LMH0341SQE/NOPB

LMH0041, LMH0051 LMH0071, LMH0341 www.ti.com SNLS272Q – APRIL 2007 – REVISED APRIL 2013 3 Gbps, HD, SD, DVB-ASI SDI Deserializer with Loopthrough and LVDS Interface Check for Samples: LMH0041, LMH0051, LMH0071, LMH0341 FEATURES DESCRIPTION • • • The LMH0341/0041/0071/0051 SDI Deserializers are part of TI’s family of FPGA-Attach SER/DES products supporting 5-bit LVDS interfaces with FPGAs. When paired with a host FPGA the LMH0341 automatically detects the incoming data rate and decodes the raw 5-bit data words compliant to any of the following standards: DVB-ASI, SMPTE 259M, SMPTE 292M, or SMPTE 424M. See Table 1 for details on which Standards are supported per device. 1 23 • • • • 5-Bit LVDS Interface No External VCO or Clock Required Reclocked Serial Loopthrough With Cable Driver Powerdown Mode 3.3V SMBus Configuration Interface Small 48-Pin WQFN Package Industrial Temperature range: -40°C to +85°C APPLICATIONS • SDI Interfaces for: – Video Cameras – DVRs – Video Switchers – Video Editing Systems KEY SPECIFICATIONS • • • Output compliant with SMPTE 259M-C, SMPTE 292M, SMPTE 424M and DVB-ASI (See Table 1) Typical power dissipation: 590 mW (loopthrough disabled, 3G datarate) 0.6 UI Minimum Input Jitter Tolerance The interface between the LMH0341 and the host FPGA consists of a 5-bit wide LVDS bus, an LVDS clock and an SMBus interface. No external VCOs or clocks are required. The LMH0341 CDR detects the frequency from the incoming data stream, generates a clean clock and transmits both clock and data to the host FPGA. The LMH0341, LMH0041 and LMH0071 include a serial reclocked loopthrough with integrated SMPTE compliant cable driver. Refer to Table 1 for a complete listing of single channel deserializers offered in this family. The FPGA-Attach SER/DES product family is supported by a suite of IP which allows the design engineer to quickly develop video applications using the SER/DES products. The product is packaged in a physically small 48 pin WQFN package. General Block Diagram RESET LOCK GPIO[2:0] DVB_ASI Loopthru_EN Control SDA SCK SMB_CS SMBus RXCLK CLK MUX CDR RXIN1 Data RX4 Bypassable 8b10b Decode RXIN0 Serial to Parallel 1:5 RX_MUX_SEL RX3 RX2 RX1 TXOUT RX0 LVDS Drivers SMPTE Cable Driver 1 2 3 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. TRI-STATE is a registered trademark of National Semiconductor Corporation. All other trademarks are the property of their respective owners. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2007–2013, Texas Instruments Incorporated LMH0041, LMH0051 LMH0071, LMH0341 SNLS272Q – APRIL 2007 – REVISED APRIL 2013 www.ti.com RX4- RX4+ RX3- RX3+ RX2- RX2+ RX1- RX1+ RX0- RX0+ RXCLK- RXCLK+ Connection Diagrams 48 47 46 45 44 43 42 41 40 39 38 37 VDD3V3 1 36 VDD3V3 Loopthru_EN 2 35 VDD2V5 GPIO_0 3 34 SMB_CS GPIO_1 4 33 SCK 32 SDA 31 LOCK 30 RESET 29 GND 28 VDDPLL LMH0341, LMH0041, LMH0071 RSVD_H 5 DVB_ASI 6 VDD2V5 7 GND 8 GND 9 GND 10 27 LF_CP GPIO_2 11 26 LF_REF RX_MUX_SEL 12 25 VDD2V5 TOP VIEW (not to scale) 48-pin WQFN Package 17 18 19 20 RSET VDD3V3 RXIN0+ RXIN0- VDD3V3 RXIN1+ RXIN1- 21 22 23 24 GND 16 GND 15 TXOUT- 14 TXOUT+ 13 DNC DAP = GND Figure 1. Connection Diagram for LMH0341 / LMH0041 / LMH0071 2 Submit Documentation Feedback Copyright © 2007–2013, Texas Instruments Incorporated Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 LMH0041, LMH0051 LMH0071, LMH0341 RX4+ RX3- RX3+ RX2- RX2+ RX1- RX1+ RX0- RX0+ RXCLK- RXCLK+ SNLS272Q – APRIL 2007 – REVISED APRIL 2013 RX4- www.ti.com 48 47 46 45 44 43 42 41 40 39 38 37 VDD3V3 1 36 VDD3V3 N/C 2 35 VDD2V5 GPIO_0 3 34 SMB_CS GPIO_1 4 33 SCK RSVD_H 5 32 SDA DVB_ASI 6 31 LOCK VDD2V5 7 30 RESET GND 8 29 GND GND 9 28 VDDPLL GND 10 27 LF_CP GPIO2 11 26 LF_REF RX_MUX_SEL 12 25 VDD2V5 LMH0051 TOP VIEW (not to scale) 48-pin WQFN Package DNC 22 23 24 GND 21 GND 20 DNC 19 RXIN1- 18 RXIN1+ 17 VDD3V3 16 RXIN0- RSET 15 RXIN0+ 14 VDD3V3 13 GND DAP = GND Figure 2. Connection Diagram for LMH0051 Copyright © 2007–2013, Texas Instruments Incorporated Submit Documentation Feedback Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 3 LMH0041, LMH0051 LMH0071, LMH0341 SNLS272Q – APRIL 2007 – REVISED APRIL 2013 www.ti.com PIN DESCRIPTIONS Pin Name Type Description RX[4:0]+ RX[4:0]- Output, LVDS LVDS Data Output Pins Five channel wide DDR interface. RXCLK+ RXCLK- Output, LVDS LVDS Clock Output Pins DDR Interface. RXIN0+ RXIN0- Input, Differential Serial differential input Pins Channel 0 RXIN1+ RXIN1- Input, Differential Serial differential input Pins Channel 1 LVDS Input Interface Serial Data Inputs Loopthrough Serial Output TXOUT+ Output, CML Serial Digital Interface Output Pin Non-Inverting Output TXOUT- Output, CML Serial Digital Interface Output Pin Inverting Output SDA I/O, LVCMOS SMBus Data I/O Pin SCK Input, LVCMOS SMBus Clock Input Pin SMB_CS Input, LVCMOS SMBus Chip Select Input Pin Device is selected when High. SMBus Interface Control and Configuration Pins RESET Input, LVCMOS Reset Input Pin H = normal mode L = device in RESET LOCK Output, LVCMOS PLL LOCK Status Output H = unlock condition L = PLL is Locked DVB_ASI Input, LVCMOS DVB_ASI Select Input H = DVB_ASI Mode enabled L = Normal Mode enabled Loopthru_EN Input, LVCMOS Loopthrough enable Input H=Reclocked Loopthrogh active L=Reclocked Loopthrough disabled RX_MUX_SEL Input, LVCMOS Input multiplexer select H=RXIN1 selected L=RXIN0selected GPIO[2:0] I/O, LVCMOS General Purpose Input / Output Software configurable I/O pins. RSVD_H Input, LVCMOS Configuration Input – Must tie High Pull High via 5 kΩ resistor to VDD3V3 RSET Input Serial Loopthrough Output Amplitude Control Resistor connected from this pin to ground to set the signal amplitude. Nominally 7.87kΩ for 800mV output (SMPTE). LF_CP Input Loop Filter Connection Analog Inputs LF_REF Loop Filter Reference DNC Do Not Connect – Leave Open Power Supply and Ground VDD3V3 Power 3.3V Power Supply connection VDDPLL Power 3.3V PLL Power Supply connection VDD2V5 Power 2.5V Power Supply connection GND Ground Ground connection – The DAP (large center pad) is the primary GND connection for the device and must be connected to Ground along with the GND pins. 4 Submit Documentation Feedback Copyright © 2007–2013, Texas Instruments Incorporated Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 LMH0041, LMH0051 LMH0071, LMH0341 www.ti.com SNLS272Q – APRIL 2007 – REVISED APRIL 2013 Table 1. Feature Table Device LMH0341 SMPTE 424M Support SMPTE 292M Support SMPTE 259M Support DVB-ASI Support Active Loopthrough × × × × × × × × × × × × × × LMH0041 LMH0071 LMH0051 × Copyright © 2007–2013, Texas Instruments Incorporated Submit Documentation Feedback Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 5 LMH0041, LMH0051 LMH0071, LMH0341 SNLS272Q – APRIL 2007 – REVISED APRIL 2013 www.ti.com These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. Absolute Maximum Ratings (1) (2) −0.3V to +4.0V Supply Voltage (VDD3V3) Supply Voltage(VDD2V5) –0.3V