Cypress B9947 3.3v, 160-mhz, 1:9 clock distribution buffer Datasheet

B9947
3.3V, 160-MHz, 1:9 Clock Distribution Buffer
Product Features
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Description
160-MHz Clock Support
LVCMOS/LVTTL Compatible Inputs
9 Clock Outputs: Drive up to 18 Clock Lines
Synchronous Output Enable
Output Three-state Control
350-ps Maximum Output-to-Output Skew
Pin Compatible with MPC947
Industrial Temp. Range: –40°C to +85°C
32-Pin TQFP Package
The B9947 is a low-voltage clock distribution buffer with the
capability to select one of two LVCMOS/LVTTL compatible
clock inputs. 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 nine outputs
are 3.3V LVCMOS or LVTTL compatible and can drive two
series terminated 50Ω transmission lines. With this capability
the B9947 has an effective fanout of 1:18. The outputs can
also be three-stated via the three-state input TS#. Low output-to-output skews make the B9947 an ideal clock distribution buffer for nested clock trees in the most demanding of
synchronous systems.
The B9947 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.
Pin Configuration
TCLK0
TCLK1
VDDC
0
9
32
31
30
29
28
27
26
25
VDD
VSS
VDDC
Q0
VSS
Q1
VDDC
Q2
VSS
Block Diagram
Q0-Q8
VSS
TCLK_SEL
TCLK0
TCLK1
SYNC_OE
TS#
VDD
VSS
1
TCLK_SEL
SYNC_OE
B9947
24
23
22
21
20
19
18
17
VSS
Q3
VDDC
Q4
VSS
Q5
VDDC
VSS
VSS
VDDC
Q8
VSS
Q7
VDDC
Q6
VSS
9
10
11
12
13
14
15
16
TS#
1
2
3
4
5
6
7
8
Cypress Semiconductor Corporation
Document #: 38-07078 Rev. *C
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3901 North First Street
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San Jose
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CA 95134 • 408-943-2600
Revised December 22, 2002
B9947
Pin Description
Pin
Name
PWR
I/O
Description
3
TCLK0
I, PU
Test Clock Input
4
TCLK1
I, PU
Test Clock Input
2
TCLK_SEL
I, PU
Test Clock Select Input. When LOW, TCLK0 is selected. When
asserted HIGH, TCLK1 is selected.
11, 13, 15, 19, 21,
23, 26, 28, 30
Q(8:0)
5
SYNC_OE
I, PU
Output Enable Input. When asserted HIGH, the outputs are
enabled and 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, 27,
31
VDDC
3.3V Power Supply for Output Clock Buffers
7
VDD
3.3V Power Supply
1, 8, 9, 12, 16, 17,
20, 24, 25, 29, 32
VSS
Common Ground
VDDC
O
Clock Outputs
Note:
1. PU = Internal Pull-Up.
Output Enable/Disable
The B9947 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.
TCLK
SYNC_OE
Q
Figure 1. SYNC_OE Timing Diagram
Document #: 38-07078 Rev. *C
Page 2 of 5
B9947
Maximum Ratings[2]
Maximum Input Voltage Relative to VDD:............. VDD + 0.3V
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:
Storage Temperature: ................................–65°C to + 150°C
VSS < (Vin or Vout) < VDD
Operating Temperature: ................................ –40°C to +85°C
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 ESD protection .............................................. 2 KV
Maximum Power Supply: ................................................5.5V
Maximum Input Current:..................................................±20 mA
DC Parameters: VDDC = 3.3V ±10%, VDD = 3.3V ±10%, TA = –40°C to +85°C
Parameter
Description
Conditions
Min.
Typ.
Max.
Unit
Input Low Voltage
VSS
0.8
V
Input High Voltage
2.0
VDD
V
–100
µA
10
µA
0.4
V
IIL
Input Low Current (@VIL = VSS) Note 3
IIH
Input High Current (@VIL =VDD)
VOL
Output Low Voltage
IOL = 20 mA, Note 4
VOH
Output High Voltage
IOH = –20 mA, VDDC = 3.3V, Note 4
IDD
Quiescent Supply Current
All VDDC and VDD
Cin
Input Capacitance
2.5
V
1
2
mA
4
pF
AC Parameters[5]: VDDC = 3.3V ±10%, VDD = 3.3V ±10%, TA = –40°C to +85°C
Parameter
Description
Conditions
Min.
Typ.
Max.
Unit
Fmax
Maximum Input Frequency[6]
160
Tpd
TCLK to Q Delay[6]
4.75
FoutDC
Output Duty Cycle[6,7]
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[6,9]
350
ps
Tskew (pp)
Part to Part Skew[10]
2.0
ns
Ts
Set-up Time[6,8]
SYNC_OE to TCLK
0.0
ps
Th
Hold Time[6,8]
TCLK to SYNC_OE
1.0
ps
Tr/Tf
Output Clocks Rise/Fall Time[9]
0.8V to 2.0V
0.20
Measured at VDDC/2 TCYCLE/2 – 800
MHz
9.25
ns
TCYCLE/2 + 800
ps
1.0
ns
Notes:
2. 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 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. Set-up and Hold times are relative to the falling edge of the input clock
9. Outputs loaded with 30pF each
10. Part to Part Skew at a given temperature and voltage
Document #: 38-07078 Rev. *C
Page 3 of 5
B9947
Package Drawing and Dimensions
32-Pin TQFP Outline Dimensions
Inches
D
D1
12°
A1
Symbol
Min.
Nom.
Max.
Min.
Nom.
Max.
A
-
-
0.047
-
-
1.20
A1
0.002
-
0.006
0.05
-
0.15
A2
0.037
-
0.041
0.95
-
1.05
D
-
0.354
-
-
9.00
-
D1
-
0.276
-
-
7.00
-
b
0.012
-
0.018
0.30
-
0.45
e
L
L
e
Millimeters
0.031 BSC
0.018
-
0.80 BSC
0.030
0.45
-
0.75
b
Ordering Information
Part Number[11]
B9947CA
Package Type
32-Pin TQFP
Production Flow
Industrial, –40°C to +85°C
Note:
11. The ordering part number is formed by a combination of device number,
device revision, package style, and screening as shown below.
Marking: Example:
Cypress
B9947CA
Date Code, Lot #
B9947CA
Package
A = TQFP
Revision
Device Number
Document #: 38-07078 Rev. *C
Page 4 of 5
© Cypress Semiconductor Corporation, 2001. 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.
B9947
Document Title: B9947 3.3V, 160-MHz, 1:9 Clock Distribution Buffer
Document Number: 38-07078
REV.
ECN NO.
Issue
Date
Orig. of
Change
Description of Change
**
107114
06/06/01
IKA
Convert from IMI to Cypress
*A
108058
07/03/01
NDP
Changed Commercial to Industrial (See page 6)
*B
109804
01/31/02
DSG
Convert from Word to Frame
*C
122763
12/22/02
RBI
Add power up requirements to maximum ratings information
Document #: 38-07078 Rev. *C
Page 5 of 5
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