Single, 3 V, CMOS, LVDS, High Speed Differential Driver ADN4661 ±15 kV ESD protection on output pins 600 Mbps (300 MHz) switching rates Flow-through pinout simplifies PCB layout 300 ps typical differential skew 700 ps maximum differential skew 1.5 ns maximum propagation delay 3.3 V power supply ±355 mV differential signaling Low power dissipation: 23 mW typical Interoperable with existing 5 V LVDS receivers Conforms to TIA/EIA-644 LVDS standards Industrial operating temperature range (−40°C to +85°C) Available in surface-mount (SOIC) package FUNCTIONAL BLOCK DIAGRAM VCC ADN4661 DOUT+ DIN DOUT– NC GND NC NC = NO CONNECT NC 07876-001 FEATURES Figure 1. APPLICATIONS Backplane data transmission Cable data transmission Clock distribution GENERAL DESCRIPTION The ADN4661 is a single, CMOS, low voltage differential signaling (LVDS) line driver offering data rates of over 600 Mbps (300 MHz) and ultra-low power consumption. It features a flow-through pinout for easy PCB layout and separation of input and output signals. The ADN4661 and a companion LVDS receiver offer a new solution to high speed point-to-point data transmission, and a low power alternative to emitter-coupled logic (ECL) or positive emitter-coupled logic (PECL). The device accepts low voltage TTL/CMOS logic signals and converts them to a differential current output of typically ±3.1 mA for driving a transmission medium such as a twistedpair cable. The transmitted signal develops a differential voltage of typically ±355 mV across a termination resistor at the receiving end, and this is converted back to a TTL/CMOS logic level by a line receiver. Rev. 0 Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 ©2008 Analog Devices, Inc. All rights reserved. ADN4661 TABLE OF CONTENTS Features .............................................................................................. 1 ESD Caution...................................................................................5 Applications ....................................................................................... 1 Pin Configuration and Function Descriptions..............................6 Functional Block Diagram .............................................................. 1 Typical Performance Characteristics ..............................................7 General Description ......................................................................... 1 Theory of Operation ...................................................................... 10 Revision History ............................................................................... 2 Applications Information .......................................................... 10 Specifications..................................................................................... 3 Outline Dimensions ....................................................................... 11 AC Characteristics........................................................................ 4 Ordering Guide .......................................................................... 11 Absolute Maximum Ratings............................................................ 