NSC LMK01000ISQ 1.6 ghz high performance clock buffer, divider, and distributor Datasheet

LMK01000/LMK01010/LMK01020
1.6 GHz High Performance Clock Buffer, Divider, and
Distributor
General Description
Features
The LMK01000/LMK01010/LMK01020 family provides an
easy way to divide and distribute high performance clock signals throughout the system. These devices provide best-inclass noise performance and are designed to be pin-to-pin
and footprint compatible with LMK03000/LMK02000 family of
precision clock conditioners.
The LMK01000/LMK01010/LMK01020 family features two
programmable clock inputs (CLKin0 and CLKin1) that allow
the user to dynamically switch between different clock domains.
Each device features 8 clock outputs with independently programmable dividers and delay adjustments. The outputs of
the device can be easily synchronized by an external pin
(SYNC*).
■ 30 fs additive jitter (100 Hz to 20 MHz)
■ Dual clock inputs
■ Programmable output channels (0 to 1600 MHz)
■
■
■
■
— LMK01000: 3 LVDS outputs (CLKout0 - CLKout2) + 5
LVPECL outputs (CLKout3 - CLKout7)
— LMK01010: 8 LVDS outputs
— LMK01020: 8 LVPECL outputs
— Channel divider values of 1, 2 to 510 (even divides)
— Programmable output skew control
External synchronization
Pin compatible family of clocking devices
3.15 to 3.45 V operation
Package: 48 pin LLP (7.0 x 7.0 x 0.8 mm)
Target Applications
■
■
■
■
■
■
High performance Clock Distribution
Wireless Infrastructure
Medical Imaging
Wired Communications
Test and Measurement
Military / Aerospace
System Diagram
30042806
TRI-STATE® is a registered trademark of National Semiconductor Corporation.
© 2008 National Semiconductor Corporation
300428
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LMK01000/LMK01010/LMK01020 1.6 GHz High Performance Clock Buffer, Divider, and
Distributor
March 6, 2008
LMK01000/LMK01010/LMK01020
Functional Block Diagram
30042801
Connection Diagram
48-Pin LLP Package
30042802
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2
Pin #
Pin Name
I/O
1, 25
GND
-
Ground
2, 7, 9,10, 32
NC
-
No Connect. Pin is not connected to the die.
-
Power Supply
3, 8, 13, 16, 19, 22, 26,
Vcc1, Vcc2, Vcc3, Vcc4, Vcc5, Vcc6, Vcc7,
30, 31, 33, 37, 40, 43, 46 Vcc8, Vcc9, Vcc10, Vcc11, Vcc12, Vcc13, Vcc14
Description
4
CLKuWire
I
MICROWIRE Clock Input
5
DATAuWire
I
MICROWIRE Data Input
6
LEuWire
I
MICROWIRE Latch Enable Input
11
GOE
I
Global Output Enable
12
Test
O
This is an output pin used strictly for test purposes
and should be not connected for normal operation.
However, any load of an impedance of more than 1
kΩ is acceptable.
14, 15
CLKout0, CLKout0*
O
Clock Output 0
17, 18
CLKout1, CLKout1*
O
Clock Output 1
20, 21
CLKout2, CLKout2*
O
Clock Output 2
23, 24
CLKout3, CLKout3*
O
Clock Output 3
27
SYNC*
I
Global Clock Output Synchronization
28, 29
CLKin0,CLKin0*
I
CLKin 0 Input; Must be AC coupled
34, 35
CLKin1, CLKin1*
I
CLKin 1 Input; Must be AC coupled
36
Bias
I
Bias Bypass
38, 39
CLKout4, CLKout4*
O
Clock Output 4
41, 42
CLKout5, CLKout5*
O
Clock Output 5
44, 45
CLKout6, CLKout6*
O
Clock Output 6
47, 48
CLKout7, CLKout7*
O
Clock Output 7
DAP
DAP
-
Die Attach Pad should be connected to ground.
The LMK01000 family is footprint compatible with the LMK03000/02000 family of devices. All CLKout pins are pin-to-pin compatible,
and CLKin0 and CLKin1 are equivalent to OSCin and Fin, respectively .
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LMK01000/LMK01010/LMK01020
Pin Descriptions
LMK01000/LMK01010/LMK01020
Absolute Maximum Ratings (Notes 1, 2)
If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors
for availability and specifications.
