BEU8635-12-S - Aeroflex Incorporated

SCD8635-12 Rev A

BEU8635-12

Cell Management Electronics for Lithium-Ion Battery

Description

The Aeroflex 8635-12 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 12 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

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 8635-12 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 Voltage Monitoring and Telemetry

www.aeroflex.com/BEU

March 3, 2008

Balancing for 12-Cell Battery

SCD8635-12 Rev A 3/3/08 Aeroflex Plainview

OFF

+30 VDC

Channel B

1553B

LOW

CELL

OVP

HIGH

CELL

Channel A

1553B

+12VDC

-12VDC

+5VDC

(ISOLATED)

SHARE BUS

MON

CLK

BAL

CLK

SELECT

MUX

VIN

CELL BALANCE

BOARD

BATTERY

12 CELLS

CONTROL BOARD

4.000V

REFERENCE

PRECISION

RELAY

XFMR

XCVR

A/D

12-B IT

MUX

BALANCING

CIRCUIT

BALANCING

CIRCUIT

BALANCING

CIRCUIT

BALANCING

CIRCUIT

BALANCING

CIRCUIT

BALANCING

CIRCUIT

POWER

SUPPLY

Block Diagram

CONTROLLER

BALANCING

CIRCUIT

CLOCK

DRIVER

DIFF. AMPS

VOLTAGE

BATTERY (3x)

HI AND LO

BATTERY

2 2 2

8635-12 Operating Details

Battery Cell Balancing

Provides 12 individual continuous balancing circuits.

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.

Cell Balancing Accuracy

When connected to a battery, the 8635-12 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.

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.

Battery Cell Voltage Monitoring

Measures cell voltages for up to 12-cells.

4V and 0V References for Calibration

Provides 4V and 0V references for cell voltage telemetry

calibration.

Battery and Cell Protection

Incorporates overvoltage protection (OVP) circuits. These

circuits monitor all of the battery cell voltages and only

cell voltage threshold of 4.40V is reached, the protection

circuit output changes state and latches within 50mS.

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.

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.

Lowest Battery Cell Voltage Telemetry

Provides lowest battery cell voltage telemetry as specified in

Tables I & IV.

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.

SCD8635-12 Rev A 3/3/08 Aeroflex Plainview

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.

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 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.

The 12-bit data reply is left justified in the 16-bit 1553B data word

with the four LSBs set to "0".

Bi-Level Telemetry

Bi-level telemetry can be requested 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.

Table I – Analog Telemetry

Item Telemetr y Tit le 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 Cell 9 Voltage 0V to 5.12V 0821

16 Cell 10 Voltage 0V to 5.12V 0822

17 Cell 11 Voltage 0V to 5.12V 0824

18 Cell 12 Voltage 0V to 5.12V 0827

19 Lowest Cell Voltage 0V to 5.12V 0871

20 Highest Cell Voltage 0V to 5.12V 0872

Table II – Bi-level Telemetry

Item Telemetry Title Status Reply

Bit

1st Data Word

of 1553B

Receive

Command

(Hex)

1 Overvoltage Latch Status 1 = Set D13 0C80

SCD8635-12 Rev A 3/3/08 Aeroflex Plainview

32-Word Telemetry

To reduce data bus bandwidth usage, the 8635-12 supports

a 32-word telemetry request on sub-address 20 as defined

in Table III.

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.

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"..

8-Word Telemetry

To reduce data bus bandwidth usage, the 8635-12 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

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 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

Item Telemetry Title Telemetry

Type Reply

Word Reply Bits

1 4V Reference Analog 1 D(15:4)

2 Total Battery Voltage 1 Analog 2 D(15:4)

3 Total Battery Voltage 2 Analog 3 D(15:4)

4 Total Battery Voltage 3 Analog 4 D(15:4)

5 Share Bus Voltage Analog 5 D(15:4)

6 Reserved - 6 -

7 Cell 1 Voltage Analog 7 D(15:4)

8 Cell 2 Voltage Analog 8 D(15:4)

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 Cell 9 Voltage Analog 15 D(15:4)

16 Cell 10 Voltage Analog 16 D(15:4)

17 Cell 11 Voltage Analog 17 D(15:4)

18 Cell 12 Voltage Analog 18 D(15:4)

19 Reserved - 19 -

20 Reserved - 20 -

21 Reser ved - 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

Table IV – 8-Word Telemetry

Item Telemetry Title Telemetry

Type Reply

Word Reply Bits

1 Overvoltage Level Status Bi-Level 1 D13

2Reserved - 2 -

3Reserved - 3 -

4Reserved - 4 -

50V Reference Analog 5 D(15:4)

6 Lowest Cell Voltage Analog 6 D(15:4)

7 Highest Cell Voltage Analog 7 D(15:4)

8 Message Count Analog 8 D(15:0)

SCD8635-12 Rev A 3/3/08 Aeroflex Plainview

Additional Commands

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.

