Information

Texas Instruments Signal Chain Guide 2013 | 89
Clocks and Timing
Clock Distribution (Fanout Buffers, Zero-Delay Buffers)
3.1-GHz Differential Clock Buffer/Level Translator
LMK00304
Key Features
• 3:1inputmultiplexer
• Twobankswithtwodifferential
outputs each
•
HighPSRR:–65/–76dBc
(LVPECL/LVDS) at 156.25 MHz
•
LVCMOSoutputwithsynchronous
enable input
• Pin-controlledconfiguration
• V
CC
core supply: 3.3 V ± 5%
• ThreeindependentV
CCO
output
supplies: 3.3 V/2.5 V ± 5%
• Industrialtemperaturerange:
–40°C to +85°C
•
Package:32-pinLLP
(5.0 x 5.0 x 0.8 mm)
Applications
• High-speeddataacquisitionand
generation
• Medicalequipment
• Opticalnetworking
• Telecombasebandunit
• Videocommunications
The LMK00304 is a 3-GHz four-output differential fanout buffer intended for high-
frequency, low-jitter clock/data distribution and level translation. The input clock can
be selected from two universal inputs or one crystal input. The selected input clock
is distributed to two banks of two differential outputs and one LVCMOS output. The
differential output banks can be mutually configured as LVPECL, LVDS, or HCSL
drivers, or disabled. The LVCMOS output has a synchronous enable input for runt-
pulse-free operation when enabled or disabled. The LMK00304 operates from a 3.3 V
core supply and three independent 3.3 V/2.5 V output supplies.
The LMK00304 provides high performance, versatility, and power efficiency, making
it ideal for replacing fixed-output buffer devices while increasing timing margin in the
system.
LMK00304 functional block diagrams
MUX
SYNC
CLKoutA0
CLKoutA0*
CLKoutA1
CLKoutA1*
CLKin0
CLKin0*
CLKin1
CLKin1*
OSCin
OSCout
REFout_EN
CLKout_TYPE[1:0]
CLKin_SEL[1:0]
GND
CLKoutB0
CLKoutB0*
CLKoutB1
CLKoutB1*
CLKout_TYPE[1:0]
V
CC
V
CCOA
V
CCOB
V
CCOC
Output Bank B
(LVPECL, LVDS,
HCSL, or Hi-Z)
Output Bank A
(LVPECL, LVDS,
HCSL, or Hi-Z)
2
2
Universal Inputs
(Differential/
Single-Ended)
Crystal
V
CCOA
V
CCOB
V
CCOC
REFout (LVCMOS)
Get more information: www.ti.com/product/LMK00304