Parameter
Power Supply Voltage
Input Voltage
Symbol
VCC
Ratings
Units
-0.3 to 3.6
V
VIN
-0.3 to (VCC + 0.3)
V
TSTG
-65 to 150
°C
Lead Temperature (solder 4 s)
TL
+260
°C
Junction Temperature
TJ
125
°C
Storage Temperature Range
Recommended Operating Conditions
Symbol
TA
Min
Typ
Max
Units
Ambient Temperature
Parameter
-40
25
85
°C
Power Supply Voltage
VCC
3.15
3.3
3.45
V
Note 1: "Absolute Maximum Ratings" indicate limits beyond which damage to the device may occur, including inoperability and degradation of device reliability
and/or performance. Functional operation of the device and/or non-degradation at the Absolute Maximum Ratings or other conditions beyond those indicated in
the Recommended Operating Conditions is not implied. The Recommended Operating Conditions indicate conditions at which the device is functional and the
device should not be operated beyond such conditions.
Note 2: This device is a high performance integrated circuit with ESD handling precautions. Handling of this device should only be done at ESD protected work
stations. The device is rated to a HBM-ESD of > 2 kV, a MM-ESD of > 200 V, and a CDM-ESD of > 1.2 kV.
Package Thermal Resistance
Package
θJA
θJ-PAD (Thermal Pad)
48-Lead LLP (Note 3)
27.4° C/W
5.8° C/W
Note 3: Specification assumes 16 thermal vias connect the die attach pad to the embedded copper plane on the 4-layer JEDEC board. These vias play a key
role in improving the thermal performance of the LLP. It is recommended that the maximum number of vias be used in the board layout.
Electrical Characteristics
(Note 4)
(3.15 V ≤ Vcc ≤ 3.45 V, -40 °C ≤ TA ≤ 85 °C, Differential Inputs/Outputs; except as specified. Typical values represent most likely
parametric norms at Vcc = 3.3 V, TA = 25 °C, and at the Recommended Operation Conditions at the time of product characterization
and are not guaranteed).
Symbol
Parameter
Conditions
Min
Typ
Max
Units
Current Consumption
ICC
Power Supply Current
(Note 5)
ICCPD
Power Down Current
fCLKin
CLKin Frequency Range
SLEWCLKin
CLKin Frequency Input Slew Rate
All outputs
enabled, no
divide or delay
( CLKoutX_MUX
= Bypassed )
LMK01000
271
LMK01010
160
LMK01020
338
Per channel, no
divide or delay
(CLKoutX_MUX
= Bypassed )
LVDS
17.8
LVPECL
(Includes Emitter
Resistors)
mA
40
POWERDOWN = 1
1
CLKin0, CLKin0*, CLKin1, CLKin1*
DUTYCLKin
CLKin Frequency Input Duty Cycle
PCLKin
Input Power Range for CLKin or
CLKin*
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1
1600
(Notes 6, 8)
0.5
fCLKin ≤ 800 MHz
30
70
fCLKin > 800 MHz
40
60
AC coupled
-13
5
4
MHz
V/ns
%
dBm
Parameter
Conditions
Min
Typ
Max
Units
Clock Distribution Section--Delays
DelayCLKout
Maximum Allowable Delay(Note 8)
fCLKoutX ≤ 1 GHz
(Delay is limited to maximum
programmable value)
2250
ps
fCLKoutX > 1 GHz
(Delay is limited to 1/2 of a period)
0.5/
fCLKoutX
Clock Distribution Section - Divides
DivideCLKoutX
Allowable divide range. (Note that 1 is fCLKinX ≤ 1300 MHz
the only allowable odd divide value) 1300 MHz < f
CLKinX ≤ 1600 MHz
1
510
1
2
n/a
Clock Distribution Section - LVDS Clock Outputs
JitterADD
Additive RMS Jitter (Note 7)
fCLKoutX = 200 MHz
RL = 100 Ω
Bandwidth =
fCLKoutX = 800 MHz
100 Hz to 20 MHz
fCLKoutX = 1600 MHz
Vboost = 1
80
30
fCLKoutX = 200 MHz
-156
fCLKoutX = 800 MHz
-153
fCLKoutX = 1600 MHz
-148
Divider Noise Floor(Note 7)
RL = 100
Vboost = 1
tSKEW
CLKoutX to CLKoutY (Note 8)
Equal loading and identical clock
configuration
RL = 100 Ω
