AMD AM79761YC-14

PRELIMINARY
Am79761
Physical Layer 10-Bit Transceiver for Gigabit Ethernet
(GigaPHY™-SD)
DISTINCTIVE CHARACTERISTICS
n Gigabit Ethernet Transceiver operates at
1.25 Gigabits per second (Gbps)
n Suitable for both Coaxial and Optical Link
applications
n 10-bit TTL Interface for Transmit and Receive
Data
n Monolithic Clock Synthesis and Clock Recovery
requires no external components
n Word Synchronization Function (Comma
Detect)
n Low Power Operation - 700 mW typical
n 64-pin Standard PQFP
— 14 x 14 mm (0˚ C - 70˚ C)
— 10 x 10 mm (0˚ C - 50˚ C)
n 125 MHz TTL Reference Clock
n Loopback Diagnostic
n Single +3.3 V Supply
GENERAL DESCRIPTION
The Am79761 Gigabit Ethernet Physical Layer Serializer/Deserializer (GigaPHY-SD) device is a 1.25 Gbps
Ethernet Transceiver optimized for Gigabit Ethernet/
1000BASE-X applications. It implements the Physical
Medium Attachment (PMA) layer for a single port.
When transmitting, the GigaPHY-SD device receives
10-bit 8B/10B code groups at 125 million code groups
per second. It then serializes the parallel data stream,
adding a reference clock, and transmits it through the
PECL drivers.
The GigaPHY-SD device can interface to fiber-optic
media to support 1000BASE-LX and 1000BASE-SX
applications and can interface to copper coax to support 1000BASE-CX applications.
When receiving, the GigaPHY-SD device receives the
PECL data stream from the network. It then recovers
the clock from the data stream, deserializes the data
stream into a 10-bit code group, and transmits it to the
Physical Coding Sublayer (PCS) logic above. Optionally, it detects comma characters used to align the incoming word.
The functions performed by the device include serializing the 8B/10B 10-bit data for transmission, deserializing received code groups, recovering the clock from the
incoming data stream, and word synchronization.
This document contains information on a product under development at Advanced Micro Devices. The information
is intended to help you evaluate this product. AMD reserves the right to change or discontinue work on this proposed
product without notice.
Publication# 21560 Rev: A Amendment/+1
Issue Date: April 1998
P R E L I M I N A R Y
BLOCK DIAGRAM
TXD[0:9]
10
TX+
Parallel
to Serial
DQ
TX-
PLL Clock
Multiply
REFCLK
EWRAP
RXD[0:9]
10
Serial to
Parallel
QD
Clock
Recovery
10
RX+
RX-
RCLK
20
RCLKN
COM_DET
Frame
Logic
Comma
Detect
21560A-1
EN_CDET
2
Am79761
P R E L I M I N A R Y
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
N/C
DVDD_P
TX+
TXDVDD_P
DVDD
AVSS
AVDD
DVSS
DVDD
RX+
DVDD_P
RXDVSS
DVDD
N/C
CONNECTION DIAGRAM
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
N/C
COM_DET
DVSS_T
RXD0
RXD1
RXD2
DVDD_T
RXD3
RXD4
RXD5
RXD6
DVDD_T
RXD7
RXD8
RXD9
DVSS_T
Note:
N/C = No Connect
N/C
TEST1
EWRAP
TEST2
DVSS
REFCLK
TEST3
EN_CDET
DVSS
TEST4
N/C
DVDD
DVDD_T
RCLKN
RCLK
DVSS_T
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
DVSS
TXD0
TXD1
TXD2
DVDD
TXD3
TXD4
TXD5
TXD6
DVDD
TXD7
TXD8
TXD9
DVSS
DVSS
N/C
21560A-2
LOGIC SYMBOL
DVDD
PHY
Control
DVDD_T
DVDD_P
REFCLK
RCLK
RCLKN
EN_CDET
EWRAP
COM_DET
TXD [0:9]
RXD [0:9]
Am79761
GigaPHY-SD
Test
Port
AVDD
TEST4
TDST [3:1]
DVSS
DVSS_D
Am79761
DVSS
TX+
TX–
RX+
RX–
To PCS
Transceiver
21560A-3
3
P R E L I M I N A R Y
ORDERING INFORMATION
Standard Products
AMD standard products are available in several packages and operating ranges. The order number (Valid Combination) is formed
by a combination of the elements below.
