XE1201A Datasheet, PDF (6/16 Pages) List of Unclassifed Manufacturers – LOW POWER UHF TRANSCEIVER

XE1201A
∗ A10 - TRANSMIT/RECEIVE MODE
When set to 1, the XE1201A is set in receiving mode and in transmitting mode when set to 0. This bit replaces the RXTX
(pin15) when A13=1
∗ A9, A8, A7, A6 – DEMODULATOR AND BIT SYNCHRONIZER BYPASSING
These bits are used in applications where the bit synchronizer is not needed for e.g. decrease the receiver wake-up time
a) The receiver is in normal mode but the demodulator is bypassed. The outputs I and Q of the limiters are available on
pin19
(I output) and pin 18 (Q output). Bits A9 to A6 must be set according to table 3 below.
A9 A8 A7 A6
0100
table 3: Receiver Mode with Demodulator Bypassed
b) The receiver is in normal mode but the internal bit synchronizer is switched off. Raw data are available at RXD output
(pin19). The CLKD (pin18) is meaningless. In this mode, no preamble is required for clock synchronization of the bit
synchronizer so that the minimum receiver wake-up time is accessed. Bits A9 to A6 must be set according to table 4.
A9 A8 A7 A6
0101
table 4: Receiver Mode with Bit Synchronizer Switched Off
∗ A5, A4, A3, A2, A1, A0 - RECEIVER DATA RATE
These bits are used to set the bit synchronizer data rate according to the following formula:
DR
=
⎛⎝⎜
−n
8
⎞⎠⎟
65574 • 2
[Hz]
Where n is the unsigned decimal value of bits A5 to A0 (A5=MSB).
The inverse function gives the value of n for a wanted data rate DR (in Hz) as showed below:
n
=
⎛
⎜
⎜
ROUND
⎜
⎜
⎡
− 8 • Log ⎢
⎣⎢
61• DR
4 • 10 ⁶
⎤
⎥
⎞
⎟
⎦⎥
⎟
⎟
⎟
⎜
Log 2
⎟
⎝⎜
⎠⎟
The rate of the data to be transmitted should then be fed accordingly in TXD (pin17).
Note: when the bit synchronizer is bypassed (bits A9,A8,A7,A6), it is not necessary to program the data rate. The data are
demodulated accordingly to the incoming data rate.
8. “B” REGISTER FORMAT (D15=0, D14=1)
D15 D14 B13 B12 B11 B10 B9 B8
B7 B6 B5 B4 B3 B2 B1 B0
table 5: “B” register format
∗ B13, B12, B11, B10, B9, B8, B7 - OFFSET FREQUENCY
These bits can be used to calibrate the oscillator central frequency (e.g. related to SAW resonator initial accuracy). A
frequency offset can be added or subtracted to the frequency of the Local Oscillator while transmitting according to the
following formula:
© Semtech 2005
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