VOD
Differential Output Voltage
(Note 9)
ΔVOD
Change in magnitude of VOD for
complementary output states
RL = 100 Ω
-50
VOS
Output Offset Voltage
RL = 100 Ω
1.070
ΔVOS
Change in magnitude of VOS for
complementary output states
RL = 100 Ω
ISA
ISB
Clock Output Short Circuit Current
single ended
ISAB
Clock Output Short Circuit Current
differential
Noise Floor
Vboost=0
fs
25
dBc/Hz
-30
±4
30
250
350
450
Vboost=1
390
ps
mV
50
mV
1.370
V
-35
35
mV
Single ended outputs shorted to GND
-24
24
mA
Complementary outputs tied together
-12
12
mA
5
1.25
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LMK01000/LMK01010/LMK01020
Symbol
LMK01000/LMK01010/LMK01020
Symbol
Parameter
Conditions
Min
Typ
Max
Units
Clock Distribution Section - LVPECL Clock Outputs
JitterADD
Noise Floor
Additive RMS Jitter(Note 7)
Divider Noise Floor(Note 7)
tSKEW
CLKoutX to CLKoutY (Note 8)
VOH
Output High Voltage
fCLKoutX = 200 MHz
RL = 100 Ω
Bandwidth =
fCLKoutX = 800 MHz
100 Hz to 20 MHz
fCLKoutX = 1600 MHz
Vboost = 1
RL = 100
Vboost = 1
65
25
fCLKoutX = 200 MHz
-158
fCLKoutX = 800 MHz
-154
fCLKoutX = 1600 MHz
-148
Equal loading and identical clock
configuration
Termination = 50 Ω to Vcc - 2 V
fs
25
-30
Termination = 50 Ω to Vcc - 2 V
±3
dBc/Hz
30
ps
Vcc 0.98
V
Vcc 1.8
V
VOL
Output Low Voltage
VOD
Differential Output Voltage
VIH
High-Level Input Voltage
VIL
Low-Level Input Voltage
0.8
V
IIH
High-Level Input Current
VIH = Vcc
-5.0
5.0
µA
IIL
Low-Level Input Current
VIL = 0
-40.0
5.0
µA
Vcc 0.4
Vboost = 0
(Note 9)
660
Vboost = 1
810
965
865
mV
Digital LVTTL Interfaces (Note 10)
2.0
VOH
High-Level Output Voltage
IOH = +500 µA
VOL
Low-Level Output Voltage
IOL = -500 µA
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Vcc
V
V
0.4
V
Parameter
Conditions
Min
Typ
Max
Units
Vcc
V
Digital MICROWIRE Interfaces (Note 11)
VIH
High-Level Input Voltage
VIL
Low-Level Input Voltage
0.4
V
IIH
High-Level Input Current
VIH = Vcc
-5.0
5.0
µA
IIL
Low-Level Input Current
VIL = 0
-5.0
5.0
µA
1.6
MICROWIRE Timing
tCS
Data to Clock Set Up Time
See Data Input Timing
tCH
Data to Clock Hold Time
tCWH
Clock Pulse Width High
tCWL
tES
25
ns
See Data Input Timing
8
ns
See Data Input Timing
25
ns
Clock Pulse Width Low
See Data Input Timing
25
ns
Clock to Enable Set Up Time
See Data Input Timing
25
ns
tCES
Enable to Clock Set Up Time
See Data Input Timing
25
ns
tEWH
Enable Pulse Width High
See Data Input Timing
25
ns
Note 4: The Electrical Characteristics tables list guaranteed specifications under the listed Recommended Operating Conditions except as otherwise modified
or specified by the Electrical Characteristics Conditions and/or Notes. Typical specifications are estimations only and are not guaranteed.
Note 5: See section 3.2 for more current consumption / power dissipation calculation information.
Note 6: For all frequencies the slew rate, SLEWCLKin1, is measured between 20% and 80%.
Note 7: The noise floor of the divider is measured as the far out phase noise of the divider. Typically this offset is 40 MHz, but for lower frequencies this
measurement offset can be as low as 5 MHz due to measurement equipment limitations. If the delay is used, then use section 1.3.
Note 8: Specification is guaranteed by characterization and is not tested in production.
Note 9: See characterization plots to see how this parameter varies over frequency.
Note 10: Applies to GOE, LD, and SYNC*.
Note 11: Applies to CLKuWire, DATAuWire, and LEuWire.