Am79761
Y
C
-10
PACKAGE SIZE OPTION
-10 = 10 x 10 mm body size
-14 = 14 x 14 mm body size
TEMPERATURE RANGE
C = Commercial (0˚C to +70˚C)
PACKAGE TYPE
Y = 64-Pin Plastic Quad Flat Pack (PDH064)
DEVICE NUMBER/DESCRIPTION
Am79761
Physical Layer 10-Bit Transceiver for Gigabit Ethernet
GigaPHY™-SD)
Valid Combinations
Valid Combinations
4
Am79761YC
-10
Am79761YC
-14
Valid Combinations list configurations planned to be supported in volume for this device. Consult the local AMD sales
office to confirm availability of specific valid combinations and
to check on newly released combinations.
Am79761
P R E L I M I N A R Y
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Am79761
5
P R E L I M I N A R Y
PIN DESIGNATION
Listed by Pin Number
6
Pin No.
Pin Name
Pin No.
Pin Name
Pin No.
Pin Name
Pin No.
Pin Name
1
DVSS
17
N/C
33
DVSS_T
49
N/C
2
TXD0
18
TEST1
34
RXD9
50
DVDD
3
TXD1
19
EWRAP
35
RXD8
51
DVSS
4
TXD2
20
TEST2
36
RXD7
52
RX-
5
DVDD
21
DVSS
37
DVDD_T
53
DVDD_P
6
TXD3
22
REFCLK
38
RXD6
54
RX+
7
TXD4
23
TEST3
39
RXD5
55
DVDD
8
TXD5
24
EN_CDET
40
RXD4
56
DVSS
9
TXD6
25
DVSS
41
RXD3
57
AVDD
10
DVDD
26
TEST4
42
DVDD_T
58
AVSS
11
TXD7
27
N/C
43
RXD2
59
DVDD
12
TXD8
28
DVDD
44
RXD1
60
DVDD_P
13
TXD9
29
DVDD_T
45
RXD0
61
TX-
14
DVSS
30
RCLKN
46
DVSS_T
62
TX+
15
DVSS
31
RCLK
47
COM_DET
63
DVDD_P
16
N/C
32
DVSS_T
48
N/C
64
N/C
Am79761
P R E L I M I N A R Y
PIN DESCRIPTION
TX+, TXSerial Transmit Data
PECL Output
EN_CDET
Enable Comma Detect
TTL Input
These pins are the 1000BASE-X port differential drivers which transmit the serial stream to the network.
These pins are connected to the copper or fiber optic
connectors.
This pin is used to enable the word synchronization
mode. When logic HIGH, the COM_DET output is enabled and word synchronization is active.
When EWRAP is LOW, the pins assume normal operation. When HIGH, TX+ is logic HIGH and TX- is logic
LOW.
RX+, RXSerial Receive Data
PECL Input
These pins are the 1000BASE-X port differential receiver pair, receiving a serial stream of data from the
network. These pins are connected to the copper or
fiber optic connectors.
When EWRAP is LOW, the pins assume normal operation. The pins are internally biased.
TXD[0:9]
Transmit Data
TTL Input
The TXD[0:9] pin is a set of 10 data signals which are
driven from the Physical Coding Sublayer (PCS) above.
The 10 bits of data are clocked in parallel on the rising
edge of REFCLK. TXD0 is transmitted first on TX±.
RXD[0:9]
Receive Data
TTL Output
The RXD[0:9] pin is a set of 10 data signals which are
sent to the Physical Coding Sublayer (PCS) above. The
10 bits of data are clocked out in parallel on the rising
edges of RCLK and RCLKN. RXD0 is received first on
RX±.
