MICREL SM840002

SM840002
ClockWorks™ Dual 10-Gigabit/Gigabit
Ethernet 62.5MHz, 125MHz, or 156.25MHz,
Ultra-Low Jitter LVCMOS Clock Frequency
Synthesizer
General Description
Features
The SM840002 is a dual 10-Gigabit Ethernet and Gigabit
Ethernet, 62.5MHz, 125MHz, or 156.25MHz LVCMOS
clock frequency synthesizer and a member of the
ClockWorks™ family of devices from Micrel. It provides a
low-noise timing solution for high-speed, high-accuracy
synthesis of clock signals. It includes a patented
RotaryWave® architecture that provides a very stable clock
with very-low noise.
Power supplies of either 2.5V or 3.3V are supported, with
superior jitter and phase-noise performance. The device
synthesizes a 62.5MHz, 125MHz, or 156.25MHz, lownoise LVCMOS output pair for Ethernet applications. The
crystal reference frequency is 25MHz.
The SM840002 is an excellent replacement for IDT
FemtoClocks®, with improved waveform integrity, and jitter.
Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
• Generates two LVCMOS outputs
• Operating supply modes:
− Core/Output
− 3.3V/3.3V, 2.5V/2.5V
• Typical phase jitter @156.25MHz~64 fs
(1.875MHz − 20MHz)
• Crystal frequency: 25MHz
• 62.5MHz, 125MHz, or 156.25MHz output frequency
• Output Skew: 12ps (maximum)
• Phase Noise @ 156.25MHz:
− 1KHz:
−126dBc/Hz
− 10KHz:
−130dBc/Hz
− 100KHz:
−126dBc/Hz
− 1MHz:
−139dBc/Hz
− 10MHz:
−165dBc/Hz
− 20MHz:
−166/dBc/Hz
• Temperature range: –40°C to +75°C
• Green-, RoHS-, and PFOS-compliant
• Available in 16-pin TSSOP
Applications
• Gigabit Ethernet
• 10-Gigabit Ethernet
ClockWorks is a trademark of Micrel, Inc.
RotaryWave is a registered trademark of Multigig, Inc.
FemtoClocks is a registered trademark of IDT, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
November 2010
M9999-110810-A
[email protected] or (408) 955-1690
Micrel, Inc.
SM840002
Block Diagram
Ordering Information(1)
Part Number
Package Type
Operating Range
Package Marking
SM840002KA
K-16
–40°C to +75°C
840002
K-16
–40°C to +75°C
840002
SM840002KA
(2)
TR
Notes:
1.
Devices are Green-, RoHS-, and PFOS-compliant.
2.
Tape and Reel.
Pin Configuration
16-Pin TSSOP (K-16)
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SM840002
Pin Description
Pin Number
Pin Name
Type
Level
1
F_SEL0
I
Pull-Up
Pin Function
2
nXTAL_SEL
I
Pull-Down
Selects between XTAL and TEST_CLK Reference Input. When HIGH,
selects TEST_CLK. When LOW, selects XTAL inputs. LVCMOS interface
levels.
3
TEST_CLK
I
Pull-Down
Single-Ended LVCMOS Clock Input.
4
OE
I
Pull-Up
5
NC
6
nPLL_SEL
I
7
VDDA
P
2.5V or 3.3V Output Power Supply. No filter resistor needed.
8
VDD
P
2.5V or 3.3V Output Power Supply.
9
XTAL_OUT
O
12pF Crystal
10
XTAL_IN
I
12pF Crystal
11
VDDO
P
12
Q1
O
LVCMOS
Single-Ended Output Clock.
13
Q0
O
LVCMOS
Single-Ended Output Clock.
14
GND
P
Ground.
15
GND
P
Ground.
16
F_SEL1
I
Frequency Select Pin. LVCMOS interface levels.
Output Enable. When HIGH, the outputs are active. When LOW, the
outputs are in a high impedance state. LVCMOS interface levels.
No Connect.
Selects between the VCO reference and the VCO Output. When LOW,
the output is driven from the VCO output. When HIGH, the PLL is
bypassed.
Pull-Down
Crystal Reference Output, no load caps needed.
Crystal Reference Input, no load caps needed.
2.5V or 3.3V Output Power Supply.
Pull-up
Frequency Select Pin. LVCMOS interface levels.
Configuring the SM840002
Xtal Frequency (MHz)
F_SEL1
F_SEL0
M Divider
N Divider
Output Frequency (MHz)
25
0
0
125
20
156.25
25
0
1
130
26
125
25
1
0
130
52
62.5
25
1
1
130
26
125
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SM840002
Absolute Maximum Ratings(1)
Operating Ratings(2)
Supply Voltage (VDD)...................................................+4.6V
Input Voltage (VIN) ................................ –0.50V to VDD+0.5V
Output Voltage (VOUT) .......................... –0.50V to VDD+0.5V
Lead Temperature (soldering, 20sec.)....................... 260°C
Storage Temperature (Ts) .........................–65°C to +150°C
Supply Voltage (VDDO) .......................... +2.375V to +3.465V
Supply Voltage (VDD, VDDA) ................... +2.375V to +3.465V
Ambient Temperature (TA) .......................... –40°C to +75°C
Junction Thermal Resistance
TSSOP (θJA)(Still Air).......................................127°C/W
DC Electrical Characteristics(3)
VDDA = VDD = 2.5V ±5%, VDDO = 2.5V ±5%, TA = –40°C to +75°C, unless noted.
Symbol
Parameter
Condition
Min.
Typ.
