TI TLK3101

TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
D
D
D
D
D
D
Hot-Plug Protection
2.5 Gigabits to 3.125 Gigabits Per Second
(Gbps) Serializer/Deserializer
High Performance 64-Pin VQFP Thermally
Enhanced Package (PowerPAD)
2.5-V Power Supply for Low Power
Operation
PECL Compatible Differential Signalling
Serial Interface
Interfaces to Backplane, Copper Cables, or
Optical Converters
D
D
D
D
D
D
On-Chip 8-Bit/10-Bit Encoding/Decoding,
Comma Alignment and Link
Synchronization
On-Chip PLL Provides Clock Synthesis
From Low-Speed Reference
Receiver Differential Input Thresholds
200 mV Min
Typical Power . . . 450 mW
Loss of Signal (LOS) Detection
Ideal for High-Speed Backplane
Interconnect and Point-to-Point Data Link
1
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48
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17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
VDD
RXD3
RXD4
RXD5
RXD6
GND
RXD7
RX_CLK
RXD8
RXD9
VDD
RXD10
RXD11
RXD12
RXD13
GND
TXD14
GND
TXD15
TX_EN
LOOPEN
TX_ER
V DD
ENABLE
LCKREFN
PRBSEN
TESTEN
GND
RX_ER/PRBS_PASS
RX_DV/LOS
RXD15
RXD14
VDD
TXD3
TXD4
TXD5
GND
TXD6
TXD7
GTX_CLK
VDD
TXD8
TXD9
TXD10
GND
TXD11
TXD12
TXD13
RXD1
RXD2
TXD2
TXD1
TXD0
GNDA
DOUTTXP
DOUTTXN
GNDA
VDDA
PREM
VDDA
DINRXP
DINRXN
GNDA
RXD0
RCP PACKAGE
(TOP VIEW)
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.
PowerPAD is a trademark of Texas Instruments.
Copyright  2001, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
1
TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
description
The TLK3101 is a member of the transceiver family of multigigabit transceivers, intended for use in
ultrahigh-speed bidirectional point-to-point data transmission systems. The TLK3101 supports an effective
serial interface speed of 2.5 Gbps to 3.125 Gbps providing up to 2.5 Gbps of data bandwidth. The TLK3101 is
functionally identical to the TLK1501, a 0.6 Gbps to 1.5 Gbps transceiver, and the TLK2501, a 1.6 Gbps to 2.5
Gbps transceiver, providing a wide range of performance solutions with no significant board layout changes.
The primary application of this chip is to provide very high-speed I/O data channels for point-to-point baseband
data transmission over controlled impedance media of approximately 50 Ω. The transmission media can be
printed-circuit board, copper cables, or fiber-optic cable. The maximum rate and distance of data transfer is
dependent upon the attenuation characteristics of the media and the noise coupling to the environment.
This device can also be used to replace parallel data transmission architectures by providing a reduction in the
number of traces, connector pins, and transmit/receive pins. Parallel data loaded into the transmitter is delivered
to the receiver over a serial channel, which can be a coaxial copper cable, a controlled impedance backplane,
or an optical link. It is then reconstructed into its original parallel format. It offers significant power and cost
savings over current solutions, as well as scalability for a higher data rate in the future.
The TLK3101 performs the data parallel-to-serial, serial-to-parallel conversion, and clock extraction functions
for a physical layer interface device. The serial transceiver interface operates at a maximum speed of 3.125
Gbps. The transmitter latches 16-bit parallel data at a rate based on the supplied reference clock (GTX_CLK).
The 16-bit parallel data is internally encoded into 20 bits using an 8-bit/10-bit encoding format. The resulting
20-bit word is then transmitted differentially at 20 times the reference clock (GTX_CLK) rate. The receiver
section performs the serial-to-parallel conversion on the input data, synchronizing the resulting 20-bit wide
parallel data to the extracted reference clock (RX_CLK). It then decodes the 20 bit wide data using 8-bit/10-bit
decoding format resulting in 16 bits of parallel data at the receive data pins (RXD0-15). This results in an
effective data payload of 2 Gbps to 2.5 Gbps (16 bits data x GTX_CLK frequency).
The TLK3101 is housed in a high-performance, thermally enhanced, 64-pin VQFP PowerPAD package. Use
of the PowerPAD package does not require any special considerations except to note that the PowerPAD, which
is an exposed die pad on the bottom of the device, is a metallic thermal and electrical conductor. It is
recommended that the TLK3101 PowerPAD be soldered to the thermal land on the board. All ac performance
specifications in this data sheet are measured with the PowerPAD soldered to the test board.
The TLK3101 provides an internal loopback capability for self-test purposes. Serial data from the serializer is
passed directly to the deserializer allowing the protocol device a functional self-check of the physical interface.
The TLK3101 is designed to be hot plug capable. An on-chip power-on reset circuit holds the RX_CLK low
during power up. Also, this circuit holds the parallel side output signal terminals as well as DOUTTXP and
DOUTTXN in a high-impedance state.
The TLK3101 has a loss of signal detection circuit for conditions where the incoming signal no longer has a
sufficient voltage amplitude to keep the clock recovery circuit in lock.
To prevent a data bit error from causing a valid data packet to be interpreted as a comma and thus causing the
erroneous word alignment by the comma detection circuit, the comma word alignment circuit is turned off after
the link is properly established in the TLK3101.
The TLK3101 allows users to implement redundant ports by connecting receive data bus terminals from two
TLK3101 devices together. Asserting LCKREFN to a low state will cause the receive data bus pins, RXD[0:15],
RX_CLK, and RX_ER, RX_DV/LOS to go to a high-impedance state. This places the device in a transmit only
mode since the receiver is not tracking the data.
The TLK3101 uses a 2.5-V supply. The I/O section is 3 V compatible. With the 2.5-V supply the chipset is very
power efficient, consuming less than 450 mW typically. The TLK3101 is characterized for operation from –40°C
to 85°C.
