ATR2406 Datasheet, PDF (14/20 Pages) ATMEL Corporation – LOW IF .4 GHZ ISM TRANSCEIVER

Table 9. Description of the Conditions/States
Conditiion
Description
C1
Power-down
ATR2406 is switched off and the supply current is lower than 1 µA.
Power-up
ATR2406 is powered up by toggling PU_REG and PU_RTX to high.
PU_REG enables the external AUX-Regulator transistor and PU_TRX
C2
enables the internal regulator like VCO_REG (VCO supply voltage
regulator) as well as wakes up the PLL, the VCO, the demodulator,
mixer, etc.
It is necessary to wait at least 40 µs until the different supply voltage
regulators have settled.
Programming
Via the tree-wire-interface the internal register of ATR2406 is programmed.
At TX, this is just the PLL (transmit channel) and the deviation (gaussian
filter).
At RX, this is just the PLL (receive channel) and if the clock recovery is
used also the bits to enable this option. At start of the
three-wire-programming, the enable signal is toggled from high to low to
C3
enable clocking the data into the internal register. When the enable signals
rises again to high, the programmed data is latched. This is the time point
at which the settling of the PLL is starting. It is necessary to wait the
settling time of 350 µs so that the VCO-Frequency is stable.
The reference clock needs to be applied to ATR2406 at minimum the time
when the PLL is in operation - which is the programming state (C3) and the
active slot (C4, C5). Out of the reference clock, several internal signals are
also derived, i.e., the gaussian filter circuitry and TX_DATA sampling.
C4
This is the receive slot where the transmit burst is received and data as
well as recovered clock are available.
This is the active transmit slot. As soon as TX_DATA is applied to
C5
ATR2406, the signal nOLE toggles to low which enables modulation in
open-loop-mode.
Received Signal Strength The RSSI is given as an analog voltage at the RSSI pin. A typical plot of the RSSI value
Indication RSSI
is shown in Figure 6.
Figure 6. Typical RSSI Value versus Input Power
2.5
2.0
1.5
1.0
0.5
0.0
-130
-110
-90
-70
-50
-30
-10
10
RF Level (dBm)
14 ATR2406 [Preliminary]
4779F–ISM–09/04