1st ON time

1st OFF time

CTRL

LED

2nd ON

time

t <

To Standby

Blank period

1st ON time

1st OFF time

CTRL

LED

2nd ON

time

2nd OFF

time

To Standby

Blank period

Command entering

period

Blank period

CTRL

LED

1st ON Time

1st OFF Time

starts

LP5522

SNVS488 – JUNE 2007

www.ti.com

TRAINING END COMMAND

Blinking sequence programming ends once Training End command is introduced. Three rising edges within time

End command. During blanc period no rising edges are allowed.

When Training End command is introduced during LED OFF time capturing, LED OFF time is recorded and chip

goes to standby mode.

If Training End command is introduced during LED ON time capturing, the associated LED ON period is not

recorded and hence neither OFF time. Notice that valid OFF time before Training End is longer than half of

Minimum LED OFF period (T_CYCLE_L).

LED TIMEOUT ON/OFF TIMES

When LP5522 is in training mode and CTRL signal is high longer than LED Timeout ON time, the ON time

counter saturates. In this case saturated ON time is recorded and LED OFF time capturing is started. At the

same time LED is switched off even if the CTRL signal is still high.

If ON time counter has saturated, LED OFF time recording is terminated either by giving a Train End command

or setting the CTRL signal to low and back to high. Setting the CTRL signal back to high records the LED OFF

time and starts next ON time capturing.

If anyhow CTRL is still high after the LED Timeout OFF time has been elapsed the OFF time counter saturates

and saturated OFF time is recorded. After that chip waits the CTRL signal to go low which cause the chip to go

Standby.

10

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