2
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
functional block diagram
LOOPEN
PRBSEN
PRBSEN
TX_EN
TX_ER
PRBS
Generator
DOUTTXP
10
DOUTTXN
10
Parallel to
Serial
10
Pre-Emphasis
Control
MUX
8
8B/10B
Encoder
TD(0–15)
16 Bit
Register
8
8B/10B
Encoder
2:1
10
MUX
PREM
Bit
Clock
10
Multiplying
Clock
Synthesizer
GTX_CLK
TESTEN
Controls:
PLL,Bias,Rx,
Tx
ENABLE
Bit
Clock
PRBSEN
Interpolator and
Clock Recovery
2:1
MUX
RX_ER
PRBS_PASS
PRBS
Verification
PRBSEN
RX_CLK
2:1
MUX
Recovered
Clock
RX_DV/LOS
RD(0–15)
16 Bit
Register
8
8
Comma
Detect
and 8B/10B
Decoding
Comma
Detect
and 8B/10B
Decoding
10
1:2
MUX
10
Serial to
Parallel
2:1 Data
MUX
DINRXP
DINRXN
10
Signal Detect
(LOS)
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3
TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
transmit interface
The transmitter portion registers valid incoming 16-bit wide data (TXD[0:15]) on the rising edge of GTX_CLK.
The data is then 8-b/10-b encoded, serialized, and transmitted sequentially over the differential high-speed I/O
channel. The clock multiplier multiplies the reference clock (GTX_CLK) by a factor of 10 times creating a bit
clock. This internal bit clock is fed to the parallel-to-serial shift register which transmits data on both the rising
and falling edges of the bit clock providing a serial data rate that is 20 times the reference clock. Data is
transmitted LSB (TXD0) first. The transmitter also inserts commas at the beginning of the transmission for byte
synchronization.
transmit data bus
The transmit bus interface accepts 16 bit wide single-ended TTL parallel data at the TXD[0:15] pins. Data is valid
on the rising edge of GTX_CLK when TX_EN is asserted high and TX_ER is deasserted low. The GTX_CLK
is used as the word clock. The data, enable, and clock signals must be properly aligned as shown in Figure 1.
Detailed timing information can be found in the TTL input electrical characteristics table.
GTX_CLK
TXDn, TX_EN, TX_ER
tsu
th
Figure 1. Transmit Timing Waveform
transmission latency
The data transmission latency of the TLK3101 is defined as the delay from the initial 16-bit word load to the serial
transmission of bit 0. The transmit latency is fixed once the link is established. However, due to silicon process
variations and implementation variables such as supply voltage and temperature, the exact delay will vary
slightly. The minimum transmit latency (Tlatency) is 34 bit times; the maximum is 38 bit times. Figure 2 illustrates
the timing relationship between the transmit data bus, GTX_CLK and serial transmit pins.
Transmitted 20 Bit Word
DOUTTXP,
DOUTTXN
td(Tx latency)
TXD(0–15)
16 Bit Word to Transmit
GTX_CLK
Figure 2. Transmitter Latency
4
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TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
transmit interface (continued)
8-b/10-b encoder
All true serial interfaces require a method of encoding to insure minimum transition density so that the receiving
PLL has a minimal number of transitions in which to stay locked on. The encoding scheme maintains the signal
DC balance by keeping the number of ones and zeros the same. This provides good transition density for clock
recovery and improves error checking. The TLK3101 uses the 8-b/10-b encoding algorithm that is used by fiber
channel and gigabit ethernet. This is transparent to the user as the TLK3101 internally encodes and decodes
the data such that the user reads and writes actual 16-bit data.
The 8-b/10-b encoder converts 8-bit wide data to a 10-bit wide encoded data character to improve its
transmission characteristics. Since the TLK3101 is a 16 bit wide interface the data is split into two 8-bit wide
bytes for encoding. Each byte is fed into a separate encoder. The encoding is dependant upon two additional
input signals, TX_EN and TX_ER. When TX_EN is asserted and TX_ER deasserted then the data bit TXD[15:0]
are encoded and transmitted normally. When TX_EN is deasserted and TX_ER is asserted, then the encoder
will generate a carrier extend consisting of two K23.7 (F7F7) codes. If TX_EN and TX_ER are both asserted
then the encoder will generate a K30.7 (FEFE) code. Table 1 provides the transmit data control decoding. Since
the data is transmitted in 20 bit serial words, K codes indicating carrier extend and transmit error propagation
are transmitted as two 10 bit K-codes.
Table 1. Transmit Data Controls
TX_EN
TX_ER
ENCODED 20 BIT OUTPUT
0
0
IDLE (<K28.5, D5.6> or <K28.5, D16.2>)
0
1
Carrier extend (K23.7, K23.7)
1
0
Normal data character
1
1
Transmit error propagation (K30.7, K30.7)
IDLE insertion
The encoder inserts the IDLE character set when no payload data is available to be sent. IDLE consist of a K28.5
(BC) code and either a D5.6 (C5) or D16.2 (50) character. The K28.5 character is defined by IEEE802.3z as
a pattern consisting of 0011111010 ( a negative number beginning disparity) with the 7 MSBs (0011111) referred
to as the comma character. Since data is latched into the TLK3101 16 bits at a time, The IDLE is converted into
two 10-bit codes that are transmitted sequentially. This means IDLE is transmitted during a single GTX_CLK
cycle.
PRBS generator
The TLK3101 has a built-in 27–1 PRBS (pseudorandom bit stream) function. When the PRBSEN pin is forced
high, the PRBS test is enabled. A PRBS is generated and fed into the 10 bit parallel-to-serial converter input
register. Data from the normal input source is ignored during the PRBS mode. The PRBS pattern is then fed
through the transmit circuitry as if it were normal data and sent out to the transmitter. The output can be sent
to a BERT (bit error rate tester), the receiver of another TLK3101 or can be looped back to the receive input.