to +3.0V LVCMOS input voltage −0.3V to (VDD3V3+0.3V) LVCMOS output voltage −0.3V to (VDD3V3+0.3V) SMBus I/O Voltage –0.3V to +3.6V LVDS Input Voltage 0.3V to 3.6V Junction Temperature +150°C Storage Temperature −65° to 150°C Lead Temperature—Soldering 4 seconds +260°C Thermal Resistance— 26°C/W Junction to Ambient—θJA ESD Rating—Human Body Model, (1) (2) ≥±8KV 1.5 KΩ, 100 pF “Absolute Maximum Ratings” are the ratings beyond which the safety of the device cannot be ensured. It is not implied that the device will operate up to these limits. If Military/Aerospace specified devices are required, please contact the TI Sales Office/Distributors for availability and specifications. Recommended Operating Conditions Min Typ Max Units Supply Voltage (VDD3V3-GND) Parameter 3.135 3.3 3.465 V Supply Voltage (VDD2V5-GND) 2.375 2.5 2.625 V 100 mVP-P +85 °C Supply noise amplitude (10 Hz to 50 MHz) −40 Ambient Temperature +25 Case Temperature Input Data Rate 270 2970 Mbps LMH0041 270 1485 Mbps LMH0071 270 270 Mbps LMH0051 270 1485 Mbps 25 cm RSTERM — SMBus termination resistor value Ω 1000 Loopthrough Output Driver Pullup Resistor Termination Voltage (1) 6 °C LMH0341 LVDS PCB board trace length (mismatch 12dB to 3 GHz dB Typical Parameters measured at VDD=3.3V, TA=25°C. They are for reference purposes and are not production tested. Specification ensured by characterization LVDS Output Electrical Characteristics Over supply and Operating Temperature ranges unless otherwise specified. Symbol Parameter VOD Differential Output Voltage ΔVOD Change in VOD between complementary output states VOS Offset Voltage ΔVOS Change in VOS between complementary output states IOS Output Short Circuit Current (1) 8 Condition RL = 100Ω (1) Min 230 1.125 VOUT = 0V, RL = 100Ω Typ 1.25 Max Units 310 mV 35 mV 1.375 V 35 mV —50 mA Typical Parameters measured at VDD=3.3V, TA=25°C. They are for reference purposes and are not production tested. Submit Documentation Feedback Copyright © 2007–2013, Texas Instruments Incorporated Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 LMH0041, LMH0051 LMH0071, LMH0341 www.ti.com SNLS272Q – APRIL 2007 – REVISED APRIL 2013 LVDS Switching Characteristics Over supply and Operating Temperature ranges unless otherwise specified. Symbol Parameter (1) Condition Min tROTR LVDS Low to High Transition time tROTF LVDS High to Low Transition time tROCP Receiver output clock period tRODC RxCLKOUT Duty Cycle tROCH RxCLKOUT high time tROCL RxCLKOUT low time tRBIT Receiver output bit width tDVBC tDVAC RX data transition to RXCLK transition See Receiver timing specifications (2) RXCLK transition to RX data transition tROJR Receiver output Random Jitter tROJT Peak-to-Peak Receiver Output Jitter tRD Receiver Propagation Delay See Figure 5 Receiver (LVDS Interface) Propagation Delay tRLA Receiver Link Acquisition Time From device reset or change in input data rate to locked condition tLVSK LVDS Output Skew LVDS Differential Output Skew between + and − pins (1) (2) (3) Typ Max Units See Figure 3 LVDS Switching times 300 ps 300 ps RxCLKOUT is DDR. If divide by 4 is enabled, the output clock period will be doubled 2T ns 45 See Receiver timing specifications 50 55 1.51 % ns 1.51 ns T ns 650 ps 650 ps Receiver output intrinsic random jitter. Bit error rate ≤ 10-15. Alternating 10 pattern. RMS (3) 2.5 (3) ps 70 125 ps 24 ms 12 T 20 ps Typical Parameters measured at VDD=3.3V, TA=25°C. They are for reference purposes and are not production tested. Specification Characterized at 2.97 Gbps, 1.485 Gbps and 270 Mbps, production tested at 270 Mbps only Specification ensured by characterization t ROCL tROCH 80% 80% RXCLKOUT 20% 20% tROTR tROTF RX[4:0] t DVBC t DVBC t DVAC t DVAC Figure 3. LVDS Switching Times Copyright © 2007–2013, Texas Instruments Incorporated Submit Documentation Feedback Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 9 LMH0041, LMH0051 LMH0071, LMH0341 SNLS272Q – APRIL 2007 – REVISED APRIL 2013 www.ti.com SMBus Input Electrical Characteristics Over supply and Operating Temperature ranges unless otherwise specified. Symbol Parameter Condition VSIL Data, Clock Input Low Voltage VSIH Data, Clock Input High Voltage VSDD Nominal Bus Voltage VOL Output Low voltage Min Typ (2) Input Leakage per bus segment See ISLEAKP Input Leakage per pin SCK and SDA pins CSI Capacitance for SMBdata and SMBclk See Max Units 0.8 V 2.1 VSDD V 2.375 3.465 V 0.3 V −200 200 μA −10 10 μA 10 pF IOL=2mA ISLEAKB (1) (2) (3) (1) (2) (3) Typical Parameters measured at VDD=3.3V, TA=25°C. They are for reference purposes and are not production tested. Recommended value—Parameter is not tested. Recommended maximum capacitance load per bus segment is 400 pF. SMBus Switching Characteristics Over supply and Operating Temperature ranges unless otherwise specified. Symbol Parameter (1) Condition Min Typ Max Units 100 kHz fSMB Bus Operating Frequency 10 tBUF Bus free time between stop and start condition 4.7 μs tSU:CS Minimum time between SMB_CS being active and Start condition (2) 30 ns tH:CS Minimum time between stop condition and releasing SMB_CS (2) 100 ns tHD:STA Hold time after (repeated) start condition. After this period, the first clock is generated 4.0 μs tSU:STA Repeated Start condition setup time 4.7 μs tSU:STO Stop Condition setup time 4.0 μs tHD:DAT Data hold time 300 ns tSU:DAT Data setup time 250 ns tLOW Clock Low Period 4.7 μs tHIGH Clock high time 4.0 tPOR Time in which a device must be operational after power on (1) (2) At ISPULLUP = MAX 50 μs 500 ms Typical Parameters measured at VDD=3.3V, TA=25°C. They are for reference purposes and are not production tested. Specification ensured by characterization tSU:CS SMB_CS tLOW tR tH:CS tHIGH SCK tHD:STA tBUF tHD:DAT tF tSU:STA tSU:DAT tSU:STO SDA SP ST SP ST Figure 4. SMBus Timing Parameters 10 Submit Documentation Feedback Copyright © 2007–2013, Texas Instruments Incorporated Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 LMH0041, LMH0051 LMH0071, LMH0341 www.ti.com SNLS272Q – APRIL 2007 – REVISED APRIL 2013 SDI Output Switching Characteristics (LMH0341 / LMH0041 / LMH0071) Over supply and Operating Temperature ranges unless otherwise specified. Symbol Parameter (1) Condition Min SDI Output Datarate tr 270 SDI Output Rise Time SDI Output Fall Time MHz 135 ps DR=1.485 Gbps (2) 145 DR=2.97 Gbps 400 1000 (2) DR = 270 Mbps (2) Mismatch between Rise and Fall times tSD Propagation Delay Latency tJ Peak to Peak Output Jitter 2.97 Gbps 400 ps 145 ps 1000 ps 25 ps 1.485 Gbps (2) 30 ps 270 Mbps (2) 100 ps tCIP 2.97 Gbps (2) 270 Mbps (2) (3) ns 25 (3) (3) VOD SDI Output Voltage(Loopthrough Output) Into 75Ω Load RL Output Return Loss Measured 5 MHz to 1483 MHz (2) (1) (2) (3) 135 (2) 1.485 Gbps (2) tOS Units 2970 DR=1.485 Gbps (2) Δtt Max DR=2.97 Gbps (2) DR=270 Mbps (2) tf Typ 720 40 35 50 65 110 800 880 15 dB (2) Output Overshoot mV 5 % Typical Parameters measured at VDD=3.3V, TA=25°C. They are for reference purposes