SI4311-B10-GM Silicon Laboratories Inc, SI4311-B10-GM Datasheet - Page 10

• Manufacturer Part Number: SI4311-B10-GM
• Description: IC RX FSK 315/434MHZ 20VQFN
• Manufacturer: Silicon Laboratories Inc
• Series: EZRadio®r
• Type: ISM Receiverr

Specifications of SI4311-B10-GM

• Package / Case: 20-VQFN
• Frequency: 315MHz, 434MHz
• Sensitivity: -104dBm
• Data Rate - Maximum: 10 kBaud
• Modulation Or Protocol: FSK
• Applications: Garage Openers, RKE, Security Alarms
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Voltage - Supply: 2.7 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Operating Frequency: 315 MHz to 434 MHz
• Operating Supply Voltage: 2.7 V to 3.6 V
• Maximum Operating Temperature: + 95 C
• Minimum Operating Temperature: - 45 C
• Mounting Style: SMD/SMT
• Supply Current: 20 mA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Memory Size: -
• Current - Receiving: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1976-5

Si 4311
3.4. Bit Time BT[1:0] Selection
The Si4311 can operate with data rates of up to 10 kbps non-return to zero (NRZ) data or 5 kbps Manchester
encoded data. However, FSK modulation uses other encoding schemes, such as pulse width modulation (PWM)
and pulse position modulation (PPM) in which a bit can be encoded into a pulse with a certain duty cycle or pulse
width (see Figure 4).
In order to set the data filter bandwidth correctly, the shortest pulse width of the transmitted encoded data should
be chosen as the bit time. In the PPM example shown in Figure 4, the shortest pulse width is 100 µs, so the bit time
is chosen as BT = 100 µs even though the actual data rate is 1 kbps (1000 µs). After finding BT, Table 9 can be
used to find the bit settings for pins 14 and 15, BT[1:0]. In this PPM example, BT[1:0] is set as logic BT1 = 1 and
BT0 = 1 or BT[1:0] = (1,1) since BT = 100 µs.
10
Digital Data
Manchester
Encoding
Encoding
Encoding
PPM
NRZ
Table 9. How to Choose BT[1:0] Based on the Bit Time
1000< BT ≤ 500
500 < BT ≤ 200
200 < BT ≤ 100
1000 us
Bit Time [us]
BT ≥ 1000
“1”
Table 8. Carrier Frequency Selection
Figure 4. Example Data Waveforms
Pin 6 (315/434)
0
1
BT1 (pin 14)
Rev. 0.6
“0”
Frequency [MHz]
0
0
1
1
433.92
315
100 us
BT0 (pin 15)
“1”
0
1
0
1
“1”