Since the PRBS is not really random but a predetermined sequence of ones and zeroes the data can be
captured and checked for errors by a BERT.
parallel to serial
The parallel-to-serial shift register takes in the 20 bit wide data word multiplexed from the two parallel 8-b/10-b
encoders and converts it to a serial stream. The shift register is clocked on both the rising and falling edge of
the internally generated bit clock, which is 10 times the GTX_CLK input frequency. The LSB (TXD0) is
transmitted first.
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5
TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
transmit interface (continued)
high-speed data output
The high-speed data output driver consists of a voltage mode differential driver for a 50-Ω impedance
environment. The magnitude of the signal swing the differential driver pair is compatible with pseudo emitter
coupled logic (PECL) levels when ac-coupled. When ac-coupled the TLK3101 can interface to a PECL
transmitter and receiver. The line can be directly coupled or ac-coupled. Refer to Figure 18 and Figure 19 for
termination details.
The PECL outputs also provide pre-emphasis to compensating for ac loss when driving a cable or PCB
backplane over long distance (see Figure 3). The level of preemphasis is controlled by PREM as shown in
Table 2.
Table 2. Preemphasis Levels
PREM
PREEMPHASIS LEVEL (%)
(Vodp/Vodd –1)†
0
5%
1
20%
† Vodp: Differential voltage swing when there is a
transition in the data stream.
Vodd: Differential voltage swing when there is no
transition in the data stream.
VOD(p)
VOD(d)
VOD(d)
Bit
Time
Bit
Time
VOD(p)
Figure 3. Output Differential Voltage Under Preemphasis (|VTXP – VTXN|)
receive interface
The receiver portion of the TLK3101 accepts 8-b/10-b encoded differential serial data. The interpolator and
clock recovery circuit will lock to the data stream and extract the bit rate clock. This recovered clock is used to
retime the input data stream. The serial data is then aligned to two separate 10-bit word boundaries, 8-b/10-b
decoded and output on a 16 bit wide parallel bus synchronized to the extracted receive clock.
receive data bus
The receive bus interface drives 16 bit wide single-ended TTL parallel data at the RXD[0:15] pins. Data is valid
on the rising edge of RX_CLK when RX_DV/LOS is asserted high and RX_ER is deasserted low. The RX_CLK
is used as the recovered word clock. The data, enable and clock signals are aligned as shown in Figure 4.
Detailed timing information can be found in the TTL output switching characteristics table.
6
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TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
receive data bus (continued)
RX_CLK
RXDn, RX_DV, RX_ER
tsu
th
Figure 4. Receive Timing Waveform
data reception latency
The serial-to-parallel data receive latency is the time from when the first bit arrives at the receiver until it is output
in the aligned parallel word with RXD0 received as first bit. The receive latency is fixed once the link is
established. However, due to silicon process variations and implementation variables such as supply voltage
and temperature, the exact delay will vary slightly. The minimum receive latency (Rlatency) is 76 bit times; the
maximum is 107 bit times. Figure 5 illustrates the timing relationship between the serial receive pins, the
recovered word clock (RX_CLK), and the receive data bus.
20-Bit Encoded Word
DINTXP,
DINTXN
td(Rx latency)
RXD(0–15)
16-Bit Decoded Word
RX_CLK
Figure 5. Receiver Latency
serial to parallel
Serial data is received on the DINRXP, DINRXN pins. The interpolator and clock recovery circuit will lock to the
data stream if the clock to be recovered is within ±200 PPM of the internally generated bit rate clock. The
recovered clock is used to retime the input data stream. The serial data is then clocked into the serial-to-parallel
shift registers. The 10 bit wide parallel data is then multiplexed and fed into two separate 8-b/10-b decoders
where the data is then synchronized to the incoming data steam word boundary by detection of the K28.5
synchronization pattern.
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7
TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
receive interface (continued)
common detect and 8-b/10-b decoding
The TLK3101 has two parallel 8-b/10-b decode circuits. Each 8-b/10-b decoder converts 10 bit encoded data
(half of the 20 bit received word) back into 8 bits. The comma detect circuit is designed to provide for byte
synchronization to an 8-b/10-b transmission code. When parallel data is clocked into a parallel to serial
converter, the byte boundary that was associated with the parallel data is now lost in the serialization of the data.
When the serial data is received and converted to parallel format again a way is needed to be able to recognize
the byte boundary again. Generally this is accomplished through the use of a synchronization pattern. This is
generally a unique pattern of 1s and 0s that either cannot occur as part of valid data or is a pattern that repeats
at defined intervals. 8-bit/10-bit encoding contains a character called the comma (b’0011111’ or b’1100000’)
which is used by the comma detect circuit on the TLK3101 to align the received serial data back to its original
byte boundary. The decoder detects the K28.5 comma, generating a synchronization signal aligning the data
to their 10 bit boundaries for decoding. It then converts the data back into 8 bit data, removing the control words.
The output from the two decoders is latched into the 16 bit register synchronized to the recovered parallel data
clock (RX_CLK) and the output is valid on the rising edge of RX_CLK.
It is possible for a single bit error in a data packet to be misinterpreted as a comma on an erroneous boundary.
If the erroneous comma were taken as the new byte boundary, all subsequent data would be erroneously
decoded until a properly aligned comma was detected. To prevent a data bit error in a data packet from being
interpreted as a comma, the comma word alignment circuit is turned off after receiving a properly aligned comma
after the link is properly established. The link is established after three idle patterns or one valid data pattern
is properly received. The comma alignment circuit is re-enabled when the synchronization state machine
detects a loss of synchronization condition (see synchronization and initialization).
