AT86RF231 datasheet(5/180 Pages) ATMEL

5 / 180 page

8111A–AVR–05/08

AT86RF231

1.2

Analog and RF Pins

1.2.1

Supply and Ground Pins

EVDD, DEVDD

EVDD and DEVDD are analog and digital supply voltage pins of the AT86RF231 radio

transceiver.

AVDD, DVDD

AVDD and DVDD are outputs of the internal 1.8V voltage regulators. The voltage regulators are

controlled independently by the radio transceivers state machine and are activated dependent

on the current radio transceiver state. The voltage regulators can be configured for external

supply.

For details, refer to Section 9.4 “Voltage Regulators (AVREG, DVREG)” on page 110.

AVSS, DVSS

AVSS and DVSS are analog and digital ground pins respectively. The analog and digital power

domains should be separated on the PCB.

1.2.2

RF Pins

RFN, RFP

A differential RF port (RFP/RFN) provides common-mode rejection to suppress the switching

noise of the internal digital signal processing blocks. At board-level, the differential RF layout

ensures high receiver sensitivity by rejecting any spurious emissions originated from other digital

ICs such as a microcontroller.

The RF port is designed for a 100

Ω differential load. A DC path between the RF pins is allowed.

A DC path to ground or supply voltage is not allowed. Therefore, when connecting an RF-load

providing a DC path to the power supply or ground, AC-coupling is required as indicated in Table

1-2 on page 6.

A simplified schematic of the RF front end is shown in Figure 1-2 on page 5.

Figure 1-2.

Simplified RF Front-end Schematic

LNA

RFP

RFN

RXTX

0.9V

Feedback

AT86RF231

PCB

AT86RF231 Datasheet(PDF) 5 Page - ATMEL Corporation