REFCLK
Reference Clock
TTL Input
This input is used for the 125-Mhz clock. The rising
edge of this clock latches TXD[0:9] into an input register. This clock serves as the reference clock at 1/10th
the baud rate for the PLL.
RCLK, RCLKN
Receive Clock
TTL Output
These pins provide the differential receive clock signals, derived from the RX± data stream, and are at
1/20th the baud rate of the receive stream. Parallel data
on RXD[0:9] is provided at each rising transition of
RCLK and RCLKN.
COM_DET
Comma Detect Indicator
TTL Output
Comma Detect is asserted to indicate that the incoming
word on RXD[0:9] contains a Comma character
(0011111xxx). COM_DET goes HIGH for half of a RCLK
period, and can be captured when RCKLN is rising.
In order for COM_DET to provide indication, EN_CDET
must be enabled (logic HIGH).
EWRAP
Loopback Enable
TTL Input
When EWRAP is asserted, the transmitted data stream
is sent back to the receiver through an internal loopback path. TX+ is logic HIGH, and TX- is logic LOW in
this mode.
This pin is logic LOW for normal operation.
TEST[1:3]
Factory Test Pins
Input
These pins should be tied to DVDD for normal operation.
TEST[4]
Factory Test Pin
Output
This pin should be left unconnected for normal operation.
DVDD
Power
These pins supply power to the digital blocks of the
device. They must be connected to a 3.3 V ±5% source.
DVDD_T
TTL Power
These pins supply power to the TTL blocks of the device. They must be connected to a 3.3 V ±5% source.
DVDD_P
PECL Power
These pins supply power to the PECL blocks of the device. They must be connected to a 3.3 V ±5% source. It
is critical that the signal supplied to these pins are
clean to ensure good performance of the device.
Am79761
7
P R E L I M I N A R Y
AVDD
Analog Power
DVSS_T
Ground
These pins supply power to the analog blocks of the
device. They must be connected to a 3m.3 V ± 5%
source and require careful decoupling to ensure
proper device performance.
These pins are the ground connections for the TTL
blocks. They must be connected to the common external ground plane.
DVSS
Ground
These pins are the ground connections for the digital
blocks. They must be connected to the common
external ground plane.
8
AVSS
Ground
These pins are the ground connections for the
analog blocks. They must be connected to an analog
ground plane.
Am79761
P R E L I M I N A R Y
FUNCTIONAL DESCRIPTION
Overview
Clock Synthesizer
The GigaPHY-SD device provides the PMA functionality
for 1000BASE-X systems. The GigiaPHY-SD communicates with the PCS through the 10-bit code groups and
communicates with the Physical Medium Dependent
(PMD) layer to transmit and receive data from the network, through either fiber optic or copper coax media.
The GigaPHY-SD device consists of the following
functional blocks:
n 1000BASE-X Transmit block including:
— Clock Synthesizer
— Serializer and Transmission interface
n 1000BASE-X Receive block including:
— Clock Recovery
Serializer
The Am79761 device accepts TTL input data as a parallel 10-bit character on the TXD[0:9] bus which is
latched into the input latch on the rising edge of
REFCLK. This data will be serialized and transmitted
on the TX PECL differential outputs at a baud rate of
ten times the frequency of the REFCLK input, with bit
TXD0 transmitted first. User data should be encoded
for transmission using the 8B/10B block code described in the IEEE 802.3 specification.
Transmission Character Interface
— Deserializer
An encoded byte is 10 bits and is referred to as a transmission character. The 10-bit interface on the
Am79761 device corresponds to a transmission character. This mapping is shown in Table 20.
— Word Alignment and synchronization
Table 20.
The Am79761 clock synthesizer multiplies the reference frequency provided on the REFCLK pin by 10 to
achieve a baud rate clock at nominally 1.25 GHz. The
clock synthesizer contains a fully monolithic PLL which
does not require any external components.