Two output signals, RX_DV/LOS and RX_ER, are generated along with the decoded 16-bit data output on the
RXD[0:15] pins. The output status signals are asserted according to Table 3. When the TLK3101 decodes
normal data and outputs the data on RXD[0:15], RX_DV/LOS is asserted (logic high) and RX_ER is deasserted
(logic low). When the TLK3101 decodes a K23.7 code (F7F7) indicating carrier extend, RX_DV/LOS is
deasserted and RX_ER is asserted. If the decoded data is not a valid 8-b/10-b code, an error is reported by the
assertion of both RX_DV/LOS and RX_ER. If the error was due to an error propagation code, the RXD[15:0]
pins will output hex FEFE. If the error was due to an invalid pattern, the data output on RXD is undefined. When
the TLK3101 decodes an IDLE code, both RX_DV/LOS and RX_ER are deasserted and a K28.5 (BC) code is
output on the RXD[7:0] pins and either a D5.6 (C5) or D16.2 (50) code is output on the RXD[15:8] pins.
Table 3. Receive Status Signals
RX_DV/LOS
RX_ER
IDLE (<K28.5, D5.6>, <K28.5, D16.2>)
RECEIVED 20 BIT DATA
0
0
Carrier extend (K23.7, K23.7)
0
1
Normal data character (DX.Y)
1
0
Receive error propagation (K30.7, K30.7)
1
1
loss of signal detection
The TLK3101 has a loss of signal detection circuit for conditions where the incoming signal no longer has a
sufficient voltage level to keep the clock recovery circuit in lock. The signal detection circuit is intended to be
an indication of gross signal error conditions such as a detached cable or no signal being transmitted, and not
an indication of signal coding health. The TLK3101 reports this condition by asserting, RX_DV/LOS, RX_ER
and RXD[0:15] all to a high state. As long as the signal is above 200 mV in differential magnitude, the LOS circuit
will not signal an error condition.
8
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TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
receive interface (continued)
power down mode
When the ENABLE pin is deasserted low, the TLK3101 will go into a power down mode. In the power down
mode, the serial transmit pins (DOUTTXP, DOUTTXN), the receive data bus pins (RXD[0:15]), and RX_ER will
go into a high-impedance state. In the power-down mode the RX_DV/LOS pin acts as an output of the signal
detection circuit which remains active. If the signal detection circuit detects a valid differential signal amplitude
of >200 mV on each of the serial receive pins (DINRXP, DINRXN), RX_DV/LOS is driven high. If no signal of
sufficient amplitude is detected, the signal detection circuit will indicate a loss of signal by driving RX_DV/LOS
low. In the power-down condition, the signal detection circuit draws less than 5 mW.
synchronization and initialization
The TLK3101 has a synchronization state machine which is responsible for handling link initialization and
synchronization. Upon power up or reset, the state machine enters the acquisition (ACQ) state and searches
for IDLE. Upon receiving three consecutive IDLEs or carrier extends, the state machine will enter the
synchronization (SYNC) state. If, during the acquisition process, the state machine receives valid data or an
error propagation code, it will immediately transition to the SYNC state. The SYNC state is the state for normal
device transmission and reception. The initialization and synchronization state diagram is provided in Figure 6.
Invalid Code
Word Received
ACQ
(Link Acquisition)
Power-Up/Reset
3 Consecutive Valid IDLEs or Carrier Extends,
or
1 Valid Data or Error Propagation
3 Invalid Code
Words Received
Loss of Link
Link Established
Valid Code
Word Received
CHECK
(Look for Valid Code)
1 Invalid Code
Word Received
Link in Question
SYNC
(Normal Operation)
Link Re-established
4 Consecutive Valid Code Words Received
Figure 6. Initialization and Synchronization State Diagram
If, during normal transmission and reception, an invalid code is received, the TLK3101 will notify the attached
system or protocol device as described in comma detect and 8-b/10-b decoding. The synchronization state
machine will transition to the CHECK state. The CHECK state will determine whether the invalid code received
was caused by a spurious event or a loss of the link. If, in the CHECK state, the decoder sees 4 consecutive
valid codes, the state machine will determine the link is good and transition back to the SYNC state for normal
operation. If, in the CHECK state, the decoder sees three invalid codes (not required to be consecutive), the
TLK3101 will determine a loss of the link has occurred and transition the synchronization state machine back
to the link acquisition state (ACQ).
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TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
synchronization and initialization (continued)
The state of the transmit data bus, control pins, and serial outputs during the link acquisition process is illustrated
in Figure 7.
ACQ
SYNC
TX_EN
xx
xx
xx
xx
TX_ER
xx
xx
xx
xx xx
TXD(0–15)
xx
xx
xx
xx
xx xx
xx
xx
xx
xx xx
DOUTTXP,
DOUTTXN
xx
xx
D0–D15
IDLE
D0–D15
Ca. Ext.
Error
Figure 7. Transmit Side Timing Diagram
The state of the receive data bus, status pins, and serial inputs during the link acquisition process is illustrated
in Figure 8 and Figure 9.
ACQ
DINRXP,
DINRXN
RXD(0–15)
IDLE or Carrier
Extend
SYNC
IDLE or Carrier
Extend
IDLE or Carrier
Extend
IDLE or Carrier
Extend
XXXXXXXXXXXXXXXXXXX
D0–D15
IDLE or Carrier
Extend
D0–D15
RX_DV,
RX_ER
RESET
(Internal Signal)
Figure 8. Receive Side Timing Diagram (IDLE or Carrier Extend)
ACQ
DINRXP,
DINRXN
RXD(0–15)
IDLE
SYNC
Valid Data or
Error Prop
XXXXXXXXXXXXXXXXXXX
RX_DV,
RX_ER
D0–D15
Valid Data or
Error Prop
ÉÉÉÉ
ÉÉÉÉ
D0–D15
D0–D15
D0–D15
RESET
(Internal Signal)
Figure 9. Receive Side Timing Diagram (Valid Data or Error Propagation)
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TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
redundant port operation
The TLK3101 allows users to design redundant ports by connecting receive data bus pins from two TLK3101
devices together. Asserting LCKREFN to a low state will cause the receive data bus pins, RXD[0:15], RX_CLK
and RX_ER, RX_DV/LOS to go to a high-impedance state.
