IDT
®
19-Output Differential Zbuffer for PCIe Gen2/3 and QPI 1648H- 12/08/11
9ZX21901C
19-Output Differential Zbuffer for PCIe Gen2/3 and QPI
6
Electrical Characteristics - Clock Input Parameters
TA = T
COM;
Supply Voltage VDD/VDDA = 3.3 V +/-5%, See Test Loads for Loading Conditions
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS NOTES
Input High Voltage - DIF_IN V
IHDIF
Differential inputs
(sin
le-ended measurement)
600 750 1150 mV 1
Input Low Voltage - DIF_IN V
ILDIF
Differential inputs
(sin
le-ended measurement)
V
SS
- 300 0 300 mV 1
Input Common Mode
Volta
e - DIF_IN
V
COM
Common Mode Input Voltage 300 1000 mV 1
Input Amplitude - DIF_IN V
SWING
Peak to Peak value 300 1450 mV 1
Input Slew Rate - DIF_IN dv/dt Measured differentiall
0.4 8 V/ns 1,2
Input Leakage Current I
IN
V
IN
= V
DD ,
V
IN
=
GND -5 5 uA 1
Input Duty Cycle d
tin
Measurement from differential wavefrom 45 55 % 1
Input Jitter - Cycle to Cycle J
DIFIn
Differential Measurement 0 125 ps 1
1
Guaranteed b
desi
n and characterization, not 100% tested in production.
2
Slew rate measured through +/-75mV window centered around differential zero
Electrical Characteristics - Current Consumption
TA = T
COM;
Supply Voltage VDD/VDDA = 3.3 V +/-5%, See Test Loads for Loading Conditions
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS NOTES
Operating Supply Current I
DD3. 3OP
All outputs active @100MHz, C
L
= Full load; 407 500 mA 1
Powerdown Current
I
DD3. 3PDZ
All differential pairs tri-stated 12 36 mA 1
1
Guaranteed by design and characterization, not 100% tested in production.
Electrical Characteristics - DIF 0.7V Current Mode Differential Outputs
TA = T
COM;
Supply Voltage VDD/VDDA = 3.3 V +/-5%, See Test Loads for Loading Conditions
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS NOTES
Slew rate dV/dt Scope avera
in
on 1 2.5 4
V/ns
1, 2, 3
Slew rate matchin
ΔdV/dt
Slew rate matchin
, Scope avera
in
on 20
%
1, 2, 4
Rise/Fall Time Matching Trf Rise/fall matching, Scope averaging off 125
ps
1, 7, 8
Voltage High VHigh 660 750 850 1
Voltage Low VLow -150 150 1
Max Voltage Vmax 1150 1
Min Voltage Vmin -300 1
Vswin
Vswin
Scope avera
in
off 300 mV 1, 2
Crossin
Volta
e (abs) Vcross_abs Scope avera
in
off 250 550 mV 1, 5
Crossing Voltage (var)
Δ
-Vcross Scope averaging off 140 mV 1, 6
2
Measured from differential waveform
7
Measured from single-ended waveform
8
Measured with scope averaging off, using statistics function. Variation is difference between min and max.
6
The total variation of all Vcross measurements in any particular system. Note that this is a subset of V_cross_min/max (V_cross
absolute) allowed. The intent is to limit Vcross induced modulation by setting V_cross_delta to be smaller than V_cross absolute.
mV
Statistical measurement on single-ended signal
using oscilloscope math function. (Scope
averaging on)
Measurement on single ended signal using
absolute value. (Scope averaging off)
mV
1
Guaranteed by design and characterization, not 100% tested in production. IREF = VDD/(3xR
R
). For R
R
= 475
Ω
(1%), I
REF
= 2.32mA.
I
OH
= 6 x I
REF
and V
OH
= 0.7V @ Z
O
=50
Ω
(100
Ω
differential impedance).
3
Slew rate is measured through the Vswing voltage range centered around differential 0V. This results in a +/-150mV window around
differential 0V.
4
Matching applies to rising edge rate for Clock and falling edge rate for Clock#. It is measured using a +/-75mV window centered on
the average cross point where Clock rising meets Clock# falling. The median cross point is used to calculate the voltage thresholds the
oscilloscope is to use for the edge rate calculations.
5
Vcross is defined as voltage where Clock = Clock# measured on a component test board and only applies to the differential rising
edge (i.e. Clock rising and Clock# falling).
