AS8506 datasheet(26/89 Pages) AMSCO

26 / 89 page

AS8506 – 26

ams Datasheet, Confidential:2013-Sep [1-00]

De tail ed De sc rip t ion

AS8506 System Operation

The AS8506 battery stack system can be set up by configuring

one AS8506 device as ‘Master’ and the rest as ‘Slave’ devices.

The AS8506 Master device is connected to the microcontroller,

and the Slave devices are connected to Master through a

daisy-chain of 3-wire customized SPI protocol. The

microcontroller can communicate to the Slave devices through

the Master. On power-up of the system, the microcontroller

must assign an address to all AS8506 devices including the

Master. The microcontroller can assign the address to AS8506

devices by initiating the address allocation process, by writing

a top most Slave device address into dadd_for_allc_reg register

of Master and then writing ‘07’ data into spi3_cmd_reg. Once

the address allocation process is successful, the microcontroller

can start the cell balancing. If cell balancing or check status

command is not triggered by the microcontroller, after WAIT

mode timeout period all devices enter into SLEEP mode.

The complete system communication procedure is explained

below.

• The microcontroller gives wake pulse on WAKE_IN to

bring the Master and Slaves in NORMAL mode.

• After the wake-up time period, the microcontroller (μC)

sends the reference voltage digital code to the Master

device through a 4-wire SPI.

• After receiving the digital reference code from μC, the

Master device initiates a 3-wire custom SPI operation to

send the digital reference code to the Slave devices.

• The microcontroller waits for the 3-wire SPI operation

time period. After the 3-wire SPI time period, it initiates

the cell balancing through TRIG_IN. The balancing will

continue as long as TRIG_IN is ‘High’.

• The microcontroller can change the reference value at any

time by making TRIG_IN ‘Low’ and initiating a 4-wire SPI

with new value of reference code. From here on, the

procedure is same as from point 3.

• The balance done is indicated on BD_OUT pin.

• The failure in the 3-wire SPI operation is indicated on

CVT_NOK_OUT pin.

AS8506 Folha de dados(PDF) 26 Page - ams AG