Multicell Battery Stack Monitor

Daisy - Chainable Serial

Description

Niveau: Supérieur, Doctorat, Bac+8
LTC6802-1 1 68021fa TYPICAL APPLICATION DESCRIPTION Multicell Battery Stack Monitor 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. FEATURES APPLICATIONS n Measures up to 12 Li-Ion Cells in Series (60V Max) n Stackable Architecture Enables >1000V Systems n 0.25% Maximum Total Measurement Error n 13ms to Measure All Cells in a System n Cell Balancing: On-Chip Passive Cell Balancing Switches Provision for Off-Chip Passive Balancing n Two Thermistor Inputs Plus On-Board Temperature Sensor n 1MHz Daisy-Chainable Serial Interface n High

• vreg vref


• ?a ?a


• pin sdi


• pins csbo


• mv mv


• current high


• voltage range


• digital input


• cell voltage

Sujets

• Serial
• Requirement
• Linear Technology

Informations

• Publié par: profil-zyak-2012
• Nombre de lectures: 90
• Langue: English

Extrait

LTC6802-1
Multicell
Battery Stack Monitor
FEATURES DESCRIPTION
®n Measures up to 12 Li-Ion Cells in Series (60V Max) The LTC 6802-1 is a complete battery monitoring IC that
n Stackable Architecture Enables >1000V Systems includes a 12-bit ADC, a precision voltage reference, a
n high voltage input multiplexer and a serial interface. Each 0.25% Maximum Total Measurement Error
n LTC6802-1 can measure up to 12 series connected bat- 13ms to Measure All Cells in a System
n tery cells with an input common mode voltage up to 60V. Cell Balancing:
In addition, multiple LTC6802-1 devices can be placed in On-Chip Passive Cell Balancing Switches
series to monitor the voltage of each cell in a long battery Provision for Off-Chip Passive Balancing
n string. The unique level-shifting serial interface allows the Two Thermistor Inputs Plus On-Board
serial ports of these devices to be daisy-chained without Temperature Sensor
n optocouplers or isolators. 1MHz Daisy-Chainable Serial Interface
n High EMI Immunity When multiple LTC6802-1 devices are connected in series
n Delta Sigma Converter with Built-In Noise Filter they can operate simultaneously, permitting all cell voltages
n Open Wire Connection Fault Detection in the stack to be measured within 13ms.
n Low Power Modes
To minimize power , the L TC6802-1 offers a measure mode, n 44-Lead SSOP Package
which simply monitors each cell for overvoltage and un-
dervoltage conditions. A standby mode is also provided.APPLICATIONS
Each cell input has an associated MOSFET switch for
n Electric and Hybrid Electric Vehicles
discharging overcharged cells.
n High Power Portable Equipment
n For large battery stack applications requiring individually Backup Battery Systems
n addressable serial communications, see the LTC6802-2. 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 Measurement Error Over
SERIAL DATAPACK ABOVE LTC6802-1
+ Extended TemperatureTO LTC6802-1V
ABOVEDIE TEMP 0.30
0.25
7 REPRESENTATIVE
0.20REGISTERS UNITS
AND 0.15
CONTROL
0.10
12-CELL 0.05
MUXBATTERY
0STRING
–0.05
12-BIT
–0.10Δ∑ ADC
–0.15
–0.20
–0.25VOLTAGE
– SERIAL DATAV REFERENCE –0.30EXTERNAL TO LTC6802-1 –50 –25 0 25 50 75 100 125TEMPNEXT 12-CELL BELOW TEMPERATURE (°C)PACK BELOW 68021 TA01a
68021 TA01b
100k
100k NTC
68021fa
1
MEASUREMENT ERROR (%)LTC6802-1
ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION
(Note 1)
TOP VIEW+ –Total Supply Voltage (V to V ) .................................60V
CSBO 1 44 CSBI–Input Voltage (Relative to V )
SDOI 2 43 SDO
C1 ............................................................ –0.3V to 9V
SCKO 3 42 SDI+ +C12 .......................................... V – 0.6V to V + 0.3V +V 4 41 SCKI
Cn (Note 5) ......................... –0.3V to min (9 • n, 60V)
C12 5 40 VMODE
Sn (Note 5) –0in (9 • n, 60V) S12 6 39 GPIO2
+ +CSBO, SCKO, SDOI .................. V – 0.6V to V + 0.3V C11 7 38 GPIO1
All other pins ........................................... –0.3V to 7V S11 8 37 WDTB
Voltage Between Inputs C10 9 36 MMB
S10 10 35 TOSCn to Cn-1 ................................................ –0.3V to 9V
C9 11 34 VREGSn to Cn-1 –0
S9 12 33 VREFC12 to C8 ............................................... –0.3V to 25V
C8 13 32 VTEMP2C8 to C4 ................................................. –0V
– S8 14 31 VTEMP1C4 to V –0.3V to 25V
C7 15 30 NCOperating Temperature Range .................–40°C to 85°C
–S7 16 29 V
Specified Temperatur..................–40°C to 85°C
C6 17 28 S1
Junction Temperature ........................................... 150°C