PRBS verification
The TLK3101 also has a built-in BERT function in the receiver side that is enabled by PRBSEN. It checks for
errors and reports the errors by forcing the RX_ER/PRBSPASS pin low.
reference clock input
The reference clock (GTX_CLK) is an external input clock that synchronizes the transmitter interface. The
reference clock is then multiplied in frequency 10 times to produce the internal serialization bit clock. The internal
serialization bit clock is frequency-locked to the reference clock and used to clock out the serial transmit data
on both its rising and falling edges, providing a serial data rate that is 20 times the reference clock.
operating frequency range
The TLK3101 is optimized for operation at a serial data rate of 3.125 Gbit/s. The TLK3101 may operate at a
serial data rate between 2.5 Gbit/s to 3.125 Gbit/s. GTX_CLK must be within ±100 PPM of the desired parallel
data rate clock.
testability
The TLK3101 has a comprehensive suite of built-in self-tests. The loopback function provides for at-speed
testing of the transmit/receive portions of the circuitry. The ENABLE pin allows for all circuitry to be disabled so
that a quiescent current test can be performed. The PRBS function allows for BIST (built-in self-test).
loop-back testing
The transceiver can provide a self-test function by enabling (LOOPEN) the internal loopback path. Enabling this
pin will cause serial transmitted data to be routed internally to the receiver. The parallel data output can be
compared to the parallel input data for functional verification. The external differential output is held in a
high-impedance state during the loopback testing.
built-in self-test
The TLK3101 has a BIST (built-in self-test) function. By combining PRBS with loopback, an effective self-test
of all the circuitry running at full speed can be realized. The successful completion of the BIST is reported on
the RX_ER/PRBS_PASS pin.
power-on reset
Upon application of minimum valid power, the TLK3101 generates a power-on reset. During the power-on reset
the RXD, RX_ER and RX_DV/LOS signal pins go to 3-state mode. RX_CLK is held low. The length of the
power-on reset cycle is dependent upon the REFCLK frequency but is less than 1-ms in duration.
POST OFFICE BOX 655303
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11
TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
Terminal Functions
signal
TERMINAL
NAME
NO.
TYPE
DESCRIPTION
DOUTTXP
DOUTTXN
60
59
Output†
Serial transmit outputs. DOUTTXP and DOUTTXN are differential serial outputs that interface to copper or
an optical I/F module. These terminals transmit NRZ data at a rate of 20 times the GTX_CLK value.
DOUTTXP and DOUTTXN are put in a high-impedance state when LOOPEN is high and are active when
LOOPEN is low . During power-on-reset these pins are high-impedance.
DINRXP
DINRXN
54
53
Input
Serial receive inputs. DINRXP and DINRXN together are the differential serial input interface from a copper
or an optical I/F module.
GTX_CLK
8
Input
Reference clock. GTX_CLK is a continuous external input clock that synchronizes the transmitter interface
signals TX_EN, TX_ER and TXD. The frequency range of GTX_CLK is 125 MHz to 156.25 MHz. The
transmitter uses the rising edge of this clock to register the 16-bit input data (TXD) for serialization.
LCKREFN
25
Input‡
Lock to reference. When LCKREFN is low, the receiver clock is frequency locked to GTX_CLK. This places
the device in a transmit only mode, since the receiver is not tracking the data. When LCKREFN is asserted
low, the receive data bus pins, RXD[0:15], RX_CLK and RX_ER, RX_DV/LOS are in a high-impedance
state.
When LCKREFN is deasserted high, the receiver is locked to the received data stream and must receive
valid codes from the synchronization state machine before the transmitter is enabled.
TXD0
TXD1
TXD2
TXD3
TXD4
TXD5
TXD6
TXD7
TXD8
TXD9
TXD10
TXD11
TXD12
TXD13
TXD14
TXD15
62
63
64
2
3
4
6
7
10
11
12
14
15
16
17
19
Input
Transmit data bus. These inputs carry the 16-bit parallel data output from a protocol device to the transceiver
for encoding, serialization, and transmission. This 16-bit parallel data is clocked into the transceiver on the
rising edge of GTX_CLK as shown in Figure 10.
RXD0
RXD1
RXD2
RXD3
RXD4
RXD5
RXD6
RXD7
RXD8
RXD9
RXD10
RXD11
RXD12
RXD13
RXD14
RXD15
51
50
49
47
46
45
44
42
40
39
37
36
35
34
32
31
Output†
Receive data bus. These outputs carry 16-bit parallel data output from the transceiver to the protocol device,
synchronized to RX_CLK. The data is valid on the rising edge of RX_CLK as shown in Figure 12. These pins
are in high-impedance state during power-on reset.
RX_CLK
41
Output§
Recovered clock. Output clock that is synchronized to RXD, RX_ER, RX_DV/LOS. RX_CLK is the
recovered serial data rate clock divided by 20. RX_CLK is held low during power-on reset.
† Hi-Z on power up
‡ Internal pullup
§ Low on power up
12
POST OFFICE BOX 655303
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TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
Terminal Functions (Continued)
signal (continued)
TERMINAL
NAME
NO.
TYPE
DESCRIPTION
PREM
56
Input‡
Preemphasis control. Selects the amount of preemphasis to be added to the high speed data output drivers.
Left low or unconnected, 5% of pre-emphasis is added. Pulled high, 20% of preemphasis is added.
RX_ER/
PRBS_PASS
29
Output†
Receive error. When RX_ER and RX_DV/LOS are asserted, indicates that an error was detected
somewhere in the frame presently being output on the receive data bus. When RX_ER is asserted and
RX_DV/LOS is deasserted, indicates that carrier extension data is being presented. RX_ER goes to high
impedance state during power-on reset.
When PRBSEN= low (deasserted), this pin is used to indicate receive error (RX_ER). When PRBSEN = high
(asserted), this pin indicates status of the PRBS test results (high=pass).
