SY89645L Precision Low Skew, 1-to-4 LVCMOS/LVTTL-to-LVDS Fanout Buffer General Description The SY89645L is a 3.3V, fully differential, low skew, 1:4 LVDS fanout buffer that accepts LVTTL or LVCMOS inputs. It is capable of processing clock signals as fast as 650MHz. The LVDS signals are optimized to provide less than 40ps of output skew. The single-ended input takes a 3.3V LVTTL or LVCMOS, with a signal swing as small as 1.2V. The outputs are 280mV LVDS, with fast rise and fall times, guaranteed to be less than 400ps. The SY89645L operates from a 3.3V + 5% power supply and is guaranteed over the full industrial temperature range (–40°C to +85°C). The SY89645L is part of Micrel’s Precision Edge® product line. Data sheets and support documentation can be found on Micrel’s web site at: www.micrel.com. Precision Edge® Features • • • • • • • • • • Four identical LVDS outputs CLKIN accepts LVCMOS or LVTTL input levels Maximum output frequency: 650MHz Translates LVCMOS/LVTTL input signals to LVDS levels <40ps output-to-output skew <3ns propagation delay <400ps rise/fall times 3.3V ±5% operating supply Industrial temperature range: –40°C to +85°C Available in 20-pin TSSOP Block Diagram Applications • Communications • High-performance computing • Clock and data distribution Markets • • • • • Datacom Telecom Storage ATE Test and Measurement Precision Edge is a registered trademark of Micrel, 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 June 2011 M9999-060711 [email protected] or (408) 955-1690 Micrel, Inc. SY89645L Ordering Information Part Number Package Type Operating Range Package Marking Lead Finish NiPdAu Pb-Free NiPdAu Pb-Free SY89645LK4G K4-20-1 Industrial SY89645LK4G with Pb-Free bar-line indicator SY89645LK4GTR(2) K4-20-1 Industrial SY89645LK4G with Pb-Free bar-line indicator Notes: 1. Contact factory for die availability. Dice are guaranteed at TA = 25°C, DC Electricals only. 2. Tape and Reel. Pin Configuration 20-Pin TSSOP (K4-20-1) Pin Description Pin Number Pin Name 1, 9, 13 GND 2 CLK_EN 3, 5, 6, 7, 8 NC 4 CLKIN 10, 18 VCC 11, 12 /Q3, Q3 14, 15 /Q2, Q2 16, 17 /Q1, Q1 19, 20 /Q0, Q0 June 2011 Pin Function Power Supply Ground. Clock Enable. When LOW, Q outputs are forced low, /Q outputs are forced high. The synchronous nature of the enable function forces the output clocks to enable or disable following a rising and a falling edge of the input clock. When HIGH, clock outputs follow input clock. Internal 50kΩ pull-up resistor. VTH = VCC/2. See “Clock Enable (CLK_EN) Description” section. No Connect. LVCMOS/LVTTL Clock Input. This is the input to the device. Input accepts single-ended input signals as small as 1.2V. VTH = VCC/2. Internal 50kΩ pull-down resistor. Positive Supply Pins. Connect to 3.3V supply, bypass with low ESR capacitors, as close to pins as possible. LVDS Differential Output Pairs: Differential buffered copies of the input signal. The output swing is typically 280mV. Normally terminated with 100Ω across the output pairs (Q and /Q). See “LVDS Output Termination” section. 3 M9999-060711 [email protected] or (408) 955-1690 Micrel, Inc. SY89645L Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (VCC)............................... –0.5V to +4.6V Input Voltage (VIN) ............................ –0.5V to VCC +0.3V LVDS Output Current (IOUT)..................................±10mA Lead Temperature (soldering, 20sec.).................. 260°C Storage Temperature (Ts) ....................–65°C to +150°C Supply Voltage (VIN)............................. +3.135V to +3.465V Ambient Temperature (TA) ..........................