SM840002
ClockWorks™ Dual 10-Gigabit/Gigabit
Ethernet 62.5MHz, 125MHz, or 156.25MHz, Ultra-Low Jitter LVCMOS Clock Frequency Synthesizer
General Description
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.
Features
• 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
www.DataSheet4U.com
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 SM840002KA SM840002KA
Notes: 1. 2. Devices are Green-, RoHS-, and PFOS-compliant. Tape and Reel.
Package Type K-16 TR
(2)
Operating Range
Package Marking 840002 840002
–40°C to +75°C –40°C to +75°C
K-16
Pin Configuration
16-Pin TSSOP (K-16)
www.DataSheet4U.com
November 2010
2
M9999-110810
[email protected] or (408) 955-1690
Micrel, Inc.
SM840002
Pin Description
Pin Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Pin Name F_SEL0 nXTAL_SEL TEST_CLK OE NC nPLL_SEL VDDA VDD XTAL_OUT XTAL_IN VDDO Q1 Q0 GND GND F_SEL1 I P P O I P O O P P I Pull-up LVCMOS LVCMOS 12pF Crystal 12pF Crystal Pull-Down Type I I I I Level Pull-Up Pull-Down Pull-Down Pull-Up Pin Function Frequency Select Pin. LVCMOS interface levels. Selects between XTAL and TEST_CLK Reference Input. When HIGH, selects TEST_CLK. When LOW, selects XTAL inputs. LVCMOS interface levels. Single-Ended LVCMOS Clock Input. 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. 2.5V or 3.3V Output Power Supply. No filter resistor needed. 2.5V or 3.3V Output Power Supply. Crystal Reference Output, no load caps needed. Crystal Reference Input, no load caps needed. 2.5V or 3.3V Output Power Supply. Single-Ended Output Clock. Single-Ended Output Clock. Ground. Ground. Frequency Select Pin. LVCMOS interface levels.
Configuring the SM840002
Xtal Frequency (MHz) 25 25 25 25 F_SEL1 0 0 1 1 F_SEL0 0 1 0 1 M Divider 125 130 130 130 N Divider 20 26 52 26 Output Frequency (MHz) 156.25 125 62.5 125
www.DataSheet4U.com
November 2010
3
M9999-110810
[email protected] or (408) 955-1690
Micrel, Inc.
SM840002
Absolute Maximum Ratings(1)
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
Operating Ratings(2)
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 VDD VDDA VDDO IDD IDDA IDDO Parameter Core Supply Voltage Analog Supply Voltage Output Supply Voltage Core Supply Current Analog Supply Current Output Supply Current No Load Condition Min. 2.375 2.375 2.375 Typ. 2.50 2.50 2.50 0.1 48 15 Max. 2.625 2.625 2.625 1 55 23 Units V V V mA mA mA
VDDA = VDD = 3.3V ±5%, VDDO = 3.3V ±5%, TA = –40°C to +75°C, unl.