AD9789 Analog Devices, AD9789 Datasheet - Page 65

• Manufacturer Part Number: AD9789
• Description: 14-Bit, 2400 MSPS RF DAC with 4-Channel Signal Processing
• Manufacturer: Analog Devices

Specifications of AD9789

• Resolution (bits): 14bit
• Dac Update Rate: 2.4GSPS
• Dac Settling Time: 13ns
• Max Pos Supply (v): +3.47V
• Single-supply: No
• Dac Type: Current Out
• Dac Input Format: LVDS,Par

QAM CONSTELLATION MAPS
I
I
K
K
Q
Q
K
K
= 10
= 11
101100 101110 100110 100100
101101 101111 100111 100101
101001 101011 100011 100001
101000 101010 100010 100000
110100 110101 110001 110000
110110 110111 110011 110010
111110 111111 111011 111010
111100 111101 111001 111000
I
K
I
I
I
K
K
K
Q
Q
Q
Q
K
Figure 121. DVB-C 16-QAM Constellation
Figure 122. DVB-C 64-QAM Constellation
K
K
K
ARE THE TWO MSBs IN EACH QUADRANT.
ARE THE TWO MSBs IN EACH QUADRANT.
= 10
= 11
1011
1010
1101
1111
1001
1000
1100
1110
Q
Q
001000 001001 001101 001100
001010 001011 001111 001110
000010 000011 000111 000110
000000 000001 000101 000100
010000 010010 011010 011000
010001 010011 011011 011001
010101 010111 011111 011101
010100 010110 011110 011100
0010
0000
0100
0101
0011
0001
0110
0111
I
I
K
K
Q
Q
K
K
= 00
= 01
I
I
I
K
K
Q
Q
K
K
I
= 00
= 01
Rev. A | Page 65 of 76
π
π
/2 ROTATION
I
I
K
K
ROTATION
Q
Q
I
I
K
K
K
K
Q
Q
= 10
= 11
K
K
= 10
= 11
I
I
K
K
Figure 124. DVB -C128-QAM Constellation3
Q
Q
Figure 123. DVB-C 32-QAM Constellation
K
K
10010
10110
11011
11111
ARE THE TWO MSBs IN EACH QUADRANT.
ARE THE TWO MSBs IN EACH QUADRANT.
11
9
7
5
3
1
10101
10100
11001
11010
10111
11101
11010
11000
10000
10010
00010
00000
1
10011
10001
10000
11000
11100
11110
11001
10001
10011
00011
00001
11011
Q
3
00110
00100
00000
01000
01001
01011
3
01011
01001
10101
00101
10111
00111
π
00010
00101
00001
01100
01101
01111
5
/2 ROTATION
I
K
Q
K
01010
01000
10100
00100
10110
00110
= 01
00011
01010
00111
01110
7
I
I
K
K
11100
11110
01110
01100
Q
Q
K
K
9
I
AD9789
K
= 00
= 01
Q
K
11101
01101
= 00
11111
01111
11
I