Gigabit Ethernet SerDes Circuit with Differential PECL Clock Inputs HDMP-1637A SerDes Features • IEEE 802.3z Gigabit Ethernet Compatible, Supports 1250 MBd Gigabit Ethernet • Based on X3T11 “10 Bit Specification” • Low Power Consumption • 10 mm 64-pin PQFP Package • Transmitter and Receiver Functions Incorporated onto a Single IC • 5-Volt Tolerant I/Os • 10 Bit Wide Parallel TTL Compatible I/Os • Single +3.3 V Power Supply • Differential PECL Clock Inputs • 2 kV Human Body ESD Protection on all Pins Applications • 1250 MBd Gigabit Ethernet Interface • High Speed Proprietary Interface • Backplane Serialization / Bus Extender Description The HDMP-1637A transceiver is a single silicon bipolar integrated circuit packaged in a plastic QFP package. It provides a low-cost, low-power physical layer solution for 1250 MBd Gigabit Ethernet or proprietary link interfaces. It provides complete Serialize/ Deserialize (SerDes) for copper transmission, incorporating both the Gigabit Ethernet transmit and receive functions into a single device. This chip is used to build a high speed interface (as shown in Figure 1) while minimizing board space, power, and cost. It is compatible with the IEEE 802.3z specification. The transmitter section accepts 10-bit wide parallel TTL data and serializes this data into a high speed serial data stream. The parallel data is expected to be “8B/10B” encoded data, or equivalent. This parallel data is latched into the input register of the transmitter section on the rising edge of the 125 MHz reference clock (used as the transmit byte clock). The transmitter section’s PLL locks to this user supplied 125 MHz byte clock. This clock is then multiplied by 10, to generate the 1250 MHz serial signal clock used to generate the high speed output. The high speed outputs are capable of interfacing directly to copper cables for electrical transmission or to a separate fiber optic module for optical transmission. The receiver section accepts a serial electrical data stream at 1250 MBd and recovers the original 10-bit wide parallel data. The receiver PLL locks onto the incoming serial signal and recovers the high speed serial clock and data. The serial data is converted back into 10-bit parallel data, recognizing the 8B/10B comma character to establish byte alignment. The recovered parallel data is presented to the user at TTL compatible outputs. The receiver section also recovers two 62.5 MHz receiver byte clocks which are 180 degrees out of phase with each other. The parallel data is properly aligned with the rising edge of alternating clocks. For test purposes, the transceiver provides for on-chip local loopback functionality controlled through an external input pin. Additionally, the byte synchronization feature may be disabled. This may be useful in proprietary applications which use alternative methods to align the parallel data. CAUTION: As with all semiconductor ICs, it is advised that normal static precautions be taken in handling and assembly of this component to prevent damage and/or degradation which may be induced by electrostatic discharge (ESD). 2 HDMP-1637A TRANSMITTER SECTION SERIAL DATA OUT PLL PROTOCOL DEVICE RBC0 RBC1 PLL SERIAL DATA IN RECEIVER SECTION BYTSYNC ± REFCLK ENBYTSYNC DATA BYTE TX[0-9] INPUT LATCH Figure 1. Typical Application using the HDMP-1637A. FRAME MUX OUTPUT SELECT INTERNAL LOOPBACK TXCAP0 TXCAP1 TX PLL/CLOCK GENERATOR INTERNAL TX CLOCKS ± DOUT LOOPEN INPUT SELECT ± DIN SIGNAL DETECT SIG_DET ± REFCLK RX PLL/CLOCK RECOVERY DATA BYTE RX[0-9] OUTPUT DRIVER RXCAP0 RXCAP1 RBC0 RBC1 FRAME DEMUX AND BYTE SYNC BYTSYNC INTERNAL RX CLOCKS INPUT SAMPLER ENBYTSYNC Figure 2. HDMP-1637A Transceiver Block Diagram. 