CC1010-RTY1 datasheet(126/152 Pages) TI

126 / 152 page

CC1010

SWRS047

Page 126 of 152

17.20 RSSI Output

CC1010 has a built-in RSSI (Received

Signal Strength Indicator) giving an analog

output signal at the AD2(RSSI/IF) pin.

RSSI

enabled

when

setting

FREND.RSSI (see page 119). The output

current of this pin is then inversely

proportional to the input signal level. The

output should be terminated in a resistor to

convert the current output into a voltage. A

capacitor is used to low-pass filter the

signal.

The RSSI voltage range is from 0 – 1.2 V

when using a 27 k

Ω terminating resistor,

giving approximately 50 dB/V. This RSSI

voltage can be measured by the on-chip

A/D converter using the AD2 input. Note

that a higher voltage means a lower input

signal.

The RSSI measures the power referred to

the RF_IN pin. The input power can be

calculated using the following equations:

P = -48.8 VRSSI– 57.2 [dBm] at 433 MHz

P = -46.9 VRSSI– 53.9 [dBm] at 868 MHz

The external network for RSSI operation is

shown in

Figure 41. R281 = 27 k

Ω, C281 = 1nF.

A typical plot of RSSI voltage as function

of input power is shown in Figure 42.

When using the on-chip A/D converter, set

ADCON = 0x06 to initiate a single

conversion using VDD as reference. The

converted RSSI voltage can then be read

from the ADDATH and ADDATL registers.

CC1010

AD2 (RSSI/IF)

C281

R281

Figure 41. RSSI circuit

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1,1

1,2

1,3

-105 -100 -95

-90

-85

-80

-75

-70

-65

-60

-55

-50

dBm

433Mhz

868Mhz

Figure 42. Typical RSSI voltage vs. input

power

CC1010-RTY1 Datenblatt(PDF) 126 Page - Texas Instruments

CC1010-RTY1 Datenblatt(HTML) 126 Page - Texas Instruments

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

Datenblatt Download

Link URL