IDTCSPU877A_06 Datasheet, PDF (1/13 Pages) Integrated Device Technology – 1.8V PHASE LOCKED LOOP DIFFERENTIAL 1:10 SDRAM CLOCK DRIVER

IDTCSPU877A
1.8V PLL DIFFERENTIAL 1:10 SDRAM CLOCK DRIVER
COMMERCIAL TEMPERATURE RANGE
1.8V PHASE LOCKED LOOP
DIFFERENTIAL 1:10 SDRAM
CLOCK DRIVER
IDTCSPU877A
FEATURES:
• 1 to 10 differential clock distribution
• Optimized for clock distribution in DDR2 (Double Data Rate)
SDRAM applications
• Operating frequency: 125MHz to 340MHz
• Very low skew: ≤40ps
• Very low jitter: ≤40ps
• 1.8V AVDD and 1.8V VDDQ
• CMOS control signal input
• Test mode enables buffers while disabling PLL
• Low current power-down mode
• Tolerant of Spread Spectrum input clock
• Available in 52-Ball VFBGA and 40-pin VFQFPN packages
APPLICATIONS:
• Meets or exceeds JEDEC standard 82.8 for registered DDR2
clock driver
• Along with SSTU32864/65/66, DDR2 register, provides complete
solution for DDR2 DIMMs
DESCRIPTION:
The CSPU877A is a PLL based clock driver that acts as a zero delay buffer
to distribute one differential clock input pair(CLK, CLK ) to 10 differential
output pairs (Y [0:9], Y [0:9]) and one differential pair of feedback clock output
(FBOUT, FBOUT). External feedback pins (FBIN, FBIN) for synchronization
of the outputs to the input reference is provided. OE, OS, and AVDD control the
power-down and test mode logic. When AVDD is grounded, the PLL is turned
off and bypassed for test mode purposes. When the differential clock inputs
(CLK, CLK) are both at logic low, this device will enter a low power-down mode.
In this mode, the receivers are disabled, the PLL is turned off, and the output
clock drivers are disabled, resulting in a current consumption device of less than
500μA.
The CSPU877A requires no external components and has been optimised
for very low phase error, skew, and jitter, while maintaining frequency and duty
cycle over the operating voltage and temperature range. The CSPU877A,
designed for use in both module assemblies and system motherboard based
solutions, provides an optimum high-performance clock source.
The CSPU877A is available in Commercial Temperature Range (0°C to
+70°C). See Ordering Information for details.
FUNCTIONAL BLOCK DIAGRAM
OE
OS
AVDD
LD or OE
POWER
DOWN
AND _{LD, OS, or OE}
TEST
MODE
LOGIC
PLL BYPASS
LD
CLK
CLK
10KΩ - 100KΩ
PLL
FBIN
FBIN
NOTE:
The Logic Detect (LD) powers down the device when a logic LOW is applied to both CLK and CLK.
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
COMMERCIAL TEMPERATURE RANGE
1
c 2006 Integrated Device Technology, Inc.
Y0
Y0
Y1
Y1
Y2
Y2
Y3
Y3
Y4
Y4
Y5
Y5
Y6
Y6
Y7
Y7
Y8
Y8
Y9
Y9
FBOUT
FBOUT
OCTOBER 2006
DSC-6495/8