January 2006 LMH0034 SMPTE 292M / 259M Adaptive Cable Equalizer General Description Features The LMH0034 SMPTE 292M / 259M 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 1.485 Gbps and supports SMPTE 292M, SMPTE 344M and SMPTE 259M. n SMPTE 292M, SMPTE 344M and SMPTE 259M compliant n Supports DVB-ASI at 270 Mbps n High data rates: 143 Mbps to 1.485 Gbps n Equalizes up to 140 meters of Belden 1694A at 1.485 Gbps or up to 350 meters of Belden 1694A at 270 Mbps n Manual bypass, cable length indicator, and output mute with a programmable threshold n Single-ended or differential input n 50Ω differential outputs n Single 3.3V supply operation n 208mW typical power consumption with 3.3V supply n Replaces the GS1524 and GS1524A The LMH0034 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 combined carrier detect and output mute pin which mutes the output when no signal is present. A programmable mute reference is used to mute the output at a selectable level of signal degradation. A cable length indicator is provided to determine the amount of cable being equalized. Applications n SMPTE 292M, SMPTE 344M, and SMPTE 259M serial digital interfaces n Serial digital data equalization and reception n Data recovery equalization Typical Application 20173401 © 2006 National Semiconductor Corporation DS201734 www.national.com LMH0034 SMPTE 292M / 259M Adaptive Cable Equalizer PRELIMINARY LMH0034 Absolute Maximum Ratings (Note 1) Supply Voltage Input Voltage (all inputs) Storage Temperature Range Recommended Operating Conditions −0.5V to 3.6V −0.3V to VCC+0.3V Supply Voltage (VCC – VEE) 3.3V ± 5% −65˚C to +150˚C Input Coupling Capacitance 1.0 µF Junction Temperature +150˚C Lead Temperature (Soldering 4 Sec) AEC Capacitor (Connected between AEC+ and AEC-) 1.0 µF +260˚C Operating Free Air Temperature (TA) 0˚C to +85˚C Package Thermal Resistance θJA 16-pin SOIC θJC 16-pin SOIC +115˚C/W +105˚C/W ESD Rating (HBM) 8kV ESD Rating (MM) 250V DC Electrical Characteristics Over Supply Voltage and Operating Temperature ranges, unless otherwise specified (Notes 2, 3). Symbol Parameter VCMIN Input Common Mode Voltage VSDI Input Voltage Swing Conditions Reference At LMH0034 input, (Notes 4, 6) VCMOUT Output Common Mode Voltage VSDO Min SDI, SDI 50Ω load, differential CLI DC Voltage 0m cable 720 Carrier not present Min to mute outputs Supply Current (Note 7) www.national.com mVP-P 2.5 V 1.6 V MUTEREF 1.3 V 0.7 V CD/MUTE 2.6 V 0.4 3.0 V V 63 2 mVP−P V Max to force outputs active ICC 950 VCC – VSDO/2 Carrier present CD/MUTE Input Voltage V 750 MUTEREF Range CD/MUTE Output Voltage 800 Units CLI Max cable MUTEREF DC Voltage (floating) Max 1.9 SDO, SDO Output Voltage Swing Typ 2.0 V 77 mA Over Supply Voltage and Operating Temperature ranges, unless otherwise specified (Note 3). Symbol Parameter BRSDI Maximum Equalized Cable Length (with equalizer pathological) tr,tf Conditions Input Data Rate Reference Min SDI, SDI 143 Typ Max Units 1485 Mbps 270 Mbps, Belden 1694A, 0.2UI output jitter, (Note 4) 350 m 270 Mbps, Belden 8281, 0.2UI output jitter, (Note 4) 280 m 1.485 Gbps, Belden 1694A, 0.25UI output jitter, (Note 4) 140 m 1.485 Gbps, Belden 8281, 0.25UI output jitter, (Note 4) 100 m Output Rise Time, Fall Time 20% – 80%, (Note 4) 100 220 ps Mismatch in Rise/Fall Time (Note 4) 2 15 ps tOS Output Overshoot (Note 4) 1 5 % ROUT Output Resistance single-ended, (Note 5) RLIN Input Return Loss (Note 8) RIN Input Resistance single-ended CIN Input Capacitance single-ended, (Note 5) SDO, SDO SDI, SDI 15 50 Ω 18-20 dB 1.3 kΩ 1 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 Figures 1, 2. Note 8: Input return loss is dependent on board design. The LMH0034 meets this specification on the SD034 evaluation board from 5MHz to 1.5GHz. 3 www.national.com LMH0034 AC Electrical Characteristics LMH0034 Connection Diagram 20173403 16-Pin SOIC Order Number LMH0034MA See NS Package Number M16A Pin Descriptions Pin # Name Description 1 CLI Cable length indicator. Provides a voltage inversely proportional to the cable length being equalized. 2 VCC Positive power supply (+3.3V). 