ATmega644PR231 Atmel Corporation, ATmega644PR231 Datasheet - Page 5

• Manufacturer Part Number: ATmega644PR231
• Manufacturer: Atmel Corporation

Specifications of ATmega644PR231

• Flash (kbytes): 64 Kbytes
• Max. Operating Frequency: 20 MHz
• Max I/o Pins: 32
• Spi: 3
• Twi (i2c): 1
• Uart: 2
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Crypto Engine: AES
• Sram (kbytes): 4
• Eeprom (bytes): 2048
• Operating Voltage (vcc): 1.8 to 3.6
• Timers: 3
• Frequency Band: 2.4 GHz
• Max Data Rate (mb/s): 2
• Antenna Diversity: Yes
• External Pa Control: Yes
• Power Output (dbm): 3
• Receiver Sensitivity (dbm): -101
• Receive Current Consumption (ma): 13.2
• Transmit Current Consumption (ma): 14.4
• Link Budget (dbm): 104

1.2
1.2.1
1.2.2
8111C–MCU Wireless–09/09
Analog and RF Pins
Supply and Ground Pins
RF 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
AVSS, DVSS
AVSS and DVSS are analog and digital ground pins respectively. The analog and digital power
domains should be separated on the PCB.
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.
A simplified schematic of the RF front end is shown in
Figure 1-2.
The RF port is designed for a 100Ω 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
1-2 on page
6.
Simplified RF Front-end Schematic
Section 9.4 “Voltage Regulators (AVREG, DVREG)” on page
RFP
RFN
PCB
AT86RF231
M0
0.9V
RXTX
Figure 1-2 on page
CM
Feedback
LNA
PA
RX
TX
AT86RF231
5.
110.
Table
5