EM2420-STR Ember, EM2420-STR Datasheet - Page 45

• 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: -

The
requirements in [1] for CCM.
Linear IF and AGC Settings
The
where the signal amplification is done in
an analog VGA (variable gain amplifier).
The gain of the VGA is digitally controlled.
The AGC (Automatic Gain Control) loop
ensures that the ADC operates inside its
RSSI / Energy Detection
The
Signal Strength Indicator) giving a digital
value that can be read form the 8 bit,
signed 2’s complement RSSI.RSSI_VAL
register.
The RSSI value is always averaged over 8
symbol periods (128 µs), in accordance
with [1]. The RSSI_VALID status bit
(Table 5) indicates when the RSSI value is
valid, meaning that the receiver has been
enabled for at least 8 symbol periods.
The RSSI register value RSSI.RSSI_VAL
can be referred to the power P at the RF
pins by using the following equations:
Ember Part Number: 120-0049-000D
EM2420
EM2420
only
has a built-in RSSI (Received
is based on a linear IF chain
differences
Mode
CCM
CTR
CBC
Stand-
alone
are
Table 8. Security timing examples
from
l(a)
50
-
17
-
EM2420 Datasheet
the
l(m)
69
15
98
16
Timing
Table 8 shows some examples of the time
used by the security module for different
operations.
dynamic range by using an analog/digital
feedback loop.
The AGC characteristics are set through
the AGCCTRL, AGCTST0, AGCTST1 and
AGCTST2 registers. The reset values
should be used for all AGC control and
test registers.
where
empirically during system development
from the front end gain. RSSI_OFFSET is
approximately –45. E.g., if reading a value
of –20 from the RSSI register, the RF
input power is approximately –65 dBm.
A typical plot of the RSSI_VAL reading as
function of input power is shown in Figure
25. It can be seen from the figure that the
RSSI reading from the
linear and has a dynamic range of about
100 dB.
l(MIC)
8
-
12
-
P = RSSI_VAL + RSSI_OFFSET [dBm]
the
Time
[us]
222
99
99
14
RSSI_OFFSET
EM2420
EM2420
Page 45 of 84
is
is very
found