Cell Management Electronics for Lithium-Ion Battery BEU8635-08 Balancing for 8-Cell Battery Cell Voltage Monitoring and Telemetry www.aeroflex.com/BEU March 3, 2008 Description The Aeroflex 8635-08 is a Lithium-Ion cell balancing system. It controls the balancing of one battery consisting of a series stack of Lithium-Ion cells to ensure that each cell is precisely charged to its proper level of energy and to monitor each cell's operational voltage. The cell balancing circuitry uses a set of bilateral DC-DC converters which tie each cell of a battery to a common share bus. Cell charge is distributed among the multiple cells so that the charge of each cell is automatically matched to the average charge of the other cells. Features ● Cell Balancing to within ±5.0mV ● Cell Voltage Monitoring Accuracy ±10.0mV (±20.0mV Space Mission Life) ● Total Battery Voltage Monitoring Accuracy ±0.3% of Full Scale ● Supports 8 Lithium-Ion battery cells in series ● Battery Drain Current at Balance 15mA maximum ● Discrete output lines for critical signaling with user definable thresholds: Overvoltage Protection 4.40V typ Cell Voltage High 4.20V typ Cell Voltage Low 3.20V typ ● MIL-STD-1553B telemetry for data logging and monitoring SCD8635-08 Rev A Safety The safety of Lithium-Ion battery technology requires that extreme care be taken in the provisions made for cell charging and cell monitoring. Precision measurements of each of the individual cell voltages in the battery stack and precise charge balancing to each individual cell are critical. The Aeroflex 8635-08 provides the necessary precision of control and monitoring to ensure that safety. Discrete logic outputs are provided for critical signaling, enabling the user to initiate load shedding and/or to halt charging. Low operating losses enable continuous operation. Continuous balancing provides maximum protection against any one cell becoming overcharged. CELL BALANCE BOARD CONTROL BOARD OVP 1553B Channel A VIN A/D 12-BIT HIGH CELL LOW CELL 12 MUX SELECT XFMR 7 XCVR 1553B Channel B ON OFF +30 VDC CONTROLLER XFMR BALANCING CIRCUIT CLOCK DRIVER RELAY POWER SUPPLY -12VDC BAL CLK MON CLK BALANCING CIRCUIT 1 + - BALANCING CIRCUIT 2 + - BALANCING CIRCUIT 3 + - BALANCING CIRCUIT 4 + - BALANCING CIRCUIT 8 + - PRECISION REFERENCE 4.000V +12VDC (ISOLATED) +5VDC MUX BATTERY 8 CELLS 2 2 2 BATTERY VOLTAGE DIFF. AMPS BATTERY HI AND LO ( 3x ) +12VDC SHARE BUS Block Diagram 8635-08 Operating Details Battery Cell Balancing Provides 8 individual continuous balancing circuits. Battery and Cell Protection Incorporates overvoltage protection (OVP) circuits. These circuits monitor all of the battery cell voltages and only register the highest of all cell voltages monitored. When a cell voltage threshold of 4.40V is reached, the protection circuit output changes state and latches within 50mS. Maximum Cell Balancing Current Limit Each cell is provided with a 1Amp fuse for overload interrupt in the event of a shorted cell to protect the remaining cell balance functionality. Battery Cell Overvoltage Latch Output The status of the OVP latch is provided by telemetry as specified in Tables II, III & IV and also as a discrete output. Cell Balancing Accuracy When connected to a battery, the 8635-08 provides balancing currents into each of the battery's cells. The directions and the magnitudes of the individual currents are