3 HDMP-1637A Block Diagram The HDMP-1637A was designed to transmit and receive 10-bit wide parallel data over a single high-speed line. The parallel data applied to the transmitter is expected to be encoded per the Gigabit Ethernet specification, which uses an 8B/10B encoding scheme with special reserve characters for link management purposes. In order to accomplish this task, the HDMP-1637A incorporates the following: • TTL Parallel I/Os • High Speed Phase Locked Loops • Parallel to Serial Converter • Serial Clock and Data Recovery • Comma Character Recognition • Byte Alignment Circuitry • Serial to Parallel Converter INPUT LATCH The transmitter accepts 10-bit wide TTL parallel data at inputs TX[0..9]. The user-provided reference clock signal, REFCLK, (from this point forward, REFCLK is defined as the difference between PECL inputs +REFCLK and -REFCLK) is used as the transmit byte clock. The TX[0..9] and REFCLK signals must be properly aligned, as shown in Figure 3. TX PLL/CLOCK GENERATOR The transmitter Phase Locked Loop and Clock Generator (TX PLL/CLOCK GENERATOR) block is responsible for generating all internal clocks needed by the transmitter section to perform its functions. These clocks are based on the supplied reference byte clock (REFCLK). REFCLK is used as both the frequency reference clock for the PLL and the transmit byte clock for the incoming data latches. It is expected to be 125 MHz and properly aligned to the incoming parallel data (see Figure 3). This clock is then multiplied by 10 to generate the 1250 MHz clock necessary for clocking the high speed serial outputs. FRAME MUX The FRAME MUX accepts the 10bit wide parallel data from the INPUT LATCH. Using internally generated high speed clocks, this parallel data is multiplexed into the 1250 MBd serial data stream. The data bits are transmitted sequentially, from the least significant bit (TX[0]) to the most significant bit (TX[9]). OUTPUT SELECT The OUTPUT SELECT block provides for an optional internal loopback of the high speed serial signal for testing purposes. In normal operation, LOOPEN is set low and the serial data stream is placed at +/- DOUT. When wrap-mode is activated by setting LOOPEN high, the +/- DOUT pins are held static at logic 1 and the serial output signal is internally wrapped to the INPUT SELECT box of the receiver section. INPUT SELECT The INPUT SELECT block determines whether the signal at +/- DIN or the internal loop-back serial signal is used. In normal operation, LOOPEN is set low and the serial data is accepted at +/- DIN. When LOOPEN is set high, the high speed serial signal is internally looped-back from the transmitter section to the receiver section. This feature allows for loop back testing exclusive of the transmission medium. RX PLL/CLOCK RECOVERY The RX PLL/CLOCK RECOVERY block is responsible for frequency and phase locking onto the incoming serial data stream and recovering the bit and byte clocks. An automatic locking feature allows the Rx PLL to lock onto the input data stream without external PLL training controls. It does this by continually frequency locking onto the 125 MHz reference clock, and then phase locking onto the input data stream. An internal