CYPRESS CY29948AXI

CY29948
2.5 V or 3.3 V, 200-MHz,
1:12 Clock Distribution Buffer
2.5 V or 3.3 V, 200-MHz, 1:12 Clock Distribution Buffer
Features
Description
■
2.5 V or 3.3 V operation
■
200-MHz clock support
■
LVPECL or LVCMOS/LVTTL clock input
■
LVCMOS-/LVTTL-compatible inputs
■
12 clock outputs: drive up to 24 clock lines
■
Synchronous Output Enable
■
Output three-state control
■
150 ps typical output-to-output skew
■
Pin compatible with MPC948, MPC948L, MPC9448
■
Available in Commercial and Industrial temp. range
■
32-pin TQFP package
The CY29948 is a low-voltage 200-MHz clock distribution buffer
with the capability to select either a differential LVPECL or a
LVCMOS/LVTTL compatible input clock. The two clock sources
can be used to provide for a test clock as well as the primary
system clock. All other control inputs are LVCMOS/LVTTL
compatible. The 12 outputs are LVCMOS or LVTTL compatible
and can drive 50  series or parallel terminated transmission
lines. For series terminated transmission lines, each output can
drive one or two traces giving the device an effective fanout of
1:24. The outputs can also be three-stated via the three-state
input TS#. Low output-to-output skews make the CY29948 an
ideal clock distribution buffer for nested clock trees in the most
demanding of synchronous systems.
The CY29948 also provides a synchronous output enable input
for enabling or disabling the output clocks. Since this input is
internally synchronized to the input clock, potential output
glitching or runt pulse generation is eliminated.
Block Diagram
VDD
PECL_CLK
PECL_CLK#
0
TCLK
1
VDDC
12
Q0-Q11
TCLK_SEL
SYNC_OE
TS#
Cypress Semiconductor Corporation
Document Number: 38-07288 Rev. *E
•
VSS
Q0
VDDC
Q1
VSS
Q2
VDDC
Q3
31
30
29
28
27
26
25
9
10
11
12
13
14
15
16
VSS
Q9
VDDC
Q8
VSS
CY29948
Q11
1
2
3
4
5
6
7
8
VDDC
Q10
TCLK_SEL
TCLK
PECL_CLK
PECL_CLK#
SYNC_OE
TS#
VDD
VSS
32
Pin Configuration
198 Champion Court
24
23
22
21
20
19
18
17
•
VSS
Q4
VDDC
Q5
VSS
Q6
VDDC
Q7
San Jose, CA 95134-1709
•
408-943-2600
Revised May 2, 2011
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CY29948
Pin Description[1]
Pin
Name
PWR
I/O
Description
3
PECL_CLK
–
I, PU PECL Input Clock
4
PECL_CLK#
–
I, PD PECL Input Clock
I, PU External Reference/Test Clock Input
2
TCLK
–
9, 11, 13, 15,
17, 19, 21, 23,
25, 27, 29, 31
Q(11:0)
VDDC
1
TCLK_SEL
–
I, PU Clock Select Input. When LOW, PECL clock is selected. When HIGH
TCLK is selected.
5
SYNC_OE
–
I, PU Output Enable Input. When asserted HIGH, the outputs are enabled.
When set LOW the outputs are disabled in a LOW state.
6
TS#
–
I, PU Three-state Control Input. When asserted LOW, the output buffers
are three-stated. When set HIGH, the output buffers are enabled.
10, 14, 18, 22,
26, 30
VDDC
–
–
7
VDD
–
–
2.5 V or 3.3 V Power Supply
8, 12, 16, 20,
24, 28, 32
VSS
–
–
Common Ground
O
Clock Outputs
2.5 V or 3.3 V Power Supply for Output Clock Buffers
Output Enable/Disable
The CY29948 features a control input to enable or disable the outputs. This data is latched on the falling edge of the input clock. When
SYNC_OE is asserted LOW, the outputs are disabled in a LOW state. When SYNC_OE is set HIGH, the outputs are enabled as shown
in Figure 1.
Figure 1. SYNC_OE Timing Diagram
TCLK
SYNC_OE
Q
Note
1. PD = Internal pull-down, PU = Internal pull-up.
Document Number: 38-07288 Rev. *E
Page 2 of 10
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CY29948
Maximum Ratings[2]
Maximum Input Voltage Relative to VSS ............. VSS – 0.3 V
Maximum Input Voltage Relative to VDD............. VDD + 0.3 V
Storage Temperature ............................... –65 °C to + 150 °C
Operating Temperature............................... –40 °C to +85 °C
Maximum ESD protection............................................... 2 kV
Maximum Power Supply................................................ 5.5 V
This device contains circuitry to protect the inputs against
damage due to high static voltages or electric field; however,
precautions should be taken to avoid application of any voltage
higher than the maximum rated voltages to this circuit. For proper
operation, Vin and Vout should be constrained to the range:
VSS < (Vin or Vout) < VDD
Unused inputs must always be tied to an appropriate logic
voltage level (either VSS or VDD).