3 VEE Negative power supply (ground). 4 SDI Serial data true input. 5 SDI Serial data complement input. 6 VEE Negative power supply (ground). 7 AEC+ AEC loop filter external capacitor (1µF) positive connection. 8 AEC- AEC loop filter external capacitor (1µF) negative connection. 9 BYPASS Bypasses equalization and DC restoration when high. No equalization occurs in this mode. 10 MUTEREF Mute reference. Determines the maximum cable to be equalized before muting. May be unconnected for maximum equalization. 11 VEE Negative power supply (ground). 12 SDO Serial data complement output. 13 SDO Serial data true output. 14 VEE Negative power supply (ground). 15 VCC Positive power supply (+3.3V). 16 CD/MUTE Bi-directional carrier detect and output mute. CD/MUTE is high when no signal is present. If unconnected, MUTE is controlled automatically by carrier detect. To force MUTE on, tie to VCC. To disable MUTE, tie to GND. CD/MUTE has no function in BYPASS mode. www.national.com 4 LMH0034 Block Diagram 20173402 cable to equalize. As the applied MUTEREF voltage is increased, the amount of cable that can be equalized before carrier detect is de-asserted and the outputs are muted is decreased. MUTEREF may be left unconnected for maximum equalization before muting. 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 Carrier Detect / Mute block generates the carrier detect signal and controls the mute function of the output. This block utilizes the bi-directional CD/MUTE signal along with Mute Reference (MUTEREF). The Output Driver produces SDO and SDO. CARRIER DETECT / MUTE (CD/MUTE) Carrier Detect / Mute is bi-directional, serving as both a carrier detect (output function) and mute (input function). When used as an output, CD/MUTE determines if a valid signal is present at the LMH0034 input. If MUTEREF is used, the carrier detect threshold will be altered accordingly. CD/MUTE provides a high voltage when no signal is present at the LMH0034 input, and the outputs are automatically muted. CD/MUTE is low when a valid input signal has been detected, and the outputs are automatically enabled. As an input, CD/MUTE can be used to override the carrier detect and manually mute or enable the LMH0034 outputs. Applying a high input to CD/MUTE will mute the LMH0034 outputs. Applying a low input will force the outputs to be active regardless of the length of cable or the state of MUTEREF. INPUT INTERFACING The LMH0034 accepts either differential or single-ended input. The input must be AC coupled. Transformer coupling is not supported. The LMH0034 correctly handles equalizer pathological signals for standard definition and high definition serial digital video, as described in SMPTE RP 178 and RP 198, respectively. 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 REFERENCE (MUTEREF) The mute reference determines the amount of cable to equalize before automatically muting the outputs. This is set by applying a voltage inversely proportional to the length of 5 www.national.com LMH0034 Device Operation (Continued) 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 on National’s website: AN-1372, “CLC034 PCB Layout Techniques.” REPLACING THE GENNUM GS1524 The LMH0034 is form-fit-function compatible with the Gennum GS1524 and GS1524A. 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 1.485 Gbps data and Figure 2 shows supply current vs. Belden 1694A cable length for 270 Mbps data. 20173415 FIGURE 2. Supply Current vs. Belden 1694A Cable Length, 270 Mbps 20173413 FIGURE 1. Supply Current vs. Belden 1694A Cable Length, 1.485 Gbps www.national.com 6 LMH0034 SMPTE 292M / 259M Adaptive Cable Equalizer Physical Dimensions inches (millimeters) unless otherwise noted 16-Pin SOIC Order Number LMH0034MA NS Package Number M16A National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications. For the most current product information visit us at www.national.com. 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 AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. 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