and are not production tested. Specification ensured by characterization Measured in accordance with SMPTE RP184. Symbol N-1 Symbol N+1 Symbol N Symbol N+3 Symbol N+2 Symbol N+4 RXIN tRD RXCLK RX[0..4] Symbol N-4 Symbol N-3 Symbol N-2 Symbol N-1 Symbol N T Figure 5. Receiver (LVDS Interface) Propagation Delay Copyright © 2007–2013, Texas Instruments Incorporated Submit Documentation Feedback Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 11 LMH0041, LMH0051 LMH0071, LMH0341 SNLS272Q – APRIL 2007 – REVISED APRIL 2013 www.ti.com FUNCTIONAL DESCRIPTION DEVICE OPERATION The DES is used in digital video signal origination equipment. It is intended to be operated in conjunction with an FPGA host which processes data received by the SER, and converts the five bit output data to an appropriate parallel video format — usually 10 or 20 bits wide. In most applications, the input data to the DES will be data compliant with DVB ASI, SMPTE 259M-C, SMPTE 292M or SMPTE 424M, and the decoding will be done by the IP provided by TI or similar IP to result in a decoded output. TI offers IP in source code format to perform the appropriate decoding of the data, as well as evaluation platforms to assist in the development of target applications. For more information please contact your local TI Sales Office/Distributor POWER SUPPLIES The DES has several power supply pins, at 2.5V as well as 3.3V. It is important that these pins all be connected, and properly bypassed. Bypassing should consist of parallel 4.7μF and 0.1μF capacitors as a minimum, with a 0.1μF capacitor on each power pin. The device has a large contact in the center of the bottom of the package. This contact must be connected to the system GND as it is the major ground connection for the device. A 22 μF capacitor is required on the VDDPLL pin which is connected to the 3.3V rail Discrete bypassing is ineffective above 30 MHz to 50 MHz in power plane-based distribution systems. Above this frequency range, the intrinsic capacitance of the power-ground system can be used to provide additional RF bypassing. To make the best use of this, make certain that there are PCB layers dedicated to the Power supplies and to GND, and that they are placed next to each other to provide a distributed capacitance between power and GND. The DES will work best when powered from linear regulators. The output of linear regulators is generally cleaner with less noise than switching regulators. Output filtering and power system frequency compensation are generally simpler and more effective with linear regulators. Low dropout linear regulators are available which can usually operate from lower input voltages such as logic power supplies, thereby reducing regulator power dissipation. Cascading of low dropout regulators should not be done since this places the entire supply current load of both load systems on the first regulator in the cascade and increases its loading and thermal output. POWER UP The 3.3V power supply should be brought up before the 2.5V supply. The timing of the supply sequencing is not important. The device has a power on reset sequence which takes place once both power supplies are brought up. This sequence will reset all register contents to their default values, and will place the PLLs into link acquisition mode, attempting to lock on the RXIN0input. RESET There are three ways in which the device may be reset. There is an automatic reset which happens on power-up; there is a reset pin, which when brought low will reset the device, with normal operation resuming when the pin is driven high again. The third way to reset the device is a soft reset, implemented via a write to the reset register. This reset will put all of the register values back to their default values, except it will not affect the address register value if the SMBus default address has been changed. LVDS OUTPUTS The DES has LVDS outputs, compatible with ANSI/TIA/EIA-644. LVDS outputs expect to drive a 100Ω transmission line which is properly terminated at the host FPGA inputs. It is recommended that the PCB trace between the FPGA and the receiver be less than 25 cm. Longer PCB traces may introduce signal degradation as well as channel skew which could cause serialization errors. The LVDS outputs on the DES have a programmable output swing. The default condition is for the smaller size swing, in order to save power. If a larger amplitude output swing is desired, this can be effected through the use of register 0x27h 12 Submit Documentation Feedback Copyright © 2007–2013, Texas Instruments Incorporated Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 LMH0041, LMH0051 LMH0071, LMH0341 www.ti.com SNLS272Q – APRIL 2007 – REVISED APRIL 2013 LVDS OUTPUT TIMING The DES output timing, in it's default condition, is described in LVDS Switching Characteristics. The user has the ability to adjust the LVDS output timing to make it easier to latch into the host FPGA if desired. This is done via register 0x28h where both the clock to data timing may be adjusted, as well as changing the RXCLK from being a DDR clock to a clock at the rate of DDR/2 LOOP FILTER The DES has an internal PLL which is used to recover the embedded clock from the input data. The loop filter for this PLL has external components, and for optimum results in Serial Digital Interface applications, a capacitor and a resistor in series should be connected between pins 26 and 27 as shown in the typical interface circuit. DVB-ASI MODE DVB-ASI mode is enabled when the DVB-ASI pin is brought to a high state. When the DVB-ASI mode is enabled, an internal framer and 8b10b decoder is engaged such that the data appearing on RX0-RX3 will represent a nibble of the decoded 8b10b data. RX4 is an Idle character detect and can be used as an enable to allow the receiver to not write data into an external FIFO. RX4 is high if the data being presented on RX0-RX3 represents the idle character. The Least Significant Nibble of data is presented on the rising edge of RXCLK, and the most significant on the falling edge of RXCLK. The internal 8b10b decoder needs to receive up to 110 consecutive K28.5 characters to properly initialize and frame the data so that the decoded 8b10b data presented at the output of the device is correct. SDI INPUT INTERFACING The device has two inputs, one of which is selected via a multiplexer with the RX_MUX_SEL pin. Whichever input is selected will be routed to the clock recovery portion of the deserializer, and once it is reclocked, the signal will be fed to the loopthrough outputs. Most SDI interfaces require an equalizer to meet performance requirements. For HD-SDI and SD-SDI applications, the LMH0044 is an ideal equalizer to use for this. The LMH0044 is packaged in a small compact package and the outputs can be connected directly to the RXIN inputs of the LMH0041. The LMH0344 is pin compatible with the LMH0044 and will support 3 Gbps data, making it an ideal