LMH0024MA

LMH0024 3.3V SMPTE 259M / 344M Adaptive Cable Equalizer January 3, 2008 LMH0024 3.3V SMPTE 259M / 344M Adaptive Cable Equalizer General Description The LMH0024 SMPTE 259M / 344M adaptive cable equalizer is a monolithic integrated circuit for equalizing data transmitted over cable (or any media with similar dispersive loss characteristics). The equalizer operates over a wide range of data rates from 143 Mbps to 540 Mbps and supports SMPTE 259M and SMPTE 344M. The LMH0024 implements DC restoration to correctly handle pathological data conditions. DC restoration can be bypassed for low data rate applications. The equalizer is flexible in allowing either single-ended or differential input drive. Additional features include a mute pin which can be used to manually mute the output and a cable length indicator which determines the amount of cable being equalized. Features ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ SMPTE 259M and SMPTE 344M compliant Supports DVB-ASI at 270 Mbps Data rates: 143 Mbps to 540 Mbps Equalizes up to 350 meters of Belden 1694A at 270 Mbps Manual bypass, cable length indicator, and output mute Single-ended or differential input 50Ω differential outputs Single 3.3V supply operation Industrial temperature range: −40°C to +85°C 198mW typical power consumption with 3.3V supply Footprint compatible with the LMH0034 and the GS9064 Applications ■ SMPTE 259M and SMPTE 344M serial digital interfaces ■ Serial digital data equalization and reception ■ Data recovery equalization Typical Application 20172501 © 2008 National Semiconductor Corporation 201725 www.national.com LMH0024 Absolute Maximum Ratings (Note 1) Supply Voltage Input Voltage (all inputs) Storage Temperature Range Junction Temperature Lead Temperature (Soldering 4 Sec) Package Thermal Resistance  θJA 16-pin SOIC  θJC 16-pin SOIC ESD Rating (HBM) ESD Rating (MM) −0.5V to 3.6V −0.3V to VCC+0.3V −65°C to +150°C +150°C +260°C +115°C/W +105°C/W 8kV 250V Recommended Operating Conditions Supply Voltage (VCC – VEE) Input Coupling Capacitance AEC Capacitor (Connected between AEC+ and AEC-) Operating Free Air Temperature (TA) 3.3V ±5% 1.0 µF 1.0 µF −40°C to +85°C DC Electrical Characteristics Over Supply Voltage and Operating Temperature ranges, unless otherwise specified (Notes 2, 3). Symbol Parameter VCMIN VSDI VCMOUT VSDO Input Common Mode Voltage Input Voltage Swing Output Common Mode Voltage Output Voltage Swing CLI DC Voltage MUTE Input Voltage ICC Supply Current 50Ω load, differential 0m cable no signal Min to mute outputs Max to force outputs active (Note 7) 60 MUTE 3.0 2.0 77 CLI At LMH0024 input, (Notes 4, 6) SDO, SDO Conditions Reference SDI, SDI 720 Min Typ 1.9 800 VCC – VSDO/2 750 2.5 1.2 950 Max Units V mVP−P V mVP-P V V V V mA www.national.com 2 LMH0024 AC Electrical Characteristics Over Supply Voltage and Operating Temperature ranges, unless otherwise specified (Note 3). Symbol Parameter BRSDI Input Data Rate Maximum Equalized Cable Length (with equalizer pathological) 270 Mbps, Belden 1694A, 0.2UI output jitter, (Note 4) 270 Mbps, Belden 8281, 0.2UI output jitter, (Note 4) 540 Mbps, Belden 1694A, 0.2UI output jitter, (Note 4) 540 Mbps, Belden 8281, 0.2UI output jitter, (Note 4) tr,tf tOS ROUT RLIN RIN CIN Output Rise Time, Fall Time Mismatch in Rise/Fall Time Output Overshoot Output Resistance Input Return Loss Input Resistance Input Capacitance 20% – 80%, (Note 4) (Note 4) (Note 4) single-ended, (Note 5) (Note 8) single-ended single-ended, (Note 5) SDI, SDI 15 SDO, SDO Conditions Reference SDI, SDI Min 143 350 280 250 180 100 2 1 50 18-20 1.3 1 220 15 5 Typ Max 540 Units Mbps m m m m ps ps % Ω dB kΩ pF Note 1: "Absolute Maximum Ratings" are those parameter values beyond which the life and operation of the device cannot be guaranteed. The stating herein of these maximums shall not be construed to imply that the device can or should be operated at or beyond these values. The table of "Electrical Characteristics" specifies acceptable device operating conditions. Note 2: Current flow into device pins is defined as positive. Current flow out of device pins is defined as negative. All voltages are stated referenced to VEE = 0 Volts. Note 3: Typical values are stated for VCC = +3.3V and TA = +25°C. Note 4: Specification is guaranteed by characterization. Note 5: Specification is guaranteed by design. Note 6: The maximum input voltage swing assumes a nonstressing, DC-balance signal; specifically, the SMPTE-recommended color bar test signal. Pathological or other stressing signals may not be used. This specification is for 0m cable only. Note 7: Supply current depends on the amount of cable being equalized. The current is highest for short cable and decreases as the cable length is increased. Refer to Figure 1. Note 8: Input return loss is dependent on board design. The LMH0024 meets this specification on the SD024 evaluation board from 5MHz to 1.5GHz. 3 www.national.com LMH0024 Connection Diagram 20172503 16-Pin SOIC Order Number LMH0024MA See NS Package Number M16A Pin Descriptions