ETC CY26502

CY26501/CY26502
533-MHz Direct Rambus™ Clock Generator
Features
Overview
• Differential clock source for Direct Rambus™ memory
subsystem for up to 1066-MHz data transfer rate
• Provide synchronization flexibility: the Rambus® Channel can optionally be synchronous to an external system or processor clock
• Power managed output allows Rambus Channel clock
to be turned off to minimize power consumption for
mobile applications
• Cycle to Cycle Jitter below 50 ps
• Low-power CMOS design packaged in a 24-pin, 150-mil
SSOP package
• Support up to 533MHz for Commercial temperature and
400 MHz for Industrial temperature.
The Cypress CY26501 and CY26502 provide the differential
clock signals for a Direct Rambus memory subsystem. It includes signals to synchronize the Direct Rambus Channel
clock to an external system clock but can also be used in systems that do not require synchronization of the Rambus clock.
Key Specifications
Supply Voltage: ..................................... VDD = 3.3V±0.165V
Operating Temperature(Commercial): ............. 0°C to +70°C
Operating Temperature(Industrial): .............. -40°C to +85°C
Input Threshold: .................................................. 1.5V typical
Maximum Input Voltage:.........................................VDD+0.5V
Maximum Input Frequency: ..................................... 100 MHz
Output Duty Cycle: .................................. 40/60% worst case
Output Type:........................... Rambus signaling level (RSL)
Block Diagram
REFCLK
MULT0:1
PCLKM
Pin Configuration
PLL
Phase
Alignment
Output
Logic
CLK
VDDIR
1
24
S0
REFCLK
2
23
S1
VDD
3
22
VDD
GND
4
21
GND
GND
5
20
CLK
PCLKM
6
19
NC
SYNCLKN
7
18
CLKB
GND
8
17
GND
VDD
9
16
VDD
VDDIPD
10
15
MULT0
STOPB
11
14
MULT1
PWRDNB
12
13
GND
CLKB
SYNCLKN
S0:1
Test
Logic
STOPB
Direct Rambus is a trademark and Rambus is a registered trademark of Rambus Inc.
Intel is a registered trademark of Intel Corporation.
Cypress Semiconductor Corporation
Document #: 38-07356 Rev. *A
•
3901 North First Street
•
San Jose
•
CA 95134 • 408-943-2600
Revised December 26, 2002
CY26501/CY26502
Pin Definitions
Pin
No.
2
Pin
Type
I
PCLKM
6
I
SYNCLKN
7
I
STOPB
11
I
PWRDNB
12
I
MULT 0:1
15, 14
I
Pin Name
REFCLK
Pin Description
Reference Clock Input: Reference clock input, normally supplied by a system
frequency synthesizer (Cypress W133).
Phase Detector Input: The phase difference between this signal and SYNCLKN
is used to synchronize the Rambus Channel Clock with the system clock. Both
PCLKM and SYNCLKN are provided by the Gear Ratio Logic in the memory controller. If Gear Ratio Logic is not used, this pin would be connected to Ground.
Phase Detector Input: The phase difference between this signal and PCLKM is
used to synchronize the Rambus Channel Clock with the system clock. Both
PCLKM and SYNCLKN are provided by the Gear Ratio Logic in the memory controller. If Gear Ratio Logic is not used, this pin would be connected to Ground.
Clock Output Enable: When this input is driven to active LOW, it disables the
differential Rambus Channel clocks.
Active LOW Power-Down: When this input is driven to active LOW, it disables
the differential Rambus Channel clocks and places the CY26501/CY26502 in power-down mode.
PLL Multiplier Select: These inputs select the PLL prescaler and feedback dividers to determine the multiply ratio for the PLL for the input REFCLK:
MULT0
0
0
1
1
CLK, CLKB
S0, S1
20, 18
24, 23
O
I
19
1
10
RefV
RefV
VDD
3, 9, 16, 22
P
GND
4, 5, 8, 13,
17, 21
G
Document #: 38-07356 Rev. *A
CY26502
PLL/REFCLK
4
6
8
5.333
Complementary Output Clock: Differential Rambus Channel clock outputs.