RX_DV/
LOS
30
Output†
Receive data valid. RX_DV/LOS is output by the transceiver to indicate that recovered and decoded data is
being output on the receive data bus. RX_DV/LOS is asserted continuously from the first recovered word of
the frame through the final recovered word and is deasserted prior to the first rising edge of RX_CLK that
follows the final word. RX_DV/LOS is in high-impedance state during power-on reset.
If, during normal operation, the differential signal amplitude on the serial receive pins is below 200 mV,
RX_DV/LOS is asserted high along with RX_ER and the receive data bus to indicate a loss of signal
condition. If the device is in power-down mode, RX_DV/LOS is the output of the signal detect circuit and is
asserted low when a loss of signal condition is detected.
TX_EN
20
Input‡
Transmit enable. TX_EN in combination with TX_ER indicates the protocol device is presenting data on the
transmit data bus for transmission. TX_EN must be high with the first word of the preamble and remain
asserted while all words to be transmitted are presented on the transmit data bus. TX_EN must be negated
prior to the first rising edge of GTX_CLK following the final word of a frame.
TX_ER
22
Input‡
Transmit error coding. When TX_ER and TX_EN are high, indicates that the transceiver generates an error
somewhere in the frame presently being transferred. When TX_ER is asserted and TX_EN is deasserted,
indicates the protocol device is presenting carrier extension data. When TX_ER is deasserted with TX_EN
asserted, indicates that normal data is being presented.
TYPE
DESCRIPTION
† Hi-Z on power-up
‡ Internal pull-down
test
TERMINAL
NAME
NO.
ENABLE
24
Input§
Device enable. When this pin is held low, the device is placed in power-down mode. Only the signal detect
circuit on the serial receive pair is active. When asserted high, the transceiver goes into power-on reset
before beginning normal operation.
LOOPEN
21
Input‡
Loop enable. When LOOPEN is high, the internal loopback path is activated. The transmitted serial data is
directly routed internally to the inputs of the receiver. This provides a self-test capability in conjunction with
the protocol device. The DOUTTXP and DOUTTXN outputs are held in a high-impedance state during the
loopback test. LOOPEN is held low during standard operational state with external serial outputs and inputs
active.
PRBSEN
26
Input‡
PRBS test enable. When asserted high results of pseudorandom bit stream (PRBS) tests can be monitored
on the RX_ER/PRBS_PASS pin. A high on PRBS_PASS indicates that valid PRBS is being received.
TESTEN
27
‡ Internal pulldown
§ Internal pullup
Input‡
Test mode enable. This pin should be left unconnected or tied low.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
13
TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
Terminal Functions (Continued)
power
TERMINAL
NAME
NO.
TYPE
DESCRIPTION
VDD
1, 9,
23, 38,
48
Supply
Digital logic power. Provides power for all digital circuitry and digital I/O buffers.
VDDA
55, 57
Supply
Analog power. VDDA provides a supply reference for the high-speed analog circuits, receiver and
transmitter
GNDA
52, 58,
61
Ground
Analog ground. GNDA provides a ground reference for the high-speed analog circuits, RX and TX.
GND
5, 13,
18, 28,
33, 43
Ground
Digital logic ground. Provides a ground for the logic circuits and digital I/O buffers.
absolute maximum ratings over operating free-air temperature (unless otherwise noted)†
Supply voltage, VDD (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to 3 V
Voltage range at TXD, ENABLE, GTX_CLK, TX_EN, TX_ER, LOOPEN, PRBS_PASS . . . . . . . . –0.3 V to 4 V
Voltage range at any other terminal except above . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to VDD + 0.3 V
Package power dissipation, PD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Dissipation Rating Table
Storage temperature, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 65°C to 150°C
Electrostatic discharge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HBM:3 kV, CDM: 1.5 kV
Characterized free-air operating temperature range, TA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 40°C to 85°C
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260°C
† Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTE 1: All voltage values, except differential I/O bus voltages, are with respect to network ground.
DISSIPATION RATING TABLE
PACKAGE
RCP64§
RCP64¶
TA ≤ 25°C
POWER RATING
OPERATING FACTOR‡
ABOVE TA = 25°C
TA = 70°C
POWER RATING
5.25 W
46.58 mW/°C
2.89 W
3.17 W
23.70 mW/°C
1.74 W
RCP64#
2.01 W
13.19 mW/°C
1.11 W
‡ This is the inverse of the traditional junction-to-ambient thermal resistance (RθJA).