proportional to the deviations of the cell voltages from the average cell voltage. The transfer ratio of voltage to current is 1.0 Ohm nominal and is satisfied for cell voltages of up to 4.2V. Recovery from Cell Overvoltage Indication The OVP latch is reset by a 1553B reset command or by recycling the input power. Highest Battery Cell Voltage Telemetry Provides highest battery cell voltage telemetry as specified in Tables I & IV. Battery Cell Current Drawn in Off State In the off state, the differential mode battery cell current drawn by each cell balancing circuit is less than 50μA. Lowest Battery Cell Voltage Telemetry Provides lowest battery cell voltage telemetry as specified in Tables I & IV. Battery Cell Voltage Monitoring Measures cell voltages for up to 8-cells. Test Points Provides test points for total battery voltage, low cell indicator and high cell indicator. Access to the total battery voltage is provided to permit pre-charging before connection to the battery. 4V and 0V References for Calibration Provides 4V and 0V references for cell voltage telemetry calibration. Aeroflex Plainview SCD8635-08 Rev A 3/3/08 2 MIL-STD-1553B Telemetry & Commands Analog or bi-level telemetry can be requested from the controller and reported over the dual redundant 1553B interface with the RT addresses configurable at the J1 connector. Bi-Level Telemetry Bi-level telemetry can be requested on sub-addresses 18, 19 or 22. Analog Telemetry Each analog telemetry item can be requested individually on sub-addresses 18, 19 or 22. First a 1553B receive command with one data word as defined in Table II, which specifies the telemetry item being requested, must be issued. After a minimum delay of 1.2ms, the data can be retrieved by sending a 1553B transmit command for one data word on the same sub-address on which the request was initiated. First a 1553B receive command with one data word as defined in Table I, which specifies the telemetry item being requested, must be issued. After a minimum delay of 1.2ms, the data can be retrieved by sending a 1553B transmit command for one data word on the same sub-address on which the request was initiated. Table II – Bi-level Telemetry The 12-bit data reply is left justified in the 16-bit 1553B data word with the four LSBs set to "0". Item Telemetry Title Status Reply Bit 1st Data Word of 1553B Receive Command (Hex) D13 0C80 Table I – Analog Telemetry Item Telemetry Title Telemetry Reply Scale 1st Data Word of 1553B Receive Command (Hex) 1 4V Reference -0.40V to 4.89V 0800 2 0V Reference -0.40V to 4.89V 0803 3 Total Battery Voltage 1 0V to 122.88V 0805 4 Total Battery Voltage 2 0V to 122.88V 0806 5 Total Battery Voltage 3 0V to 122.88V 0809 6 Share Bus Voltage 0V to 5.12V 080A 7 Cell 1 Voltage 0V to 5.12V 0811 8 Cell 2 Voltage 0V to 5.12V 0812 9 Cell 3 Voltage 0V to 5.12V 0814 10 Cell 4 Voltage 0V to 5.12V 0817 11 Cell 5 Voltage 0V to 5.12V 0818 12 Cell 6 Voltage 0V to 5.12V 081B 13 Cell 7 Voltage 0V to 5.12V 081D 14 Cell 8 Voltage 0V to 5.12V 081E 15 Lowest Cell Voltage 0V to 5.12V 0871 16 Highest Cell Voltage 0V to 5.12V 0872 1 Overvoltage Latch Status 1 = Set Aeroflex Plainview SCD8635-08 Rev A 3/3/08 3 32-Word Telemetry To reduce data bus bandwidth usage, the 8635-08 supports a 32-word telemetry request on sub-address 20 as defined in Table III. 8-Word Telemetry To reduce data bus bandwidth usage, the 8635-08 