SL28DB200 - Silicon Labs

SL28DB200
100 MHz Differential Buffer for PCI Express and SATA
Features
• Two differential 0.7V clock output pairs
• OE# input for enabling SRC outputs
• Individual OE controls
Functional Description
The SL28DB200 is a differential buffer capable of distributing
the Serial Reference Clock (SRC) for PCI Express Gen2 and
SATA implementations. The buffer enables the application
system to control the distribution of the SRC.
• Low CTC jitter (< 50 ps)
• Spread Aware
• 3.3V operation
• Industrial Temperature Grade -40oC to +85oC
• 16-pin TSSOP package
Applications
• Network/Media Attached Storage
• Routers/IP Gateways
• Multi-function Printers
Block Diagram
Pin Configuration
16 TSSOP
.........................Document #: 38-07722 Rev 0.4 Page 1 of 8
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SL28DB200
Pin Description
Pin
Name
Type
Description
2,3
SRCIN, SRCIN#
I,DIF
5,6,13,12
SRC[1:2], SRC[1:2]#
O,DIF 0.7V Differential Clock Outputs
I,SE
0.7V Differential inputs
7,11
OE[1:2]#
15
IREF
I
3.3V LVTTL input for enabling differential outputs
1
VDDA
PWR
3.3V Power Supply
A precision resistor 475 ohmis attached to this pin to set the differential
output current
16
VSSA
GND
Ground
8,10,14
VDD
PWR
3.3V power supply for outputs
4,9
VSS
GND
Ground for outputs
Notes: I=Input, O=Output, DIF=Differential signal, SE=Single Ended, PWR=Power input, GND=Ground
Table 1. Buffer Power-up State Machine
State
S0
Description
3.3V Buffer power off
S1
After 3.3V supply is detected to rise above 1.8V - 2.0V, the buffer enters state 1 and initiates a 0.2-ms–0.3-ms delay
S2
Buffer waits for a valid clock on the SRCIN input
S3
Once a valid input is detected, the buffer enters state 3 and enables outputs for normal operation
Figure 1. Buffer Power-up State Diagram
........................ Document #: 38-07722 Rev 0.4 Page 2 of 8
SL28DB200
Output Enable Clarification
OE Deassertion
OE# functionality allows for enabling and disabling individual
outputs. OE1# and OE2# are Active LOW inputs. Disabling the
outputs may be implemented by deasserting the OE# input
pin. If the OE# pin is deasserted, the output of interest will be
tri-stated. (The assertion and deassertion of this signal is
absolutely asynchronous.)
The impact of deasserting OE# is that each corresponding
output will transition from normal operation to tri-state in a
glitch-free manner. The maximum latency from the
deassertion to tri-stated outputs is between 2–6 DIF clock
periods.
OE Assertion
Table 2. OE Functionality
All differential outputs that were tri-stated will resume normal
operation in a glitch-free manner. The maximum latency from
the assertion to active outputs is between 2–6 SRC clock
periods. In addition, SRC clocks will be driven high within 15
ns of OE# assertion to a voltage greater than 200 mV
OE#
SRC,SRC#
0
Enable
1
Tri-State
Absolute Maximum Conditions
Parameter
Description
Condition
Min.
Max.
Unit
VDD
Core Supply Voltage
–0.5
4.6
V
VDDA
Analog Supply Voltage
–0.5
4.6
V
VIN
Input Voltage
Relative to VSS
–0.5
VDD + 0.5
VDC
TS
Temperature, Storage
Non-functional
–65
+150
°C
TA
Temperature, Operating Ambient
(Commercial Grade)
Functional
0
85
°C
TA
Temperature, Operating Ambient
(Industrial Grade)
Functional
-40
85
°C
TJ
Temperature, Junction
Functional
150
°C
ESDHBM
ESD Protection (Human Body Model)
JEDEC (JESD 22 - A114)
–
V
UL-94
Flammability Rating
UL (Class)
2000
V–0
DC Electrical Specifications
Parameter
Description
VDDA,
VDD
3.3V Operating Voltage
VIL
3.3V Input Low Voltage
Condition
3.3 ± 5%
Min.
Max.
Unit
3.135
3.465
V
VSS – 0.5
0.8
V
2.0
VDD + 0.5
VIH
3.3V Input High Voltage
IIL
Input Low Leakage Current
except internal pull-up resistors, 0 < VIN < VDD
IIH
Input High Leakage Current
except internal pull-down resistors, 0 < VIN < VDD
5
A
CIN
Input Pin Capacitance
1.5
5
pF
COUT
Output Pin Capacitance
–-
6
pF
LIN
Pin Inductance
–
7
nH
IDD3.3V
Dynamic Supply Current
–
60
mA
At max. load, Full Active, at 100MHz
........................ Document #: 38-07722 Rev 0.4 Page 3 of 8
V
A
–5
SL28DB200
AC Electrical Specifications
All measurements at VDD (typical) = 3.3V, TA = 25oC unless otherwise stated
Parameter
Description
Condition
Min.
Max.