5 REVISION HISTORY 12/08—Revision 0: Initial Version Rev. 0 | Page 2 of 12 ADN4661 SPECIFICATIONS VCC = 3 V to 3.6 V; RL = 100 Ω; CL = 15 pF to GND; all specifications TMIN to TMAX, unless otherwise noted. Table 1. Parameter 1, 2 LVDS OUTPUTS (DOUT+, DOUT−) Differential Output Voltage Change in Magnitude of VOD for Complementary Output States Offset Voltage Change in Magnitude of VOS for Complementary Output States Output High Voltage Output Low Voltage INPUTS (DIN, VCC) Input High Voltage Input Low Voltage Input High Current Input Low Current Input Clamp Voltage LVDS OUTPUT PROTECTION (DOUT+, DOUT−) Output Short-Circuit Current 3 LVDS OUTPUT LEAKAGE (DOUT+, DOUT−) Power-Off Leakage POWER SUPPLY Supply Current, Unloaded Supply Current, Loaded ESD PROTECTION DOUT+, DOUT− Pins All Pins Except DOUT+, DOUT− Symbol Min Typ Max Unit Test Conditions VOD ΔVOD 250 355 1 450 35 mV |mV| See Figure 2 and Figure 4 See Figure 2 and Figure 4 VOS ΔVOS 1.125 1.2 3 1.375 25 V |mV| See Figure 2 and Figure 4 See Figure 2 and Figure 4 1.4 1.1 1.6 V V See Figure 2 and Figure 4 See Figure 2 and Figure 4 VCC 0.8 +10 +10 V V μA μA V VIN = 3.3 V or 2.4 V VIN = GND or 0.5 V ICL = −18 mA −5.7 −8.0 mA DIN = VCC, DOUT+ = 0 V or DIN = GND, DOUT− = 0 V ±1 +10 μA VOUT = VCC or GND, VCC = 0 V 4.0 7 8.0 10 mA mA No load, DIN = VCC or GND DIN = VCC or GND kV kV Human body model Human body model VOH VOL 0.90 VIH VIL IIH IIL VCL 2.0 GND −10 −10 −1.5 IOS IOFF ICC ICCL −10 ±2 ±1 −0.6 ±15 ±4 1 Current into device pins is defined as positive. Current out of device pins is defined as negative. All voltages are referenced to ground except VOD, ΔVOD, and ΔVOS. The ADN4661 is a current mode device and functions within data sheet specifications only when a resistive load is applied to the driver outputs. Typical range is 90 Ω to 110 Ω. 3 Output short-circuit current (IOS) is specified as magnitude only; minus sign indicates direction only. 2 Rev. 0 | Page 3 of 12 ADN4661 AC CHARACTERISTICS VCC = 3 V to 3.6 V; RL = 100 Ω; CL 1 = 15 pF to GND; all specifications TMIN to TMAX, unless otherwise noted. Table 2. Parameter 2 Differential Propagation Delay High to Low Differential Propagation Delay Low to High Differential Pulse Skew |tPHLD − tPLHD| 5 Differential Part-to-Part Skew 6 Differential Part-to-Part Skew 7 Rise Time Fall Time Maximum Operating Frequency 8 Symbol tPHLD tPLHD tSKD1 tSKD3 tSKD4 tTLH tTHL fMAX Min 0.3 0.3 0 0 0 0.2 0.2 Typ 0.8 1.1 0.3 Max 1.5 1.5 0.7 1.0 1.2 1.0 1.0 0.5 0.5 350 Conditions/Comments 3, 4 See Figure 3 and Figure 4 See Figure 3 and Figure 4 See Figure 3 and Figure 4 See Figure 3 and Figure 4 See Figure 3 and Figure 4 See Figure 3 and Figure 4 See Figure 3 and Figure 4 See Figure 3 Unit ns ns ns ns Ns ns ns MHz 1 CL includes probe and jig capacitance. AC parameters are guaranteed by design and characterization. Generator waveform for all tests, unless otherwise specified: f = 50 MHz, ZO = 50 Ω, tTLH ≤ 1 ns, and tTHL ≤ 1 ns. 4 All input voltages are for one channel unless otherwise specified. Other inputs are set to GND. 5 tSKD1 = |tPHLD − tPLHD| is the magnitude difference in differential propagation delay time between the positive going edge and the negative going edge of the same channel. 6 tSKD3, differential part-to-part skew, is defined as the difference between the minimum and maximum specified differential propagation delays. This specification applies to devices at the same VCC and within 5°C of each other within the operating temperature range. 