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Power supply, 1 off mode, 2 standby mode – Rainbow Electronics ATA5746 User Manual

Page 20

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20

4596A–RKE–05/06

ATA5745/ATA5746 [Preliminary]

5.

Power Supply

Figure 5-1.

Power Supply

The supply voltage range of the ATA5745/ATA5746 is 2.7V to 3.3V or 4.5V to 5.5V.

Pin VS3V_AVCC is the supply voltage input for the range 2.7V to 3.3V, and is used in battery
applications using a single lithium 3V cell. Pin VS5V is the voltage input for the range 4.5V to
5.5V (car applications) in this case the voltage regulator V_REG regulates VS3V_AVCC to typi-
cally 3.0V. If the voltage regulator is active, a blocking capacitor of 2.2 µF has to be connected to
VS3V_AVCC (see

Figure 10-1 on page 28

).

DVCC is the internal operating voltage of the digital control logic and is fed via the switch
SW_DVCC by VS3V_AVCC. DVCC must be blocked on pin DVCC with 68 nF (see

Figure 9-1

on page 27

and

Figure 10-1 on page 28

).

Pin RX is the input to activate the RX signal processing and set the receiver to Active mode.

5.1

OFF Mode

A low level on pin RX and ENABLE will set the receiver to OFF mode (low power mode). In this
mode, the crystal oscillator is shut down and no clock is available on pin CLK_OUT. The
receiver is not sensitive to a transmitter signal in this mode.

5.2

Standby Mode

The receiver activates the Standby mode if pin ENABLE is set to “1”.

In Standby mode, the XTO is running and the clock on pin CLK_OUT is available after the
s t a r t - u p t i m e o f t h e X T O h a s e l a p s e d ( d e p e n d e n t o n p i n C L K _ O U T _ C T R L 0 a n d
CLK_OUT_CTRL1). During Standby mode, the receiver is not sensitive to a transmitter signal.

In Standby mode, the RX signal path is disabled and the power consumption I

Standby

is typically

50 µA (CLK_OUT output off, VS3V_AVCC = VS5V = 3V). The exact value of this current is
strongly dependent on the application and the exact operation mode, therefore check the sec-
tion

“Electrical Characteristics: General” on page 29

for the appropriate application case.

V_REG

3.0V typ.

SW_DVCC

OUT

RX

DVCC

VS5V

VS3V_AVCC

IN

EN

Table 5-1.

Standby Mode

RX

ENABLE

Function

0

0

OFF mode

Table 5-2.

Standby Mode

RX

ENABLE

Function

0

1

Standby mode