Unit
Measured at crossing point VOX
9.9970
10.0533
ns
TABSMIN-IN Absolute minimum clock periods
Measured at crossing point VOX
9.8720
T R / TF
SRC and SRC# Rise and Fall Times
Single ended measurement: VOL = 0.175 to
VOH = 0.525V (Averaged)
4
V/ns
VIH
Differential Input High Voltage
VIL
Differential Input Low Voltage
VOX
Crossing Point Voltage at 0.7V Swing
Single-ended measurement
VOX
Vcross Variation over all edges
Single-ended measurement
VRB
SRCIN at 0.7V
TPERIOD
Average Period
0.6
ns
150
mV
–150
mV
250
550
mV
140
mV
Differential Ringback Voltage
–100
100
mV
TSTABLE
Time before ringback allowed
500
VMAX
Absolute maximum input voltage
VMIN
Absolute minimum input voltage
TDC
SRC and SRC# Duty Cycle
Measured at crossing point VOX
TRFM
Rise/Fall Matching
Determined as a fraction of 2*(TR – TF)/(TR + TF)
ps
1.15
V
45
55
%
–
20
%
–0.3
V
SRC at 0.7V
FIN
Input Frequency
90
210
MHz
FERROR
Input/Output Frequency Error
–
0
ppm
TDC
SRC and SRC# Duty Cycle
Measured at crossing point VOX
45
55
%
TPERIOD
Average Period
Measured at crossing point VOX at 100 MHz
9.9970
10.0533
ns
T R / TF
SRC[1:2] and SRC[1:2]# Rise and Fall
Times
Single-ended measurement: VOL = 0.175 to
VOH = 0.525V (Averaged)
175
700
ps
TRFM
Rise/Fall Matching
Determined as a fraction of
2 * (TR – TF)/(TR + TF)
–
20
%
TR/TF
Rise and Fall Time Variation Variation
Single-ended measurement: VOL = 0.175 to
VOH = 0.525V (Real Time)
–
125
ps
VHIGH
Voltage High
Single-ended measurement
660
850
mv
VLOW
Voltage Low
Single-ended measurement
–150
–
mv
VOX
Crossing Point Voltage at 0.7V Swing
Single-ended measurement
250
550
mv
VOX
Vcross Variation over all edges
Single-ended measurement
–
140
mV
VOVS
Maximum Overshoot Voltage
Single-ended measurement
–
VHIGH +
0.3
V
VUDS
Minimum Undershoot Voltage
Single-ended measurement
–
–0.3
V
VRB
Ring Back Voltage
Single-ended measurement
0.2
N/A
V
TCCJ
Cycle to Cycle Jitter
Jitter is additive
–
50
ps
TSKEW
Any SRC/SRC# to SRC/SRC# Clock
Skew
Measured at crossing point VOX
–
50
ps
TPD
Input to output skew
Measured at crossing point VOX
2.5
4.5
ns
........................ Document #: 38-07722 Rev 0.4 Page 4 of 8
SL28DB200
Test and Measurement Setup
Figure 1. Differential Clock Termination
Switching Waveforms
TRise (CLOCK)
VOH = 0.525V
CL
OC
K
OC
CL
K#
VCROSS
VOL = 0.175V
TFall (CLOCK)
Figure 2. Single-Ended Measurement Points for TRise and TFall
........................ Document #: 38-07722 Rev 0.4 Page 5 of 8
SL28DB200
VOVS
VRB
VRB
VLOW
VUDS
Figure 3. Single-ended Measurement Points for VOVS,VUDS and VRB
TPERIOD
High Duty Cycle %
Low Duty Cycle %
Skew Management Point
0.000V
Figure 4. Differential (Clock-Clock#) Measurement Points (Tperiod, Duty Cycle and Jitter)
Ordering Information
Ordering Code
Package Type
Operating Range
Lead-free
SL28DB200AZC
16-pin TSSOP
Commercial, 0°C to 85°C
SL28DB200AZCT
16-pin TSSOP—(Tape and Reel)
Commercial, 0°C to 85°C
SL28DB200AZI
16-pin TSSOP
Industrial, -40°C to 85°C
SL28DB200AZIT
16-pin TSSOP—(Tape and Reel)
Industrial, -40°C to 85°C
Note: All oderables are Lead-free and RoHS compliant
........................ Document #: 38-07722 Rev 0.4 Page 6 of 8
SL28DB200
Package Drawing and Dimensions
16-Lead Thin Shrunk Small Outline Package
........................ Document #: 38-07722 Rev 0.4 Page 7 of 8
SL28DB200
Document History Page
Document Title: SL28DB200 PCI Express Gen2 and SATA Differential Buffer
Document #: 38-07722 Rev 0.4
REV.
ECR# Issue Date
Orig. of
Change
Description of Change
1.0
06/17/10
TRP
Initial Release
AA
09/27/10
TRP
Updated Dynamic Supply Current
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of information included herein. Additionally, Silicon Laboratories assumes no responsibility for the functioning of undescribed features or
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........................ Document #: 38-07722 Rev 0.4 Page 8 of 8