Mode Control Input: These inputs control the operating mode of the
CY26501/CY26502:
S0
0
0
1
1
NC
VDDIR
VDDIPD
CY26501
PLL/REFCLK
4.5
6
8
5.333
MULT1
0
1
1
0
S1
0
1
0
1
MODE
Normal
Output Enable Test
Bypass
Test
No Connect
Reference for REFCLK: Voltage reference for input reference clock.
Reference for Phase Detector: Voltage reference for phase detector inputs and
STOPB.
Power Connection: Power supply for core logic and output buffers. Connected to
3.3V supply.
Ground Connection: Connect all ground pins to the common system ground
plane.
Page 2 of 13
CY26501/CY26502
CY26501/CY26502
System
Clock
Refclk
Phase
Align
PLL
Busclk
D
RAC
Synclk/N
Pclk/M
RMC
M
N
Pclk
4
DLL
Synclk
Gear
Ratio
Logic
Figure 1. DDLL System Architecture
DDLL System Architecture and Gear Ratio Logic
Figure 1 shows the Distributed Delay Lock Loop (DDLL) system architecture, including the main system clock source, the
Direct Rambus Clock Generator (DRCG), the core logic that
contains the Rambus Access Cell (RAC), the Rambus Memory Controller (RMC), and the Gear Ratio Logic. (This diagram
abstractly represents the differential clocks as a single Busclk
wire.)
The purpose of the DDLL is to frequency-lock and phase-align
the core logic and Rambus clocks (Pclk and Synclk) at the
RMC/RAC boundary in order to allow data transfers without
incurring additional latency. In the DDLL architecture, a PLL is
used to generate the desired Busclk frequency, while a distributed loop forms a DLL to align the phase of Pclk and Synclk at
the RMC/RAC boundary.
The main clock source drives the System Clock (Pclk) to the
core logic, and also drives the Reference Clock (Refclk) to the
DRCG. For typical Intel® architecture platforms, Refclk will be
half the CPU front side bus frequency. A PLL inside the DRCG
multiplies Refclk to generate the desired frequency for Busclk,
and Busclk is driven through a terminated transmission line
(Rambus Channel). At the mid-point of the channel, the RAC
senses Busclk using its own DLL for clock alignment, followed
by a fixed divide-by-4 that generates Synclk.
Pclk is the clock used in the Memory Controller (RMC) in the
core logic, and Synclk is the clock used at the core logic interface of the RAC. The DDLL, together with the Gear Ratio Log-
ic, enables users to exchange data directly from the Pclk domain to the Synclk domain without incurring additional latency
for synchronization. In general, Pclk and Synclk can be of different frequencies, so the Gear Ratio Logic must select the
appropriate M and N dividers such that the frequencies of
Pclk/M and Synclk/N are equal. In one interesting example,
Pclk =1 33 MHz, Synclk = 100 MHz, and M = 4 while N = 3;
giving Pclk/M = Synclk/N = 33 MHz. This example of the clock
waveforms with the Gear Ratio Logic is shown in Figure 2.
The output clocks from the Gear Ratio Logic, Pclk/M, and
Synclk/N are output from the core logic and routed to the
DRCG Phase Detector inputs. The routing of Pclk/M and
Synclk/N must be matched in the core logic as well as on the
board.
After comparing the phase of Pclk/M vs. Synclk/N, the DRCG
Phase Detector drives a phase aligner that adjusts the phase
of the DRCG output clock, Busclk. Since everything else in the
distributed loop is fixed delay, adjusting Busclk adjusts the
phase of Synclk and thus the phase of Synclk/N. In this manner the distributed loop adjusts the phase of Synclk/N to match
that of Pclk/M, nulling the phase error at the input of the DRCG
Phase Detector. When the clocks are aligned, data can be
exchanged directly from the Pclk domain to the Synclk domain.
Table 1 shows the combinations of Pclk and Busclk frequencies of greatest interest, organized by Gear Ratio.
