AT86RF212 Atmel Corporation, AT86RF212 Datasheet - Page 142

• Manufacturer Part Number: AT86RF212
• Manufacturer: Atmel Corporation

Specifications of AT86RF212

• Max. Operating Frequency: 0 MHz
• Crypto Engine: AES
• Operating Voltage (vcc): 1.8 to 3.6
• Frequency Band: 700/800/900MHz
• Max Data Rate (mb/s): 1
• Antenna Diversity: No
• External Pa Control: Yes
• Power Output (dbm): 10
• Receiver Sensitivity (dbm): -110
• Receive Current Consumption (ma): 9.0
• Transmit Current Consumption (ma): 18 at 5dBm
• Link Budget (dbm): 120

9.4 RX/TX Indicator
9.4.1 Overview
9.4.2 External RF-Front End Control
142
AT86RF212
Table 9-12. Antenna Diversity RF Switch Enable
• Bit 1:0 – ANT_CTRL
These register bits provide a static control of an Antenna Diversity switch. Although it is
possible to change register bits ANT_CTRL in state TRX_OFF, this change will be
effective at pins DIG1 and DIG2 in states PLL_ON and RX_ON.
Table 9-13. Antenna Diversity Switch Control
The main features are:
• RX/TX Indicator to control an external RF front-end
• Microcontroller independent RF front-end control
• Providing TX timing information
While IEEE 802.15.4 is targeting low cost and low power applications, solutions
supporting higher transmit output power are occasionally desirable. To simplify the
control of an optional external RF front-end, a differential control pin pair can indicate
that the AT86RF212 is currently in transmit mode.
The control of an external RF front-end is done via digital control pins DIG3/DIG4. The
function of this pin pair is enabled with register bit PA_EXT_EN (register 0x04,
TRX_CTRL_1). While the transmitter is turned off, pin 1 (DIG3) is set to low level and
pin 2 (DIG4) to high level. If the radio transceiver starts to transmit, the two pins change
the polarity. This differential pin pair can be used to control PA, LNA, and RF switches.
If the AT86RF212 is not in a receive or transmit state, it is recommended to disable
register bit PA_EXT_EN (register 0x04, TRX_CTRL_1) to reduce the power
consumption or avoid leakage current of external RF switches and other building
blocks, especially during SLEEP state. If register bits PA_EXT_EN = 0, output pins
DIG3/DIG4 are internally connected to analog ground.
When using an external RF front-end including a power amplifier (PA), it may be
required to adjust the setup time of the external PA relative to the internal building
blocks to optimize the overall power spectral density (PSD) mask.
Register Bit
ANT_EXT_SW_EN
Register Bit
ANT_CTRL
Value
Value
0
1
0
1
2
3
Description
Antenna Diversity RF switch control disabled
Antenna Diversity RF switch control enabled
Description
Reserved
Antenna 0
DIG1 = L
DIG2 = H
Antenna 1
DIG1 = H
DIG2 = L
Reserved
8168C-MCU Wireless-02/10