Typ
Temp
tWH, tWL (W_CLK Min PulseWidth High/Low)
t
DS, tDH (Data toW_CLK Setup and HoldTimes)
tFH, tFL (FQ_UD Min PulseWidth High/Low)
t
CD (REFCLK Delay After FQ_UD)5
tFD (FQ_UD Min Delay AfterW_CLK)
t
CF (Output Latency from FQ_UD)
Frequency Change
Full
Full
Full
IV
IV
IV
3.5
7
7
ns
ns
ns
Full
Full
IV
IV
18
13
SYSCLK
Cycles
SYSCLK
Cycles
ns
Phase Change
tRH (CLKIN Delay After RESET Rising Edge)
t
RL (RESET Falling Edge After CLKIN)
tRR (Recovery from RESET)
Full
Full
IV
IV
3.5
2
SYSCLK
Cycles
SYSCLK
Cycles
SYSCLK
Cycles
µs
tRS (Minimum RESETWidth)
Full
Full
25°C
IV
IV
V
5
tOL (RESET Output Latency)
13
Wake-UpTime from Power-Down Mode6
5
Logic 1Voltage, 5V Supply
Logic 1Voltage, 3.3V Supply
Logic 1Voltage, 2.7V Supply
Logic 0Voltage
Logic 1 Current
Logic 0 Current
Rise/FallTime
Input Capacitance
25°C
25°C
25°C
25°C
I
3.5
2.0
V
V
µA
µA
ns
pF
IV
I
IV
12
100
POWER SUPPLY
62.5 MHz Clock, 2.7V Supply
100 MHz Clock, 2.7V Supply
62.5 MHz Clock, 3.3V Supply
125 MHz Clock, 3.3V Supply
62.5 MHz Clock, 5V Supply
125 MHz Clock, 5V Supply
180 MHz Clock, 5V Supply
Power Dissipation @ :
25°C
25°C
25°C
25°C
VI
VI
VI
VI
30
35
50
110
35
45
65
130
mA
mA
mA
mA
62.5 MHz Clock, 5V Supply
62.5 MHz Clock, 3.3V Supply
62.5 MHz Clock, 2.7V Supply
100 MHz Clock, 2.7V Supply
125 MHz Clock, 5V Supply
125 MHz Clock, 3.3V Supply
180 MHz Clock, 5V Supply
5V Supply
25°C
25°C
25°C
25°C
VI
VI
VI
VI
250
85
365
555
325
95
450
650
mW
mW
mW
mW
25°C
25°C
VI
VI
17
4
55
20
mW
mW
2.7V Supply
NOTES
1+VS collectively refers to the positive voltages applied to DVDD, PVCC, and AVDD.Voltages applied to these pins should be of the same potential.
2Indicates the minimum signal levels required to reliably clock the device at the indicated supply voltages.This specifies the p-p signal level and dc offset needed when the
clocking signal is not of CMOS/TTL origin, i.e., a sine wave with 0V dc offset.
3The comparator’s jitter contribution to any input signal.This is the minimum jitter on the outputs that can be expected from an ideal input. Considerably more output
jitter is seen when nonideal input signals are presented to the comparator inputs. Nonideal characteristics include the presence of extraneous, nonharmonic signals (spur’s,
noise), slower slew rate, and low comparator overdrive.
4Timing of input signals FQ_UD,WCLK, RESET are asynchronous to the reference clock; however, the presence of a reference clock is required to implement those
functions. In the absence of a reference clock, the AD9851 automatically enters power-down mode rendering the IC, including the comparator, inoperable until a refer-
ence clock is restored.Very high speed updates of frequency/phase word will require FQ_UD andWCLK to be externally synchronized with the external reference clock to
ensure proper timing.
5Not applicable when 6
REFCLK Multiplier is engaged.
6Assumes no capacitive load on DACBP (Pin 17).
Specifications subject to change without notice.