signal detection circuit monitors the presence of the input, and invokes the phase detection as the data stream appears. Once bit locked, the receiver generates the high speed sampling clock at 1250 MHz for the input sampler, and recovers the two 62.5 MHz receiver byte clocks (RBC1/RBC0). These clocks are 180 degrees out of phase with each other, and are alternately used to clock the 10bit parallel output data. INPUT SAMPLER The INPUT SAMPLER is responsible for converting the serial input signal into a retimed serial bit stream. In order to accomplish this, it uses the high speed serial clock recovered from the RX PLL/CLOCK RECOVERY block. This serial bit stream is sent to the FRAME DEMUX and BYTE SYNC block. 4 FRAME DEMUX AND BYTE SYNC The FRAME DEMUX AND BYTE SYNC block is responsible for restoring the 10-bit parallel data from the high speed serial bit stream. This block is also responsible for recognizing the comma character (or a K28.5 character) of positive disparity (0011111xxx). When recognized, the FRAME DEMUX AND BYTE SYNC block works with the RX PLL/CLOCK RECOVERY block to properly align the receive byte clocks to the parallel data. When a comma character is detected and realignment of the receiver byte clocks (RBC1/RBC0) is necessary, these clocks are stretched, not slivered, to the next possible correct alignment position. These clocks will be fully aligned by the start of the second 2-byte ordered set. The second comma character received shall be aligned with the rising edge of RBC1. As per the 8B/10B encoding scheme, comma characters must not be transmitted in consecutive bytes to allow the receiver byte clocks to maintain their proper recovered frequencies. OUTPUT DRIVERS The OUTPUT DRIVERS present the 10-bit parallel recovered data byte properly aligned to the receive byte clocks (RBC1/ RBC0), as shown in Figure 5. These output data buffers provide TTL compatible signals. SIGNAL DETECT The SIGNAL DETECT block examines the differential amplitude of the inputs ± DIN. When this input signal is too small, it outputs a logic 0 at SIG_DET (refer to SIG_DET pin definition for detection thresholds), and at the same time, forces the parallel output RX[0]..RX[9] to all logic one (1111111111). The main purpose of this circuit is to prevent the generation of random data when the serial input lines are disconnected. When the signal at ± DIN is of a valid amplitude, SIG_DET is set to logic 1, and the output of the INPUT SELECT block is passed through. 5 HDMP-1637A (Transmitter Section) Timing Characteristics TA = 0°C to +70°C, VCC = 3.15 V to 3.45 V Symbol Parameter tsetup Setup Time thold Hold Time t_txlat[1] Transmitter Latency Units nsec nsec nsec bits Min. 1.5 1.0 Typ. Max. 3.5 4.4 Note: 1. The transmitter latency, as shown in Figure 4, is defined as the time between the latching in of the parallel data word (as triggered by the rising edge of the transmit byte clock, REFCLK) and the transmission of the first serial bit of that parallel word (defined by the rising edge of the first bit transmitted). tSETUP REFCLK 0.0 V AC 2.0 V TX[9]-TX[0] DATA DATA DATA DATA DATA 0.8 V tHOLD Figure 3. Transmitter Section Timing. DATA BYTE A ± DOUT T5 T6 T7 T8 T9 T0 T1 T2 T3 T4 T5 DATA BYTE B T6 T7 T8 T9 T0 T1 T2 T3 T4 T5 t_TXLAT TX[0]-TX[9] REFCLK Figure 4. Transmitter Latency. DATA BYTE B DATA BYTE C 0.0 V AC 6 HDMP-1637A (Receiver Section) Timing Characteristics TA = 0°C to +70°C, Symbol f_lock b_sync[1,2] tvalid_before tvalid_after tduty tA-B[4] t_rxlat[3] VCC = 3.15 V to 3.45 V Parameter Frequency Lock at Powerup Bit Sync Time Time Data Valid Before Rising Edge of RBC Time Data Valid After Rising Edge of RBC RBC Duty Cycle Rising Edge Time Difference between RBC0 and RBC1 Receiver Latency Units µs bits nsec nsec % nsec Min. Typ. Max. 500 2500 2.5 1.5 40 7.5 60 8.5 nsec bits 22.4 28.0 Notes: 1. This is the recovery time for input phase jumps, per the Fibre Channel Specification X3.230-1994 FC-PH Standard, Sec 5.3. 