Pclk
Synclk
Pclk/M =
Synclk/N
Figure 2. Gear Ratio Timing Diagram
Document #: 38-07356 Rev. *A
Page 3 of 13
CY26501/CY26502
Table 1. Supported Pclk and Busclk Frequencies, by Gear Ratio
Gear Ratio and Busclk
Pclk
2.0
1.5
1.33
67 MHz
100 MHz
133 MHz
267 MHz
356 MHz
400 MHz
533 MHz
150 MHz
200 MHz
1.0
0.66
267 MHz
400 MHz
300 MHz
400 MHz
400 MHz
533 MHz
400 MHz
S0/S1 StopB
CY26501/CY26502
System
Clock
Refclk
Phase
Align
PLL
Busclk
D
RAC
Synclk/N
Pclk/M
RMC
M
N
Pclk
4
DLL
Synclk
Gear
Ratio
Logic
Figure 3. DDLL Including Details of DRCG
Figure 3 shows more details of the DDLL system architecture,
including the DRCG output enable and bypass modes.
directly by bypassing the Phase Aligner. If PclkM and SynclkN
are not used, those inputs must be grounded.
Phase Detector Signals
Selection Logic
The DRCG Phase Detector receives two inputs from the core
logic, PclkM (Pclk/M) and SynclkN (Synclk/N). The M and N
dividers in the core logic are chosen so that the frequencies of
PclkM and SynclkN are identical. The Phase Detector detects
the phase difference between the two input clocks, and drives
the DRCG Phase Aligner to null the input phase error through
the distributed loop. When the loop is locked, the input phase
error between PclkM and SynclkN is within the specification
tERR,PD given in Table 14 after the lock time given in the State
Transition Section.
Table 2 shows the logic for selecting the PLL prescaler and
feedback dividers to determine the multiply ratio for the PLL
from the input Refclk. Divider A sets the feedback and divider
B sets the prescaler, so the PLL output clock frequency is set
by: PLLclk=Refclk*A/B.
The Phase Detector aligns the rising edge of PclkM to the
rising edge of SynclkN. The duty cycle of the phase detector
input clocks will be within the specification DCIN,PD given in
Table 13. Because the duty cycles of the two phase detector
input clocks will not necessarily be identical, the falling edges
of PclkM and SynclkN may not be aligned when the rising edges are aligned.
The voltage levels of the PclkM and SynclkN signals are determined by the controller. The pin VDDIPD is used as the
voltage reference for the phase detector inputs and should be
connected to the output voltage supply of the controller. In
some applications, the DRCG PLL output clock will be used
Document #: 38-07356 Rev. *A
Table 2. PLL Divider Selection
CY26501
CY26502
Mult0
Mult1
A
B
A
B
0
0
9
2
4
1
0
1
6
1
6
1
1
1
8
1
8
1
1
0
16
3
16
3
Table 3 shows the logic for enabling the clock outputs, using
the StopB input signal. When StopB is HIGH, the DRCG is in
its normal mode, and Clk and ClkB are complementary outputs
following the Phase Aligner output (PAclk). When StopB is
LOW, the DRCG is in the Clk Stop mode, the output clock
drivers are disabled (set to Hi-Z), and the Clk and ClkB settle
to the DC voltage VX,STOP as given in Table 14. The level of
VX,STOP is set by an external resistor network.
Page 4 of 13
CY26501/CY26502
Table 3. Clock Stop Mode Selection
Table 5. Power-down Mode Selection
Mode
StopB
Clk
ClkB
Normal
1
PAclk
PAclkB
Clk Stop
0
VX,STOP
VX,STOP
Mode
PwrDnB
Clk
ClkB
Normal
1
PAclk
PAclkB
Power-down
0
GND
GND
Table 4 shows the logic for selecting the Bypass and Test
modes. The select bits, S0 and S1, control the selection of
these modes. The Bypass mode brings out the full-speed PLL
output clock, bypassing the Phase Aligner. The Test mode
brings the Refclk input all the way to the output, bypassing
both the PLL and the Phase Aligner. In the Output Test mode
(OE), both the Clk and ClkB outputs are put into a high-impedance state (Hi-Z). This can be used for component testing and
for board-level testing.