choice to accompany the LMH0341. VDD3V3 500 PF RXIN+ 500 PF 8 k5 8 k5 RXIN- 1005 Figure 6. Simplified SDI Input Circuit SWITCHING SDI INPUTS When the input to the DES is switched from one source to another, either via the internal 2:1 multiplexor on the inputs, or via an external crosspoint switch, there are a variety of behaviors possible If the input switch is between two signals operating at the same datarate, then in most cases, the DES will not lose lock. There will be a small number of words with corrupted data as the PLL slews it's phase to match the new input signal. Under some circumstances (dependent on phase difference between the inputs, temperature, etc) it is possible that the Copyright © 2007–2013, Texas Instruments Incorporated Submit Documentation Feedback Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 13 LMH0041, LMH0051 LMH0071, LMH0341 SNLS272Q – APRIL 2007 – REVISED APRIL 2013 www.ti.com PLL will lose lock, and then reacquire lock. This condition can be seen by monitoring the LOCK pin where a high going pulse will indicate a loss of lock condition. If a loss of lock happens, it will be for a time period of approximately 5ms before lock is reattained. In the invent that the switch on the input is between signals at different datarates — for example from a 270 Mbps signal to a 1.485 Gbps input, then the lock procedure is much more complex, and the lock time will be significantly longer. In either case, the IP that is processing the received signal will need to reestablish the proper framing of the words. SDI OUTPUT INTERFACING The serial loopthrough outputs provide low-skew complementary or differential signals. The output buffer is a current mode design, and as such has a high impedance output. To drive a 75Ω transmission line, a 75Ω resistor from each of the output pins to VDD2V5 should be connected. This resistor has two functions—it converts the current output to a voltage, which is used to drive the cable, and it acts as the back termination resistor for the transmission line. The output driver automatically adjusts its slew rate depending on the input datarate so that it will be in compliance with SMPTE 259M, SMPTE292M or SMPTE 424M as appropriate. In addition to output amplitude and rise/fall time specifications, the SMPTE specs require that SDI outputs meet an Output Return Loss (ORL) specification. There are parasitic capacitances that will be present both at the output pin of the device and on the application printed circuit board. To optimize the return loss, these must be compensated for, usually with a series network comprising a parallel inductor and resistor. The actual values for these components will vary from application to application, but the typical interface circuit shows values that would be a good starting point. TXOUT+ TXOUT2.5V 2.5V 24 mA Figure 7. Simplified SDI Output Circuit JITTER MANAGEMENT SMPTE 424M (the 3 Gbps standard) relaxed the requirements of SDI transmitters from 0.2UI to 0.3UI, which means that the challenge of receiving these signals error free is very difficult. The parameter of importance to determine if the DES will be able to receive the signal error free is the Jitter Tolerance. Figure 10 shows the LMH0341 Jitter tolerance curve with a 2.97 Gbps input — any signal which has less jitter than what is on the upper curve of Figure 10 will be able to be received by the DES. The lower line in the curve shows the SMPTE requirement for any receiver. There is a slight dip in the level at frequencies abive about 10MHz which is an artifact of the test equipment that was used to capture the data. Once the signal is received, the next concern as far as jitter goes is how much of the jitter that was on the input signal will be passed through to the RXCLK output. This is answered by the Jitter transfer characteristics. The Jitter transfer function is the ratio of the input jitter to the output jitter, measured as a function of frequency. The specification tables show two of the parameters related to this curve — δ is the jitter peaking and indicates what the maximum gain of the jitter is. Ideally δ is 0, but a lower number is better. If several devices are used in a system, and the frequency at which δ is maximum is the same for all of them, then the gains will multiply, and there is a risk that there will be excessive jitter accumulating at that frequency. The LMH0341 has very low Jitter peaking, so this should not be a concern. The other parameter of interest is λ which is the jitter transfer bandwidth. Jitter on the input at the 14 Submit Documentation Feedback Copyright © 2007–2013, Texas Instruments Incorporated Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 LMH0041, LMH0051 LMH0071, LMH0341 www.ti.com SNLS272Q – APRIL 2007 – REVISED APRIL 2013 frequency λ is attenuated by 3dB, and any jitter at frequencies greater than λ is attenuated by more than this. From a design standpoint, it means that you primarily only need to worry about the jitter at frequencies below λ. The LMH0341 adjusts it's loop bandwidth dependent on datarate, so for the lower datarates, it has a lower loop bandwidth.Figure 10 shows the jitter transfer curve of an LMH0341 with a 2.97 Gbps signal input, 0.5UI of input jitter, and nominal power supplies and temperature. INJECTED JITTER LEVEL 1000 100 LMH0341 Jitter Tolerance 10 1 SMPTE Jitter Tolerance Spec 0.1 1.E+02 1.E+04 1.E+06 1.E+08 1.E+03 1.E+05 1.E+07 1.E+09 FREQUENCY Figure 8. Jitter Tolerance Curve 5.00 0.00 P P-3dB -20 dB/decade f1 è BW JITTER FREQUENCY JITTER TRANSFER (dB) JITTER TRANSFER GAIN á -5.00 -10.00 -15.00 -20.00 -25.00 -30.00 -35.00 -40.00 1.00E+03 1.00E+04 1.00E+05 1.00E+06 1.00E+07 1.00E+08 FREQUENCY Figure 9. Jitter Transfer Curve Parameters Figure 10. Jitter Transfer Curve SMBus INTERFACE The configuration bus conforms to the System Management Bus (SMBus) 2.0 specification. SMBus 2.0 includes multiple options. The optional ARP (Address Resolution Protocol) feature is not supported. The I/O rail is 3.3V only and is not 5V tolerant. The use of the SMB_CS signal is recommended for applications with multi-drop applications (multiple devices to a host). The System Management Bus (SMBus) is a two wire interface designed for the communication between various system component chips. By accessing the control functions of the circuit via the SMBus, pin count is kept to a minimum while allowing a maximum amount of versatility. The SMBus has three pins to control it, there is an SMBus CS pin which enables the SMBus interface for the device, a Clock and a Data line. In applications where there might be several devices, the SDA and SCK pins can be bussed together and the individual devices to be communicated with may be selected via the CS pin The SCL and SDA are both open drain and are pulled high by external pullup resistors. The DES has several internal configuration registers which may be accessed via the SMBus. These registers are