Serial Data Timing Diagram
30042803
Data bits set on the DATAuWire signal are clocked into a shift register, MSB first, on each rising edge of the CLKuWire signal. On
the rising edge of the LEuWire signal, the data is sent from the shift register to the addressed register determined by the LSB bits.
After the programming is complete the CLKuWire, DATAuWire, and LEuWire signals should be returned to a low state. The slew
rate of CLKuWire, DatauWire, and LEuWire should be at least 30 V/µs.
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LMK01000/LMK01010/LMK01020
Symbol
LMK01000/LMK01010/LMK01020
Typical Performance Characteristics
LVDS Single-Ended Peak to Peak Voltage
LVPECL Single-Ended Peak to Peak Voltage
30042807
30042808
LVDS Output Noise Floor
LVPECL Output Noise Floor
30042809
30042810
Delay Noise Floor (Adds to Output Noise Floor)
30042811
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8
The LMK010X0 family of clock distribution devices include a
programmable divider, a phase synchronization circuit, a programmable delay, a clock output mux, and an LVDS or
LVPECL output buffer in each channel. This allows multiple
integer-related and phase-adjusted copies of the reference to
be distributed to up to eight system components.
This family of devices comes in a 48-pin LLP package that is
pin-to-pin and footprint compatible with other LMK02000/
LMK03000 family of clocking devices.
1.1 BIAS PIN
To properly use the device, bypass Bias (pin 36) with a low
leakage 1 µF capacitor connected to Vcc. This is important
for low noise performance.
30042804
The SYNC* pin provides an internal pull-up resistor as shown
on the functional block diagram. If the SYNC* pin is not terminated externally the clock outputs will operate normally. If
the SYNC* function is not used, clock output synchronization
is not guaranteed.
1.2 CLKin0/CLKin0* and CLKin1/CLKin1 INPUT PORTS
The device can be driven either by the CLKin0/CLKin0* or the
CLKin1/CLKin1* pins. The choice of which one to use is software selectable. These input ports must be AC coupled. To
drive these inputs in a single ended fashion, AC ground the
complementary input with a 0.1 µF capacitor.
1.6 CONNECTION TO LVDS OUTPUTS
LMK01000/10 LVDS outputs can be connected in AC or DC
coupling configurations; however, in DC coupling configuration, proper conditions must be presented by the LVDS receiver. To ensure such conditions, we recommend the usage
of LVDS receivers without fail-safe or internal input bias such
as DS90LV110T. LMK01000/10 LVDS drivers will provide the
adequate DC bias for the LVDS receiver. We recommend AC
coupling when using LVDS receivers with fail-safe or internal
input bias.
1.3 CLKout DELAYS
Each individual clock output includes a delay adjustment.
Clock output delay registers (CLKoutX_DLY) support a 150
ps step size and range from 0 to 2250 ps of total delay. When
the delay is enabled it adds to the output noise floor; the total
additive noise is 10(log( 10^(Output Noise Floor/10) + 10^
(Delay Noise Floor/10) ). Refer to the Typical Performance
Characteristics plots for the Delay Noise Floor information.
1.7 CLKout OUTPUT STATES
Each clock output may be individually enabled with the
CLKoutX_EN bits. Each individual output enable control bit is
gated with the Global Output Enable input pin (GOE) and the
Global Output Enable bit (EN_CLKout_Global).
All clock outputs can be disabled simultaneously if the GOE
pin is pulled low by an external signal or EN_CLKout_Global
is set to 0.
1.4 LVDS/LVPECL OUTPUTS
Each LVDS or LVPECL output may be disabled individually
by programming the CLKoutX_EN bits. All the outputs may
be disabled simultaneously by pulling the GOE pin low or
programming EN_CLKout_Global to 0.
1.5 GLOBAL CLOCK OUTPUT SYNCHRONIZATION
The SYNC* pin synchronizes the clock outputs. When the
SYNC* pin is held in a logic low state, the divided outputs are
also held in a logic low state. When the SYNC* pin goes high,
the divided clock outputs are activated and will transition to a
high state simultaneously. Clocks in the Bypassed state are
not affected by SYNC* and are always synchronized with the
divided outputs.
The SYNC* pin must be held low for greater than one clock
cycle of the Frequency Input port, also known as the distribution path. Once this low event has been registered, the outputs will not reflect the low state for four more cycles. When
the SYNC* pin becomes high, the outputs will not simultaneously transition high until four more distribution path clock
cycles have passed. See the SYNC* timing diagram for further detail. In the timing diagram below the clocks are programmed as CLKout0_MUX = Bypassed, CLKout1_MUX =
Divided, CLKout1_DIV = 2, CLKout2_MUX = Divided, and
CLKout2_DIV = 4.
