Rainbow-electronics AT73C246 Manual do Utilizador descarregar pdf (Página 33)

11050A–PMAAC–07-Apr-10

AT73C246

When RUN state is reached from the STANDBY state, the power supplies are sequentially

started-up according to the Figure 11-6.

Figure 11-6. AT73C246 - STANDBY to RUN state Supplies Start-Up timing diagram.

Note: 1. VDDx activity during STANDBY state is set by register PMU_STANDBY_SUPPLIES.

11.4.3 STANDBY STATE

When AT73C246 is in STANDBY state:

•V

BACKUP

is ON.

•VDD

{0,1,2,3}

are ON or OFF according to the status in register 0x03

(PMU_STANDBY_SUPPLIES)

•VDD

is ON or OFF according to the status in register 0x0A (VDD4_CTRL)

• Audio function is OFF

• ADC function is ON or OFF according to the status in register 0x30 (ADC_CTRL)

• RSTB pin is forced to ground.

• TWI pins are ignored to prevent TWI registers from corruption

• Led pin is driven according to register PMU_LED (0x0B)

To reach the STANDBY state, the appropriate power supplies are shut down as described in the

Figure 11-7 on page 34.

Table 11-5. STANDBY to RUN state timing table

Symbol Parameter Comments Min Typ Max Units

ON_SYS

Start-up Time

Time from validated WAKEUP event (end of debounce

time when applicable) to VDD2 or VDD3 power on.

810 900 990 µs

PFM

PFM/PWM Switching

time

Time from validated WAKEUP event (end of debounce

time when applicable) to PFM/PWM switching if

applicable.

420 470 520 µs

ON_VDDx

VDDx Start-up Time

VDDx is OFF during STANDBY state

(1)

5.2 5.4 5.7 ms

VDDx is ON during STANDBY state

(1)

58 62 66 µs

RESET

All Regulators ON To

RSTB High

30.4 32 33.6 ms

SEQUENCE A SEQUENCE B

STANDBY

S TATE

SUPPLIES START UP

TON_SYS

RUN STATE

WAKEUP

EVENT

DD3

(3.3V)

TON_VDD3

TON_VDD0

TON_VDD1

DD2

(1V)

3.3V

1.85V

1.2V

TON_VDD2

RSTB

VPAD LEVEL

TRESET

DD3

or OFF