DS90C402 Dual Low Voltage Differential Signaling (LVDS) Receiver General Description Features The DS90C402 is a dual receiver device optimized for high data rate and low power applications. This device along with the DS90C401 provides a pair chip solution for a dual high speed point-to-point interface. The device is in a PCB space saving 8 lead small outline package. The receiver offers ± 100 mV threshold sensitivity, in addition to common-mode noise protection. n n n n n n Ultra Low Power Dissipation Operates above 155.5 Mbps Standard TIA/EIA-644 8 Lead SOIC Package saves PCB space VCM ± 1V center around 1.2V ± 100 mV Receiver Sensitivity Connection Diagram DS100006-1 Order Number DS90C402M See NS Package Number M08A Functional Diagram DS100006-2 TRI-STATE ® is a registered trademark of National Semiconductor Corporation. © 1998 National Semiconductor Corporation DS100006 www.national.com DS90C402 Dual Low Voltage Differential Signaling (LVDS) Receiver June 1998 Absolute Maximum Ratings (Note 1) Maximum Junction Temperature ESD Rating (Note 4) (HBM, 1.5 kΩ, 100 pF) (EIAJ, 0 Ω, 200 pF) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage (VCC) −0.3V to +6V −0.3V to (VCC + 0.3V) Input Voltage (RIN+, RIN−) −0.3V to (VCC + 0.3V) Output Voltage (ROUT) Maximum Package Power Dissipation @ +25˚C M Package 1025 mW Derate M Package 8.2 mW/˚C above +25˚C Storage Temperature Range −65˚C to +150˚C Lead Temperature Range Soldering (4 sec.) +260˚C +150˚C ≥ 3,500V ≥ 250V Recommended Operating Conditions Supply Voltage (VCC) Receiver Input Voltage Operating Free Air Temperature (TA) Min +4.5 GND Typ +5.0 Max +5.5 2.4 Units V V −40 +25 +85 ˚C Min Typ Max Units +100 mV Electrical Characteristics Over Supply Voltage and Operating Temperature ranges, unless otherwise specified. (Note 2) Symbol Parameter Conditions VTH Differential Input High Threshold VTL Differential Input Low Threshold IIN Input Current Pin VCM = + 1.2V RIN+, RIN− Output High Voltage mV −10 ±1 ±1 3.8 4.9 V IOH = −0.4mA, Inputs terminated 3.8 4.9 V IOH = −0.4mA, Inputs Open 3.8 4.9 V VIN = +2.4V VCC = 5.5V −10 VIN = 0V VOH −100 IOH = −0.4 mA, VID = +200 mV ROUT +10 µA +10 µA IOH = −0.4mA, Inputs Shorted 4.9 0.07 0.3 V −60 −100 mA 3.5 10 mA VOL Output Low Voltage IOL = 2 mA, VID = −200 mV IOS Output Short Circuit Current VOUT = 0V (Note 8) ICC No Load Supply Current Inputs Open −15 VCC V Switching Characteristics VCC = +5.0V ± 10%, TA = −40˚C to +85˚C (Notes 3, 4, 5, 6, 9) Symbol Parameter Conditions Min Typ Max Units CL = 5 pF, VID = 200 mV (Figure 1 and Figure 2) 1.0 3.40 6.0 ns 1.0 3.48 6.0 ns 0 0.08 1.2 ns 0 0.6 1.5 ns 5.0 ns Rise Time 0.5 2.5 ns Fall Time 0.5 2.5 ns tPHLD Differential Propagation Delay High to Low tPLHD Differential Propagation Delay Low to High tSKD Differential Skew |tPHLD − tPLHD| tSK1 Channel-to-Channel Skew (Note 5) tSK2 Chip to Chip Skew (Note 6) tTLH tTHL www.national.com 2 Parameter Measurement Information DS100006-4 FIGURE 1. Receiver Propagation Delay and Transition Time Test Circuit DS100006-5 FIGURE 2. Receiver Propagation Delay and Transition Time Waveforms Typical Application DS100006-8 FIGURE 3. Point-to-Point Application ceiver input pins should honor their specified operating input voltage range of 0V to +2.4V (measured from each pin to ground), exceeding these limits may turn on the ESD protection circuitry which will clamp the bus voltages. Fail-Safe Feature: The LVDS receiver is a high gain, high speed device that amplifies a small differential signal (20mV) to CMOS logic levels. Due to the high gain and tight threshold of the receiver, care should be taken to prevent noise from appearing as a valid signal. Applications Information LVDS drivers and receivers are intended to be primarily used in an uncomplicated point-to-point configuration as is shown in Figure 3. This configuration provides a clean signaling environment for the quick edge rates of the drivers. The receiver is connected to the driver through a balanced media which may be a standard twisted pair cable, a parallel pair cable, or simply PCB traces. Typically the characteristic impedance of the media is in the range of 100Ω. A termination resistor of 100Ω should be selected to match the media, and is located as close to the receiver input pins as possible. The termination resistor converts the current sourced by the driver into a voltage that is detected by the receiver. Other configurations are possible such as a multi-receiver configuration, but the effects of a mid-stream connector(s), cable stub(s), and other impedance discontinuities as well as ground shifting, noise margin limits, and total termination loading must be taken into account. The DS90C402 differential line receiver is capable of detecting signals as low as 100 mV, over a ± 1V common-mode range centered around +1.2V. This is related to the driver offset voltage which is typically +1.2V. The driven signal is centered around this voltage and may shift ± 1V around this center point. The ± 1V shifting may be the result of a ground potential difference between the driver’s ground reference and the receiver’s ground reference, the common-mode effects of coupled noise, or a combination of the two. Both re- The receiver’s internal fail-safe circuitry is designed to source/sink a small amount of current, providing fail-safe protection (a stable known state HIGH output voltage) for floating, terminated or shorted receiver inputs. 