CLKoutX
_EN bit
EN_CLKout
_Global bit
GOE pin
Clock X
Output State
1
1
Low
Low
Don't care
0
Don't care
Off
0
Don't care
Don't care
Off
1
1
High / No
Connect
Enabled
When an LVDS output is in the Off state, the outputs are at a
voltage of approximately 1.5 volts. When an LVPECL output
is in the Off state, the outputs are at a voltage of approximately
1 volt.
1.8 GLOBAL OUTPUT ENABLE
The GOE pin provides an internal pull-up resistor. If it is not
terminated externally, the clock output states are determined
by the Clock Output Enable bits (CLKoutX_EN) and the
EN_CLKout_Global bit.
1.9 POWER-ON-RESET
When supply voltage to the device increases monotonically
from ground to Vcc, the power-on-reset circuit sets all registers to their default values, which are specified in the General
Programming Information section. Voltage should be applied
to all Vcc pins simultaneously.
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LMK01000/LMK01010/LMK01020
SYNC* Timing Diagram
1.0 Functional Description
LMK01000/LMK01010/LMK01020
2.0 General Programming
Information
The LMK01000/LMK01010/LMK01020 device is programmed using several 32-bit registers which control the
device's operation. The registers consist of a data field and
an address field. The last 4 register bits, ADDR[3:0] form the
address field. The remaining 28 bits form the data field DATA
[27:0].
During programming, LEuWire is low and serial data is
clocked in on the rising edge of clock (MSB first). When
LEuWire goes high, data is transferred to the register bank
selected by the address field. Only registers R0 to R7 and R14
need to be programmed for proper device operation.
It is required to program register R14.
2.1 RECOMMENDED PROGRAMMING SEQUENCE
The recommended programming sequence involves programming R0 with the reset bit set (RESET = 1) to ensure the
device is in a default state. It is not necessary to program R0
again, but if R0 is programmed again, the reset bit is programmed clear (RESET = 0). An example programming sequence is shown below.
• Program R0 with the reset bit set (RESET = 1). This
ensures the device is in a default state. When the reset bit
is set in R0, the other R0 bits are ignored.
— If R0 is programmed again, the reset bit is programmed
clear (RESET = 0).
• Program R0 to R7 as necessary with desired clocks with
appropriate enable, mux, divider, and delay settings.
• Program R14 with global clock output bit, power down
setting.
— R14 must be programmed in accordance with the
register map as shown in the register map (see 2.2).
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10
11
0
1
0
R7
R9
R14
0
R4
0
0
R3
R6
0
R2
0
0
R1
R5
0
R0
0
0
0
0
0
0
0
0
0
30
31
Register
0
1
0
0
0
0
0
0
0
0
29
0
0
0
0
0
0
0
0
0
28
0
0
0
0
0
0
0
0
0
27
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
POWERDOWN
0
24
25
26
0
0
0
0
0
0
0
0
0
0
23
0
0
0
0
0
0
0
0
0
0
22
0
0
0
0
0
0
0
0
0
0
21
0
0
0
0
0
0
0
0
0
0
20
0
0
0
0
0
0
0
0
0
0
19
17
0
0
0
1
CLKout7
_MUX
[1:0]
CLKout6
_MUX
[1:0]
CLKout5
_MUX
[1:0]
CLKout4
_MUX
[1:0]
CLKout3
_MUX
[1:0]
CLKout2
_MUX
[1:0]
CLKout1
_MUX
[1:0]
CLKout0
_MUX
[1:0]
Data [27:0]
18
2.2 LMK01000/LMK01010/LMK01020 REGISTER MAP
RESET
16
0
Vbo
ost
0
0
15
0
0
14
0
1
13
11
0
0
0
1
CLKout7_DIV
[7:0]
CLKout6_DIV
[7:0]
CLKout5_DIV
[7:0]
CLKout4_DIV
[7:0]
CLKout3_DIV
[7:0]
CLKout2_DIV
[7:0]
CLKout1_DIV
[7:0]
CLKout0_DIV
[7:0]
12
0
0
10
0
1
9
0
0
8
0
0
7
5
0
0
0
0
CLKout7_DLY
[3:0]
CLKout6_DLY
[3:0]
CLKout5_DLY
[3:0]
CLKout4_DLY
[3:0]
CLKout3_DLY
[3:0]
CLKout2_DLY
[3:0]
CLKout1_DLY
[3:0]
CLKout0_DLY
[3:0]
6
0
0
4
1
1
0
0
0
0
0
0
0
1
0
1
1
1
1
0
0
0
0
A2
A3
0
2
3
1
0
1
1
0
0
1
1
0
0
A1
1
0
1
1
0
1
0
1
0
1
0
A0
0
LMK01000/LMK01010/LMK01020
CLKout0 CLKout1 CLKout2 CLKout3 CLKout4 CLKout5 CLKout6 CLKout7
_EN
_EN
_EN
_EN
_EN
_EN
_EN
_EN
EN_CLKout
_Global
CLKin
_SELECT
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LMK01000/LMK01010/LMK01020
Aside from this, the functions of these bits are identical. The
X in CLKoutX_MUX, CLKoutX_DIV, CLKoutX_DLY, and
CLKoutX_EN denote the actual clock output which may be
from 0 to 7.