Table 6 shows several supported Pclk and Busclk frequencies,
the corresponding A and B dividers required in the DRCG PLL,
and the corresponding M and N dividers in the gear ratio logic.
The column Ratio gives the Gear Ratio as defined Pclk/Synclk
(same as M and N). The column [email protected] gives the divided down
frequency (in MHz) at the Phase Detector, where
[email protected] = Pclk/M = Synclk/N.
Table 4. Bypass and Test Mode Selection
State Transitions
S0
S1
Bypclk
(int.)
Clk
ClkB
Normal
0
0
Gnd
PAclk
PAclkB
Output Test (OE)
0
1
-
Hi-Z
Hi-Z
Bypass
1
0
PLLclk
PLLclk
PLLclkB
Test
1
1
Refclk
Refclk
RefclkB
Mode
Table of Frequencies and Gear Ratios
The clock source has three fundamental operating states. Figure 4 shows the state diagram with each transition labelled A
through H. Note that the clock source output may NOT be
glitch-free during state transitions.
Upon powering up the device, the device can enter any state,
depending on the settings of the control signals, PwrDnB and
StopB.
In Power-down mode, the clock source is powered down with
the control signal, PwrDnB, equal to 0. The control signals S0
and S1 must be stable before power is applied to the device,
and can only be changed in Power-down mode (PwrDnB=0).
The reference inputs, VDDR and VDDPD, may remain on or may
be grounded during the Power-down mode.
Table 5 shows the logic for selecting the Power-down mode,
using the PwrDnB input signal. PwrDnB is active LOW (enabled when 0). When PwrDnB is disabled, the DRCG is in its
normal mode. When PwrDnB is enabled, the DRCG is put into
a powered-off state, and the Clk and ClkB outputs are threestated.
Table 6. Examples of Frequencies, Dividers, and Gear Ratios
Pclk
Refclk
Busclk
Synclk
A
B
M
N
Ratio
[email protected]
67
33
267
67
8
1
2
2
1.0
33
100
50
300
75
6
1
8
6
1.33
12.5
100
50
400
100
8
1
4
4
1.0
25
133
67
267
67
4
1
4
2
2.0
33
133
67
400
100
6
1
8
6
1.33
16.7
VDD Turn-On
G
VDD Turn-On
M
J
L
Test
Normal
N
F
B
K
A
VDD Turn-On
E
VDD Turn-On
D
Power-Down
Clk Stop
C
H
Figure 4. Clock Source State Diagram
Document #: 38-07356 Rev. *A
Page 5 of 13
CY26501/CY26502
The control signals Mult0 and Mult1 can be used in two ways.
If they are changed during Power-down mode, then the Power-down transition timings determine the settling time of the
DRCG. However, the Mult0 and Mult1 control signals can also
be changed during Normal mode. When the Mult control signals are “hot swapped” in this manner, the Mult transition timings determine the settling time of the DRCG.
In Clock Stop mode, the clock source is on, but the output is
disabled (StopB asserted). The VDDPD reference input may
remain on or may be grounded during the Clk Stop mode. The
VDDR reference input must remain on during the Clock Stop
mode.
In Normal mode, the clock source is on, and the output is enabled.
Table 7 lists the control signals for each state.
Table 7. Control Signals for Clock Source States
State
PwrDnB
StopB
Clock
Source
Output
Buffer
Power-down
0
X
OFF
Ground
Clock Stop
1
0
ON
Disabled
Normal
1
1
ON
Enabled
Figure 5 shows the timing diagrams for the various transitions
between states, and Table 8 specifies the latencies of each
state transition. Note that these transition latencies assume
the following:
• Refclk input has settled and meets specification shown in
Table 13.
• Mult0, Mult1, S0 and S1 control signals are stable.
