SI4330-B1-FMR Silicon Laboratories Inc, SI4330-B1-FMR Datasheet - Page 51
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SI4330-B1-FMR
Manufacturer Part Number
SI4330-B1-FMR
Description
IC RX ISM 240-960MHZ 20VQFN
Manufacturer
Silicon Laboratories Inc
Specifications of SI4330-B1-FMR
Frequency
240MHz ~ 960MHz
Sensitivity
-121dBm
Data Rate - Maximum
256 kbps
Modulation Or Protocol
FSK, GFSK, OOK
Applications
Remote Control, RKE, Security Systems
Current - Receiving
18.5mA
Data Interface
PCB, Surface Mount
Antenna Connector
PCB, Surface Mount
Features
RSSI Equipped
Voltage - Supply
1.8 V ~ 3.6 V
Operating Temperature
-40°C ~ 85°C
Package / Case
20-VQFN
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Memory Size
-
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
SI4330-B1-FMR
Manufacturer:
HIROSE
Quantity:
3 200
Part Number:
SI4330-B1-FMR
Manufacturer:
SILICON LABS/芯科
Quantity:
20 000
8.10. RSSI and Clear Channel Assessment
Received signal strength indicator (RSSI) is an estimate of the signal strength in the channel to which the receiver
is tuned. The RSSI value can be read from an 8-bit register with 0.5 dB resolution per bit. Figure 23 demonstrates
the relationship between input power level and RSSI value.The absolute value of the RSSI will change slightly
depending on the modem settings. The RSSI may be read at anytime, but an incorrect error may rarely occur. The
RSSI value may be incorrect if read during the update period. The update period is approximately 10 ns every
4 Tb. For 10 kbps, this would result in a 1 in 40,000 probability that the RSSI may be read incorrectly. This
probability is extremely low, but to avoid this, one of the following options is recommended: majority polling,
reading the RSSI value within 1 Tb of the RSSI interrupt, or using the RSSI threshold described in the next
paragraph for Clear Channel Assessment (CCA).
For CCA, threshold is programmed into rssith[7:0] in "Register 27h. RSSI Threshold for Clear Channel Indicator."
After the RSSI is evaluated in the preamble, a decision is made if the signal strength on this channel is above or
below the threshold. If the signal strength is above the programmed threshold then the RSSI status bit, irssi, in
"Register 04h. Interrupt/Status 2" will be set to 1. The RSSI status can also be routed to a GPIO line by configuring
the GPIO configuration register to GPIOx[3:0] = 1110.
Add R/W
26
27
R/W
R
250
200
150
100
50
RSSI Threshold for Clear Channel Indicator
0
-120
Received Signal Strength Indicator
Function/Description
-100
Figure 23. RSSI Value vs. Input Power
-80
rssith[7]
RSSI vs Input Power
rssi[7]
D7
-60
rssith[6]
rssi[6]
Rev 1.0
In Pow [dBm]
D6
rssith[5]
rssi[5]
D5
-40
rssith[4]
rssi[4]
D4
rssith[3]
rssi[3]
D3
-20
rssith[2]
rssi[2]
D2
rssith[1]
rssi[1]
0
Si4330-B1
D1
rssith[0]
rssi[0]
D0
20
POR Def.
00h
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