2. Tested using CPLL = 0.1 µF. 3. The receiver latency, as shown in Figure 6, is defined as the time between receiving the first serial bit of a parallel data word (defined as the first edge of the first serial bit) and the clocking out of that parallel word (defined by the rising edge of the receive byte clock, either RBC1 or RBC0). 4. Guaranteed at room temperature. tvalid_before tvalid_after RBC1 1.4 V 2.0 V RX[0]-RX[9] K28.5 DATA DATA DATA DATA 0.8 V 2.0 V BYTSYNC 0.8 V 1.4 V RBC0 tA-B Figure 5. Receiver Section Timing. DATA BYTE C ± DIN R5 R6 R7 R8 DATA BYTE D R9 R0 R1 R2 R3 R4 R5 R6 R7 R8 R9 R2 R3 R4 R5 t_rxlat RX[0]-RX[9] RBC1/0 Figure 6. Receiver Latency. DATA BYTE A DATA BYTE D 1.4 V 7 HDMP-1637A (TRx) Absolute Maximum Ratings TA = 25°C, except as specified. Operation in excess of any one of these conditions may result in permanent damage to this device. Symbol VCC VIN,TTL VIN,HS_IN IO,TTL Tstg Tj Parameter Supply Voltage TTL Input Voltage HS_IN Input Voltage TTL Output Source Current Storage Temperature Junction Temperature Units V V V mA °C °C Min. –0.5 –0.7 2.0 Max. 5.0 VCC + 2.8 VCC 18 +150 +150 –65 0 HDMP-1637A (TRx) Guaranteed Operating Rates TA = 0°C to +70°C, VCC = 3.15 V to 3.45 V Parallel Clock Rate (MHz) Serial Baud Rate (MBaud) Min. Max. Min. Max. 124.0 126.0 1240 1260 HDMP-1637A (TRx) Transceiver Reference Clock Requirements TA = 0°C to +70°C, VCC = 3.15 V to 3.45 V Symbol Parameter f Nominal Frequency (for Gigabit Ethernet Compliance) Ftol Frequency Tolerance Symm Symmetry (Duty Cycle) Unit MHz ppm % Min. Typ. 125 –100 40 Max. +100 60 HDMP-1637A (TRx) DC Electrical Specifications TA= 0°C to +70°C, VCC = 3.15 V to 3.45 V Symbol Parameter VIH,TTL TTL Input High Voltage Level, Guaranteed High Signal for All Inputs VIL,TTL TTL Input Low Voltage Level, Guaranteed Low Signal for All Inputs VOH,TTL TTL Output High Voltage Level, IOH = -400 µA VOL,TTL TTL Output Low Voltage Level, IOL = 1 mA IIH,TTL Input High Current (Magnitude), VIN = 2.4 V, VCC = 3.45 V IIL,TTL Input Low Current (Magnitude), VIN = 0.4 V, VCC = 3.45 V [1,2] ICC,TRx Transceiver VCC Supply Current, TA = 25°C Unit V Min. 2 Typ. Max. 5.5 V 0 0.8 V V µA µA mA 2.2 0 VCC 0.6 40 –600 200 Notes: 1. Measurement Conditions: Tested sending 1250 MBd PRBS 27 -1 sequence from a serial BERT with ± DOUT outputs biased with 150 Ω resistors. 2. Typical value specified with VCC = 3.3 volts. 8 HDMP-1637A (TRx) PECL DC Electrical Specifications for REFCLK TA = 0°C to +70°C, VCC = 3.15 V to 3.45 V Symbol Parameter VIH,PECL PECL Input High Voltage Level VIL,PECL PECL Input Low Voltage Level Unit V V Min. 2.14 1.49 Typ. Max. 2.42 1.82 HDMP-1637A (TRx) AC Electrical Specifications TA= 0°C to +70°C, VCC = 3.15 V to 3.45 V Symbol Parameter tr,REFCLK +REFCLK/-REFCLK Rise Time, 20% to 80% tf,REFCLK +REFCLK/-REFCLK Fall Time, 80% to 20% tr,TTLout Output TTL Rise Time, 0.8 to 2.0 volts, 10pF Load tf,TTLout Output TTL Fall Time, 2.0 to 0.8 volts, 