Timing Diagrams
s
Power-Down Exit and Entry
PwrDnB
tPOWERDN
tPOWERUP
Clk/ClkB
Output Enable Control
tON
StopB
tSTOP
tCLKON
tCLKOFF
tCLKSETL
Clk/ClkB
Output clock
not specified
glitches may
occur
Clock enabled
and glitch free
Clock output settled within
50 ps of the phase before
disabled
Figure 5. State Transition Timing Diagram
Mult0 and/or Mult1
tMULT
Clk/ClkB
Figure 6. Multiply Transition Timing
Document #: 38-07356 Rev. *A
Page 6 of 13
CY26501/CY26502
Table 8. State Transition Latency Specifications
Transition Latency
Transition
From
To
Symbol
Max.
Description
A
Power-down
Normal
tPOWERUP
3 ms
Time from PwrDnB to Clk/ClkB output settled
(excluding tDISTLOCK).
C
Power-down
Clk Stop
tPOWERUP
3 ms
Time from PwrDnB until the internal PLL and
clock has turned ON and settled.
K
Power-down
Test
tPOWERUP
3 ms
Time from PwrDnB to Clk/ClkB output settled
(excluding tDISTLOCK).
G
VDD ON
Normal
tPOWERUP
3 ms
Time from VDD is applied and settled until
Clk/ClkB output settled (excluding tDISTLOCK).
H
VDD ON
Clk Stop
tPOWERUP
3 ms
Time from VDD is applied and settled until
internal PLL and clock has turned ON and
settled.
M
VDD ON
Test
tPOWERUP
3 ms
Time from VDD is applied and settled until
internal PLL and clock has turned ON and
settled.
J
Normal
Normal
tMULT
1 ms
Time from when Mult0 or Mult1 changed until
Clk/ClkB output resettled (excluding
tDISTLOCK).
E
Clk Stop
Normal
tCLKON
10 ns
Time from StopB until Clk/ClkB provides
glitch-free clock edges.
E
Clk Stop
Normal
tCLKSETL
20 cycles
F
Normal
Clk Stop
tCLKOFF
5 ns
Time from StopB Φ to Clk/ClkB output
disabled.
L
Test
Normal
tCTL
3 ms
Time from when S0 or S1 is changed until
CLK/CLKB output has resettled (excluding
tDISTLOCK).
N
Normal
Test
tCTL
3 ms
Time from when S0 or S1 is changed until
CLK/CLKB output has resettled (excluding
tDISTLOCK).
B,D
Normal or Clk Stop
Power-down
tPOWERDN
1 ms
Time from PwrDnB Φ to the device in Powerdown.
Figure 5 shows that the Clk Stop to Normal transition goes
through three phases. During tCLKON, the clock output is not
specified and can have glitches. For tCLKON < t < tCLKSETL, the
clock output is enabled and must be glitch-free. For
t > tCLKSETL, the clock output phase must be settled to within
Document #: 38-07356 Rev. *A
Time from StopB to Clk/ClkB output settled to
within 50 ps of the phase before CLK/CLKB
was disabled.
50 ps of the phase before the clock output was disabled. At
this time, the clock output must also meet the voltage and timing specifications of Table 14. The outputs are in a high-impedance state during the Clk Stop mode.
Page 7 of 13
CY26501/CY26502
Table 9. Distributed Loop Lock Time Specification
Parameter
tDISTLOCK
Min.
Max.
Unit
5
ms
Description
Time from when Clk/ClkB output is settled to when the phase error between
SynclkN and PclkM falls within the tERR,PD spec in Table 14.
Table 10. Supply and Reference Current Specification
Min.
Max.
Unit
IPOWERDOWN
Parameter
“Supply” current in Power-down state (PwrDnB = 0)
Description
--
800
µA
ICLKSTOP
“Supply” current in Clk Stop state (StopB = 0)
--
100
mA
INORMAL
“Supply” current in Normal state (StopB = 1,PwrDnB = 1)
--
150
mA
IREF,PWDN
Current at VDDIR or VDDIPD reference pin in Power-down
state (PwrDnB = 0)
--
1
µA
IREF,NORM
Current at VDDIR or VDDIPD reference pin in Normal or Clk
Stop state (PwrDnB = 1)
--
1.5
mA
Table 11 represents stress ratings only, and functional operation at the maximums is not guaranteed.
