EM2420 ETC [List of Unclassifed Manufacturers], EM2420 Datasheet - Page 60

• Manufacturer Part Number: EM2420
• Description: 2.4 GHz IEEE 802.15.4 / ZigBee RF Transceiver
• Manufacturer: ETC [List of Unclassifed Manufacturers]

EM2420 enables a high level of security
even with a low-cost 8 bit controller.
Low cost systems
As the EM2420 provides 250 kbps multi-
channel performance without any external
filters, a very low cost system can be
made.
A differential antenna will eliminate the
need for a balun, and the DC biasing can
be achieved in the antenna topology.
Battery operated systems
In low power applications, the EM2420
should be powered down when not being
active. Extremely low power consumption
may be achieved when disabling also the
voltage
reprogramming of the register and RAM
configuration.
BER / PER measurements
The EM2420 includes test modes where
data is received infinitely and output to
pins (RX_MODE 2, see page 38). This
mode may be used for Bit Error Rate
(BER)
following actions must be taken to do such
a measurement:
Ember Part Number: 120-0049-000C
•
•
A preamble and SFD sequence
must be used, even if pseudo
random data is transmitted, since
receiving the DSSS modulated
signal
synchronization,
synchronization like e.g. in 2FSK
systems. The SYNCWORD may be
set to another value to fit to the
measurement setup if necessary.
The data transmitted over air must
be spread according to [1] and the
description on page 22. This
means that the transmitter used
during measurements must be
able to do spreading of the bit
data to chip data. Remember that
the chip sequence transmitted by
the test setup is not the same as
the bit sequence which is output
by the EM2420.
measurements.
regulator.
requires
This
However,
will
not
require
symbol
EM2420 Datasheet
the
bit
In
communication is based on packets. The
sensitivity limit specified by [1] is based on
Packet Error Rate (PER) measurements
instead of BER. This is a more accurate
measurement of the true RF performance
since it mirrors the way the actual system
operates.
Ember
measurements
measurements
performance of IEEE 802.15.4 systems.
To do PER measurements, the following
may be used as a guideline:
•
•
•
•
•
•
•
an
When operating at or below the
sensitivity limit, the EM2420 may
lose symbol synchronization in
infinite receive mode. A new SFD
and restart of the receiver may be
required
synchronization.
A valid preamble, SFD and length
field must be used for each
packet.
The PSDU (see Figure 15 on
page 34) length should be 20
bytes for sensitivity measurements
as specified by [1].
The sensitivity limit specified by [1]
is the RF level resulting in a 1%
PER. The packet sample space
for a given measurement must
then be >> 100 to have a
sufficiently large sample space.
E.g. at least 1000 packets should
be
sensitivity.
The data transmitted over air must
be spread according to [1] and the
description on page 22. Pre-
generated packets may be used,
although [1] requires that the PER
is averaged over random PSDU
data.
The EM2420 receive FIFO may be
used to buffer data received
during PER measurements, since
it is able to buffer up to 128 bytes.
The
control register should be set to
recommends
IEEE
used
802.15.4
instead
to
MDMCTRL1.CORR_THR
to
EM2420
performing
to
evaluate
measure
system,
of
Page 60 of 89
re-gain
PER
BER
the
the
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