supports an 8-word telemetry request on sub-address 24 as defined in Table IV. First a 1553B receive command with one data word of AAAA(Hex) must be issued. After a minimum delay of 1.2ms, the data can be retrieved by sending a 1553B transmit command for 32 data words on sub-address 20. First a 1553B receive command with one data word of 5555(Hex) must be issued. After a minimum delay of 1.2ms, the data can be retrieved by sending a 1553B transmit command for 8 data words on sub-address 24. Reply word 31 is a modulo-16 message count. This counter increments by one for each valid telemetry request. The 12-bit analog data reply is left justified in the 16-bit 1553B data word with the four LSBs set to "0".. Reply word 8 is a modulo-16 message count. This counter increments by one for each valid telemetry request. The 12-bit analog data reply is left justified in the 16-bit 1553B data word with the four LSBs set to "0". Table III – 32-Word Telemetry Table IV – 8-Word Telemetry Item Telemetry Title Telemetry Reply Type Word Reply Bits Item Telemetry Title Telemetry Type Reply Word Reply Bits Bi-Level 1 D13 1 4V Reference Analog 1 D(15:4) 1 Overvoltage Level Status 2 Total Battery Voltage 1 Analog 2 D(15:4) 2 Reserved - 2 - D(15:4) 3 Reserved - 3 - D(15:4) 4 Reserved - 4 - 0V Reference Analog 5 D(15:4) 3 4 Total Battery Voltage 2 Total Battery Voltage 3 5 Share Bus Voltage 6 Reserved Analog Analog 3 4 Analog 5 D(15:4) 5 - 6 - 6 Lowest Cell Voltage Analog 6 D(15:4) Highest Cell Voltage Analog 7 D(15:4) Message Count Analog 8 D(15:0) 7 Cell 1 Voltage Analog 7 D(15:4) 7 8 Cell 2 Voltage Analog 8 D(15:4) 8 9 Cell 3 Voltage Analog 9 D(15:4) 10 Cell 4 Voltage Analog 10 D(15:4) 11 Cell 5 Voltage Analog 11 D(15:4) 12 Cell 6 Voltage Analog 12 D(15:4) 13 Cell 7 Voltage Analog 13 D(15:4) 14 Cell 8 Voltage Analog 14 D(15:4) - 15 Reserved - 15 16 Reserved - 16 - 17 Reserved - 17 - 18 Reserved - 18 - 19 Reserved - 19 20 Reserved - 20 - 21 Reserved - 21 - 22 Reserved - 22 - 23 Reserved - 23 - 24 Reserved - 24 - 25 Reserved - 25 - 26 Reserved - 26 - 27 Reserved - 27 28 Reserved - 28 - 29 Reserved - 29 - 30 Reserved - 30 - 31 Message Count Analog 31 D(15:0) 32 Overvoltage Latch Status Bi-level 32 D13 Aeroflex Plainview SCD8635-08 Rev A 3/3/08 4 Additional Commands indicate that the unit is busy and cannot accept another command. Data Load Command 1553B receive commands consist of 2 data words to the sub-address specified in Table V. Only the first data word is used. 1553B Data Wrap Around Sub-address 30 is dedicated to data wrap around as specified in MIL-STD-1553B. Supported Mode Codes The 8635-08 supports the 1553B Mode Codes in Table VI. Table V – Commands Item Function Title 1 Reserved 2 Reserved 3 Reset OVP Latch 1st Data Word of 1553B Sub-Address Receive Command (Hex) Table VI – 1553B Mode Codes Mode Code Name Mode Code Number Transmit Status Word 2 - Transmitter Shutdown 4 14 - Override Transmitter Shutdown 5 15 0400 Reset Remote Terminal 8 13 Telemetry Frame Sync Command 1553B broadcast command on sub-address 17 (any data word) commands the 8635-08 to refresh its RT address. 