1. 3 Open Input Pins. The DS90C402 is a dual receiver device, and if an application requires only one receiver, the unused channel(s) inputs should be left OPEN. Do not tie unused receiver inputs to ground or any other voltages. The input is biased by internal high value pull up and pull down resistors to set the output to a HIGH state. This internal circuitry will guarantee a HIGH, stable output state for open inputs. www.national.com Applications Information Pin Descriptions (Continued) 2. Terminated Input. If the driver is disconnected (cable unplugged), or if the driver is in a power-off condition, the receiver output will again be in a HIGH state, even with the end of cable 100Ω termination resistor across the input pins. The unplugged cable can become a floating antenna which can pick up noise. If the cable picks up more than 10mV of differential noise, the receiver may see the noise as a valid signal and switch. To insure that any noise is seen as common-mode and not differential, a balanced interconnect should be used. Twisted pair cable will offer better balance than flat ribbon cable 3. Shorted Inputs. If a fault condition occurs that shorts the receiver inputs together, thus resulting in a 0V differential input voltage, the receiver output will remain in a HIGH state. Shorted input fail-safe is not supported across the common-mode range of the device (GND to 2.4V). It is only supported with inputs shorted and no external common-mode voltage applied. www.national.com 4 Pin No. Name Description 2, 6 ROUT Receiver output pin 3, 7 RIN+ Positive receiver input pin 4, 8 RIN- Negative receiver input pin 5 GND Ground pin 1 VCC Positive power supply pin, +5V ± 10% Ordering Information Operating Temperature Package Type/ Number Order Number −40˚C to +85˚C SOP/M08A DS90C402M RECEIVE MODE RIN+ − RIN− ROUT > +100 mV < −100 mV 100 mV > & > −100 mV H L X H = Logic High Level L = Logic Low level X = Indeterminant State Note 1: “Absolute Maximum Ratings” are those values beyond which the safety of the device cannot be guaranteed. They are not meant to imply that the devices should be operated at these limits. The table of “Electrical Characteristics” specifies conditions of device operation. Note 2: Current into device pins is defined as positive. Current out of device pins is defined as negative. All voltages are referenced to ground unless otherwise specified. Note 3: All typicals are given for: VCC = +5.0V, TA = +25˚C. Note 4: Generator waveform for all tests unless otherwise specified: f = 1 MHz, ZO = 50Ω, tr and tf (0%–100%) ≤ 1 ns for RIN. Note 5: Channel-to-Channel Skew is defined as the difference between the propagation delay of one channel and that of the others on the same chip with an event on the inputs. Note 6: Chip to Chip Skew is defined as the difference between the minimum and maximum specified differential propagation delays. Note 7: ESD Rating: HBM (1.5 kΩ, 100 pF) ≥ 3,500V EIAJ (0Ω, 200 pF) ≥ 250V Note 8: Output short circuit current (IOS) is specified as magnitude only, minus sign indicates direction only. Only one output should be shorted at a time, do not exceed maximum junction temperature specification. Note 9: CL includes probe and jig capacitance. Typical Performance Characteristics Output High Voltage vs Power Supply Voltage Output High Voltage vs Ambient Temperature DS100006-9 DS100006-10 5 www.national.com Typical Performance Characteristics (Continued) Output Low Voltage vs Power Supply Voltage Output Low Voltage vs Ambient Temperature DS100006-11 Output Short Circuit Current vs Power Supply Voltage DS100006-12 Output Short Circuit Current vs Ambient Temperature DS100006-13 Differential Propagation Delay vs Power Supply Voltage DS100006-14 Differential Propagation Delay vs Ambient Temperature DS100006-15 www.national.com DS100006-16 6 Typical Performance Characteristics (Continued) Differential Skew vs Power Supply Voltage Differential Skew vs Ambient Temperature DS100006-17 Transition Time vs Power Supply Voltage DS100006-18 Transition Time vs Ambient Temperature DS100006-19 DS100006-20 7 www.national.com DS90C402 Dual Low Voltage Differential Signaling (LVDS) Receiver Physical Dimensions inches (millimeters) unless otherwise noted 8-Lead (0.150" Wide) Molded Small Outline Package, JEDEC Order Number DS90C402M NS Package Number M08A LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMICONDUCTOR CORPORATION. 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