–40°C to +85°C Package Thermal Resistance(3) TSSOP Junction-to-Ambient (θJA) Still-Air, Multi-Layer Board..............................75°C/W Junction-to-Case (θJC)...........................................21°C/W DC Electrical Characteristics(4) VDD = 3.3V ±5%, TA = –40°C to +85°C, unless otherwise stated. Symbol Parameter VCC Positive Supply Voltage Range ICC Power Supply Current Condition Min. Typ. Max. Units 3.135 3.3 3.465 V 43 60 mA Typ. Max. Units No Load LVCMOS/LVTTL DC Electrical Characteristics(4) VCC = 3.3V ±5%, TA = –40°C to +85°C, unless otherwise stated. Symbol Parameter Condition Min. VIH Input HIGH Voltage CLKIN, CLK_EN 2 VCC+0.15 VIL Input LOW Voltage CLKIN, CLK_EN -0.3 0.8 IIH Input HIGH Current CLKIN CLK_EN VCC = VIN = 3.465V IIL Input LOW Current CLKIN CLK_EN VCC = 3.465V, VIN = 0V VCC = 3.465V, VIN = 0V VCC = VIN = 3.465V 150 70 -70 -150 V V µA µA LVDS Outputs DC Electrical Characteristics(4) VCC = 3.3V ±5%, RL = 100Ω across the outputs, TA = –40°C to +85°C, unless otherwise stated. Symbol Parameter Condition Min. Typ. VOUT Output Voltage Swing See Figure 1a 200 280 VDIFF_OUT Differential Output Voltage Swing See Figure 1b VOCM Output Common Mode Voltage ΔVOCM Change in Common Mode Voltage Max. Units mV 400 560 1.125 1.25 1.375 mV V 5 25 mV 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 ratings 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. ψJB and θJA values are determined for a 4-layer board in still-air number, unless otherwise stated. 4. The circuit is designed to meet the DC specifications shown in the above table after thermal equilibrium has been established. June 2011 4 M9999-060711 [email protected] or (408) 955-1690 Micrel, Inc. SY89645L AC Electrical Characteristics(5) VCC = +3.3V ±5%, RL = 100Ω across the outputs, TA = –40°C to +85°C, unless otherwise stated. Symbol Parameter Condition Min. Typ. Max. Units 1.8 3.0 ns fMAX Maximum Frequency VOUT > 140mV 650 tPD Propagation Delay fMAX ≤ 650MHz, Note 6 1.0 Output Skew Note 7 40 ps Part-to-Part Skew Note 8 500 ps Output Rise/Fall Times (20% to 80%) fMAX ≤ 266MHz 400 ps tSKEW tr, tf Duty Cycle 150 MHz 250 fMAX ≤ 266MHz 45 55 % fMAX > 266MHz 40 60 % Notes: 5. All parameters measured at fMAX ≤ 650MHz, unless otherwise stated. 6. Measured from VCC/2 of the input to the differential output crossing point. 7. Defined as skew between outputs at the same supply voltage and with equal load conditions. Measured at VCC/2 of the input to the differential output crossing point. 8. Defined as skew between outputs on different devices operating at the same supply voltages and with equal load conditions. Using the same type of inputs on each device, the outputs are measured at the differential cross points. Timing Diagram Clock Enable (CLK_EN) Description The enable function is synchronous so that the clock outputs will be enabled or disabled following a rising and a falling edge of the input clock. June 2011 5 M9999-060711 [email protected] or (408) 955-1690 Micrel, Inc. SY89645L Typical Operating Techniques VCC = 3.3V ± 5%; VIN > 2V; TA = 25°C, RL = 100Ω across output pair; unless otherwise stated. June 2011 6 M9999-060711 [email protected] or (408) 955-1690 Micrel, Inc. SY89645L Single-Ended and Differential Swings Figure 1a. Single-Ended Voltage Swing Figure 1b. Differential Voltage Swing June 2011 7 M9999-060711 [email protected] or (408) 955-1690 Micrel, Inc. SY89645L LVDS Output Interface Applications LVDS specifies a small swing of 280mV typical, on a nominal 1.25V common mode above ground. The common mode voltage has tight limits to permit large variations in ground between an LVDS driver and receiver. Also, change in common mode voltage, as a function of data input, is kept to a minimum, to keep EMI low. Figure 2a. LVDS Differential Measurement Figure 2b. LVDS Common-Mode Measurement June 2011 8 M9999-060711 [email protected] or (408) 955-1690 Micrel, Inc. SY89645L Package Information 20-Pin TSSOP (MM) 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. Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 2006 Micrel, Incorporated. June 2011 9 M9999-060711 [email protected] or (408) 955-1690