Table 2-3 – Rainbow Electronics ATA5746 User Manual
Page 7
7
4596A–RKE–05/06
ATA5745/ATA5746 [Preliminary]
Conditions for the sensitivity measurement:
The given sensitivity values are valid for Manchester-modulated signals. For the sensitivity mea-
surement the distance from edge to edge must be evaluated. As can be seen in
, in a Manchester-modulated data stream, the time segments T
EE
and 2
× T
EE
occur.
To reach the specified sensitivity for the evaluation of T
EE
and 2
× T
EE
in the data stream, the
following limits should be used (T
EE
min, T
EE
max, 2
× T
EE
min, 2
× T
EE
max).
2.3
Sensitivity Versus Supply Voltage, Temperature and Frequency Offset
To calculate the behavior of a transmission system, it is important to know the reduction of the
sensitivity due to several influences. The most important are frequency offset due to crystal
oscillator (XTO) and crystal frequency (XTAL) errors, temperature and supply voltage depen-
dency of the noise figure, and IF-filter bandwidth of the receiver.
and
show the typical sensitivity at 315 MHz, ASK, 2.4 Kbits/s and 9.6 Kbits/s, Manchester,
show a typical sensitivity at 315 MHz, FSK, 2.4 Kbits/s and
9.6 Kbits/s, ±38 kHz, Manchester versus the frequency offset between transmitter and receiver
at T
amb
= –40°C, +25°C, and +105°C and supply voltage VS = VS3V_AVCC = VS5V = 2.7V,
3.0V and 3.3V.
Table 2-3.
Measured Typical Sensitivity FSK,
±38 kHz, Manchester, BER = 10
–3
RF Frequency
BR_Range_0
1.0 Kbit/s
BR_Range_0
2.5 Kbits/s
BR_Range_1
5 Kbits/s
BR_Range_2
10 Kbits/s
BR_Range_3
10 Kbits/s
BR_Range_3
20 Kbits/s
315 MHz
–108 dBm
–108 dBm
–107 dBm
–105 dBm
–104 dBm
–104 dBm
433.92 MHz
–107 dBm
–107 dBm
–106 dBm
–104 dBm
–103 dBm
–103 dBm
Table 2-4.
Measured Typical Sensitivity 100% ASK, Manchester, BER = 10
–3
RF Frequency
BR_Range_0
1.0 Kbit/s
BR_Range_0
2.5 Kbits/s
BR_Range_1
5 Kbits/s
BR_Range_2
10 Kbits/s
BR_Range_3
10 Kbits/s
315 MHz
–114 dBm
–114 dBm
–113 dBm
–111 dBm
–109 dBm
433.92 MHz
–113 dBm
–113 dBm
–112 dBm
–110 dBm
–108 dBm
Table 2-5.
Limits for Sensitivity Measurements
Bit Rate
T
EE
Min
T
EE
Typ
T
EE
Max
2
× T
EE
Min
2
× T
EE
Typ
2
× T
EE
Max
1.0 Kbit/s
260 µs
500 µs
790 µs
800 µs
1000 µs
1340 µs
2.4 Kbits/s
110 µs
208 µs
310 µs
320 µs
416 µs
525 µs
5.0 Kbits/s
55 µs
100 µs
155 µs
160 µs
200 µs
260 µs
9.6 Kbits/s
27 µs
52 µs
78 µs
81 µs
104 µs
131 µs