ML7406 datasheet(48/104 Pages) LAPIS

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FEDL7406-02

ML7406

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●Timer Function

○Wake-up timer

ML7406 has automatic wake-up function using wake-up timer. The following operations are possible by using wake-up timer.

• Upon timer completion, automatically wake-up from SLEEP state. After wake-up operation can be selected as RX_ON

state or TX_ON state by WAKEUP_MODE ([SLEEP/WU_SET: B0 0x2D(6)]).

• By setting WUT_1SHOT_MODE ([SLEEP/WU_SET: B0 0x2D(7)]), continuous wake-up operation (interval operation)

or one shot operation can be selected

• In interval operation, if RX_ON /TX_ON state is caused by wake-up timer, continuous operation timer is in operation..

• After moving to RX_ON state by wake-up timer, when continuous operation timer completed, move to SLEEP state

automatically. However, if SyncWord is detected before timer completion, RX_ON state will be maintained. In this case,

ML7406 does not go back to SLEEP state automatically. SLEEPsetting (SLEEP_EN[SLEEP/WU_SET: B0

0x2D(0)])=0b1) is necessary to go back to SLEEP state. However if RXDONE_ MODE[1:0]([RF_STATUS_CTRL:B0

0x0A(3-2)]) =0b11, after RX completion, move to SLEEP state automatically.

• After moving to TX_ON state by wake-up timer, when continuous operation timer completed, go back to SLEEPstate

automatically.

• After wake-up by combining with high speed carrier checking mode, CCA is automatically performed, if IDLE is

detected, able to move to SLEEP state immediately. For details, please refer to the “(3) high speede carrier detection

mode”.

• By setting WU_CLK_SOURCE ([SLEEP/WU_SET:B0 0x2D(2)]), clock source for wake-up timer are selectable from

EXT_CLK pin or on-chip RC OSC.

Wake-up intervalm, wake-up timer interval and continuous operation timer can be calculated in the following formula.

Wake-up interval [s] = Wake-up timer interval [s] + Continuous operation timer [s]

Wake-uptimer interval [s] = Wake-up timer clock cycle *

Division setting ([WUT_CLK_SET: B0 0x2E(3-0)]) *

Wake-up timer interval setting ([WUT_INTERVAL_H/L: B0 0x2F/0x30])

Continuous operation timer [s] = Wake-up timer clock cycle *

Division setting([WUT_CLK_SET: B0 0x2E(7-4)]) *

Continuous operation timer setting ([WU_DURATION: B0 0x31])

(Note)

• In case of moving to TX_ON state after wake-up, move to SLEEP state when timer completed even in the middle of

transmission. Continuous oeration timer should be set in such manner that timer completing after TX completion.

• WUDT_CLK_SET[3:0] ([WUT_CLK_SET: B0 0x2E(7-4)]) and WUT_CLK_SET[3:0] ([WUT_CLK_SET: B0 0x2E

(3-0)]) can be set independently.

• Minimum value for wake-up timer interval setting ([WUT_INTERVAL_H/L: B0 0x2F/0x30]) is 0x02. And minimum value

for continuous operation timer setting ([WU_DURATION: B0 0x31]) is 0x01.

• Be noted that the SyncWord detection is not issued when in DIO mode with RXDIO_CTRL([DIO_SET: B0

0x0C(7-6)])=0b01. Therefore, when continuous operation timer completed, forcibly move to SLEEP state.

ML7406 Datasheet(PDF) 48 Page - LAPIS Semiconductor Co., Ltd.