Table 11. Absolute Maximum Ratings
Parameter
Description
Min.
Max.
Unit
VDD, ABS
Max. voltage on VDD with respect to ground
–0.5
4.0
V
VI, ABS
Max. voltage on any pin with respect ground
–0.5
VDD+0.5
V
Table 12 gives the nominal values of the external components and their maximum acceptable tolerance, assuming ZCH = 28Ω.
Table 12. External Component Values
Parameter
Description
Test Load
Recommended
Value
Tolerance
Unit
RS
Serial Resistor
47
39
±5%
Ω
RS
RP
Parallel Resistor
47
51
±5%
Ω
RP
CF
Edge Rate Filter Capacitor
Note 1
Note 1
±10%
pF
CF
100 pF
0.1
±20%
µF
CMID
CMID
AC Ground Capacitor
Note:
1. Do not populate CF. Leave pads for future use.
Parameter
Figure 7. Example System Clock Driver Equivalent Circuit
Document #: 38-07356 Rev. *A
Page 8 of 13
CY26501/CY26502
Table 13. Operating Conditions[2]
Parameter
Description
Min.
Max.
Unit
VDD
Supply Voltage
3.135
3.465
V
TA
Ambient Operating Temperature
0
70
°C
tCYCLE,IN
Refclk Input Cycle Time
10
40
ns
-
250
ps
[3]
tJ,IN
Input Cycle-to-Cycle Jitter
DCIN
Input Duty Cycle over 10,000 Cycles
40
60
%tCYCLE
FMIN
Input Frequency of Modulation
30
33
kHz
PMIN[4]
Modulation Index for Triangular Modulation
0.6
%
Modulation Index for Non-Triangular Modulation
0.5
tCYCLE,PD
Phase Detector Input Cycle Time at PclkM & SynclkN
tERR,INIT
Initial Phase error at Phase Detector Inputs
DCIN,PD
[6]
%
30
100
ns
–0.5
0.5
tCYCLE,PD
Phase Detector Input Duty Cycle over 10,000 Cycles
25
75
tCYCLE,PD
tI,SR
Input Slew Rate (measured at 20%-80% of input voltage) for PclkM,
SynclkN, and Refclk
1
4
V/ns
CIN,PD
Input Capacitance at PclkM, SynclkN, and Refclk[5]
7
pF
0.5
pF
∆CIN,PD
Input Capacitance matching at PclkM and SynclkN
CIN,CMOS
Input Capacitance at CMOS pins (excluding PclkM, SynclkN, and
Refclk)[5]
10
pF
VIL
Input (CMOS) Signal Low Voltage
0.3
VDD
VIH
Input (CMOS) Signal High Voltage
VIL,R
Refclk input Low Voltage
0.3
VDDIR
VIH,R
Refclk input High Voltage
VIL,PD
Input Signal Low Voltage for PD Inputs and StopB
VIH,PD
Input Signal High Voltage for PD Inputs and StopB
VDDIR
Input Supply Reference for Refclk
[5]
0.7
VDD
0.7
VDDIR
0.3
0.7
1.235
VDDIPD
VDDIPD
3.465
V
Input Supply Reference for PD Inputs
1.235
2.625
V
VDDIPD
Notes:
2. Multiple Supplies: The Voltage on any input or I/O pin cannot exceed the power pin during power-up. Power supply sequencing is NOT required.
3. Refclk jitter measured at VDDIR (nom)/2.
4. If input modulation is used: input modulation is allowed but not required.
5. Capacitance measured at Freq = 1 MHz, DC bias = 0.9V and VAC < 100 mV.
6. The amount of allowed spreading for any non-triangular modulation is determined by the induced downstream tracking skew, which cannot exceed the skew
generated by the specified 0.6% triangular modulation. Typically, the amount of allowed non-triangular modulation is about 0.5%.
Document #: 38-07356 Rev. *A
Page 9 of 13
CY26501/CY26502
Table 14. Device Characteristics
Parameter
Description
Min.
