EVAL-ADF7021-VDB2Z Analog Devices Inc, EVAL-ADF7021-VDB2Z Datasheet - Page 27

• Manufacturer Part Number: EVAL-ADF7021-VDB2Z
• Description: 868 - 870MHz - EVALUATION BOARD
• Manufacturer: Analog Devices Inc
• Type: Transceiverr

Specifications of EVAL-ADF7021-VDB2Z

• Frequency: 868MHz ~ 870MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: ADF7021
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

MODULATION AND FILTERING OPTIONS
The various modulation and data filtering options for the
ADF7021-V are described in Table 10.
Table 10. Modulation and Filtering Options
Modulation
Binary FSK
Three-Level FSK
Four-Level FSK
1
2
3
TRANSMIT LATENCY
Transmit latency is the delay time from the sampling of a
bit/symbol by the TxRxCLK signal to when that bit/symbol
appears at the RF output. The latency without any data filtering
is 1 bit. The addition of data filtering adds a further latency as
indicated in Table 11.
It is important that the ADF7021-V be left in transmit mode
after the last data bit is sampled by the data clock to account for
this latency. The ADF7021-V should stay in transmit mode for
a time equal to the number of latency bit periods for the applied
modulation scheme. This ensures that all of the data sampled by
the TxRxCLK signal appears at RF.
GMSK is GFSK with a modulation index = 0.5.
MSK is 2FSK modulation with a modulation index = 0.5.
Offset quadrature phase shift keying (OQPSK) with half sine baseband
shaping is spectrally equivalent to MSK.
2FSK
MSK
OQPSK with Half Sine
GFSK
GMSK
RC2FSK
Oversampled 2FSK
3FSK
RC3FSK
4FSK
RC4FSK
Baseband Shaping
1
3
2
Raised cosine
Raised cosine
Raised cosine
Data Filtering
None
None
None
Gaussian
Gaussian
None
None
None
Register 2,
Bits[DB6:DB4]
000
000
000
001
001
101
100
010
110
011
111
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The figures for latency in Table 11 assume that the positive
TxRxCLK edge is used to sample data (default). If the TxRxCLK
is inverted by setting Register 2, Bits[DB29:DB28], an additional
0.5 bit latency can be added to all values in Table 11.
Table 11. Bit/Symbol Latency in Transmit Mode for Various
Modulation Schemes
Modulation
2FSK
3FSK
4FSK
TEST PATTERN GENERATOR
The ADF7021-V has a number of built-in test pattern generators
that can be used to facilitate radio link setup or RF measurement.
A full list of the supported test patterns is shown in Table 12.
The data rate for these test patterns is the programmed data rate
set in Register 3.
The PN9 sequence is suitable for test modulation when carrying
out adjacent channel power (ACP) or occupied bandwidth
measurements.
Table 12. Transmit Test Pattern Generator Options
Test Pattern
Normal
Transmit carrier only
Transmit +f
Transmit −f
Transmit 1010 pattern
Transmit PN9 sequence
Transmit SWD pattern repeatedly
GFSK
RC2FSK, alpha = 0.5
RC2FSK, alpha = 0.7
RC3FSK, alpha = 0.5
RC3FSK, alpha = 0.7
RC4FSK, alpha = 0.5
RC4FSK, alpha = 0.7
DEV
DEV
tone only
tone only
Latency
1 bit
4 bits
5 bits
4 bits
1 bit
5 bits
4 bits
1 symbol
5 symbols
4 symbols
Register 15,
Bits[DB10:DB8]
000
001
010
011
100
101
110
ADF7021-V