7 tSKD4, differential part-to-part skew, is the differential channel-to-channel skew of any event between devices. This specification applies to devices over recommended operating temperatures and voltage ranges, and across process distribution. tSKD4 is defined as |maximum − minimum| differential propagation delay. 8 fMAX generator input conditions: tTLH = tTHL < 1 ns (0% to 100%), 50% duty cycle, 0 V to 3 V. Output criteria: duty cycle = 45% to 55%, VOD > 250 mV, all channels switching. 2 3 Test Circuits and Timing Diagrams DOUT+ VCC VCC RL/2 DIN V VOS V VOD 07876-002 RL/2 DOUT– Figure 2. Test Circuit for Driver VOD and VOS VCC DOUT+ CL SIGNAL GENERATOR DIN DOUT– 50Ω 07876-003 CL NOTES 1. CL INCLUDES PROBE AND JIG CAPACITANCE. Figure 3. Test Circuit for Driver Propagation Delay, Transition Time, and Maximum Operating Frequency 3V DIN 1.5V 0V tPLHD tPHLD VOD DOUT– VOH 0V (DIFFERENTIAL) VOL DOUT+ 80% 0V VDIFF = DOUT+ – DOUT– tTLH 20% tTHL Figure 4. Driver Propagation Delay and Transition Time Waveforms Rev. 0 | Page 4 of 12 07876-004 VDIFF ADN4661 ABSOLUTE MAXIMUM RATINGS TA = 25°C, unless otherwise noted. All voltages are relative to their respective ground. Table 3. Parameter VCC to GND Input Voltage (DIN) to GND Output Voltage (DOUT+, DOUT−) to GND Short-Circuit Duration (DOUT+, DOUT−) to GND Operating Temperature Range Industrial Storage Temperature Range Junction Temperature (TJ max) Power Dissipation SOIC Package θJA Thermal Impedance Reflow Soldering Peak Temperature Pb-Free Rating −0.3 V to +4 V −0.3 V to VCC + 0.3 V −0.3 V to VCC + 0.3 V Continuous Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ESD CAUTION −40°C to +85°C −65°C to +150°C 150°C (TJ max − TA)/θJA 149.5°C/W 260°C ± 5°C Rev. 0 | Page 5 of 12 ADN4661 VCC 1 DIN 2 NC 3 ADN4661 TOP VIEW GND 4 (Not to Scale) 8 DOUT– 7 DOUT+ 6 NC 5 NC NC = NO CONNECT 07876-005 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS Figure 5. Pin Configuration Table 4. Pin Function Descriptions Pin No. 1 Mnemonic VCC 2 3 4 5 6 7 8 DIN NC GND NC NC DOUT+ DOUT− Description Power Supply Input. The part can be operated from 3.0 V to 3.6 V, and the supply should be decoupled with a 10 μF solid tantalum capacitor in parallel with a 0.1 μF capacitor to GND. Driver Logic Input. No Connect. This pin should be left unconnected. Ground. Reference point for all circuitry on the part. No Connect. This pin should be left unconnected. No Connect. This pin should be left unconnected. Noninverting Output Current Driver. When DIN is high, current flows out of DOUT+. When DIN is low, current flows into DOUT+. Inverting Output Current Driver. When DIN is high, current flows into DOUT−. When DIN is low, current flows out of DOUT−. Rev. 0 | Page 6 of 12 ADN4661 TYPICAL PERFORMANCE CHARACTERISTICS 325.0 1.414 1.413 3.2 3.3 3.4 3.5 3.6 POWER SUPPLY VOLTAGE, VCC (V) DIFFERENTIAL OUTPUT VOLTAGE, VOD (mV) 3.3 3.4 3.5 3.6 POWER SUPPLY VOLTAGE, VCC (V) OFFSET VOLTAGE, VOS (mV) 3.3 3.4 3.5 3.6 3.6 400 350 300 100 110 120 130 140 150 POWER SUPPLY VOLTAGE, VCC (V) TA = 25°C RL = 100Ω 1.251 1.250 1.249 3.0 07876-008 SHORT-CIRCUIT CURRENT, I OS (mA) –4.1 3.2 3.5 450 1.252 TA = 25°C VIN = GND OR VCC