Telemetry Frame Sync Command

1553B broadcast command on sub-address 17 (any data

word) commands the 8635-12 to refresh its RT address.

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

indicate that the unit is busy and cannot accept another

command.

1553B Data Wrap Around

Sub-address 30 is dedicated to data wrap around as

specified in MIL-STD-1553B.

Supported Mode Codes

The 8635-12 supports the 1553B Mode Codes in Table VI.

1553B Status Flag Bits

The 8635-12 supports the following 1553B status flag bits:

1. Message Error bit

2. Broadcast Message Received bit

All other status bits are set to "0".

Table V – Commands

Item Function Title Sub-Address

1st Data Word

of 1553B

Receive

Command

(Hex)

1Reserved 13 -

2Reserved 14 -

3 Reset OVP Latch 15 0400

Table VI – 1553B Mode Codes

Mode Code Name Mode Code Number

Transmit Status Word 2

Transmitter Shutdown 4

Override Transmitter Shutdown 5

Reset Remote Terminal 8

SCD8635-12 Rev A 3/3/08 Aeroflex Plainview

Connector P1

26 Pin Subminiature-D Plug

Cell Sense

#Function Name Pin

#Function Name

23 CELL_12+ 17 RESERVED

9 CELL_11+ 7 RESERVED

3 CELL_10+ 14 RESERVED

19 CELL_9+ 1 RESERVED

10 CELL_8+ 20 RESERVED

13 CELL_7+ 12 RESERVED

16 CELL_6+ 18 RESERVED

26 CELL_5+ 8 RESERVED

5 CELL_4+ 4 RESERVED

2 CELL_3+ 21 RESERVED

15 CELL_2+ 22 RESERVED

24 CELL_1+ 6 RESERVED

11 CELL_1- 25 RESERVED

Connector J2 for Control Board

Triaxial

1553B Bus A

CHA_DATA_H

CHA_DATA_L

SHIELD

Connector J3 for Control Board

Triaxial

1553B Bus B

CHB_DATA_H

CHB_DATA_L

SHIELD

Connector J1 for Control Board

51 Pin Micro -D Receptacle

Control & Test Points

#Function Pin

#Function

1 30V_RTN 18 V_BAT_3 35 V_BAT_2

2NC_ISOLATION 19 NC_ISOLATION 36 NC_ISOLATION

3NC_ISOLATION 20 +30V_POWER 37 NC_ISOLATION

4NC_ISOLATION 21 +30V_POWER 38 NC_ISOLATION

530V_RTN 22 NC_ISOLATION 39 SPARE

6NC_ISOLATION 23 NC_ISOLATION 40 CHASSIS GND

7CHASSIS GND 24 CHASSIS GND 41 RESERVED

8CELL_CHG_12 25 LOW_CELL 42 SPARE

9SPARE 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

SCD8635-12 Rev A 3/3/08 Aeroflex Plainview

3-D View

Outline

11.50

5.250

0.20

2x 0.25

2x 0.40

2x 1.00

11.002x

2.01

1.50

2.50

3.25

0.76

SCD8635-12 Rev A 3/3/08

PLAINVIEW, NEW YORK

Toll Free: 800-THE-1553

Fax: 516-694-6715

SE AND MID-ATLANTIC

Tel: 321-951-4164

Fax: 321-951-4254

INTERNATIONAL

Tel: 805-778-9229

Fax: 805-778-1980

WEST COAST

Tel: 949-362-2260

Fax: 949-362-2266

NORTHEAST

Tel: 603-888-3975

Fax: 603-888-4585

CENTRAL

Tel: 719-594-8017

Fax: 719-594-8468

www.aeroflex.com info-ams@aeroflex.com

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, pe rformance-driven and customer-focuse d

EXPORT CONTROL: EXPOR T 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.)

Standard Configuration

Power Dissipation

7.1 Watts from 30V Supply

0.75 Watts from battery

Operating Base Plate Temperature

BEU8635-12-S -34°C to +71°C

BEU8635-12 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

BEU8635-12-S High Reliablilty Space Grade

BEU8635-12 Commerical Flow