RFM95 datasheet(81/121 Pages) HOPERF

81 / 121 page

Page 81

RFM95/96/97/98(W)

Tel: +86-755-82973805 Fax: +86-755-82973550 E-mail: sales@hoperf.com http://www.hoperf.com

WIRELESS & SENSING

PRELIMINARY

DATASHEET

Table 82 LNA Gain Control and Performances

RX input level (Pin)

Gain

Setting

LnaGain

Relative LNA

Gain [dB]

Lower/Higher

band

[dB]

IIP3

Lower/Higher

band [dBm]

Pin <= AgcThresh1

‘001’

0 dB

5/7

-22/-12

AgcThresh1 < Pin <= AgcThresh2

‘010’

-6 dB

9/11

-15/-8

AgcThresh2 < Pin <= AgcThresh3

‘011’

-12 dB

AgcThresh3 < Pin <= AgcThresh4

‘100’

-24 dB

AgcThresh4 < Pin <= AgcThresh5

‘110’

-26 dB

AgcThresh5 < Pin

‘111’

-48 dB

TBC

5.5.4. RSSI in FSK/OOK Mode

The RSSI provides a measure of the incoming signal power at RF input port, measured within the receiver bandwidth. The

signal power is available in RssiValue. This value is absolute in units of dBm and with a resolution of 0.5 dB. The formula

below relates the register value to the absolute input signal level at the RF input port:

RssiValue

= −2· RF level

[dBm]+ RssiOffset [dB]

The RSSI value can be compensated to take into account the loss in the matching network or even the gain of an

additional LNA by using RssiOffset. The offset can be chosen in 1 dB steps from -16 to +15 dB. When compensation is

applied, the effective signal strength is read as follows:

RSSI

[dBm]= − RssiValue

The RSSI value is smoothed on a user defined number of measured RSSI samples. The precision of the RSSI value is

related to the number of RSSI samples used. RssiSmoothing selects the number of RSSI samples from a minimum of 2

samples up to 256 samples in increments of power of 2. Table 83 gives the estimation of the RSSI accuracy for a 10 dB

SNR and response time versus the number of RSSI samples programmed in RssiSmoothing.

RFM95 Datasheet(PDF) 81 Page - Shenzhen Hope Microelectronics Co., Ltd.

RFM95 Datasheet(HTML) 81 Page - Shenzhen Hope Microelectronics Co., Ltd.

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL