ATA5429-PLSW datasheet(31/100 Pages) ATMEL

31 / 100 page

4841D–WIRE–10/07

ATA5423/ATA5425/ATA5428/ATA5429

AVCC is the internal operation voltage of the RF transceiver and is fed by VS1 via the switch

SW_AVCC. AVCC must be blocked with a 68 nF capacitor (see Figure 2-1 on page 7, Figure 2.2

on page 8 and Figure 2-3 on page 9).

DVCC is the internal operation voltage of the digital control logic and is fed by VS1 or VSOUT

via the switch SW_DVCC. DVCC must be blocked on pin DVCC with 68 nF (see Figure 2-1 on

page 7, Figure 2.2 on page 8 and Figure 2-3 on page 9).

Pin VSOUT is a power supply output voltage for external devices (for example, microcontrollers)

and is fed by VS1 via the switch SW_VSOUT, or by the auxiliary voltage supply VAUX via

V_REG2. The voltage regulator V_REG2 regulates VSOUT to typically 3.25V. If the voltage reg-

ulator is active, a blocking capacitor of 2.2 µF has to be connected to VSOUT. VSOUT can be

switched off by the VSOUT_EN bit in control register 3 and is then reactivated by conditions

found in Figure 5-2 on page 32.

Pin N_RESET is set to low if the voltage V

VSOUT at pin VSOUT drops below 2.3V (typically) and

can be used as a reset signal for a connected microcontroller (see Figure 5-3 on page 34 and

Figure 5-4 on page 35).

Pin PWR_ON is an input to switch on the transceiver (active high).

Pin T1 to T5 are inputs for push buttons and can also be used to switch on the transceiver

(active low).

For current consumption reasons it is recommended to set T1 to T5 to GND, or PWR_ON to

VCC only temporarily. Otherwise, an additional current flows because of a 50 k

Ωpull-up resistor.

There are two voltage monitors generating the following signals (see Figure 5-1 on page 30):

• DVCC_OK if DVCC > 1.5V typically

• VSOUT_OK if VSOUT > V

Thres1 (2.3V typically)

• Low_Batt if VSOUT < V

Thres2 (2.38V typically)

ATA5429-PLSW Datasheet(PDF) 31 Page - ATMEL Corporation