JAJSNB9C November 2012 – November 2021
PRODUCTION DATA
A clock stretch can occur during all modes of fuel gauge operation. In SLEEP and HIBERNATE modes, a short clock stretch occurs on all I2C traffic as the device must wake-up to process the packet. In the other modes (BAT INSERT CHECK, NORMAL, SNOOZE) clock stretching only occurs for packets addressed for the fuel gauge. The majority of clock stretch periods are small as the I2C interface performs normal data flow control. However, less frequent yet more significant clock stretch periods may occur as blocks of Data Flash are updated. The following table summarizes the approximate clock stretch duration for various fuel gauge operating conditions.
GAUGING MODE | OPERATING CONDITION or COMMENT | APPROXIMATE DURATION |
---|---|---|
SLEEP HIBERNATE |
Clock stretch occurs at the beginning of all traffic as the device wakes up. | 5 ms |
BAT INSERT CHECK, NORMAL, SNOOZE |
Clock stretch occurs within the packet for flow control (after a start bit, ACK or first data bit). | 100 µs |
Normal Ra table Data Flash updates. | 24 ms | |
Data Flash block writes. | 72 ms | |
Restored Data Flash block write after loss of power. | 116 ms | |
End of discharge Ra table Data Flash update. | 144 ms |