Datasheet

AD9785/AD9787/AD9788
Rev. A | Page 48 of 64
07098-027
ADC
VCO
DAC
INTERPOLATION
RATE
LOOP
FILTER
REFCLK
(PIN 5 AND PIN 6)
0x04 [23:21]
VCO CONTROL
VOLTAGE
0x04 [15]
PLL ENABLE
DAC CLOCK
DATACLK (PIN 37)
0x01 [7:6]
0x04 [14:13]
PLL VCO
DIVISOR
0x04 [12:11]
PLL LOOP
DIVISOR
÷IF
÷N
2
÷N
1
PLL_LOCK (PIN 65)
0x09 [3]
PHASE
DETECTION
Figure 68. Clock Multiplication Circuit
Table 35. Typical VCO Freq Range vs. PLL Band Select Value
PLL Lock Ranges over Temperature, −40°C to +85°C
PLL Band Select
VCO Frequency Range in MHz
1
f
LOW
f
HIGH
111111 (63) Auto mode Auto mode
111110 (62) 1975 2026
111101 (61) 1956 2008
111100 (60) 1938 1992
111011 (59) 1923 1977
111010 (58) 1902 1961
111001 (57) 1883 1942
111000 (56) 1870 1931
110111 (55) 1848 1915
110110 (54) 1830 1897
110101 (53) 1822 1885
110100 (52) 1794 1869
110011 (51) 1779 1853
110010 (50) 1774 1840
110001 (49) 1748 1825
110000 (48) 1729 1810
101111 (47) 1730 1794
101110 (46) 1699 1780
101101 (45) 1685 1766
101100 (44) 1684 1748
101011 (43) 1651 1729
101010 (42) 1640 1702
101001 (41) 1604 1681
101000 (40) 1596 1658
100111 (39) 1564 1639
100110 (38) 1555 1606
100101 (37) 1521 1600
100100 (36) 1514 1575
100011 (35) 1480 1553
100010 (34) 1475 1529
100001 (33) 1439 1505
100000 (32) 1435 1489
PLL Lock Ranges over Temperature, −40°C to +85°C
PLL Band Select
VCO Frequency Range in MHz
1
f
LOW
f
HIGH
011111 (31) 1402 1468
011110 (30) 1397 1451
011101 (29) 1361 1427
011100 (28) 1356 1412
011011 (27) 1324 1389
011010 (26) 1317 1375
011001 (25) 1287 1352
011000 (24) 1282 1336
010111 (23) 1250 1313
010110 (22) 1245 1299
010101 (21) 1215 1277
010100 (20) 1210 1264
010011 (19) 1182 1242
010010 (18) 1174 1231
010001 (17) 1149 1210
010000 (16) 1141 1198
001111 (15) 1115 1178
001110 (14) 1109 1166
001101 (13) 1086 1145
001100 (12) 1078 1135
001011 (11) 1055 1106
001010 (10) 1047 1103
001001 (9) 1026 1067
001000 (8) 1019 1072
000111 (7) 998 1049
000110 (6) 991 1041
000101 (5) 976 1026
000100 (4) 963 1011
000011 (3) 950 996
000010 (2) 935 981
000001 (1) 922 966
000000 (0) 911 951
1
The lock ranges in this table are typical values. Actual lock ranges will vary
from device to device.