listed in Table 2 . Copyright © 2007–2013, Texas Instruments Incorporated Submit Documentation Feedback Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 15 LMH0041, LMH0051 LMH0071, LMH0341 SNLS272Q – APRIL 2007 – REVISED APRIL 2013 www.ti.com Transfer Of Data To The Device Via The SMBus During normal operation the data on SDA must be stable during the time when SCK is high. START / STOP / IDLE conditions— There are three unique states for the SMBus: START A HIGH to LOW transition on SDA while SCK is high indicates a message START condition, STOP A LOW to HIGH transition on SDA while SCK is high indicates a message STOP condition. IDLE If SCK and SDA are both high for a time exceeding tBUF from the last detected STOP condition or if they are high for a total exceeding the maximum specification for tHIGH then the bus will transfer to the IDLE state. SMBus Transactions A transaction begins with the host placing the DES SMBus into the START condition, then a byte (8 bits) is transferred, MSB first, followed by a ninth ACK bit. ACK bits are ‘0’ to signify an ACK, or ‘1’ to signify NACK, after this the host holds the SCL line low, and waits for the receiver to raise the SDA line as an ACKnowledge that the byte has been received. WRITING TO REGISTERS VIA THE SMBus INTERFACE To write a data value to a register in the DES, the host writes three bytes, the first byte is the device address—the device address is a 7 bit value, and if writing to the DES the last bit (LSB) is set to ‘0’ to signify that the operation is a write. The second byte written is the register address, and the third byte written is the data to be written into the addressed register. If additional data writes are performed, the register address is automatically incremented. At the end of the write cycle the host places the bus in the STOP state. READING FROM REGISTERS VIA THE SMBus INTERFACE To read the data value from a register, first the host writes the device address with the LSB set to a ‘0’ denoting a write, then the register address is written to the device. The host then reasserts the START condition, and writes the device address once again, but this time with the LSB set to a ‘1’ denoting a read, and following this the DES will drive the SDA line with the data from the addressed register. The host indicates that it has finished reading the data by asserting a ‘1’ for the ACK bit. After reading the last byte, the host will assert a ‘0’ for NACK to indicate to the DES that it does not require any more data. SMBus Device FPGA Host 3V3 SMB_CS SDA SCK LVCMOS GPIO SMBus Interface 3V3 Figure 11. SMBus Configuration 1 — Host to single device 16 Submit Documentation Feedback Copyright © 2007–2013, Texas Instruments Incorporated Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 LMH0041, LMH0051 LMH0071, LMH0341 www.ti.com SNLS272Q – APRIL 2007 – REVISED APRIL 2013 SMBus Device FPGA Host SMBus Device SMBus Device SMB_CS SDA SCK SMB_CS SDA SCK SMB_CS SDA LVCMOS GPIO SMBus Interface SCK 3V3 Figure 12. SMBus Configuration 2 — Host to multiple devices with SMB_CS signals SMBus Device SMBus Device SMBus Device SMB_CS SDA SCK SMB_CS SDA SMB_CS SDA LVCMOS GPIO SMBus Interface SCK 3V3 3V3 3V3 3V3 SCK FPGA Host Figure 13. SMBus Configuration 3 — Host to multiple devices with multiple SMBus Interfaces GENERAL PURPOSE I/O PINS (GPIO) The DES has three pins which can be configured to provide direct access to certain register values via a dedicated pin. For example if a particular application required fast action to the condition of the deserializer losing it’s input signal, the PCLK detect status bit could be routed directly to an external pin where it might generate an interrupt for the host processor. GPIO pins can be configured to be in TRI-STATE® (High Impedance) mode, the buffers can be disabled, and when used as inputs can be configured with a pullup resistor, a pulldown resistor or no input pin biasing at all. Each of the GPIO pins has a register to control it. For each of these registers, the upper 4 bits are used to define what function is desired of the GPIO pin with options being slightly different for each of the three GPIO pins. The pins can be used to monitor the status of various internal states of the LMH0040 device, to serve as an input from some external stimulus, and for output to control some external function. GPIO0 Functions • Allow for the output of a signal programmed by the SMBus • Allow the monitoring of an external signal via the SMBus • Monitor the status of the signal on input 0 GPIO1 Functions • Monitor Power On Reset Copyright © 2007–2013, Texas Instruments Incorporated Submit Documentation Feedback Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 17 LMH0041, LMH0051 LMH0071, LMH0341 SNLS272Q – APRIL 2007 – REVISED APRIL 2013 • • • www.ti.com Allow for the output of a signal programmed by the SMBus Allow the monitoring of an external signal via the SMBus Monitor the status of the signal on input 1 Monitor Lock condition of the input clock recovery PLL GPIO2 Functions • Allow for the output of a signal programmed by the SMBus • Allow the monitoring of an external signal via the SMBus • Provides a constant clock signal • LVDS TX Clock at 1/20 full rate • CDR Clock at 1/20 full rate Bits 2 and 3 are used to determine the status of the internal pullup/pulldown resistors on the device—they are loaded according to the following truth table: • 00: pullup and pulldown disabled • 01: pulldown enabled • 10: pullup enabled • 11: reserved Bit 1 is used to enable or disable the input buffer. If the GPIO pin is to be used as an output pin, then this bit must be set to a ‘0’ disabling the output. The LSB is used to switch the output between normal output state and high impedance mode. If the GPIO is to be used as an input pin, this bit must be set to ‘0’ placing the output in high Z mode. As an example, if you wanted to use the GPIO0 pin to monitor the status of the input signal on input 0, you would load register 02h with the value 0010 0001b VDD3V3 VDD3V3 p p Output Input n n Figure 14. Simplified LVCMOS Input Circuit Figure 15. Simplified LVCMOS Output Circuit POTENTIAL APPLICATIONS FOR GPIO PINS In addition to being useful debug tools while bringing a DES design up, there are other practical uses to which the GPIO pins can be put: Automatic Switching To Secondary Input If The Signal On The Primary Input Is Lost By setting GPIO0 to monitor the status of input0 when there is a signal present on input 0, the GPIO0 pin will go low when there is no signal present on the Input0 pin, if this signal is inverted and then used to drive the RX_MUX_SEL then if the input on Input0 is lost, the device will automatically switch to Input1. Another possible use of the GPIO pins is to provide access to external signals such as the CD output from an equalizer or the LOCK output from the DES itself via the SMBus, helping to minimize the number of connections between the DES