EM2420-STR Ember, EM2420-STR Datasheet - Page 55

• Manufacturer Part Number: EM2420-STR
• Description: IC RF TXRX ZIGBEE 2.4GHZ 48-QLP
• Manufacturer: Ember

Specifications of EM2420-STR

• Mfg Application Notes: EM2420
• Frequency: 2.4GHz
• Data Rate - Maximum: 250kbps
• Modulation Or Protocol: 802.15.4
• Applications: ZigBee™
• Power - Output: -3dBm
• Sensitivity: -94dBm
• Voltage - Supply: 2.1 V ~ 3.6 V
• Current - Receiving: 19.7mA
• Current - Transmitting: 17.4mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 48-QLP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Memory Size: -

Low cost systems
As the
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
should be powered down when not being
active. Extremely low power consumption
can be achieved when disabling the
voltage
reprogramming of the register and RAM
configuration.
BER / PER measurements
The
data is received infinitely and output to
pins (RX_MODE 2, see page 36). This
mode may be used for Bit Error Rate
(BER)
following actions must be taken to do such
a measurement:
Ember Part Number: 120-0049-000D
•
•
•
EM2420
A preamble and SFD sequence
must be used, even if pseudo-
random data is transmitted, since
receiving the DSSS modulated
signal
synchronization,
synchronization
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 21. 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
When operating at or below the
sensitivity limit, the
lose symbol synchronization in
infinite receive mode. A new SFD
and restart of the receiver may be
EM2420
measurements.
regulator.
includes test modes where
EM2420
provides 250 kbps multi-
requires
.
This
as
However,
will
EM2420
not
in
EM2420
require
symbol
2FSK
may
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
required
synchronization.
A valid preamble, SFD and length
field must be used for each
packet.
The PSDU (see Figure 15 on
page 32) 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 21. Pre-
generated packets may be used,
although [1] requires that the PER
is averaged over random PSDU
data.
The
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
20,
Demodulator,
Synchronizer and Data Decision
section.
recommends
IEEE
EM2420
used
as
802.15.4
instead
to
MDMCTRL1.CORR_THR
receive FIFO may be
described
to
EM2420
performing
to
evaluate
measure
system,
of
Page 55 of 84
in
Symbol
re-gain
PER
BER
the
the
the
all