Max.
Units
VDD
Core Supply Voltage
2.375
2.50
2.625
V
VDDA
Analog Supply Voltage
2.375
2.50
2.625
V
VDDO
Output Supply Voltage
2.375
2.50
2.625
V
IDD
Core Supply Current
0.1
1
mA
IDDA
Analog Supply Current
48
55
mA
IDDO
Output Supply Current
15
23
mA
Typ.
Max.
Units
No Load
VDDA = VDD = 3.3V ±5%, VDDO = 3.3V ±5%, TA = –40°C to +75°C, unless noted.
Symbol
Parameter
Condition
Min.
VDD
Core Supply Voltage
3.135
3.30
3.465
V
VDDA
Analog Supply Voltage
3.135
3.30
3.465
V
VDDO
Output Supply Voltage
3.135
3.30
3.465
V
IDD
Core Supply Current
0.1
1
IDDA
Analog Supply Current
49
55
mA
IDDO
Power Supply Current
25
32
mA
No Load
Notes:
1.
Permanent device damage may occur if absolute maximum ratings are exceeded. This is a stress rating only and functional operation is not implied
at conditions other than those detailed in the operational sections of this data sheet. Exposure to absolute maximum rating conditions for extended
periods may affect device reliability.
2.
The data sheet limits are not guaranteed if the device is operated beyond the operating ratings.
3.
The circuit is designed to meet the DC specifications shown in the above table after thermal equilibrium has been established.
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SM840002
LVCMOS DC Electrical Characteristics(3)
VDDA = VDD =2.5V or 3.3V ±5%, VDDO = 2.5V or 3.3V ±5%, TA = –40°C to +75°C, unless noted.
Symbol
Parameter
Condition
VIH
Input HIGH Voltage
VIL
Input LOW Voltage
OE, F_SEL0, F_SEL1
IIH
Input HIGH Current
nPLL_SEL, MR,
nXTAL_SEL, TEST_CLK
OE, F_SEL0, F_SEL1
IIL
Input LOW Current
VOH
VOL
nPLL_SEL, MR,
nXTAL_SEL, TEST_CLK
Output HIGH Voltage(4)
Min.
Typ.
Max.
Units
2
VDD +
0.3
V
−0.30
0.80
V
5
µA
150
µA
VDD = VIN =3.465V
or 2.625V
VDD = VIN =3.465V
or 2.625V
VDD = 3.465V or 2.625V
−150
µA
−5
µA
VDDO = 3.3V ±5%
2.6
V
VDDO = 2.5V ±5%
1.8
V
VIN = 0V
VDD = 3.465V or 2.625V
VIN = 0V
VDDO = 3.3V ±5% or 2.5V
±5%
Output LOW Voltage(4)
0.5
V
Max.
Units
AC Electrical Characteristics(5)
VDDA = VDD =2.5V or 3.3V ±5%, VDDO = 2.5V or 3.3V ±5%, TA = –40°C to +75°C, unless noted.
Symbol
Parameter
Condition
Min.
Typ.
FOUT
Output Frequency
F_SEL[1:0] = 00
156.25
MHz
FOUT
Output Frequency
F_SEL[1:0] = 01
125
MHz
FOUT
Output Frequency
F_SEL[1:0] = 10
62.5
MHz
FOUT
Output Frequency
F_SEL[1:0] = 11
125
MHz
(6)
tSKEW
Output Skew
tJITTER
RMS Phase Jitter
156.25MHz
0.064
ps
tJITTER
RMS Phase Jitter
125MHz
0.065
ps
tJITTER
RMS Phase Jitter
62.5MHz
tR/tF
Output Rise/ Fall Time
20% to 80%
ODC
Output Duty Cycle
12
0.077
100
48
50
ps
ps
350
ps
52
%
Notes:
4.
Outputs terminated with 50Ω to VDD/2. See Parameters measurements 3.3V load test circuit.
5.
The circuit is designed to meet the AC specifications shown in the above table(s) after thermal equilibrium has been established.
6.
Defined as skew between outputs at the same supply voltage and with equal load conditions; Measured at the output differential crossing points.
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SM840002
Crystal Characteristics
Parameter
Condition
Mode of Oscillation
Frequency
Equivalent Series Resistance (ESR)
Shunt Capacitor, C0
Correlation Drive Level
12pF Load
Min.
Typ.
Max.
Fundamental, Parallel Resonant
25
50
3
7
100
300
Phase Noise Plot: 62.5MHz @ 3.3V
Units
MHz
Ω
pF
uW
Phase Noise Plot: 125MHz @ 3.3V
Phase Noise Plot: 156.25MHz @ 3.3V
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SM840002
Figure 1. Duty Cycle Timing
Figure 2. All Outputs Rise/Fall Time
Figure 3. RMS Phase Noise/Jitter
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SM840002
Figure 4. LVCMOS Output Load and Test Circuit
Figure 5. Crystal Input Interface
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SM840002
Package Information
16-Pin TSSOP (K-16)
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com
Micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this data sheet. This
information is not intended as a warranty and Micrel does not assume responsibility for its use. Micrel reserves the right to change circuitry,
specifications and descriptions at any time without notice. No license, whether express, implied, arising by estoppel or otherwise, to any intellectual
property rights is granted by this document. Except as provided in Micrel’s terms and conditions of sale for such products, Micrel assumes no liability
whatsoever, and Micrel disclaims any express or implied warranty relating to the sale and/or use of Micrel products including liability or warranties
relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right
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© 2010 Micrel, Incorporated.
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