Max.
Unit
tCYCLE
Clock Cycle Time (Commercial temperature)
1.87
3.75
ns
tCYCLE
Clock Cycle Time (Industrial temperature)
2.5
3.75
ns
tJ
Cycle-to-Cycle Jitter at Clk/ClkB[7]
-
50
ps
tSTEP
Phase Aligner Phase Step Size (at Clk/ClkB)
1
-
ps
tERR,PD
Phase Detector Phase Error for Distributed Loop Measured at PclkMSynclkN (rising edges) (does not include clock jitter)
–100
100
ps
tERR,SSC
PLL Output Phase Error when Tracking SSC
–100
100
ps
VX,STOP
Output Voltage during Clk Stop (StopB=0)
1.1
2.0
V
VX
Differential Output Crossing-Point Voltage
1.3
1.8
V
VCOS
Output Voltage Swing (p-p single-ended)[8]
0.8
1.2
V
VOH
Output High Voltage
-
2.2
V
VOL
Output Low voltage
0.8
-
V
rOUT
Output Dynamic Resistance (at pins)[9]
12
50
Ω
IOZ
Output Current during Hi-Z (S0 = 0, S1 = 1)
-
50
µA
IOZ,STOP
Output Current during Clk Stop (StopB = 0)
-
500
µA
DC
Output Duty Cycle over 10,000 Cycles
40
60
%tCYCLE
tDC,ERR
Output Cycle-to-Cycle Duty Cycle Error
-
50
ps
tR,tF
Output Rise and Fall Times (measured at 20%-80% of output voltage)
150
400
ps
tCR,CF
Difference between Output Rise and Fall Times on the Same Pin of a
Single Device (20%-80%)
-
100
ps
Notes:
7. Output Jitter spec measured at tCYCLE = 1.87 ns. (Commercial Temperature)
8. VCOS = VOH–VOL.
9. rOUT = ∆VO/ ∆ IO. This is defined at the output pins.
Ordering Information
Ordering Code
Package Type
Temperature Range
CY26501PVI
CY26501PVC
CY26502PVI
CY26502PVC
24-pin SSOP (150 mils)
I = Industrial
C = Commercial
Document #: 38-07356 Rev. *A
Page 10 of 13
CY26501/CY26502
Layout Example
+3.3V Supply
FB
C4
0.005 µF
G
10 µF
C3
G
VDDIR
G
G
G
G
G
G
G
VDDIPD
1
2
3
4G
5G
6
7
8G
9
10
11
12
24
23
22
G21
20
19
18
G17
46
15
14
G13
G
G
G
G
G
Internal Power Supply Plane
FB = Dale ILB1206 - 300 (300Ω @ 100 MHz)
G = VIA to GND plane layer
All Bypass cap = 0.1 Ceramic XR7
Document #: 38-07356 Rev. *A
Page 11 of 13
CY26501/CY26502
Package Diagram
24-Pin Small Shrink Outline Package (SSOP, 150 mils)
Document #: 38-07356 Rev. *A
Page 12 of 13
© Cypress Semiconductor Corporation, 2002. The information contained herein is subject to change without notice. Cypress Semiconductor Corporation assumes no responsibility for the use
of any circuitry other than circuitry embodied in a Cypress Semiconductor product. Nor does it convey or imply any license under patent or other rights. Cypress Semiconductor does not authorize
its products for use as critical components in life-support systems where a malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress
Semiconductor products in life-support systems application implies that the manufacturer assumes all risk of such use and in doing so indemnifies Cypress Semiconductor against all charges.
CY26501/CY26502
Document Title: CY26501, CY26502 533-MHz Direct Rambus™ Clock Generator
Document Number: 38-07356
ECN NO.
Issue
Date
Orig. of
Change
**
112251
03/01/02
DSG
Change from Spec number: 38-00942 to 38-07356
*A
122904
12/26/02
RBI
Add power up requirements to operating conditions requirements
REV.
Document #: 38-07356 Rev. *A
Description of Change
Page 13 of 13