10pF Load trs, HS_OUT HS_OUT Single-Ended (+DOUT) Rise Time tfs,HS_OUT HS_OUT Single-Ended (+DOUT) Fall Time trd, HS_OUT HS_OUT Differential Rise Time tfd,HS_OUT HS_OUT Differential Fall Time VIP,HS_IN HS_IN Input Peak-To-Peak Differential Voltage VOP,HS_OUT[1] HS_OUT Output Pk-Pk Diff. Voltage (Z0=50 Ohms, Fig.10) Note: 1. Output Peak-to-Peak Differential Voltage specified as DOUT+ minus DOUT-. X1 WAVEFORM MATH f1 = 3 – 4 f2 = 1 – 2 X2 FUNCTION f1 f2 DEFINE FUNCTION... DISPLAY off on VERTICAL SCALE auto 120.0 ps/div CURRENT RISETIME (f2) < 1 ps FALLTIME (f2) < 1 ps 130.3664 ns Y 1 (f2) = –637.00 mV 2 (f2) = 636.00 mV ∆ = 1.27300 V 1/∆X = manual Y SCALE X 130.549 ns 131.349 ns 800 ps 1.250 GHz Figure 7. Eye Diagram of a High Speed Differential Output. 250 mV/div Y OFFSET 0.0 V Units ns ns ns ns ps ps ps ps mV mV Min. Typ. 0.8 0.5 85 85 85 85 200 1200 1200 1600 Max. 0.6 0.6 2.4 2.4 327 327 327 327 2000 2200 9 HDMP-1637A (Transmitter Section) Output Jitter Characteristics (measured with equivalent parts which have TTL REFCLK input) TA = 0°C to +70°C, VCC = 3.15 V to 3.45 V Symbol Parameter [1] RJ Random Jitter at DOUT, the High Speed Electrical Data Port, specified as 1 sigma deviation of the 50% crossing point (RMS) DJ [1] Deterministic Jitter at DOUT, the High Speed Electrical Data Port (pk-pk) Units ps Typ. 8 ps 25 Note: 1. Defined by Fibre Channel Specification X3.230-1994 FC-PH Standard, Annex A, Section A.4 and tested using measurement method shown in Figure 8. 70841B PATTERN GENERATOR 70311A CLOCK SOURCE +K28.5, -K28.5 70841B PATTERN GENERATOR* 83480A OSCILLOSCOPE 83480A OSCILLOSCOPE 0000011111 + DATA - DATA 125 MHz TRIGGER CH1 1.25 GHz CH2 + DATA - DATA 1.25 GHz DIVIDE BY 10 CIRCUIT (DUAL OUTPUT) DIVIDE BY 2 TRIGGER CH1 CH2 70311A CLOCK SOURCE +DOUT -DOUT +DOUT HDMP-1637A PECL * PATTERN GENERATOR PROVIDES A DIVIDE BY 10 FUNCTION. VARIABLE DELAY PECL -DIN +DIN HDMP-1637A REFCLK LOOPEN Txi[0..9] -DOUTi 125 MHz REFCLK Txi[0..9] ENBYTSYNC LOOPEN Rx[0..9] 0011111000 (STATIC K28.7) A. BLOCK DIAGRAM OF RJ MEASUREMENT METHOD B. BLOCK DIAGRAM OF DJ MEASUREMENT METHOD Figure 8. Transmitter Jitter Measurement Method. HDMP-1637A (TRx) Thermal and Power Temperature Characteristics TA = 0°C to +70°C, VCC = 3.15 V to 3.45 V Symbol Parameter PD,TRx[1,2] Transceiver Power Dissipation, Outputs connected per recommended bias terminations with idle pattern [3] Θjc Thermal Resistance, Junction to Case Units mW Typ. 620 °C/W 11 Max. 900 Notes: 1. PD is obtained by multiplying VCC by ICC and subtracting the power dissipated outside the chip at the high speed bias resistors. 2. Specified with high speed outputs biased with 150 Ω resistors and receiver TTL outputs driving 10 pF loads. 3. Based on independent package testing by Agilent Technologies. Θja for these devices is 56.1°C/W for the HDMP-1637A. Θja is measured on a standard 3x3" FR4 PCB in a still air environment. To determine the actual junction temperature in a given application, use the following: Tj = TC + (Θjc x PD), where TC is the case temperature measured on the top center of the package and P D is the power being dissipated. 