2.3 REGISTER R0 to R7
Registers R0 through R7 control the eight clock outputs. Register R0 controls CLKout0, Register R1 controls CLKout1, and
so on. There is one additional bit in register R0 called RESET.
Default Register Settings after Power-on-Reset
Default
Bit Value
Bit Name
Bit State
Bit Description
Register
Bit
Location
RESET
0
No reset, normal operation
Reset to power on defaults
CLKoutX_MUX
0
Bypassed
CLKoutX mux mode
CLKoutX_EN
0
Disabled
CLKoutX enable
CLKoutX_DIV
1
Divide by 2
CLKoutX clock divide
CLKoutX_DLY
0
0 ps
CLKoutX clock delay
7:4
CLKin_SELECT
0
CLKin1
Select CLKin0 or CLKin1
28
EN_CLKout_Global
1
Normal - CLKouts normal
Global clock output enable
POWERDOWN
0
Normal - Device active
Device power down
2.3.1 RESET Bit -- R0 only
This bit is only in register R0. The use of this bit is optional
and it should be set to '0' if not used. Setting this bit to a '1'
forces all registers to their power-on-reset condition and
therefore automatically clears this bit. If this bit is set, all other
R0 bits are ignored and R0 needs to be programmed again if
used with its proper values and RESET = 0.
Mode
0
Bypassed (default)
0 ps
1
Divided
100 ps
Delayed
400 ps
(In addition to the
programmed
delay)
Divided and
Delayed
500 ps
(In addition to the
programmed
delay)
2
3
2.3.3 CLKoutX_DIV[7:0] -- Clock Output Dividers
These bits control the clock output divider value. In order for
these dividers to be active, the respective CLKoutX_MUX
(See 2.3.2) bit must be set to either "Divided" or "Divided and
Delayed" mode. After all the dividers are programed, the
SYNC* pin must be used to ensure that all edges of the clock
outputs are aligned (See 1.7). By adding the divider block to
the output path a fixed delay of approximately 100 ps is incurred.
The actual Clock Output Divide value is twice the binary value
programmed as listed in the table below.
0
0
0
0
0
0
0
Invalid
0
0
0
0
0
0
0
1
2 (default)
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15:8
R14
27
26
Clock Output
Divider value
0
0
0
0
0
0
1
0
4
0
0
0
0
0
0
1
1
6
0
0
0
0
0
1
0
0
8
0
0
0
0
0
1
0
1
10
.
.
.
.
.
.
.
.
...
1
1
1
1
1
1
1
1
510
CLKoutX_DLY[3:0]
Delay (ps)
0
0 (default)
1
150
2
300
3
450
4
600
5
750
6
900
7
1050
8
1200
9
1350
10
1500
11
1650
12
1800
13
1950
14
2100
15
2250
2.3.5 CLKoutX_EN bit -- Clock Output Enables
These bits control whether an individual clock output is enabled or not. If the EN_CLKout_Global bit is set to zero or if
GOE pin is held low, all CLKoutX_EN bit states will be ignored
and all clock outputs will be disabled.
Clock Output
Divider value
0
16
R0 to R7
2.3.4 CLKoutX_DLY[3:0] -- Clock Output Delays
These bits control the delay stages for each clock output. In
order for these delays to be active, the respective
CLKoutX_MUX (See 2.3.2) bit must be set to either "Delayed"
or "Divided and Delayed" mode. By adding the delay block to
the output path a fixed delay of approximately 400 ps is incurred in addition to the delay shown in the table below.
