITS)
0.5
0
–0.5
–1.0
–1.5
–2.0
0
1
3
2
INPUT (V)
4
5
68021 G07
ADC DNL
1.0
0.8
C PIN BIAS CURRENT (nA)
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1.0
0
1
3
2
INPUT (V)
4
5
68021 G08
Cell Input Bias Current in Standby
50
40
30
20
C12
10
0
C2 TO C11
–10
–40 –20
0
20 40 60 80
TEMPERATURE (°C)
100 120
68021 G09
C1
68021fa
5
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