10 I/O Type Definitions I/O Type I-TTL O-TTL HS_OUT HS_IN C S PECL Definition Input TTL, Floats High When Left Open Output TTL High Speed Output, ECL Compatible High Speed Input External Circuit Node Power Supply or Ground Positive ECL HDMP-1637A (TRx) Pin Input Capacitance Symbol CINPUT Parameter Input Capacitance on TTL Input Pins O_TTL Units pF Typ. 1.6 Max. I_TTL VCC_TTL VCC_TTL VCC VBB 1.4 V GND GND_TTL ESD PROTECTION ESD PROTECTION GND_TTL Figure 9. O-TTL and I-TTL Simplified Circuit Schematic. HS_OUT HS_IN VCC VCC_TXHS VCC_TXECL Zo + – A + – VCC Zo VCC Zo = 50 Ω Zo +DOUT R R 0.01 µF +DIN RPAD 2*Z0 = 100 Ω 150 -DOUT RPAD Zo Zo = 50 Ω GND ESD PROTECTION 0.01 µF -DIN GND ESD 150 PROTECTION GND_TXHS GND NOTES: 1. HS_IN INPUTS SHOULD NEVER BE CONNECTED TO GROUND AS PERMANENT DAMAGE TO THE DEVICE MAY RESULT. 2. THE OPTIONAL SERIES PADDING RESISTORS (RPAD) HELP DAMPEN LOAD REFLECTIONS. TYPICAL RPAD VALUES FOR MISMATCHED LOADS RANGE BETWEEN 25-Z0 Ω. 3. FOR PECL REFCLK INPUT PAIR, THE CONSTANT VOLTAGE SUPPLIES (SHOWN AS A) AND RESISTORS R ARE OMITTED. Figure 10. HS_OUT and HS_IN Simplified Circuit Schematic. VCC_RXA RXCAP1 -DIN GND_RXA *VCC *VCC +DIN *GND GND VCC VCC VCC_TXHS +DOUT -DOUT VCC_TXECL GND_TXHS 11 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 *GND TX[0] 1 48 2 TX[1] TX[2] 3 47 46 4 5 6 45 44 43 7 8 9 42 VCC_RXTTL 41 40 RX[3] *VCC TX[3] TX[4] TX[5] TX[6] *VCC TX[7] TX[8] TX[9] *GND GND_TXA TXCAP1 HDMP-1637A xxxx-x Rz.zz S YYWW 10 11 12 39 38 37 36 35 34 33 13 14 15 16 RXCAP0 BYTSYNC GND_RXTTL RX[0] RX[1] RX[2] RX[4] RX[5] RX[6] VCC_RXTTL RX[7] RX[8] RX[9] GND_RXTTL RBC0 GND_RXTTL VCC VCC_RXTTL RBC1 SIG_DET *N/C -REFCLK ENBYTSYNC GND GND +REFCLK TXCAP0 VCC_TXA LOOPEN VCC 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 xxxx-x = WAFER LOT NUMBER–BUILD NUMBER Rz.zz = DIE REVISION S = SUPPLIER CODE YYWW = DATE CODE (YY = YEAR, WW = WORK WEEK) COUNTRY = COUNTRY OF MANUFACTURE (MARKED ON BACK OF DEVICE) *N/C: THIS PIN IS CONNECTED TO AN ISOLATED PAD AND HAS NO FUNCTIONALITY. IT CAN BE LEFT OPEN, HOWEVER, TTL LEVELS CAN ALSO BE APPLIED TO THIS PIN. *VCC: THIS PIN IS BONDED TO AN ISOLATED PAD AND HAS NO FUNCTIONALITY. HOWEVER, IT IS RECOMMENDED THAT THIS PIN BE CONNECTED TO VCC IN ORDER TO CONFORM WITH THE X3T11 "10-BIT SPECIFICATION," AND TO HELP DISSIPATE HEAT. *GND: THIS PIN IS BONDED TO AN ISOLATED PAD AND HAS NO FUNCTIONALITY. HOWEVER, IT IS RECOMMENDED THAT THIS PIN BE CONNECTED TO GND IN ORDER TO CONFORM WITH THE X3T11 "10-BIT SPECIFICATION," AND TO HELP DISSIPATE HEAT. HDMP-1637 fig 11 Figure 11. HDMP-1637A (TRx) Package Layout and Marking, Top View. 12 TRx I/O Definition Name BYTSYNC Pin 47 -DIN +DIN -DOUT +DOUT 52 54 61 62 ENBYTSYNC 24 GND 21 25 58 1 14 56 51 GND GND_RXA GND_RXTTL Type O-TTL Signal Byte Sync Output: An active high output. Used to indicate detection of a comma character (0011111XXX). It is only active when ENBYTSYNC is enabled. HS_IN Serial Data Inputs: High speed inputs. Serial data is accepted from the ± DIN inputs when LOOPEN is low. HS_OUT Serial Data Outputs: High speed outputs. These lines are active when LOOPEN is set low. When LOOPEN is set high, these outputs are held static at logic 1. I-TTL Enable Byte Sync Input: When high, turns on the internal byte sync function to allow clock synchronization to a comma character, (0011111XXX). When the line is low, the function is disabled and will not reset registers and clocks, or strobe the BYTSYNC line. S Logic Ground: Normally 0 volts. This ground is used for internal PECL logic. It should be isolated from the noisy TTL ground as well as possible. S S GND_TXA 32 33 46 15 GND_TXHS LOOPEN 64 19 S I-TTL N/C 27 RBC1 RBC0 30 31 O-TTL +REFCLK -REFCLK 22 23 PECL S This pin is bonded to an isolated pad and has no functionality. However, it is