VOUT = 0V 3.1 3.4 Figure 10. Differential Output Voltage vs. Load Resistor –4.0 –4.2 3.0 3.3 LOAD RESISTOR, RL (Ω) Figure 7. Output Low Voltage vs. Power Supply Voltage –3.9 3.2 TA = 25°C VCC = 3.3V 250 90 07876-007 OUTPUT LOW VOLTAGE, VOL (V) 1.088 3.2 3.1 POWER SUPPLY VOLTAGE, VCC (V) 500 1.089 3.1 324.2 Figure 9. Differential Output Voltage vs. Power Supply Voltage TA = 25°C RL = 100Ω 1.087 3.0 324.4 324.0 3.0 Figure 6. Output High Voltage vs. Power Supply Voltage 1.090 324.6 07876-010 3.1 324.8 3.1 3.2 3.3 3.4 3.5 POWER SUPPLY VOLTAGE, VCC (V) Figure 8. Output Short-Circuit Current vs. Power Supply Voltage Figure 11. Offset Voltage vs. Power Supply Voltage Rev. 0 | Page 7 of 12 3.6 07876-011 1.412 3.0 TA = 25°C RL = 100Ω 07876-009 DIFFERENTIAL OUTPUT VOLTAGE, VOD (mV) TA = 25°C RL = 100Ω 07876-006 OUTPUT HIGH VOLTAGE, VOH (V) 1.415 ADN4661 1200 15 13 11 9 7 1 10 100 SWITCHING FREQUENCY (MHz) 1k DIFFERENTIAL PROPAGATION DELAY (ns) 8.0 7.5 7.0 3.3 POWER SUPPLY VOLTAGE, VCC (V) 3.6 DIFFERENTIAL SKEW, tSKD1 (ps) 7 6 85 3.6 tPLHD tPHLD 1000 –20 0 20 40 60 80 100 TA = 25°C f = 1MHz CL = 15pF RL = 100Ω 80 60 40 20 0 3.0 07876-014 POWER SUPPLY CURRENT, ICC (mA) 3.5 1100 100 VCC = 3.3V f = 1MHz VIN = 0V CL = 15pF RL = 100Ω 10 35 60 AMBIENT TEMPERATURE, TA (°C) 3.4 Figure 16. Differential Propagation Delay vs. Ambient Temperature 9 –15 3.3 AMBIENT TEMPERATURE, TA (°C) Figure 13. Power Supply Current vs. Power Supply Voltage 5 –40 3.2 VCC = 3.3V f = 1MHz CL = 15pF RL = 100Ω 900 –40 07876-013 POWER SUPPLY CURRENT, ICC (mA) 1200 TA = 25°C f = 1MHz VIN = 0V TO 3V CL = 15pF RL = 100Ω 8 3.1 Figure 15. Differential Propagation Delay vs. Power Supply Voltage 8.5 6.5 3.0 1000 POWER SUPPLY VOLTAGE, VCC (V) 10.0 9.0 tPLHD 900 3.0 Figure 12. Power Supply Current vs. Switching Frequency 9.5 tPHLD 07876-016 0.1 1100 3.1 3.2 3.3 3.4 3.5 POWER SUPPLY VOLTAGE, VCC (V) Figure 14. Power Supply Current vs. Ambient Temperature Figure 17. Differential Skew vs. Power Supply Voltage Rev. 0 | Page 8 of 12 3.6 07876-017 5 0.01 TA = 25°C f = 1MHz CL = 15pF RL = 100Ω 07876-015 DIFFERENTIAL PROPAGATION DELAY (ns) 17 TA = 25°C VCC = 3.3V VIN = 0V TO 3V CL = 15pF RL = 100Ω 07876-012 POWER SUPPLY CURRENT, ICC (mA) 19 ADN4661 400 VCC = 3.3V f = 1MHz CL = 15pF RL = 100Ω TRANSITION TIME (ps) 40 30 20 380 tTLH 360 tTHL –20 0 20 40 60 80 100 AMBIENT TEMPERATURE, TA (°C) 320 –40 380 tTLH tTHL 3.1 3.2 3.3 3.4 3.5 POWER SUPPLY VOLTAGE, VCC (V) 3.6 07876-019 340 320 3.0 20 40 60 80 Figure 20. Transition Time vs. Ambient Temperature TA = 25°C f = 1MHz CL = 15pF RL = 100Ω 360 0 AMBIENT TEMPERATURE, TA (°C) Figure 18. Differential Skew vs. Ambient Temperature 400 –20 Figure 19. Transition Time vs. Power Supply Voltage Rev. 0 | Page 9 of 12 100 07876-020 0 –40 TRANSITION TIME (ps) VCC = 3.3V f = 1MHz CL = 15pF RL = 100Ω 340 10 07876-018 DIFFERENTIAL SKEW, tSKD1 (ps) 50 ADN4661 THEORY OF OPERATION When DIN is high (Logic 1), current flows out of the DOUT+ pin (current source) through RT and back to the DOUT− pin (current sink). At the receiver, this current develops a positive differential voltage across RT (with respect to the inverting input) and results in a Logic 1 at the receiver output. When DIN is low (Logic 0), DOUT+ sinks current and DOUT− sources current. A