CYPRESS CY29946

CY29946
2.5V or 3.3V, 200-MHz, 1:10 Clock Distribution Buffer
Features
Description
• 2.5V or 3.3V operation
The CY29946 is a low-voltage 200-MHz clock distribution
buffer with the capability to select one of two LVCMOS/LVTTL
compatible input clocks. These clock sources can be used to
provide for test clocks as well as the primary system clocks.
All other control inputs are LVCMOS/LVTTL compatible. The
10 outputs are LVCMOS or LVTTL compatible and can drive
50Ω 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 1:20.
• 200-MHz clock support
• Two LVCMOS-/LVTTL-compatible inputs
• Ten clock outputs: drive up to 20 clock lines
• 1× or 1/2× configurable outputs
• Output three-state control
• 250-ps max. output-to-output skew
• Pin-compatible with MPC946, MPC9446
• Available in commercial and industrial temperature
range
• 32-pin TQFP package
The CY29946 is capable of generating 1× and 1/2× signals
from a 1× source. These signals are generated and retimed
internally to ensure minimal skew between the 1× and 1/2×
signals. SEL(A:C) inputs allow flexibility in selecting the ratio
of 1× to1/2× outputs.
The CY29946 outputs can also be three-stated via MR/OE#
input. When MR/OE# is set HIGH, it resets the internal
flip-flops and three-states the outputs.
Block Diagram
Pin Configuration
TCLK0
/1
0
/2
1
/1
0
3
TCLK1
R
MR/OE#
VSS
QA0
VDDC
QA1
VSS
QA2
VDDC
TCLK_SEL
QA0:2
32
31
30
29
28
27
26
25
DSELA
3
R /2
1
/1
0
/2
1
TCLK_SEL
VDD
TCLK0
TCLK1
DSELA
DSELB
DSELC
VSS
QB0:2
DSELB
VSS
QB0
VDDC
QB1
VSS
QB2
VDDC
VDDC
QC0:3
VDDC
QC0
VSS
QC1
VDDC
QC2
VSS
QC3
DSELC
MR/OE#
Cypress Semiconductor Corporation
Document #: 38-07286 Rev. *E
CY29946
24
23
22
21
20
19
18
17
9
10
11
12
13
14
15
16
4
R
1
2
3
4
5
6
7
8
•
3901 North First Street
•
San Jose, CA 95134
•
408-943-2600
Revised April 22, 2004
CY29946
Pin Description[1]
Pin
3, 4
26, 28, 30
Name
PWR
TCLK(0,1)
QA(2:0)
I/O
Description
I, PU External Reference/Test Clock Input
VDDC
O
Clock Outputs
19, 21, 23
QB(2:0)
VDDC
O
Clock Outputs
10, 12, 14, 16
QC(0:3)
VDDC
O
Clock Outputs
5, 6, 7
DSEL(A:C)
I, PD Divider Select Inputs. When HIGH, selects ÷2 input divider. When
LOW, selects ÷1 input divider.
1
TCLK_SEL
I, PD TCLK Select Input. When LOW, TCLK0 clock is selected and when
HIGH TCLK1 is selected.
32
MR/OE#
9, 13, 17, 18,
22, 25, 29
VDDC
I, PD Output Enable Input. When asserted LOW, the outputs are enabled
and when asserted HIGH, internal flip-flops are reset and the outputs
are three-stated. If more than 1 Bank is being used in /2 Mode, a reset
must be performed (MR/OE# Asserted High) after power-up to ensure
all internal flip-flops are set to the same state.
2.5V or 3.3V Power Supply for Output Clock Buffers
2
VDD
2.5V or 3.3V Power Supply
8, 11, 15, 20,
24, 27, 31
VSS
Common Ground
Note:
1. PD = Internal pull-down. PU = Internal pull-up.
Document #: 38-07286 Rev. *E
Page 2 of 6
CY29946
Absolute Maximum Conditions[2]
Storage Temperature: ................................ –65°C to + 150°C
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:
Operating Temperature: ................................ –40°C to +85°C
VSS < (Vin or Vout) < VDD .
Maximum ESD protection ............................................... 2 kV
Unused inputs must always be tied to an appropriate logic
voltage level (either VSS or VDD).
Maximum Input Voltage Relative to VSS: ............ VSS – 0.3V
Maximum Input Voltage Relative to VDD: ............. VDD + 0.3V
Maximum Power Supply: ................................................5.5V
Maximum Input Current: ...........................................± 20 mA
DC Electrical Specifications: VDD = VDDC = 3.3V ±10% or 2.5V ±5%, over the specified temperature range
Parameter
Description
Conditions
Min.
Typ.
Max.