Maximum Input Current ............................................. ±20 mA
DC Parameters
VDD = VDDC = 3.3 V ± 10% or 2.5 V ± 5%, over the specified temperature range.
Parameter
VIL
VIH
Description
Input Low Voltage
Input High Voltage
Conditions
Min
Typ
Max
Unit
VDD = 3.3 V, PECL_CLK single ended
1.49
–
1.825
V
VDD = 2.5 V, PECL_CLK single ended
1.10
–
1.45
All other inputs
VSS
–
0.8
VDD = 3.3 V, PECL_CLK single ended
2.135
–
2.42
VDD = 2.5 V, PECL_CLK single ended
1.75
–
2.0
All other inputs
V
2.0
–
VDD
IIL
Input Low Current[3]
–
–
–100
IIH
Input High
Current[3]
–
–
100
VPP
Peak-to-Peak Input Voltage
PECL_CLK
300
–
1000
mV
VCMR
Common Mode Range[4]
PECL_CLK
VDD = 3.3 V
VDD – 2.0
–
VDD – 0.6
V
VDD = 2.5 V
VDD – 1.2
–
VDD – 0.6
Voltage[5]
VOL
Output Low
VOH
Output High Voltage[5]
IDDQ
Quiescent Supply Current
IDD
Dynamic Supply Current
Zout
Cin
Output Impedance
Input Capacitance
IOL = 20 mA
µA
–
–
0.4
V
IOH = –20 mA, VDD = 3.3 V
2.5
–
–
V
IOH = –20 mA, VDD = 2.5 V
1.8
–
–
–
5
7
mA
VDD = 3.3 V, Outputs @ 100 MHz,
CL = 30 pF
–
180
–
mA
VDD = 3.3 V, Outputs @ 160 MHz,
CL = 30 pF
–
270
–
VDD = 2.5 V, Outputs @ 100 MHz,
CL = 30 pF
–
125
–
VDD = 2.5 V, Outputs @ 160 MHz,
CL = 30 pF
–
190
–
VDD = 3.3 V
12
15
18
VDD = 2.5 V
14
18
22
–
4
–

pF
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. Inputs have pull-up/pull-down resistors that effect input current.
4. The VCMR is the difference from the most positive side of the differential input signal. Normal operation is obtained when the “High” input is within the VCMR range
and the input lies within the VPP specification.
5. Driving series or parallel terminated 50  (or 50  to VDD/2) transmission lines.
Document Number: 38-07288 Rev. *E
Page 3 of 10
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CY29948
AC Parameters[6]
VDD = VDDC = 3.3 V ± 10% or 2.5 V ± 5%, over the specified operating range.
Parameter
Fmax
Tpd
Description
Input Frequency
Conditions
[7]
PECL_CLK to Q Delay
[7]
Min
Typ
Max
Unit
VDD = 3.3 V
–
–
200
MHz
VDD = 2.5 V
–
–
170
VDD = 3.3 V
TCLK to Q Delay[7]
PECL_CLK to Q Delay[7]
VDD = 2.5 V
[7]
TCLK to Q Delay
Cycle[7, 8, 9]
–
8.0
–
8.9
6.0
–
10.0
6.4
–
10.9
ns
FoutDC
Output Duty
45
–
55
%
tpZL, tpZH
Output Enable Time (all outputs)
2
–
10
ns
tpLZ, tpHZ
Output Disable Time (all outputs)
2
–
10
ns
–
150
250
ps
ns
Tskew
Tskew(pp)
Ts
Th
Tr/Tf
Output-to-Output
Part-to-Part
Skew[7, 9]
Skew[10]
Set-up Time[7, 11]
Hold
Measured at VDD/2
4.0
4.4
Time[7, 11]
Output Clocks Rise/Fall Time[9]
PECL_CLK to Q
–
–
1.5
TCLK to Q
–
–
2.0
SYNC_OE to PECL_CLK
1.0
–
–
SYNC_OE to TCLK
0.0
–
–
PECL_CLK to SYNC_OE
0.0
–
–
TCLK to SYNC_OE
1.0
–
–
0.8 V to 2.0 V, VDD = 3.3 V
0.20
–
1.0
0.6 V to 1.8 V, VDD = 2.5 V
0.20
–
1.3
ns
ns
ns
Figure 2. LVCMOS_CLK CY29948 Test Reference for VCC = 3.3 V and VCC = 2.5 V
CY29948 DUT
Pulse
Generator
Z = 50 ohm
Zo = 50 ohm
Zo = 50 ohm
R T = 50 ohm
VTT
R T = 50 ohm
VTT
Notes
6. Parameters are guaranteed by design and characterization. Not 100% tested in production. All parameters specified with loaded outputs.
7. Outputs driving 50 transmission lines.
8. 50% input duty cycle.