Added Delay
Relative to
Bypassed Mode
CLKoutX_DIV[7:0]
31
18:17
CLKoutX_DIV[7:0]
2.3.2 CLKoutX_MUX[1:0] -- Clock Output Multiplexers
These bits control the Clock Output Multiplexer for each clock
output. Changing between the different modes changes the
blocks in the signal path and therefore incurs a delay relative
to the Bypassed mode. The different MUX modes and associated delays are listed below.
CLKoutX_MUX
[1:0]
R0
12
0
1
Conditions
2.4.2 POWERDOWN Bit -- Device Power Down
This bit can power down the device. Enabling this bit powers
down the entire device and all blocks, regardless of the state
of any of the other bits or pins.
CLKoutX State
EN_CLKout_Global Disabled (default)
bit = 1
GOE pin = High / No
Enabled
Connect 1
POWERDOWN bit
2.4 REGISTER R9 and R14
The LMK01000 family requires register R14 to be programmed as shown in the register map (see 2.2). R9 only
needs to be programmed if Vboost is set to 1.
fCLKoutX < 1300
MHz
1300 MHz ≤
fCLKoutX <
1500 MHz
0
Normal Operation (default)
1
Entire Device Powered Down
2.4.3 INPUT_MUX Bit -- Device CLKin Select
This bit determines which CLKin pin is used.
2.4.1 Vboost - Voltage Boost Bit
Enabling this bit sets all clock outputs in voltage boost mode
which increases the voltage at these outputs. This can improve the noise floor performance of the output, but also
increases current consumption, and can cause the outputs to
be too high to meet the LVPECL/LVDS specifications.
Vboost
bit
Mode
CLKin bit
Mode
0
CLKin1 (default)
1
CLKin0
1500 MHz ≤
fCLKoutX ≤
1600 MHz
0
Recommended to
hit voltage level
specifications for
LVPECL/LVDS
Insufficient voltage level for
LVDS/LVPECL
specifications, but saves
current
1
Voltage May
overdrive LVPECL/
LVDS
specifications, but
noise floor is about
2-4 dB better and
current
consumption is
increased
Voltage is
sufficient for
LVDS/
LEVPECL
specifications
. Current
consumption
is increased,
but noise floor
is about the
same.
Insufficient
voltage for
LVDS/
LVPECL
specifications
, but still
higher than
when
Vboost=0.
Increased
current
consumption.
13
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LMK01000/LMK01010/LMK01020
CLKoutX_EN bit
LMK01000/LMK01010/LMK01020
3.0 Application Information
3.1 SYSTEM LEVEL DIAGRAM
The following shows the LMK01000LMK01010/LMK01020 in
a typical application. In this setup the clock may be divided,
skewed, and redistributed.
30042870
FIGURE 1. Typical Application
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14
Block
Condition
Core Current
All outputs disabled. Includes input buffer currents.
Current
Consumptio
n at 3.3 V
(mA)
Power
Dissipated
in device
(mW)
Power
Dissipated in
LVPECL emitter
resistors (mW)
19
62.7
-
Low clock buffer The low clock buffer is enabled anytime one of CLKout0
(internal)
through CLKout3 are enabled
9
29.7
-
High clock
The high clock buffer is enabled anytime one of the CLKout4
buffer (internal) through CLKout7 are enabled
9
29.7
-
17.8
58.7
-
LVPECL output, Bypassed mode
(includes 120 Ω emitter resistors)
40
72
60
LVPECL output, disabled mode
(includes 120 Ω emitter resistors)
17.4
38.3
19.1
0
0
-
Additional current per channel due LVPECL Output
to setting Vboost from 0 to 1.
LVDS Output
0.5
1.65
-
1.5
5.0
Divide circuitry
per output
Divide enabled, divide = 2
5.3
17.5
-
Divide enabled, divide > 2
8.5
28.0
-
Delay circuitry
per output
Delay enabled, delay < 8
5.8
19.1
-
Delay enabled, delay > 7
9.9
32.7
-
Entire device
LMK01000
CLKout0 &
LMK01010
CLKout4
enabled in
LMK01020
Bypassed mode
85.8
223.1
60
63.6
209.9
-
108
236.4
120
Entire device
LMK01000
all outputs
LMK01010
enabled with no
delay and divide LMK01020
value of 2
323.8
768.5
300
212.8
702.3
-
390.4
808.3
480
LVDS output, Bypassed mode
Output buffers
LVPECL output, disabled mode.
