8

SL6679

RECEIVER CHARACTERISTICS (280MHz)

Receiver Characteristics (280MHz) are guaranteed over the following range of operating conditions unless otherwise stated.

Characteristics are not tested but are guaranteed by characterisation test or design. All measurements made using the

characterisation circuit Fig. 5. See Application Note AN137 for details of test method.

T

210

°C to 155°C, V

BER = 1 in 30, AFC open loop. LNA gain set such that an RF signal of273dBm at the LNA input, offset from the LO

by 4kHz, gives a typical IF signal level of 300mV p-p at TPI and TPQ. LNA noise figure,2dB

Characteristic

512bps, Df = 4·5kHz

1200bps, Df = 4·0kHz

2400bps, Df = 4·5kHz. LO = 215dBm

512bps, Df = 4·5kHz

1200bps, Df = 4·0kHz

2400bps, Df = 4·5kHz. LO = 215dBm. Channel

spacing 25kHz

512bps, Df = 4·5kHz

1200bps, Df = 4·0kHz

2400bps, Df = 4·5kHz. LO = 215dBm. Channel

spacing 25kHz

512bps, Df = 4·5kHz, no AFC

512bps, Df = 4·5kHz, no AFC

1200bps, Df = 4·0kHz, no AFC

1200bps, Df = 4·0kHz, no AFC

2400bps, Df = 4·5kHz, no AFC

2400bps, Df = 4·5kHz, no AFC

512bps, Df = 4·5kHz, no AFC

1200bps, Df = 4·0kHz, no AFC

2400bps, Df = 4·5kHz, no AFC

512bps, Df = 4·5kHz. All at sensitivity 13dB or above

1200bps, Df = 4·0kHz. All at sensitivity 13dB or above

2400bps, Df = 4·5kHz. All at sensitivity 13dB or above

512bps, Df = 4·5kHz

1200bps, Df = 4·0kHz

2400bps, Df = 4·5kHz. LO = 215dBm

2400bps, R14 = 120k

Ω (Fig. 5), room temperature

only. See Note.

Conditions

Sensitivity

Intermodulation, IP3

Adjacent Channel

Deviation Acceptance

Up

Down

Up

Down

Up

Down

Centre Frequency Acceptance

AFC Capture Range (AFC

Closed Loop)

1MHz Blocking

Mark:space amplitude

modulation acceptance

Value

Typ.

Min.

2129

2127

2124

57

56

53·5

72

69

60

11·9

22·5

13·0

22·9

12·5

22·3

63·1

62·9

62·5

64

63·5

64

75

75

73

23

2128

2127

52

49

62·5

60

11·8

23·8

11·7

23·0

62·0

62·0

67

65

20

Max.

dBm

dBm

dBm

dB

dB

dB

dB

dB

dB

kHz

kHz

kHz

kHz

kHz

kHz

kHz

kHz

kHz

kHz

kHz

kHz

dB

dB

dB

dB

Units

2124

2121

60

57

80

77

14·6

21·7

14·6

21·7

63·1

63·2

78

76

NOTE

The mark:space amplitude acceptance is the maximum amplitude ratio which can occur (for example due to Simulcast conditions) with 2400bps,

using a POCSAG decoder with R14 = 120k

Ω to achieve an 80% call rate and the lower amplitude set at a sensitivity of 120dB. the maxima and

minima of the amplitude modulation correspond to the positive and negative (or vice versa) frequency shifts of the FSK modulation.