and the FPGA. 18 Submit Documentation Feedback Copyright © 2007–2013, Texas Instruments Incorporated Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 LMH0041, LMH0051 LMH0071, LMH0341 www.ti.com SNLS272Q – APRIL 2007 – REVISED APRIL 2013 APPLICATION INFORMATION PCB LAYOUT RECOMMENDATIONS In almost all applications, the inputs to the DES will be driven by the output of an equalizer such as the LMH0044. You should follow the recommendations on the equalizer datasheet for the interface between the input connector and the equalizer—the DES will be placed between the equalizer and the FPGA. If the DES is too close to the equalizer, then there is a risk of crosstalk between the high speed digital outputs of the DES and the equalizer inputs. Conversely, if too far away then the interconnect between the equalizer and the DES may either pick up stray noise, or may broadcast noise since this is a very high speed signal. Be certain to treat the signal from the equalizer to the DES as a differential trace. If there is skew between the two conductors of the differential trace, not only might this cause difficulties for the DES receive circuitry, but having a phase difference between the sides of the pair makes the signal look and radiate like a common mode signal. If the loopthrough output is going to be used, it is advised that the DES be placed close to the Loopthrough output BNC connector, and the equalizer be placed close to the SDI Input BNC connector. This will minimize the lengths of the most critical connections. The DES includes a cable driver for the loopthrough output. The SMPTE Serial specifications have very stringent requirements for output return loss on drivers. The output return loss will be degraded by non-idealities in the connection between the DES and the output connector. All efforts should be taken to minimize the trace lengths for this area, and to assure that the characteristic impedance of this trace is 75Ω. The 75Ω termination resistor should be placed as close to the loopthrough output pin as is practicable. It is recommended that the PCB traces between the host FPGA and the DES be no longer than 10 inches (25cm) and that the traces be routed as differential pairs, with very tight matching of line lengths and coupling within a pair, as well as equal length traces for each of the six pairs. PCB DESIGN DO’S AND DON’TS DO Whenever possible dedicate an entire layer to each power supply whenever possible—this will reduce the inductance in the supply plane. DO use surface mount components whenever possible. DO place bypass capacitors close to each power pin. DON’T create ground loops—pay attention to the cutouts that are made in your power and ground planes to make sure that there are not opportunities for loops. DON’T allow discontinuities in the ground planes—return currents will follow the path of least resistance—for high frequency signals this will be the path of least inductance. DO place the Loopthrough outputs as close as possible to the edge of the PCB where it will connect to the outside world. DO make sure to match the trace lengths of all differential traces, both between the sides of an individual pair, and from pair to pair. DO remember that VIAs have significant inductance—when using a via to connect to a power supply or ground layer, two in parallel are better than one. DO connect the slug on the bottom of the package to a solid Ground connection. This contact is used for the major GND connection to the device as well as serving as a thermal via to keep the die at a low operating temperature. Copyright © 2007–2013, Texas Instruments Incorporated Submit Documentation Feedback Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 19 LMH0041, LMH0051 LMH0071, LMH0341 SNLS272Q – APRIL 2007 – REVISED APRIL 2013 www.ti.com 0 RETURN LOSS (dB) -10 SMPTE 424 Limit -20 -30 -40 Measured Evaluation Board Return Loss -50 -60 1.00E+07 1.00E+08 1.00E+09 1.00E+10 FREQUENCY Figure 16. Evaluation Board Loopthrough Output Return Loss TYPICAL SMPTE APPLICATIONS CIRCUIT A typical application circuit for the DES is shown in Figure 17. This circuit shows the LMH0341 3 Gbps deserializer, alternately this could employ the LMH0041 or LMH0071 deserializers in lower data rate SMPTE applications. The RX interface between the DES and the host FPGA is composed of a 5-bit LVDS Data bus and its LVDS clock. This is a point-to-point interface. Line termination should be provided by the FPGA device. If not, and external 100Ω resistor maybe used and should be located as close to the FPGA as possible to minimize stub lengths. Pairs should be of equal length to minimize any skew impact. The LVDS clock (RXCLK) uses both edges to transfer the data. An SMBus is also connected from the host FPGA to the DES. If the SMBus is shared, a chip select signal is used to select the device being addressed. The SCK and SDA signals require a pull up resistor. The SMB_CS is driven by a GPO signal from the FPGA. Depending on the FPGA I/O it may also require a pull up unless it is a push / pull output. Depending upon the application, several other Host GPIO signals maybe used. This includes the DVB_ASI and RESET input signals. If these pins are not used, then must be tied off to the desired state. The LOCK signal maybe used to monitor the DES. If it is unused, leave the pin as a NC (or route to a test point). Note also in this circuit, the LMH0341 GPIO_1 pin has been configured to provide the status of RXIN_1. When there is a signal present coming from the LMH0340, then RXIN_1 will be selected. If that signal is lost, the input MUX will automatically switch over to provide the system reference black signal as the input from RXIN_0. The DES includes a SMPTE compliant cable driver for the Loopthrough function. While this is a differential driver, it is commonly used single-endedly to drive 75 Ω coax cables. External 75 Ω pull up resistors are used to the 2.5V rail. The active output(s) also includes a matching network to meet the required Output Return Loss SMPTE specification. While application specific, in general a series 75 Ω resistor shunted by a 6.8 nH inductor will provide a starting value to design with. The signal is then AC coupled to the cable with a 4.7 µF capacitor. If the complementary output is not used, simply terminate it after its AC coupling capacitor to ground. This output (even though its inverting) may still be used for a loop back or 1:2 function due to the nature of the NRZI coding that the SMPTE standards require. The output voltage amplitude of the cable driver is set by the RSET resistor. For single-ended applications, an 7.87kΩ resistor is connected between this pin and ground to set the swing to 800mV. The PLL loop filter is external for the SER. A capacitor is connected between the LF_CP and LF_REF pins. Typical value is 30 nF. There are several configuration pins that requiring setting to the proper level. The RSVD_H pins should be pulled High to the 3.3V rail with a 5 kΩ resistor. Depending upon the application the DVB_ASI pin may be tied off or driven. 