§ 2 oz. Trace and copper pad with solder
¶ 2 oz. Trace and copper pad without solder
# Standard JEDEC high-K board
For more information, refer to TI application note PowerPAD Thermally Enhanced Package, TI
literature number SLMA002
14
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
VDD
Supply voltage
ICC
Supply current
PD
TEST CONDITIONS
MIN
TYP
MAX
2.3
2.5
2.7
VDD = 2.5V,
VDD = 2.5V,
Freq = 2.5 Gb/sec,
PRBS pattern
135
Freq = 3.125 Gb/sec,
PRBS pattern
180
Freq = 2.5 Gb/sec,
PRBS pattern
337
Power dissipation
VDD = 2.5V,
VDD = 2.5V,
Freq = 3.125 Gb/sec,
PRBS pattern
450
Freq = 3.125 Gb/sec,
Worst case pattern
Shutdown current
VDD = 2.7V,
Enable = 0,
PLL start-up lock time
VDD,VDDA = 2.3V,
EN ↑ to PLL acquire
Vdda + Vdd pins = MAX
mA
mW
µA
20
0.1
0.4
1024
Operating free-air
temperature
V
600
Data acquisition time
TA
UNIT
–40
ms
bits
85
°C
reference clock (GTX_CLK) timing requirements over recommended operating conditions (unless
otherwise noted)
PARAMETER
f
Frequency
MIN
TYP
MAX
Minimum data rate
TEST CONDITIONS
TYP–0.01%
125
TYP+0.01%
Maximum data rate
TYP–0.01%
156.25
TYP+0.01%
50%
60%
Frequency tolerance
–100
Duty cycle
40%
Jitter
Peak to peak
POST OFFICE BOX 655303
100
40
• DALLAS, TEXAS 75265
UNIT
MHz
ppm
ps
15
TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
TTL input electrical characteristics over recommended operating free-air temperature range
(unless otherwise noted)
TTL signals: TXD0 ..TXD15, GTX_CLK, LOOPEN, LCKREFN, PRBS_PASS
PARAMETER
TEST CONDITIONS
VIH
VIL
High-level input voltage
See Figure 10
Low-level input voltage
See Figure 10
IIH
IIL
Input high current
VDD = MAX,
VDD = MAX,
Input low current
CI
MIN
TYP
1.7
VIN = 2 V
VIN = 0.4 V
MAX
UNIT
3.6
V
0.80
V
40
µV
µV
–40
0.8 V to 2 V
4
pF
tr
tf
Rise time, GTX_CLK, TX_EN, TX_ER, TXD
0.8 V to 2 V,
C = 5 pF,
See Figure 10
1
ns
Fall time, GTX_CLK, TX_EN, TX_ER, TXD
2 V to 0.8 V,
C = 5 pF,
See Figure 10
1
ns
tsu
th
TXD, TX_EN, TX_ER setup to ↑ GTX_CLK
See Figure 10
1.5
ns
TXD, TX_EN, TX_ER hold to ↑ GTX_CLK
See Figure 10
0.4
ns
3.6 V
2.0 V
GTX_CLK
0.8 V
0V
tr
tf
3.6 V
2.0 V
TX_ER, TX_EN,
TXD(0–15)
0.8 V
0V
tr
tsu
tf
th
Figure 10. TTL Data Input Valid Levels for AC Measurements
16
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
TTL output switching characteristics over recommended operating free-air temperature range
(unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
IOH = –1 mA,
IOL = 1 mA,
VDD = MIN
VDD = MIN
2.10
2.3
GND
0.25
tr(slew)
Magnitude of RX_CLK, RX_ER,
RX_DV/LOS, RXD slew rate (rising)
0.8 V to 2 V,
C = 5 pF, See Figure 11
0.5
V/ns
tf(slew)
Magnitude of RX_CLK, RX_ER,
RX_DV/LOS, RXD slew rate (falling)
0.8 V to 2 V,
C = 5 pF, See Figure 11
0.5
V/ns
tsu
RXD,, RX_DV/LOS,
setup to ↑
_
, RX_ER
_
RX_CLK
50% voltage
g swing,
g,
See Figure 11
GTX_CLK = 156.25 MHz
2.5
ns
3
ns
th
RXD, RX_DV/LOS, RX_ER hold to ↑
RX_CLK
50% voltage
g swing,
g
See Figure 11
GTX_CLK = 156.25 MHz
2.5
ns
3
ns
VOH
VOL
High-level output voltage
Low-level output voltage
GTX_CLK = 125 MHz
GTX_CLK = 125 MHz
MAX
UNIT
V
0.5
V
2.7 V
2.0 V
RX_CLK
0.8 V
0V
tr(slew)
tf(slew)
2.7 V
2.0 V
RX_DV, RX_ER,
RXD(0–15)
0.8 V
0V
tr(slew)
tsu
tf(slew)
th
Figure 11. TTL Data Output Valid Levels for AC Measurements
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
17
TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
transmitter/receiver characteristics
PARAMETER
VOD(p)
OD( )
VOD(
OD(pp_p))
TEST CONDITIONS
Preemphasis VOD, direct,
VOD(p) = |VTXP – VTXN|
g with
Differential, peak-to-peak output voltage
preemphasis
MIN
TYP
MAX
Rt = 50 Ω, PREM = high, dc-coupled,
See Figure 12
655
725
795
Rt = 50 Ω, PREM = low, dc-coupled,
See Figure 12
590
650
710
Rt = 50 Ω, PREM = high, dc-coupled,
See Figure 12
1310
1450
1590
Rt = 50 Ω, PREM = low, dc-coupled,
See Figure 12
1180
1300
1420
UNIT
mV
mVp-p
VOD(d)
Deemphais output voltage,
|VTXP – VTXN|
Rt = 50 Ω, DC-coupled, See Figure 12
540
600
660
mV
VOD(pp_d)
Differential, peak-to-peak output voltage with
de-emphasis
Rt = 50 Ω, dc-coupled, See Figure 12
1080
1200
1320
mVp-p
V(cmt)
Transmit common mode voltage range,
(VTXP + VTXN)/2
Rt = 50 Ω, See Figure 12
1000
1250
1400
mV
VID
Receiver input voltage differential,
|VRXP – VRXN|
1600
mV
V(cmr)
Receiver common mode voltage range,
(VRXP + VRXN)/2
2250
mV
10
µA
2
pF
Ilkg
Ci
200
Receiver input leakage current
1250
–10
Receiver input capacitance
Differential output jitter at 3.125 Gbps,
Random + deterministic, PRBS pattern
0.20
UI†
Differential output jitter at 2.5 Gbps,
Random + deterministic, PRBS pattern
0.16
UI†
Differential output signal rise, fall time
(20% to 80%)
RL = 50 Ω, CL = 5 pF, See Figure 12
150
ps
Jitter tolerance
Differential input jitter, random +
determinisitc, PRBS pattern at zero
crossing
Serial data total jitter (peak-to-peak)
( eak-to- eak)
tt, tf
1000
td(Tx latency)
Tx latency
td(Rx latency)
Rx latency
† UI is the time interval of one serialized bit.