negative differential voltage across RT results in a Logic 0 at the receiver output. A current-mode device simply reverses a constant current between its two outputs, with no significant overlap currents. This is similar to emitter-coupled logic (ECL) and positive emitter-coupled logic (PECL), but without the high quiescent current of ECL and PECL. APPLICATIONS INFORMATION Figure 21 shows a typical application for point-to-point data transmission using the ADN4661 as the driver and the LVDS receiver. 0.1µF VCC ADN4661 Current-mode drivers offer considerable advantages over voltage mode drivers such as RS-422 drivers. The operating current remains fairly constant with increased switching frequency, whereas the current of voltage mode drivers increases exponentially in most cases. This is caused by the overlap as internal gates switch between high and low, which causes currents to flow from the device power supply to ground. Rev. 0 | Page 10 of 12 +3.3V TANTALUM DOUT+ + 10µF 0.1µF DIN+ GND +3.3V TANTALUM VCC LVDS RECEIVER RT 100Ω DOUT– DIN– DIN The output drive current is between ±2.5 mA and ±4.5 mA (typically ±3.55 mA), developing between ±250 mV and ±450 mV across a 100 Ω termination resistor. The received voltage is centered around the receiver offset of 1.2 V. Therefore, the noninverting receiver input for Logic 1 is typically (1.2 V + [355 mV/2]) = 1.377 V, and the inverting receiver input is (1.2 V − [355 mV/2]) = 1.023 V. For Logic 0, the inverting and noninverting output voltages are reversed. Note that because the differential voltage reverses polarity, the peak-to-peak voltage swing across RT is twice the differential voltage. + 10µF DOUT GND Figure 21. Typical Application Circuit 07876-021 The ADN4661 is a single line driver for low voltage differential signaling. It takes a single-ended 3 V logic signal and converts it to a differential current output. The data can then be transmitted for considerable distances, over media such as a twistedpair cable or PCB backplane, to an LVDS receiver, where it develops a voltage across a terminating resistor, RT. This resistor is chosen to match the characteristic impedance of the medium, typically around 100 Ω. The differential voltage is detected by the receiver and converted back into a single-ended logic signal. ADN4661 OUTLINE DIMENSIONS 5.00 (0.1968) 4.80 (0.1890) 8 1 5 6.20 (0.2441) 5.80 (0.2284) 4 1.27 (0.0500) BSC 0.25 (0.0098) 0.10 (0.0040) COPLANARITY 0.10 SEATING PLANE 0.50 (0.0196) 0.25 (0.0099) 1.75 (0.0688) 1.35 (0.0532) 0.51 (0.0201) 0.31 (0.0122) 45° 8° 0° 0.25 (0.0098) 0.17 (0.0067) 1.27 (0.0500) 0.40 (0.0157) COMPLIANT TO JEDEC STANDARDS MS-012-A A CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN. 012407-A 4.00 (0.1574) 3.80 (0.1497) Figure 22. 8-Lead Standard Small Outline Package [SOIC_N] Narrow Body (R-8) Dimensions shown in millimeters and (inches) ORDERING GUIDE Model ADN4661BRZ 1 ADN4661BRZ-REEL71 1 Temperature Range −40°C to +85°C −40°C to +85°C Package Description 8-Lead Standard Small Outline Package [SOIC-N] 8-Lead Standard Small Outline Package [SOIC-N] Z = RoHS Compliant Part. Rev. 0 | Page 11 of 12 Package Option R-8 R-8 ADN4661 NOTES ©2008 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D07876-0-12/08(0) Rev. 0 | Page 12 of 12