20 Submit Documentation Feedback Copyright © 2007–2013, Texas Instruments Incorporated Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 LMH0041, LMH0051 LMH0071, LMH0341 www.ti.com SNLS272Q – APRIL 2007 – REVISED APRIL 2013 There are three supply connections (see bypass discussion in POWER SUPPLIES and also PIN DESCRIPTIONS for recommendations). The two main supplies are the 3.3V rail and the 2.5V rail. There is also a 3.3V connection for the PLL circuitry. There are multiple Ground connections for the device. The main ground connection for the SER is through the large center DAP pad. This must be connected to ground for proper device operation. In addition, multiple other inputs are required to be connected to ground as show in Figure 17 and listed in PIN DESCRIPTIONS. 2.5V 3.3V All Bypass CAPS not shown 3.3V 3.3V 22 TXOUT+ TXOUT- 75Ö Reference Black Signal 16 RXIN0+ 17 RXIN0- LMH0344 19 RXIN1+ 20 RXIN1- See LMH0344 Datasheet For details 3.3V 22 µF 28 7.87 kÖ 14 30 nF 26 27 FPGA Host 4.7 µF + 47 RX4 - 48 + 45 RX3 - 46 + 43 RX2 44 + 41 RX1 42 + 39 RX0 40 + 37 RXCLK 38 VDDPLL RSET LMH0341 3.3V 3.3V LF_REF LF_CP 3 GPIO_0 4 GPIO_1 12 RX_MUX_SEL 11 GPIO_2 SMB_CS 13 DVB_ASI DNC SDA SCK RESET LOCK 32 33 34 LVCMOS GPIO SMBus Interface 21 75Ö 1,15,18,36 7,25,35 LVDS Inputs 75Ö 5 RSVD_H 75Ö 2 Loopthru_EN 5.6 nH GND SDI Loopthrough Output 4.7 µF 5 kÖ VDD3V3 5 kÖ DAP, 8,9,10, 23,24,29 VDD2V5 2.5V 6 30 31 Figure 17. Typical SMPTE Application Circuit Copyright © 2007–2013, Texas Instruments Incorporated Submit Documentation Feedback Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 21 LMH0041, LMH0051 LMH0071, LMH0341 SNLS272Q – APRIL 2007 – REVISED APRIL 2013 www.ti.com 2.5V 3.3V All Bypass CAPS not shown 3.3V 5 kÖ 19 RXIN1+ 20 RXIN13.3V 22 µF 28 7.87 kÖ 14 30 nF 26 27 VDD3V3 FPGA Host 100Ö TWP LVDS Inputs 16 RXIN0+ 17 RXIN0- + 47 RX4 - 48 + 45 RX3 - 46 + 43 RX2 44 + 41 RX1 42 + 39 RX0 40 + 37 RXCLK 38 VDDPLL RSET LMH0051 3.3V 3.3V LF_REF LF_CP 3 GPIO_0 4 GPIO_1 12 RX_MUX_SEL 11 GPIO_2 2, 21, 22 SDA SCK SMB_CS DVB_ASI DNC RESET LOCK 32 33 34 LVCMOS GPIO SMBus Interface 100Ö TWP 1,15,18,36 7,25,35 RSVD_H GND 5 VDD2V5 DAP, 8, 9,10, 13, 23, 24, 29 6 30 31 Figure 18. Typical CML Application Circuit (LMH0051) 22 Submit Documentation Feedback Copyright © 2007–2013, Texas Instruments Incorporated Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 LMH0041, LMH0051 LMH0071, LMH0341 www.ti.com SNLS272Q – APRIL 2007 – REVISED APRIL 2013 REGISTER DESCRIPTIONS Table 2 provides details on the device's configuration registers. Table 2. DES Register Detail Table ADD 'h Name Bits 00 device_identificati on The seven MSBs of this register define the SMBus address for the device. The default value is 0x58h, but this may be overwritten. The LSB of this register must always be '0' Note that since the address is shifted over by one bit, some systems may address the 058h as 'B0h 01 02 03 04 reset GPIO_0 Configuration GPIO_1 Configuration GPIO_2 Configuration Field 7:1 device_id 0 reserved R/W r/w Default 058h Description SMBus Device ID 0 If a '1' is written into the LSB of register 0x01h then the device will do a soft reset, restoring it's internal state to the same as at powerup with the exception of the contents of register 0x00h, which if modified will remain unchanged 7:1 reserved 0 sw_rst r/w 0'b Software Reset This register configures GPIO_0. Note, if this pin is to be used as an input, then the output must be TRISTATE (bit[0]=’0’) and if used as an output, then the input buffer must be disabled (bit[1]=’0’). 7:4 GPIO_0_mode[3 :0] r/w 0000'b 0000: GPout register 0001: signal detect 0 all others: reserved 3:2 GPIO_0_ren[1:0 ] r/w 01'b 00: 01: 10: 11: 1 GPIO_0_sleepz r/w 0'b 0: input buffer disabled 1: input buffer enabled 0 GPout0 enable r/w 1'b 0: output TRI-STATE 1: output enabled pullup and pulldown disabled pulldown enabled pullup enabled Reserved This register configures GPIO_1. Note, if this pin is to be used as an input, then the output must be TRISTATE (bit[0]=’0’) and if used as an output, then the input buffer must be disabled (bit[1]=’0’). 7:4 GPIO_0_mode[3 :0] r/w 0000'b 0000: POR 0001: GP_OUT[1] 0010:signal detect 1 0011:cdr_lock all others: reserved 3:2 GPIO_0_ren[1:0 ] r/w 01'b 00: 01: 10: 11: 1 GPIO_0_sleepz r/w 0'b 0: input buffer disabled 1: input buffer enabled 0 GPout0 enable r/w 1'b 0: output TRI-STATE 1: output enabled pullup and pulldown disabled pulldown enabled pullup enabled Reserved This register configures GPIO_2. Note, if this pin is to be used as an input, then the output must be TRISTATE (bit[0]=’0’) and if used as an output, then the input buffer must be disabled (bit[1]=’0’). 7:4 GPIO_0_mode[3 :0] r/w 0000'b 3:2 GPIO_0_ren[1:0 ] r/w 01'b 00: 01: 10: 11: 1 GPIO_0_sleepz r/w 0'b 0: input buffer disabled 1: input buffer enabled 0 GPout0 enable r/w 1'b 0: output TRI-STATE 1: output enabled Copyright © 2007–2013, Texas Instruments Incorporated 0000: GPout [2]register 0001:Always ON clock 0010: LVDS TX CLK 0011:CDR_CLK all others: reserved pullup and pulldown disabled pulldown enabled pullup enabled Reserved Submit Documentation Feedback Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 23 LMH0041, LMH0051 LMH0071, LMH0341 SNLS272Q – APRIL 2007 – REVISED APRIL 2013 www.ti.com Table 2. DES Register Detail Table (continued) ADD 'h Name Bits 05 GP Input If any of the GPIO pins are configured as inputs, then reading from this register provides the values on those input pins 7:3 06 GP Output Reserved 0D DVB_ASI Idle_A 0E DVB_ASI Idle_B R/W r Input data on GPIO 2 1 r Input data on GPIO 1 0 r Input data on GPIO 0 If the GPIO ins are configured as General Purpose output pins, then writing to this register has the effect of transferring the bits in this register to the output buffers of the GPIO pins. Reserved 2 r/w Output data on GPIO 2 1 r/w Output data on GPIO 1 0 r/w Output data on GPIO 0 When in DVB_ASI mode, idle characters are inserted into the datastream when there is no valid data to transmit. This character is recognized by the receiver. The default character is K28.5 but if desired that can be redefined via this register pair Variant 1E-1F Reserved 20 Control 21 24 DVB_ASI 83 Data [7:0] r/w 2 Data[9:8] Reserved 1:0 1D r/w DVB_ASI idle character MSBs 7:2 Reserved Description Reserved 7:0 0F–1C Default 2 7:3 07–0C Field Reading from this register will return an 8 bit value which indicates which variant of the DES is being addressed 7:6 Reserved r 5 Loop through enable r pin value This bit returns the state of the loop-through enable, and defaults to the same as the state of the Loopthru_EN pin 4:3 mode r pin value Returns a two bit pattern which indicates the state that the device is in 00,01,10: Standard Video Mode 11: DVB_ASI Mode 2 Reserved 1:0 Variant 7:3 Reserved 2 Data Order r/w 0 Determines