0.60
UI
See Figure 2
34
38
bits
See Figure 5
76
107
bits
VOD(p)
VOD(d)
VOD(pp_d) VOD(pp_p)
V(cmt)
tf
tr
VOD(d)
Bit
Time
Bit
Time
VOD(p)
Figure 12. Differential and Common-Mode Output Voltage Definitions (|VTXP – VTXN|)
18
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
thermal characteristics
PARAMETER
RθJA
RθJC
Junction-to-free-air
thermal resistance
Junction-to-case thermal
resistance
TEST CONDITION
MIN
TYP
Board-mounted, no air flow, high conductivity TI recommended test
board, chip soldered or greased to thermal land
21.47
Board-mounted, no air flow, high conductivity TI recommended test
board with thermal land but no solder or grease thermal connection to
thermal land
42.20
Board-mounted, no air flow, JEDEC test board
75.83
Board-mounted, no air flow, high conductivity TI recommended test
board, chip soldered or greased to thermal land
0.38
Board-mounted, no air flow, high conductivity TI recommended test
board with thermal land but no solder or grease thermal connection to
thermal land
0.38
Board-mounted, no air flow, JEDEC test board
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
MAX
UNIT
°C/W
°C/W
7.8
19
TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
1 nF – 10 nF†
1 nF – 10 nF†
1 nF – 10 nF†
1 nF – 10 nF†
Recommended use of 0.01 µF
Capacitor per VDD terminal
0.01 µF
5 Ω at 100 MHz
4
45
GND
5
44
RXD6
TXD6
6
43
GND
TXD7
7
42
RXD7
GTX_CLK
8
41
RX_CLK
VDD
TXD8
9
40
RXD8
10
39
RXD9
TXD9
11
38
VDD
TXD10
12
37
RXD10
GND
13
36
RXD11
TXD11
14
35
RXD12
TXD12
15
34
RXD13
TXD13
33
16
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
Figure 13. External Component Interconnection
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
RXD14
RXD15
46
RX_DV/LOS
GND
RX_ER/PRBS_PASS
TESTEN
PRBSEN
LCKREFN
TX_ER
V DD
ENABLE
LOOPEN
GND
TXD15
TX_EN
TXD14
GNDA
3
TXD5
DINRXN
TXD4
VDD
RXD3
RXD4
RXD5
DINRXP
47
PREM
V DDA
2
DOUTTXP
64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49
48
DOUTTXN
1
GNDA
VDD
TXD3
† For ac-coupling
20
RXD1
RXD2
RXD0
TXD0
TXD2
TXD1
0.01 µF 0.01 µF 0.01 µF
0.01 µF
GNDA
V DDA
VDD
GND
TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
TXP
50 Ω
RXP
VDDA
Transmission
Line
50 Ω
4 kΩ
50 Ω
6 kΩ
50 Ω
TXN
Transmitter
Transmission
Line
Media
+
_
GND
RXN
Receiver
Figure 14. High-Speed I/O Directly-Coupled Mode
TXP
50 Ω
RXP
VDDA
Transmission
Line
50 Ω
4 kΩ
50 Ω
6 kΩ
50 Ω
TXN
Transmitter
Transmission
Line
Media
+
_
GND
RXN
Receiver
Figure 15. High-Speed I/O AC-Coupled Mode
POST OFFICE BOX 655303
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21
TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
designing with PowerPAD
The TLK3101 is housed in a high performance, thermally enhanced, 64-pin VQFP (RCP64) PowerPAD
package. Use of the PowerPAD package does not require any special considerations except to note that the
PowerPAD, which is an exposed die pad on the bottom of the device, is a metallic thermal and electrical
conductor. Therefore, if not implementing PowerPAD PCB features, the use of solder masks (or other assembly
techniques) may be required to prevent any inadvertent shorting by the exposed PowerPAD to connection
etches or vias under the package. It is strongly recommended that the PowerPAD be soldered to the thermal
land. The recommended convention, however, is to not run any etches or signal vias under the device, but to
have only a grounded thermal land as explained below. Although the actual size of the exposed die pad may
vary, the minimum size required for the keep-out area for the 64-pin PFP PowerPAD package is 8 mm × 8 mm.
A thermal land, which is an area of solder-tinned-copper, is recommended underneath the PowerPAD package.
The thermal land will vary in size depending on the PowerPAD package being used, the PCB construction, and
the amount of heat that needs to be removed. In addition, the thermal land may or may not contain numerous
thermal vias depending on PCB construction.
Other requirements for thermal lands and thermal vias are detailed in the TI application note PowerPAD
Thermally Enhanced Package Application Report, TI literature number SLMA002, available via the TI Web
pages beginning at URL: http://www.ti.com.
Figure 16. Example of a Thermal Land
For the TLK3101, this thermal land should be grounded to the low impedance ground plane of the device. This
improves not only thermal performance but also the electrical grounding of the device. It is also recommended
that the device ground pin landing pads be connected directly to the grounded thermal land. The land size
should be as large as possible without shorting device signal pins. The thermal land may be soldered to the
exposed PowerPAD using standard reflow soldering techniques.
While the thermal land may be electrically floated and configured to remove heat to an external heat sink, it is
recommended that the thermal land be connected to the low impedance ground plane for the device. More
information may be obtained from the TI application note PHY Layout, TI literature number SLLA020.
22
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TLK3101
2.5 Gbps to 3.125 Gbps TRANSCEIVER
SCAS649A – AUGUST 2000 – REVISED FEBRUARY 2001
MECHANICAL DATA
RCP (S-PQFP-G64)
PowerPAD PLASTIC QUAD FLATPACK
0,27
0,17
0,50
48
0,08 M
33
32
49
Thermal Pad
(See Note D)
64
17
0,13 NOM
1
16
7,50 TYP
Gage Plane
10,20
SQ
9,80
12,20
SQ
11,80
0,25
0,15
0,05
0,85
0,75
0° – 7°
0,75
0,45
Seating Plane
0,08
1,00 MAX
4147711/A 10/98
NOTES: A.
B.
C.
D.
All linear dimensions are in millimeters.
This drawing is subject to change without notice.
Body dimensions do not include mold flash or protrusion.
The package thermal performance may be enhanced by bonding the thermal pad to an external thermal plane.
This pad is electrically and thermally connected to the backside of the die and possibly selected leads.
E. Falls within JEDEC MS-026
PowerPAD is a trademark of Texas Instruments.
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