AD9850 Analog Devices, AD9850 Datasheet - Page 10

• Manufacturer Part Number: AD9850
• Description: CMOS/ 125 MHz Complete DDS Synthesizer
• Manufacturer: Analog Devices

AD9850
Word
W0
W1
W2
W3
W4
data[7]
Phase-b4
(MSB)
Freq-b31
(MSB)
Freq-b23
Freq-b15
Freq-b7
COS OUT
REF CLK
W CLK
FQ UD
DATA
data[6]
Phase-b3
Freq-b30
Freq-b22
Freq-b14
Freq-b6
*OUTPUT UPDATE CAN OCCUR AFTER ANY WORD LOAD
Table III. 8-Bit Parallel-Load Data/Control Word Functional Assignment
AND IS ASYNCHRONOUS WITH THE REFERENCE CLOCK
Figure 18. Parallel-Load Frequency/Phase Update Timing Sequence
t
DS
Table II. Factory-Reserved Internal Test Control Codes
W0*
t
Loading Format
Parallel
Serial
DH
SYMBOL
data[5]
Phase-b2
Freq-b29
Freq-b21
Freq-b13
Freq-b5
t
t
t
t
t
t
t
t
t
DS
DH
WH
WL
CD
FH
FL
FD
CF
W1
t
DEFINITION
FL
DATA SETUP TIME
DATA HOLD TIME
W CLK HIGH
W CLK LOW
CLK DELAY AFTER FQ_UD
FQ UD HIGH
FQ UD LOW
FQ UD DELAY AFTER W CLK
OUTPUT LATENCY FROM FQ UD
t
W2
WH
t
data[4]
Phase-b1
Freq-b28
Freq-b20
Freq-b12
Freq-b4
WL
W3
FREQUENCY CHANGE
PHASE CHANGE
Factory-Reserved Codes
1) W0 = XXXXXX10
2) W0 = XXXXXX01
1) W32 = 1; W33 = 0
2) W32 = 0; W33 = 1
3) W32 = 1; W33 = 1
–10–
W4
t
FD
data[3]
Phase-b0
Freq-b27
Freq-b19
Freq-b11
Freq-b3
t
(LSB)
CD
t
FH
MIN
3.5ns
3.5ns
3.5ns
3.5ns
3.5ns
7.0ns
7.0ns
7.0ns
18 CLOCK CYCLES
13 CLOCK CYCLES
OLD FREQ (PHASE)
t
CF
data[2]
Power-Down
Freq-b26
Freq-b18
Freq-b10
Freq-b2
NEW FREQ (PHASE)
VALID DATA
data[1]
Control
Freq-b25
Freq-b17
Freq-b9
Freq-b1
data[0]
Control
Freq-b24
Freq-b16
Freq-b8
(LSB)
Freq-b0
REV. E