SI4431-A0-FM Silicon Laboratories Inc, SI4431-A0-FM Datasheet - Page 108

• Manufacturer Part Number: SI4431-A0-FM
• Description: IC TXRX ISM 930MHZ 3.6V 20-QFN
• Manufacturer: Silicon Laboratories Inc

Specifications of SI4431-A0-FM

• Package / Case: 20-QFN
• Mfg Application Notes: Transitioning SI4430/31 to Rev B
• Frequency: 240MHz ~ 930MHz
• Data Rate - Maximum: 128kbps
• Modulation Or Protocol: FSK, GFSK, OOK
• Power - Output: 13dBm
• Sensitivity: -118dBm
• Voltage - Supply: 1.8 V ~ 3.6 V
• Current - Receiving: 18.5mA
• Current - Transmitting: 28mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Operating Temperature: -40°C ~ 85°C
• Number Of Receivers: 2
• Number Of Transmitters: 1
• Wireless Frequency: 240 MHz to 930 MHz
• Output Power: 13 dBm
• Operating Supply Voltage: 1.8 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Maximum Supply Current: 28 mA
• Minimum Operating Temperature: - 40 C
• Modulation: FSK, GFSK, OOK
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Applications: -
• Memory Size: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 336-1633-5

Register 20h. Clock Recovery Oversampling Rate
Si4431
Reset value = 01100100
The oversampling rate can be calculated as rxosr = 500 kHz/(2
dwn3_bypass values found at Address: 1Ch – IF Filter Bandwidth register together with the receive data rate (Rb)
are the parameters needed to calculate rxosr:
The Rb unit used in this equation is in kbps. The enmanch is the Manchester Coding parameter (see Reg. 70h,
enmach is 1 when Manchester coding is enabled, enmanch is 0 when disabled). The number found in the equation
should be rounded to an integer. The integer can be translated to a hexadecimal.
For optimal modem performance it is recommended to set the rxosr to at least 8. A higher rxosr can be obtained by
choosing a lower value for ndec_exp or enable dwn3_bypass. A correction in filset might be needed to correct the
channel select bandwidth to the desired value. Note that when ndec_exp or dwn3_bypass are changed the related
parameters (rxosr, ncoff and crgain) need to be updated.
108
Name
Type
Bit
7:0
Bit
rxosr[7:0]
Name
D7
Oversampling Rate.
3 LSBs are the fraction, default = 0110 0100 = 12.5 clock cycles per data bit
D6
rxosr
D5

2
500
ndec
Preliminary Rev. 0.4
_

exp

1
D4

3


2
rxosr[7:0]
Rb

R/W
dwn

1 (
Function
3

_
D3
enmanch
bypass
ndec_exp

)
x RX_DR). The ndec_exp and the
D2
D1
D0