4313-T-B1_B_ANY Silicon Laboratories Inc, 4313-T-B1_B_ANY Datasheet - Page 24

• Manufacturer Part Number: 4313-T-B1_B_ANY
• Description: WiFi / 802.11 Modules & Development Tools WiFi/802.11 Modules & Development Tools
• Manufacturer: Silicon Laboratories Inc

Specifications of 4313-T-B1_B_ANY

• Wireless Frequency: 315 MHz to 915 MHz
• Modulation: FSK, OOK
• For Use With/related Products: Si4313
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Si4313-B1
(AFCLimiter) which is located in register 2Ah.
The AFC Limiter register is an unsigned register and its value can be obtained from the EZRadioPRO Register
Calculator spreadsheet or from WDS.
The amount of error correction feedback to the Fractional-N PLL before the preamble is detected is controlled from
afcgearh[2:0]. The default value 000 relates to a feedback of 100% from the measured frequency error and is
advised for most applications. Every bit added will half the feedback but will require a longer preamble to settle.
The AFC operates as follows. The frequency error of the incoming signal is measured over a period of two bit
times, after which it corrects the local oscillator via the Fractional-N PLL. After this correction, some time is allowed
to settle the Fractional-N PLL to the new frequency before the next frequency error is measured. The duration of
the AFC cycle before the preamble is detected can be programmed with shwait[2:0]. It is advised to use the default
value 001, which sets the AFC cycle to 4 bit times (2 for measurement and 2 for settling).
The AFC correction value may be read from register 2Bh. The value read can be converted to kHz with the
following formula:
24
AFC disabled
AFC enabled
AFC_pull_in_range = ±AFCLimiter[7:0] x (hbsel+1) x 625 Hz
AFC Correction = 156.25Hz x (hbsel +1) x afc_corr[7: 0]
Freq Offset Register
AFC
RX
Rev. 1.0
Frequency Correction
Freq Offset Register
Freq Offset Register
TX