Philips PCK2510S Datasheet
INTEGRATED CIRCUITS
PCK2510S
50–150 MHz 1:10 SDRAM clock driver
Product specification 1999 Dec 13
Philips Semiconductors Product specification
PCK2510S50–150 MHz 1:10 SDRAM clock driver
FEA TURES
•Phase-Locked Loop Clock distribution for PC100/PC133 SDRAM
applications
•Spread Spectrum clock compatible
•Operating frequency 50 to 150 MHz
•(t
phase error
– jitter) at 100 to133 MHz = ±50 ps
•Jitter (peak-peak) at 100 to 133 MHz = ± 80 ps
•Jitter (cycle-cycle) at 100 to 133 MHz = 65 ps
•Pin-to-pin skew < 200 ps
•Available in plastic 24-Pin TSSOP
•Distributes one clock input to one bank of ten outputs
•External Feedback (FBIN) terminal Is used to synchronize the
outputs to the clock input
•On-Chip series damping resistors
•No external RC network required
•Operates at 3.3 V
DESCRIPTION
The PCK2510S is a high-performance, low-skew, low-jitter,
phase-locked loop (PLL) clock driver. It uses a PLL to precisely
align, in both frequency and phase, the feedback (FBOUT) output to
the clock (CLK) input signal. It is specifically designed for use with
synchronous DRAMs. The PCK2510S operates at 3.3 V V
input compatible with both 2.5 V and 3.3 V input voltage ranges. It
also provides integrated series damping resistors that make it ideal
for driving point-to-point loads.
One bank of ten outputs provides ten low-skew, low-jitter copies of
CLK. Output signal duty cycles are adjusted to 50 percent,
CC
and is
independent of the duty cycle at CLK. All outputs can be enabled or
disabled via a single output enable input. When the G input is high,
the outputs switch in phase and frequency with CLK; when the G
input is low, the outputs are disabled to the logic-low state.
Unlike many products containing PLLs, the PCK2510S does not
require external RC networks. The loop filter for the PLL is included
on-chip, minimizing component count, board space, and cost.
Because it is based on PLL circuitry, the PCK2510S requires a
stabilization time to achieve phase lock of the feedback signal to the
reference signal. This stabilization time is required, following power
up and application of a fixed-frequency, fixed-phase signal at CLK,
and following any changes to the PLL reference. The PLL can be
bypassed for test purposes by strapping AV
to ground.
CC
The PCK2510S is characterized for operation from 0°C to +70°C.
PIN CONFIGURATION
1
AGND
2
V
CC
3
1Y0
4
1Y1
5
1Y2
6
GND
7
GND
8
1Y3
9
1Y4
10
V
CC
11
G
12 13
FBOUT
CLK
24
23
AV
22
V
21
1Y9
20
1Y8
19
GND
18
GND
17
1Y7
16
1Y6
15
1Y5
14
V
FBIN
SW00382
CC
CC
CC
ORDERING INFORMA TION
PACKAGES TEMPERATURE RANGE ORDER CODE DRAWING NUMBER
24-Pin Plastic TSSOP 0°C to +70°C PCK2510S PW SOT355-1
1999 Dec 13 853–2184 22832
2
Philips Semiconductors Product specification
PCK2510S50–150 MHz 1:10 SDRAM clock driver
PIN DESCRIPTIONS
PIN NUMBER SYMBOL TYPE NAME, FUNCTION, and DIRECTION
1 AGND GND Analog ground. AGND provides the ground reference for the analog circuitry.
2, 10, 14, 22 V
3, 4, 5, 8, 9,
15, 16, 17, 20, 21
6, 7, 18, 19 GND GND Ground
11 G IN
12 FBOUT OUT
13 FBIN IN
23 AV
24 CLK IN
CC
1Y (0–9) OUT
CC
PWR Power supply
Clock outputs. These outputs provide low-skew copies of CLK. Output bank 1Y (0–9) is enabled
via the G input. These outputs can be disabled to a logic-low state by de-asserting the G control
input. Each output has an integrated 25 Ω series-damping resistor.
Output bank enable. G is the output enable for outputs 1Y (0–9). When G is LOW, outputs 1Y
(0–9) are disabled to a logic LOW state. When G is HIGH, all outputs 1Y (0–9) are enabled and
switch at the same frequency as CLK.
Feedback output. FBOUT is dedicated for external feedback. It switches at the same frequency
as CLK. When externally wired to FBIN, FBOUT completes the feedback loop of the PLL.
FBOUT has an integrated 25 Ω series-damping resistor.
Feedback input. FBIN provides the feedback signal to the internal PLL. FBIN must be
hard-wired to FBOUT to complete the PLL. The integrated PLL synchronizes CLK and FBIN so
that there is nominally zero phase error between CLK and FBIN.
Analog power supply. AVCC provides the power reference for the analog circuitry. In addition,
PWR
AVCC can be used to bypass the PLL for test purposes. When AVCC is strapped to ground, PLL
is bypassed and CLK is buffered directly to the device outputs.
Clock input. CLK provides the clock signal to be distributed by the PCK2510S clock driver. CLK
is used to provide the reference signal to the integrated PLL that generates the clock output
signals. CLK must have a fixed frequency and fixed phase for the PLL to obtain phase lock.
Once the circuit is powered up and a valid CLK signal is applied, a stabilization time is required
for the PLL to phase lock the feedback signal to its reference signal.
FUNCTION TABLE
INPUTS OUTPUTS
G CLK 1Y (0–9) FBOUT
X L L L
L H L H
H H H H
1999 Dec 13
3
Loading...