Pin # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 CLI VCC VEE SDI SDI VEE AEC+ AECBYPASS NC VEE SDO SDO VEE VCC MUTE Name Description Cable length indicator. Provides a voltage inversely proportional to the cable length being equalized. Positive power supply (+3.3V). Negative power supply (ground). Serial data true input. Serial data complement input. Negative power supply (ground). AEC loop filter external capacitor (1µF) positive connection. AEC loop filter external capacitor (1µF) negative connection. Bypasses equalization and DC restoration when high. No equalization occurs in this mode. No connect. Negative power supply (ground). Serial data complement output. Serial data true output. Negative power supply (ground). Positive power supply (+3.3V). Output mute. To force SDO and SDO to mute, tie to VCC. To disable MUTE, tie to GND. Typical application is MUTE tied to GND to enable the outputs. MUTE must be tied either high or low; it may not be left unconnected. www.national.com 4 LMH0024 Block Diagram 20172502 Device Operation BLOCK DESCRIPTION The Equalizer Filter block is a multi-stage adaptive filter. If Bypass is high, the equalizer filter is disabled. The DC Restoration / Level Control block receives the differential signals from the equalizer filter block. This block incorporates a self-biasing DC restoration circuit to fully DC restore the signals. If Bypass is high, this function is disabled. The signals before and after the DC Restoration / Level Control block are used to generate the Automatic Equalization Control (AEC) signal. This control signal sets the gain and bandwidth of the equalizer filter. The loop response in the AEC block is controlled by an external 1µF capacitor placed across the AEC+ and AEC- pins. Cable Length Indicator (CLI) is derived from this block. The Output Driver produces SDO and SDO. SDO and SDO may be forced to mute by activating MUTE. CABLE LENGTH INDICATOR (CLI) The cable length indicator provides a voltage to indicate the length of cable being equalized. The CLI voltage decreases as the cable length increases. MUTE MUTE can be used to manually mute or enable the LMH0024 outputs. MUTE must be tied to a low-level input or ground for SDO and SDO to be active. Applying a high input to MUTE will mute the LMH0024 outputs. INPUT INTERFACING The LMH0024 accepts either differential or single-ended input. The input must be AC coupled. Transformer coupling is not supported. The LMH0024 correctly handles equalizer pathological signals for standard definition serial digital video, as described in SMPTE RP 178. OUTPUT INTERFACING The SDO and SDO outputs are internally loaded with 50Ω. They produce a 750 mVP-P differential output, or a 375 mVP-P single-ended output. Application Information PCB LAYOUT RECOMMENDATIONS Please refer to the following Application Note for the CLC034 on National's website: AN-1372, “LMH0034 PCB Layout Techniques.” The PCB layout techniques in this application note apply to the LMH0024 as well. REPLACING THE GENNUM GS9064 The LMH0024 is footprint compatible with the Gennum GS9064. Pin 16 (MUTE) of the LMH0024 must be connect to ground for correct operation. SUPPLY CURRENT VS. CABLE LENGTH The supply current (ICC) depends on the amount of cable being equalized. The current is highest for short cable and decreases as the cable length is increased. Figure 1 shows supply current vs. Belden 1694A cable length for 270 Mbps data. 5 www.national.com LMH0024 20172515 FIGURE 1. Supply Current vs. Belden 1694A Cable Length, 270 Mbps www.national.com 6 LMH0024 Physical Dimensions inches (millimeters) unless otherwise noted 16-Pin SOIC Order Number LMH0024MA NS Package Number M16A 7 www.national.com LMH0024 3.3V SMPTE 259M / 344M Adaptive Cable Equalizer Notes For more National Semiconductor product information and proven design tools, visit the following Web sites at: Products Amplifiers Audio Clock Conditioners Data Converters Displays Ethernet Interface LVDS Power Management Switching Regulators LDOs LED Lighting PowerWise Serial Digital Interface (SDI) Temperature Sensors Wireless (PLL/VCO) www.national.com/amplifiers www.national.com/audio www.national.com/timing www.national.com/adc www.national.com/displays www.national.com/ethernet www.national.com/interface www.national.com/lvds www.national.com/power www.national.com/switchers www.national.com/ldo www.national.com/led www.national.com/powerwise www.national.com/sdi www.national.com/tempsensors www.national.com/wireless WEBENCH Analog University App Notes Distributors Green Compliance Packaging Design Support www.national.com/webench www.national.com/AU www.national.com/appnotes www.national.com/contacts www.national.com/quality/green www.national.com/packaging www.national.com/quality www.national.com/refdesigns www.national.com/feedback Quality and Reliability Reference Designs Feedback THE CONTENTS OF THIS DOCUMENT ARE PROVIDED IN CONNECTION WITH NATIONAL SEMICONDUCTOR CORPORATION (“NATIONAL”) PRODUCTS. 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