AD9549
AC SPECIFICATIONS
fS = 1 GHz, DAC RSET = 10 kΩ, power supply pins within the range specified in the DC Specifications section, unless otherwise noted.
Table 2.
Parameter
Min
Typ
Max
Unit
Test Conditions/Comments
REFERENCE INPUTS
Pin 12, Pin 13, Pin 15, and Pin 16
Minimum recommended slew rate: 40 V/μs
Frequency Range (Sine Wave)
Frequency Range (CMOS)
Frequency Range (LVPECL)
Frequency Range (LVDS)
10
750
50
725
725
MHz
MHz
MHz
MHz
0.008
0.008
0.008
LVDS must be ac-coupled; lower frequency bound may
be higher, depending on the size of the decoupling
capacitor
Minimum Slew Rate
0.04
620
620
V/ns
ps
ps
Minimum Pulse Width High
Minimum Pulse Width Low
FDBK_IN INPUT
Pin 40, Pin 41
Input Frequency Range
Minimum Differential Input Level
Minimum Slew Rate
10
225
40
400
MHz
mV p-p
V/μs
−12 dBm into 50 Ω; must be ac-coupled
Pin 27, Pin 28
SYSTEM CLOCK INPUT
SYSCLK PLL Bypassed
Input Frequency Range
Duty Cycle
Minimum Differential Input Level
SYSCLK PLL Enabled
250
45
632
1000
55
MHz
%
mV p-p
Maximum fOUT is 0.4 × fSYSCLK
0 dBm into 50 Ω
VCO Frequency Range, Low Band
VCO Frequency Range, Auto Band
VCO Frequency Range, High Band
Maximum Input Rate of System Clock PFD
Without SYSCLK PLL Doubler
Input Frequency Range
Multiplication Range
700
810
900
810
900
1000
200
MHz
MHz
MHz
MHz
When in the range, use the low VCO band exclusively
When in the range, use the VCO Auto band select
When in the range, use the high VCO band exclusively
11
4
200
66
MHz
Integer multiples of 2, maximum PFD rate and system
clock frequency must be met
Minimum Differential Input Level
With SYSCLK PLL Doubler
Input Frequency Range
Multiplication Range
632
mV p-p
MHz
0 dBm into 50 Ω
6
8
100
132
Integer multiples of 8
Input Duty Cycle
50
%
Deviating from 50% duty cycle may adversely affect
spurious performance.
Minimum Differential Input Level
Crystal Resonator with SYSCLK PLL Enabled
Crystal Resonator Frequency Range
Maximum Crystal Motional Resistance
CLOCK DRIVERS
632
10
mV p-p
0 dBm into 50 Ω
50
100
MHz
Ω
AT cut, fundamental mode resonator
See the SYSCLK Inputs section for recommendations
HSTL Output Driver
Frequency Range
20
48
725
52
MHz
%
See Figure 12 for maximum toggle rate
Duty Cycle
Rise Time/Fall Time (20-80%)
Jitter (12 kHz to 20 MHz)
115
1.0
165
ps
ps
100 Ω termination across OUT/OUTB, 2 pF load
fIN = 19.44 MHz, fOUT = 155.52 MHz. 50 MHz system
clock input (see Figure 3 to Figure 11 for test conditions)
HSTL Output Driver with 2× Multiplier
Frequency Range
Duty Cycle
400
45
725
55
MHz
%
Rise Time/Fall Time (20% to 80%)
Subharmonic Spur Level
Jitter (12 kHz to 20 MHz)
115
−35
1.1
165
ps
dBc
ps
100 Ω termination across OUT/OUTB, 2 pF load
Without correction
fIN = 19.44 MHz, fOUT = 622.08 MHz, 50 MHz system
clock input (see Figure 3 to Figure 11 for test conditions)
Rev. D | Page 6 of 76