deserialization order — 0: Expects LSB to be received first 1:Expects MSB to be received first 1 Reset Channel r/w 0 Writing a '1' to this bit forces a reset of the channel 0 Digital Powerdown r/w 0 Writing a '1' to this bit will shut down several of the digital processing sections of the product to save power. r returns the part type: 00: LMH0341 01: LMH0041/LMH0051 10:LMH0071 11:Reserved This register allows the device to be placed in DVB_ASI mode or standard operation mode 7:5 Reserved 4 RX_MUX_SEL 3:2 Reserved 1:0 DVB_ASI Submit Documentation Feedback r/w 0 If enabled by register 22, then this bit will override the RX_MUX_SEL pin. r/w 0 00,01,10: Standard Operation 11: DVB_ASI Copyright © 2007–2013, Texas Instruments Incorporated Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 LMH0041, LMH0051 LMH0071, LMH0341 www.ti.com SNLS272Q – APRIL 2007 – REVISED APRIL 2013 Table 2. DES Register Detail Table (continued) ADD 'h Name Bits 22 Override This register allows the user to control the DVB_ASI and input select functions via the SMBus interface rather than the pin controls. 23–26 Reserved 27 LVDS Control 1 28 LVDS Control 2 29–2A Reserved 2B Event Configuration 2C Field 7:5 Reserved 4 RX_MUX Control Override 3:1 Reserved 0 DVB_ASI Override R/W r/w Default 0 Description Writing a '1' to this register allows register 21 to control the state of the input multiplexer — if the bit is set to '0' then the selection will be determined by the state of the RX_MUX_SEL pin Writing a '1' to this register allows register 21 to control the state of the DVB_ASI Select pin — if the bit is set to '0' then the selection will be determined by the state of the DVB_ASI pin if '1' then the contents of register 21 take precidence This register allows control of the LVDS output pins — using this register individual LVDS outputs can be enabled or disabled, and the outputs can be switched to high output mode 7 LVDS_VOD r/w 0 With a '0' the VOD of the LVDS output are as described in Electrical Characteristics, writing a '1' to this bit generates a larger VODallowing longer traces to be driven, and increasing total power dissipation 6 LVDS Control r/w 0 Writing a '1' to this bit allows the LVDS outputs to be controlled via the SMBus 5 RXCLK Enable r/w 0 Enables the RXCLK output driver 4 RX4 Enable r/w 0 Enables RX4 output driver 3 RX3 Enable r/w 0 Enables RX3 output driver 2 RX2 Enable r/w 0 Enables RX2 output driver 1 RX1 Enable r/w 0 Enables RX1 output driver 0 RX0 Enable r/w 0 Enables RX0 output driver More bits allowing control over the LVDS outputs 7 Reserved 6 LVDS Reset r/w 0 Resets LVDS Block 5 RXCLK Rate r/w 1 1: RXCLK is a DDR clock 0: RXCLI is at a rate of DDR/2 4 RXCLK Invert r/w 0 Inverts the polarity of the RXCLK signal 3:2 LVDS Clock delay r/w 10'b 1:0 Reserved Each LSB adds 80ps delay to the RXCLK signal path, allowing the setup and hold times to be adjusted. Allows control over the counting of error events on the clock recovery PLL 7:4 Reserved 3 Event Count Select r/w 0 0: Select CDR Event counter for reading — events are counted for a loss of the RXCLK signal, or a loss of lock 1: Select data event counter 2 Reset CDR Error Count r/w 0 Resets CDR Event count 1 Reset Link Error Count r/w 0 resets data event counter 0 enable count r/w 0 enables event counters Reserved Copyright © 2007–2013, Texas Instruments Incorporated Submit Documentation Feedback Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 25 LMH0041, LMH0051 LMH0071, LMH0341 SNLS272Q – APRIL 2007 – REVISED APRIL 2013 www.ti.com Table 2. DES Register Detail Table (continued) ADD 'h Name Bits 2D Error Monitor Controls Error Monitoring functions 2E Error Threshold Error Threshold Reserved 3B Data Rate 3C 3D CDR Lock Status Event Status Error Status 1 Accumulate Error Count r/w 0 Enable counting accumulation of errors 3 8b10b error disable r/w 0 When set, disables 8b10b errors from being counted, or from affecting the status of the LOCKpin 2 clear event count r/w 0 When set, clears the number of errors in both the current and previous state of the error count 1 select error count r/w 0 Select which error count to display 0: Number of errors in current run 1: Number of errors within the selected timing window 0 Normal Error Disable r/w 0 Disable exiting NORMAL state when the number of errors exceeds the error threshold r/w 0x10h Error threshold above which the device stops receiving data and transferring it to the RXOUT pins. r/w 00 Error threshold above which the device stops receiving data and transferring it to the RXOUT pins. Sets the error threshold LSBs Error Threshold Sets the error threshold MSBs This Register provides information about the rate at which the receive PLL is locked 7 Reserved 6:4 Freq Range 3:0 Reserved 7:4 Reserved 3 CDR Lock r 1: CDR Locked0: CDR Unlocked 2 Signal Detect Ch 1 r 1: signal present 1 Signal Detect Ch 0 r 1: signal present 0 Reserved Error Status 2 111 001: 011: 110: 111: 270 Mbps 1.485 Gbps 2.97 Gbps Unlocked event count r/w 0 count of errors that caused a loss of the link r/w 0 Number of errors in the data — LSB r/w 0 Number of errors in the data — MSB Error Count LSB Data Error Count 1 Error Counting Register MSB 7:0 26 r Error Counting register 7:0 3F Description Reserved 7:0 3E Default 4 Error Threshold 30–3A R/W 7:5 7:0 2F Field Data Error Count 2 Submit Documentation Feedback Copyright © 2007–2013, Texas Instruments Incorporated Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 LMH0041, LMH0051 LMH0071, LMH0341 www.ti.com SNLS272Q – APRIL 2007 – REVISED APRIL 2013 REVISION HISTORY Changes from Revision P (April 2013) to Revision Q • Page Changed layout of National Data Sheet to TI format .......................................................................................................... 26 Copyright © 2007–2013, Texas Instruments Incorporated Submit Documentation Feedback Product Folder Links: LMH0041 LMH0051 LMH0071 LMH0341 27 PACKAGE OPTION ADDENDUM www.ti.com 10-Dec-2020 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (°C) Device Marking (3) (4/5) (6) LMH0041SQ/NOPB ACTIVE WQFN RHS 48 1000 RoHS & Green SN Level-3-260C-168 HR -40 to 85 LMH0041 LMH0041SQE/NOPB ACTIVE WQFN RHS 48 250 RoHS & Green SN Level-3-260C-168 HR -40 to 85 LMH0041 LMH0041SQX/NOPB ACTIVE WQFN RHS 48 2500 RoHS & Green SN Level-3-260C-168 HR -40 to 85 LMH0041 LMH0051SQE/NOPB ACTIVE WQFN RHS 48 250 RoHS & Green SN Level-3-260C-168 HR -40 to 85 LMH0051 LMH0071SQ/NOPB ACTIVE WQFN RHS 48 1000 RoHS & Green SN Level-3-260C-168 HR -40 to 85 LMH0071 LMH0071SQE/NOPB ACTIVE WQFN RHS 48 250 RoHS & Green SN Level-3-260C-168 HR -40 to 85 LMH0071 LMH0341SQ/NOPB ACTIVE WQFN RHS 48 1000 RoHS & Green SN Level-3-260C-168 HR -40 to 85 L0341 LMH0341SQE/NOPB ACTIVE WQFN RHS 48 250 RoHS & Green SN Level-3-260C-168 HR -40 to 85 L0341 LMH0341SQX/NOPB ACTIVE WQFN RHS 48 2500 RoHS & Green SN Level-3-260C-168 HR -40 to 85 L0341 (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of