1st ON time

1st OFF time

CTRL

LED

2nd ON

time

2nd OFF

time

tENTER

To Standby

Blank period

Command entering

period

Blank period

CTRL

LED

1st ON Time

1st OFF Time

starts

LP5522

SNVS488A – JUNE 2007 – REVISED MARCH 2013

www.ti.com

TRAINING START COMMAND

Blinking sequence is programmed into memory in training mode. Blinking sequence is stored into volatile

memory, thus removing input voltage VIN resets the memory. Memory can also be reset by giving Training Start

and Training End commands without any valid LED ON/OFF times.

LP5522 enters to Training mode after Training Start command. Two rising edges within command entering

period is interpreted as the Training Start command. The first LED ON time capturing is started once the rising

edge of CTRL signal is detected after the blank period. LED output follows CTRL signal during the programming.

The first LED ON time is recorded once CTRL signal is set low. Same time the first LED OFF time capturing is

started. Programmed blinking sequence can have one to three LED ON/OFF times. In order to be programmed

correctly, at least one valid LED ON and LED OFF time must be recorded.

TRAINING END COMMAND

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

period of tENTER is interpreted as Training End command. Note that blank period is also reguired after Training

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).

10

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