9. See Figure 2 and Figure 3 on page 5.
10. Part-to-Part skew at a given temperature and voltage.
11. Setup and hold times are relative to the falling edge of the input clock.
Document Number: 38-07288 Rev. *E
Page 4 of 10
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CY29948
Figure 3. PECL_CLK CY29948 Test Reference for VCC = 3.3 V and VCC = 2.5 V
CY29948 DUT
Zo = 50 ohm
Differential
Pulse
Generator
Z = 50 ohm
Zo = 50 ohm
Zo = 50 ohm
R T = 50 ohm
VTT
R T = 50 ohm
VTT
Figure 4. Propagation Delay (tPD) Test Reference
PEC L_C LK
V CMR
VPP
PEC L_C LK
VCC
Q
V C C /2
t
PD
GND
Figure 5. LVCMOS Propagation Delay (tPD) Test Reference
VCC
LVCMOS_CLK
VCC /2
GND
VCC
Q
VCC /2
t PD
GND
Figure 6. Output Duty Cycle (FoutDC)
VCC
VCC /2
tP
GND
T0
DC = tP / T0 x 100%
Document Number: 38-07288 Rev. *E
Page 5 of 10
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CY29948
Figure 7. Output-to-Output Skew tsk(0)
VCC
VCC /2
GND
VCC
VCC /2
t SK(0)
GND
Ordering Information
Part Number
Package Type
Production Flow
CY29948AC
32-pin TQFP
Commercial, 0 °C to +70 °C
CY29948ACT
32-pin TQFP - Tape and Reel
Commercial, 0 °C to +70 °C
Pb-free
CY29948AXC
32-pin TQFP
Commercial, 0 °C to +70 °C
CY29948AXCT
32-pin TQFP - Tape and Reel
Commercial, 0 °C to +70 °C
CY29948AXI
32-pin TQFP
Industrial, –40 °C to +85 °C
CY29948AXIT
32-pin TQFP - Tape and Reel
Industrial, –40 °C to +85 °C
Ordering Code Definitions
CY 29948
A
X
X
T
T = Tape and Reel; blank = Tube
Temperature: X = C or I
C = Commercial; I = Industrial
X = Pb-free
Package: A = 32-pin TQFP
Device part number
Company ID: CY = Cypress
Document Number: 38-07288 Rev. *E
Page 6 of 10
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CY29948
Package Drawing and Dimensions
51-85063 *C
Document Number: 38-07288 Rev. *E
Page 7 of 10
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CY29948
Acronyms
Document Conventions
Acronym
Description
CMOS
complementary metal oxide semiconductor
ESD
electrostatic Discharge
I/O
input/output
LVCMOS
low voltage complementary metal oxide
semiconductor
LVPECL
Units of Measure
Symbol
°C
Unit of Measure
degree Celsius
kV
kilo Volts
MHz
Mega Hertz
low voltage positive emitter coupled logic
µA
micro Amperes
LVTTL
low voltage transistor-transistor logic
mA
milli Amperes
PLL
phase locked loop
mm
milli meter
thin quad flat pack
mV
milli Volts
ns
nano seconds

ohms
TQFP
Document Number: 38-07288 Rev. *E
%
percent
pF
pico Farad
ps
pico seconds
V
Volts
Page 8 of 10
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CY29948
Document Revision History
Document Title: CY29948, 2.5 V or 3.3 V, 200-MHz, 1:12 Clock Distribution Buffer
Document Number: 38-07288
Rev.
ECN No.
Submission
Date
Orig. of
Change
**
111099
02/13/02
BRK
*A
116782
08/14/02
HWT
*B
122880
12/22/02
RBI
*C
428221
See ECN
RGL
Added Lead-free devices
*D
2904731
04/05/10
CXQ
Removed inactive part numbers - CY29948AI and CY29948AIT. Updated
package diagram.
*E
3246222
05/02/2011
CXQ
Added Ordering Code Definitions.
Added Acronyms and Units of Measure.
Updated in new template.
Document Number: 38-07288 Rev. *E
Description of Change
New datasheet
Added Commercial Temperature Range
Added power up requirements to Maximum Ratings
Page 9 of 10
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CY29948
Sales, Solutions, and Legal Information
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© Cypress Semiconductor Corporation, 2002-2011. The information contained herein is subject to change without notice. Cypress Semiconductor Corporation assumes no responsibility for the use of
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and compile the Cypress Source Code and derivative works for the sole purpose of creating custom software and or firmware in support of licensee product to be used only in conjunction with a Cypress
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the express written permission of Cypress.
Disclaimer: CYPRESS MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARD TO THIS MATERIAL, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Cypress reserves the right to make changes without further notice to the materials described herein. Cypress does not
assume any liability arising out of the application or use of any product or circuit described herein. Cypress 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’ product in a life-support systems application implies that the manufacturer
assumes all risk of such use and in doing so indemnifies Cypress against all charges.
Use may be limited by and subject to the applicable Cypress software license agreement.
Document Number: 38-07288 Rev. *E
Revised May 2, 2011
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