No emitter resistors placed; open outputs
Vboost
From the above table, the current can be calculated in any
configuration. For example, the current for the entire device
with 1 LVDS (CLKout0) & 1 LVPECL (CLKout4) output in Bypassed mode can be calculated by adding up the following
blocks: core current, low clock buffer, high clock buffer, one
LVDS output buffer current, and one LVPECL output buffer
current. There will also be one LVPECL output drawing emitter current, but some of the power from the current draw is
dissipated in the external 120 Ω resistors which doesn't add
to the power dissipation budget for the device. If delays or
divides are switched in, then the additional current for these
stages needs to be added as well.
For power dissipated by the device, the total current entering
the device is multiplied by the voltage at the device minus the
power dissipated in any emitter resistors connected to any of
the LVPECL outputs. If no emitter resistors are connected to
the LVPECL outputs, this power will be 0 watts. For example,
in the case of 1 LVDS (CLKout0) & 1 LVPECL (CLKout4) operating at 3.3 volts for LMK01000, we calculate 3.3 V × (10 +
9 + 9 + 17.8 + 40) mA = 3.3 V × 85.8 mA = 283.1 mW. Because
the LVPECL output (CLKout4) has the emitter resistors
hooked up and the power dissipated by these resistors is 60
mW, the total power dissipation is 283.1 mW - 60 mW = 223.1
mW. When the LVPECL output is active, ~1.9 V is the average
voltage on each output as calculated from the LVPECL Voh
& Vol typical specification. Therefore the power dissipated in
each emitter resistor is approximately (1.9 V)2 / 120 Ω = 30
mW. When the LVPECL output is disabled, the emitter resistor voltage is ~1.07 V. Therefore the power dissipated in each
emitter resistor is approximately (1.07 V)2 / 120 Ω = 9.5 mW.
15
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LMK01000/LMK01010/LMK01020
3.2 CURRENT CONSUMPTION / POWER DISSIPATION
CALCULATIONS ( Vcc = 3.3 V, TA = 25° C )
LMK01000/LMK01010/LMK01020
To minimize junction temperature it is recommended that a
simple heat sink be built into the PCB (if the ground plane
layer is not exposed). This is done by including a copper area
of about 2 square inches on the opposite side of the PCB from
the device. This copper area may be plated or solder coated
to prevent corrosion but should not have conformal coating (if
possible), which could provide thermal insulation. The vias
shown in Figure 2 should connect these top and bottom copper layers and to the ground layer. These vias act as “heat
pipes” to carry the thermal energy away from the device side
of the board to where it can be more effectively dissipated.
3.3 THERMAL MANAGEMENT
Power consumption of the LMK01000/LMK01010/LMK01020
can be high enough to require attention to thermal management. For reliability and performance reasons the die temperature should be limited to a maximum of 125 °C. That is,
as an estimate, TA (ambient temperature) plus device power
consumption times θJA should not exceed 125 °C.
The package of the device has an exposed pad that provides
the primary heat removal path as well as excellent electrical
grounding to the printed circuit board. To maximize the removal of heat from the package a thermal land pattern including multiple vias to a ground plane must be incorporated
on the PCB within the footprint of the package. The exposed
pad must be soldered down to ensure adequate heat conduction out of the package. A recommended land and via
pattern is shown in Figure 2. More information on soldering
LLP packages can be obtained at www.national.com.
30042873
FIGURE 2.
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16
LMK01000/LMK01010/LMK01020
Physical Dimensions inches (millimeters) unless otherwise noted
Leadless Leadframe Package (Bottom View)
48 Pin LLP (SQA48A) Package
Order Number
Package Marking
Packing
LVDS Outputs
LVPECL
Outputs
LMK01000ISQ
K01000 I
250 Unit Tape and Reel
3
5
LMK01000ISQX
K01000 I
2500 Unit Tape and Reel
3
5
-
LMK01010ISQ
K01010 I
250 Unit Tape and Reel
8
LMK01010ISQX
K01010 I
2500 Unit Tape and Reel
8
-
LMK01020ISQ
K01020 I
250 Unit Tape and Reel
-
8
LMK01020ISQX
K01020 I
2500 Unit Tape and Reel
-
8
17
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LMK01000/LMK01010/LMK01020 1.6 GHz High Performance Clock Buffer, Divider, and
Distributor
Notes
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