Unit
VIL
Input Low Voltage
VSS
0.8
V
VIH
Input High Voltage
2.0
VDD
V
[3]
IIL
Input Low Current
–100
µA
IIH
Input High Current[3]
100
µA
Voltage[4]
VOL
Output Low
VOH
Output High Voltage[4]
IDDQ
Quiescent Supply Current
IDD
Dynamic Supply Current
ZOut
Cin
Output Impedance
IOL = 20 mA
0.4
IOH = –20 mA, VDD = 3.3V
2.5
IOH = –20 mA, VDD = 2.5V
1.8
5
7
VDD = 3.3V, Outputs @ 100 MHz, CL = 30 pF
130
VDD = 3.3V, Outputs @ 160 MHz, CL = 30 pF
225
VDD = 2.5V, Outputs @ 100 MHz, CL = 30 pF
95
VDD = 2.5V, Outputs @ 160 MHz, CL = 30 pF
160
mA
mA
VDD = 3.3V
12
15
18
VDD = 2.5V
14
18
22
Input Capacitance
V
V
4
W
pF
AC Electrical Specifications VDD = VDDC = 3.3V ±10% or 2.5V ±5%, over the specified temperature range[5]
Parameter
Description
Fmax
Input Frequency[6]
Tpd
TTL_CLK To Q Delay[6]
Conditions
Min.
Typ.
VDD = 3.3V
VDD = 2.5V
[6, 7]
Max.
Unit
200
MHz
170
5.0
11.5
ns
FoutDC
Output Duty Cycle
45
55
%
tpZL, tpZH
Output enable time (all outputs)
2
10
ns
tpLZ, tpHZ
Output disable time (all outputs)
2
10
ns
Tskew
Output-to-Output Skew[6, 8]
250
ps
Measured at VDD/2
150
Skew[9]
Tskew(pp)
Part-to-Part
Tr/Tf
Output Clocks Rise/Fall Time[8]
4.5
ns
0.8V to 2.0V,
VDD = 3.3V
0.10
2.0
1.0
ns
0.6V to 1.8V,
VDD = 2.5V
0.10
1.3
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. Driving series or parallel terminated 50Ω (or 50Ω to VDD/2) transmission lines.
5. Parameters are guaranteed by design and characterization. Not 100% tested in production. All parameters specified with loaded outputs.
6. Outputs driving 50Ω transmission lines.
7. 50% input duty cycle.
8. See Figure 1.
9. Part-to-Part skew at a given temperature and voltage.
Document #: 38-07286 Rev. *E
Page 3 of 6
CY29946
CY29946 DUT
Zo = 50 ohm
Pulse
Generator
Z = 50 ohm
Zo = 50 ohm
RT = 50 ohm
RT = 50 ohm
VTT
VTT
Figure 1. LVCMOS_CLK CY29946 Test Reference for VCC = 3.3V and VCC = 2.5V
VCC
LVCMOS_CLK
VCC /2
GND
VCC
Q
VCC /2
tPD
GND
Figure 2. LVCMOS Propagation Delay (TPD) Test Reference
VCC
VCC /2
tP
G ND
T0
DC = tP / T0 x 100%
Figure 3. Output Duty Cycle (FoutDC)
VCC
VCC /2
GND
VCC
VCC /2
tSK(0)
GND
Figure 4. Output-to-Output Skew tsk(0)
Ordering Information
Part Number
Package Type
Production Flow
CY29946AXI
32-pin TQFP
Industrial, –40°C to +85°C
CY29946AIXT
32-pin TQFP – Tape and Reel
Industrial, –40°C to +85°C
CY29946AXC
32-pin TQFP
Commercial, 0°C to +70°C
CY29946AXCT
32-pin TQFP – Tape and Reel
Commercial, 0°C to +70°C
Document #: 38-07286 Rev. *E
Page 4 of 6
CY29946
Package Drawing and Dimensions
32-Lead Thin Plastic Quad Flatpack 7 x 7 x 1.0mm A32
51-85063-*B
All product and company names mentioned in this document may be the trademarks of their respective holders.
Document #: 38-07286 Rev. *E
Page 5 of 6
© Cypress Semiconductor Corporation, 2003. 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.
CY29946
Document History Page
Document Title: CY29946 2.5V or 3.3V, 200-MHz, 1:10 Clock Distribution Buffer
Document Number: 38-07286
REV.
Orig. of
Change
ECN NO.
Issue Date
Description of Change
**
111097
02/07/02
BRK
New data sheet
*A
116780
08/15/02
HWT
Added the commercial temperature range in the Ordering Information
*B
122878
12/22/02
RBI
Added power-up requirements to Maximum Ratings
*C
130007
10/15/03
RGL
Fixed the block diagram.
Fixed the MK/OE# description in the pin description table.
*D
131375
11/21/03
RGL
Updated document history page (revision *C) to reflect changes that were
not listed.
*E
221587
See ECN
RGL
Minor Change: Moved up the word Block Diagram in the first page.
Document #: 38-07286 Rev. *E
Page 6 of 6