S6 18 27 C1
Storage Temperature Range .................. –65°C to 150°C
C5 19 26 S2
S5 20 25 C2
*n = 1 to 12 C4 21 24 S3
S4 22 23 C3
G PACKAGE
44-LEAD PLASTIC SSOP
T = 150°C, θ = 70°C/WJMAX JA
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC6802IG-1#PBF LTC6802IG-1#TRPBF LTC6802G-1 44-Lead Plastic SSOP –40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.TC 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
2LTC6802-1
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
+ –temperature range, otherwise specifications are at T = 25°C. V = 43.2V, V = 0V, unless otherwise noted.A
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
DC Specifications
V Measurement Resolution Quantization of the ADC l 1.5 mV/BitACC
lADC Offset Voltage (Note 2) –0.5 0.5 mV
ADC Gain Error (Note 2) –0.12 0.12 %
l –0.22 0.22 %
V Total Measurement Error (Note 4)ERR
V = 0V 0.8 mVCELL
V = 2.3V –2.8 2.8 mVCELL
V l –5.1 5.1 mVCELL
V = 3.6V –4.3 4.3 mVCELL
V l –7.9 7.9 mVCELL
V = 4.2V –5 5 mVCELL
V l –9.2 9.2 mVCELL
V = 4.6V ±8 mVCELL
V = 2.3V l –5.1 5.1 mVTEMP
V = 3.6V l –7.9 7.9 mVTEMP
V = 4.2V l –9.2 9.2 mVTEMP
V Cell Voltage Range Full Scale Voltage Range 5 VCELL
lV Common Mode Voltage Range Measured Range of Inputs CN for <0.25% Gain Error, N = 3 to 11 3.7 5 • N VCM
– lRelative to V Range of Input C3 for <1% Gain Error 1.8 15 V
lRange of Input C2 for <0.25% Gain Error 1.2 10 V
lRange of Input C1 for <0.25% Gain Error 0 5 V
Overvoltage (OV) Detection Level Programmed for 4.2V l 4.182 4.200 4.218 V
Undervoltage (UV) Detection Level Programmed for 2.3V l 2.290 2.300 2.310 V
Die Temperature Measurement Error Error in Measurement at 125°C 3 °C
–V Reference Pin Voltage R = 100k to V 3.020 3.065 3.110 VREF LOAD
l 3.015 3.065 3.115 V
Reference Voltage Temperature Coefficient 8 ppm/°Coltage Thermal Hysteresis 25°C to 85°C and 25°C to –40°C 100 ppm
Reference Voltage Long Term Drift 60 ppm/√khr
+ lV Regulator Pin Voltage 10 < V < 50, No Load 4.5 5.0 5.5 VREG
lI = 4mA 4.1 4.8 VLOAD
Regulator Pin Short Circuit Current Limit l 58 mA
+ –V Supply Voltage, V Relative to V V Specifications Met l 10 50 VS ERR
Timing Specifications Met l 4 50 V
I Input Bias Current In/Out of Pins C1 Thru C12B
lWhen Measuring Cells –10 10 μA
When Not Measuring Cells 1 nA
+I Supply Current, Active Current Into the V Pin when Measuring Voltages 0.8 1.1 mAS
lwith the ADC 1.2 mA
+I Supply Current, Monitor Mode Average Current Into the V Pin While Monitoring M
for UV and OV Conditions
Continuous Monitoring (CDC = 2) 800 μA
Monitor Every 130ms (CDC = 5) 225 μAy 500ms (CDC = 6) 150 μAy 2s (CDC = 7) 100 μA
+I Supply Current, Idle Current into the V Pin When Idle 35 60 80 μAQS
All Serial Port Pins at Logic ‘1’ l 30 85 μA
lI Supply Current, Serial I/O All Serial Port Pins at Logic ‘0’ V = 0, This 3 4.5 mACS MODE
Current is Added to I or IS QS
68021fa
3LTC6802-1
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
+ –temperature range, otherwise specifications are at T = 25°C. V = 43.2V, V = 0V, unless otherwise noted.A
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Discharge Switch On-Resistance V > 3V (Note 3) l 10 20 ΩCELL
lTemperature Range –40 85 °C
Thermal Shutdown Temperature 145 °C
Thermal Shutdown Hysteresis 5°C
Voltage Mode Timing Specifications
lt Measurement Cycle Time Time Required to Measure 11 or 12 Cells 11 13 16 msCYCLE
lTime Required to Measure Up to 10 Cells 9.2 11 13.5 ms
Time Required to Measure 1 Cell 1 1.2 1.5 ms
t SDI Valid to SCKI Rising Setup l 10 ns1
t SDI Valid to SCKI Rising Hold l 250 ns2
lt SCKI Low 400 ns3
lt SCKI High 400 ns4
t CSBI Pulse Width l 400 ns5
t SCKI Rising to CSBI Rising l 100 ns6
lt CSBI Falling to SCKI Rising 100 ns7
lt SCKI Falling to SDO Valid 250 ns8
Clock Frequency l 1 MHz
Watchdog Timer Time Out Period l 1 2.5 s
Timing Specifications
lt CSBI to CSBO C = 150pF 600 nsPD1 CSBO
t SCKI to SCKO C l 300 nsPD2 SCKO
t SDI to SDOI Write Delay C = 150pF l 300 nsPD3 SDOI
lt SDOI to SDI Read Delay C 300 nsPD4 SDO
Voltage Mode Digital I/O Specifications
V Digital Input Voltage High Pins SCKI, SDI, and CSBI l2VIH
Voltage Low l 0.8 VIL
lV Digital Output VPin SDO; Sinking 500μA 0.3 VOL
Current Mode Digital I/O Specifications
I Digital Input Current High Pins CSBI, SCKI, and SDI (Write) l 10 μAIH1
lI Digital Input Current Low 1000 μAIL1
lIPin SDOI (Read) –1000 μAIH2
I l –10 μAIL2
I Digital Output Current High Pins CSBO, SCKO, and SDOI (Write) l 310 &#