LTC6802IG-2 LINER [Linear Technology], LTC6802IG-2 Datasheet - Page 18

• Manufacturer Part Number: LTC6802IG-2
• Description: Multicell Addressable Battery Stack Monitor
• Manufacturer: LINER [Linear Technology]

applicaTions inForMaTion
LTC6802-2
is enabled when the LVLPL bit is low. After entering a
polling command, the data out line will be driven by the
slave devices based on their status. When polling for the
A/D converter status, data out will be low when any device
is busy performing an A/D conversion and will toggle at
1kHz when no device is busy. Similarly, when polling for
interrupt status, the output will be low when any device
has an interrupt condition and will toggle at 1kHz when
none has an interrupt condition.
Toggle Polling—Address Polling: The addressed device
drives the SDO line based on its state alone—low for
busy/in interrupt, toggling at 1kHz for not busy/not in
interrupt.
Toggle Polling—Parallel Broadcast Polling: No part
address is sent, so all devices respond simultaneously.
If a device is busy/in interrupt, it will pull SDO low. If a
device is not busy/not in interrupt, then it will release the
SDO line (TOS = 0) or attempt to toggle the SDO line at
1kHz (TOS =1).
The master controller pulls CSBI high to exit polling.
Level polling: Level polling is enabled when the LVLPL
bit is high. After entering a polling command, the data
out line will be driven by the slave devices based on their
status. When polling for the A/D converter status, data
out will be low when any device is busy performing an
A/D conversion and will be high when no device is busy.
Similarly, when polling for interrupt status, the output will
be low when any device has an interrupt condition and will
be high when none has an interrupt condition.
Level polling—Address Polling: The addressed device
drives the SDO line based on its state alone—pulled low for
busy/in interrupt, released for not busy/not in interrupt.

Level polling—Parallel Broadcast Polling: No part address
is sent, so all devices respond simultaneously. If a device
is busy/in interrupt, it will pull SDO low. If a device is not
busy/not in interrupt, then it will release the SDO line. If
any device is busy or in interrupt the SDO signal will be
low. If all devices are not busy/not in interrupt, the SDO
signal will be high.
The master controller pulls CSBI high to exit polling.
Polling Methods: For A/D conversions, three methods can
be used to determine A/D completion. First, a controller can
start an A/D conversion and wait for the specified conver-
sion time to pass before reading the results. The second
method is to hold CSBI low after an A/D start command
has been sent. The A/D conversion status will be output
on SDO. A problem with the second method is that the
controller is not free to do other serial communication
while waiting for A/D conversions to complete. The third
method overcomes this limitation. The controller can send
an A/D start command, perform other tasks, and then
send a Poll A/D Converter Status (PLADC) command to
determine the status of the A/D conversions.
For OV/UV interrupt status, the poll interrupt status (PLINT)
command can be used to quickly determine whether
any cell in a stack is in an overvoltage or undervoltage
condition.
Bus Protocols
There are 6 different protocol formats, depicted in Table 3
through Table 8. Table 2 is the key for reading the protocol
diagrams.
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