recommended that this pin be connected to GND in order to conform with the X3T11 “10-bit specification,” and to help dissipate heat. Analog Ground: Normally 0 volts. Used to provide a clean ground plane for the receiver PLL and high-speed analog cells. TTL Receiver Ground: Normally 0 volts. Used for the TTL output cells of the receiver section. Analog Ground: Normally 0 volts. Used to provide a clean ground plane for the PLL and high-speed analog cells. Ground: Normally 0 volts. Loopback Enable Input: When set high, the high-speed serial signal is internally wrapped from the transmitter’s serial loopback outputs back to the receiver’s loopback inputs. Also, when in loopback mode, the ± DOUT outputs are held static at logic 1. When set low, ± DOUT outputs and ± DIN inputs are active. This pin is connected to an isolated pad and has no functionality. It can be left open, however, TTL levels can also be applied to this pin. Receiver Byte Clocks: The receiver section recovers two 62.5 MHz receive byte clocks. These two clocks are 180 degrees out of phase. The receiver parallel data outputs are alternately clocked on the rising edge of these clocks. The rising edge of RBC1 aligns with the output of the comma character (for byte alignment) when detected. Reference Clock and Transmit Byte Clock: A 125 MHz clock supplied by the host system. The transmitter section accepts this signal as the frequency reference clock. It is multiplied by 10 to generate the serial bit clock and other internal clocks. The transmit side also uses this clock as the transmit byte clock for the incoming parallel data TX[0]..TX[9]. It also serves as the reference clock for the receive portion of the transceiver. 13 TRx I/O Definition (cont’d.) Name RX[0] RX[1] RX[2] RX[3] RX[4] RX[5] RX[6] RX[7] RX[8] RX[9] RXCAP0 RXCAP1 SIG_DET Pin 45 44 43 41 40 39 38 36 35 34 48 49 26 TX[0] TX[1] TX[2] TX[3] TX[4] TX[5] TX[6] TX[7] TX[8] TX[9] TXCAP0 TXCAP1 VCC 2 3 4 6 7 8 9 11 12 13 17 16 20,28 57,59 5 10,53 55 50 I-TTL S VCC_TXA 29 37 42 18 VCC_TXECL 60 S VCC_TXHS 63 S VCC VCC _RXA VCC_RXTTL Type O-TTL Signal Data Outputs: One 10 bit data byte. RX[0] is the first bit received. RX[0] is the least significant bit. When there is a loss of input signal at ± DIN, these outputs are held static at logic 1. Refer to SIG_DET (pin 26) pin definition for more details. C Loop Filter Capacitor: A loop filter capacitor for the internal PLL must be connected across the RXCAP0 and RXCAP1 pins. (typical value = 0.1 µF). Signal Detect: Indicates a loss of signal on the high-speed differential inputs, ± DIN, as in the case where the transmission cable becomes disconnected. If ± DIN >= 200 mV peak-to-peak, SIG_DET = logic 1. If ± DIN < 200 mV and ± DIN > 50 mV, SIG_DET = undefined. If ± DIN <= 50 mV, SIG_DET = logic 0, RX[0:9] = 1111111111. Data Inputs: One 10 bit, 8B/10B-encoded data byte. TX[0] is the first bit transmitted. TX[0] is the least significant bit. O-TTL C S S S Loop Filter Capacitor: A loop filter capacitor must be connected across the TXCAP1 and TXCAP0 pins (typical value = 0.1 µF). Logic Power Supply: Normally 3.3 volts. Used for internal PECL logic. It should be isolated from the noisy TTL supply as well as possible. This pin is bonded to an isolated pad and has no functionality. However, it is recommended that this pin be connected to VCC in order to conform with the X3T11 “10-bit specification,” and to help dissipate heat. Analog Power Supply: Normally 3.3 volts. Used to provide a clean supply line for the PLL and high-speed analog cells. TTL Power Supply: Normally 3.3 volts. Used for all TTL receiver output buffer cells. Analog Power Supply: Normally 3.3 volts. Used to provide a clean supply line for the PLL and high-speed analog cells. High-Speed ECL Supply: Normally 3.3 volts. Used only for the last stage of the high-speed transmitter output cell (HS_OUT) as shown in Figure 10. Due to high current transitions, this VCC should be well bypassed to a ground plane. High-Speed Supply: Normally 3.3 volts. Used by the transmitter side for the high-speed circuitry. Noise on this line should be minimized for best operation. 14 VCC** VCC VCC_RXA RXCAP1 GND_RXA VCC* VCC* GND* VCC GND VCC GND* VCC_TXECL GND_TXHS VCC_TXHS CPLLR RXCAP0 GND_RXTTL VCC* VCC_RXTTL VCC HDMP-1637A VCC* TOP VIEW GND_RXTTL GND VCC GND TXCAP0 VCC_TXA TXCAP1 VCC VCC_RXTTL VCC_RXTTL GND* GND_TXA GND_RXTTL CPLLT VCC VCC** *IT IS RECOMMENDED THAT THESE PINS BE CONNECTED TO THE APPROPRIATE SUPPLY LINE, EITHER VCC OR GND, EVEN THOUGH THE PIN IS BONDED TO AN ISOLATED PAD. REFER TO THE I/O DEFINITIONS SECTION FOR THESE PINS FOR MORE DETAILS. ** SUPPLY VOLTAGE INTO VCC_RXA AND VCC_TXA SHOULD BE FROM A LOW NOISE SOURCE. ALL BYPASS CAPACITORS AND PLL FILTER CAPACITORS ARE 0.1 µF. Figure 12. Power Supply Bypass. Startup Procedure: The transceiver startup procedure(s) use the following conditions: VCC = +3.3 V +/- 5% and REFCLK = 125 MHz +/- 100 ppm. After the above conditions have been met, apply valid data using a balanced code such as 8B/10B. Frequency lock occurs within 500 ms. After frequency lock, phase lock occurs within 2500 bit times. Transceiver Power Supply Bypass and Loop Filter Capacitors Bypass capacitors should be used and placed as close as possible to the appropriate power supply pins of the HDMP-1637A as shown on the schematic of Figure 12. All bypass chip capacitors are 0.1 µF. The VCC _RXA and VCC_TXA pins are the analog power supply pins for the PLL sections. The voltage into these pins should be clean with minimum noise. The PLL loop filter capacitors and their pin locations are also shown on Figure 12. Notice that only two capacitors are required: CPLLT for the transmitter and CPLLR for the receiver. Nominal capacitance is 0.1 µF. The maximum voltage across the capacitors is on the order of 1 volt, so the capacitor can be a low voltage type and physically small. The PLL capacitors are placed physically close to the appropriate pins on the HDMP1637A. Keeping the lines short will prevent them from picking up stray noise from surrounding lines or components. 15 Package Information Item Package Material Lead Finish Material Lead Finish Thickness Lead Coplanarity Details Plastic 85% Tin, 15% Lead 300-800 µm 0.08 mm max. Mechanical Dimensions PIN #1 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 1 2 3 4 5 6 7 8 9 48 47 46 45 44 43 42 41 40 HDMP-1637A A1 A2 10 39 TOP VIEW 11 38 12 37 13 36 14 35 15 34 16 33 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 B4 B1 A1 B5 B2 B3 A2 C1 C3 C2 ALL DIMENSIONS ARE IN MILLIMETERS. PART NUMBER A1 A2 B1 B2 B3 B4 B5 C1 C2 C3 HDMP-1637A 10.00 13.20 0.22 0.50 0.88 0.17 0.25 2.00 0.25 MIN. 2.45 TOLERANCE ± 0.10 ± 0.25 ± 0.05 BASIC + 0.15/ MAX. – 0.10 Figure 13. Mechanical Dimensions of HDMP-1637A. + 0.10/ – 0.05 MAX. www.semiconductor.agilent.com Data subject to change. Copyright © 1999 Agilent Technologies, Inc. 5968-5119E (11/99)