1553B Status Flag Bits The 8635-08 supports the following 1553B status flag bits: 1. Message Error bit 2. Broadcast Message Received bit All other status bits are set to "0". Remote Terminal State Command 1553B transmit command on sub-address 21 for one data word. The reply word will be 4000(Hex), to indicate that the unit is ready to accept another command or 5000(Hex), to Aeroflex Plainview SCD8635-08 Rev A 3/3/08 5 Connector P1 26 Pin Subminiature-D Plug Cell Sense Connector J2 for Control Board Triaxial 1553B Bus A CHA_DATA_H Pin # Function Name Pin # Function Name 23 RESERVED 17 RESERVED 9 RESERVED 7 RESERVED CHA_DATA_L SHIELD 3 RESERVED 14 RESERVED 19 RESERVED 1 RESERVED 10 CELL_8+ 20 RESERVED 13 CELL_7+ 12 RESERVED 16 CELL_6+ 18 RESERVED Connector J3 for Control Board Triaxial 1553B Bus B 26 CELL_5+ 8 RESERVED CHB_DATA_H 5 CELL_4+ 4 RESERVED CHB_DATA_L 2 CELL_3+ 21 RESERVED SHIELD 15 CELL_2+ 22 RESERVED 24 CELL_1+ 6 RESERVED 11 CELL_1- 25 RESERVED Connector J1 for Control Board 51 Pin Micro-D Receptacle Control & Test Points Pin # Function Pin # Function Pin # Function 1 30V_RTN 18 V_BAT_3 35 V_BAT_2 2 NC_ISOLATION 19 NC_ISOLATION 36 NC_ISOLATION 3 NC_ISOLATION 20 +30V_POWER 37 NC_ISOLATION 4 NC_ISOLATION 21 +30V_POWER 38 NC_ISOLATION 5 30V_RTN 22 NC_ISOLATION 39 SPARE 6 NC_ISOLATION 23 NC_ISOLATION 40 CHASSIS GND 7 CHASSIS GND 24 CHASSIS GND 41 RESERVED 8 CELL_CHG_8 25 LOW_CELL 42 SPARE 9 SPARE 26 RESERVED 43 BEU_ON_CMD_1 10 BEU_OFF_CMD_2 27 BAL_ON_1 44 BEU_ON_CMD_2 11 BEU_OFF_CMD_1 28 BAL_ON_2 45 HIGH_CELL 12 RTA_2 29 RTA_0 46 RTA_4 13 RTA_GND 30 RTA_GND 47 RTA_GND 14 RTA_GND 31 RTA_GND 48 RTA_GND 15 RTA_1 32 RTA_3 49 RTPTY 16 OV_PROT 33 V_BAT_TP 50 V_BAT_RTN1 17 V_BAT_RTN3 34 V_BAT_RTN2 51 V_BAT_1 Aeroflex Plainview SCD8635-08 Rev A 3/3/08 6 3-D View 2x 0.25 2x 11.00 2x 0.40 2x 1.00 4x 0.20 J3 0.76 J2 P1 5.250 J1 3.25 2.50 1.50 11.50 2.01 Outline Aeroflex Plainview SCD8635-08 Rev A 3/3/08 7 Standard Configuration Power Dissipation 6.6 Watts from 30V Supply 0.5 Watts from battery Operating Base Plate Temperature BEU8635-08-S -34°C to +71°C BEU8635-08 0°C to +70°C Storage Temperature -34°C to +71°C Dimensions 11.5'' L x 2.01'' W x 5.25'' H Weight 3.5 lbs (1.59 kg) Ordering Information MODEL NUMBER SCREENING BEU8635-08-S High Reliablilty Space Grade BEU8635-08 Commerical Flow EXPORT CONTROL: EXPORT WARNING: This product is controlled for export under the International Traffic in Arms Regulations (ITAR). A license from the U.S. Department of State is required prior to the export of this product from the United States. Aeroflex’s military and space products are controlled for export under the International Traffic in Arms Regulations (ITAR) and may not be sold or proposed or offered for sale to certain countries. (See ITAR 126.1 for complete information.) PLAINVIEW, NEW YORK Toll Free: 800-THE-1553 Fax: 516-694-6715 INTERNATIONAL Tel: 805-778-9229 Fax: 805-778-1980 NORTHEAST Tel: 603-888-3975 Fax: 603-888-4585 SE AND MID-ATLANTIC Tel: 321-951-4164 Fax: 321-951-4254 WEST COAST Tel: 949-362-2260 Fax: 949-362-2266 CENTRAL Tel: 719-594-8017 Fax: 719-594-8468 www.aeroflex.com [email protected] Aeroflex Microelectronic Solutions reserves the right to change at any time without notice the specifications, design, function, or form of its products described herein. All parameters must be validated for each customer's application by engineering. No liability is assumed as a result of use of this product. No patent licenses are implied. Our passion for performance is defined by three attributes represented by these three icons: solution-minded, performance-driven and customer-focused SCD8635-08 Rev A 3/3/08 8