Transmission Order and Mapping of an 8B/10B Character
Parallel Data Bits
T9
T8
T7
T6
T5
T4
T3
T2
T1
T0
8B/10B Bit Position
j
h
g
f
i
e
d
c
b
a
Comma Character
X
X
X
1
1
1
1
1
0
0
First Data Bit
Transmitted
Last Data Bit
Transmitted
Clock Recovery
The Am79761 device accepts differential high speed
serial inputs on the RX± pins, extracts the clock and
retimes the data. The Am79761 clock recovery circuitry
is completely monolithic and requires no external components. For proper operation, the baud rate of the
data stream to be recovered should be within 0.01% of
ten times the REFCLK frequency. For example, if the
REFCLK used is 125 MHz, then the incoming serial
baud rate must be 1.25 gigabaud ±0.01 percent.
Deserializer
The re-timed serial bit stream is converted into a 10-bit
parallel output character. The Am79761 device provides
complementary TTL recovered clocks, RCLK and
RCLKN, which are at 1/20th of the serial baud rate. This
architecture is designed to simplify demultiplexing of the
10-bit data characters into a 20-bit half-word in the
downstream controller chip. The clocks are generated by
dividing down the high-speed clock which is phase
locked to the serial data. The serial data is re-timed by
the internal high-speed clock and deserialized.
The resulting parallel data will be captured by the
adjoining protocol logic on the rising edges of RCLK and
RCLKN. In order to maximize the setup and hold times
available at this interface, the parallel data is loaded into
the output register at a point nominally midway between
the transition edges of RCLK and RCLKN.
If serial input data is not present or does not meet the
required baud rate, the Am79761 will continue to produce a recovered clock so that downstream logic may
continue to function. The RCLK and RCLKN output
frequency under these circumstances may differ from
their expected frequency by no more than ±1 percent.
Am79761
9
P R E L I M I N A R Y
Word Alignment
The Am79761 device provides 7-bit comma character
recognition and data word alignment. Word synchronization is enabled by asserting EN_CDET HIGH. When
synchronization is enabled, the Am79761 device constantly examines the serial data for the presence of the
Comma character. This pattern is 0011111XXX, where
the leading zero corresponds to the first bit received.
The comma sequence is not contained in any normal
8B/10B coded data character or pair of adjacent characters. It occurs only within special characters, known
as K28.1, K28.5, and K28.7, which are defined specifically for synchronization purposes. Improper alignment
of the comma character is defined as any of the following conditions:
1. The comma is not aligned within the 10-bit transmission character such that TXD0...TXD6 =
“0011111.”
2. The comma straddles the boundary between two
10-bit transmission characters.
3. The comma is properly aligned but occurs in the received character presented during the rising edge
of RCLK rather than RCLKN.
When EN_CDET is HIGH and an improperly aligned
comma is encountered, the internal data is shifted in
such a manner that the comma character is aligned
properly in RXD[0:9]. This results in proper character
and half-word alignment. When the parallel data
alignment changes in response to an improperly
aligned comma pattern, some data which would have
been presented on the parallel output port may be
lost. However, the synchronization character and
subsequent data will be output correctly and properly
aligned. When EN_CDET is LOW, the current alignment of the serial data is maintained indefinitely,
regardless of data pattern.
When encountering a comma character, COM_DET is
driven HIGH to inform the user that realignment of the
parallel data field may have occurred. The COM_DET
pulse is presented simultaneously with the comma character and has a duration equal to the data, or half of an
RCLK period. The COM_DET signal is timed such that it
can be captured by the adjoining protocol logic on the
rising edge of RCLKN. Functional waveforms for
synchronization are given in Figure 18 and Figure 19.
Figure 18 shows the case when a comma character is
detected and no phase adjustment is necessary. It illustrates the position of the COM_DET pulse in relation to
the comma character on RXD[0:9]. Figure 19 shows the
case where K28.5 is detected, but it is out of phase and
a change in the output data alignment is required. Note
that up to three characters prior to the comma character
may be corrupted by the realignment process.
RCLK
RCLKN
COM_DET
RXD[0:9]
K28.5
TChar
TChar
TChar
Note : TChar = 10-bit Transmission Character
Figure 18.
10
21560A-4
Detection of a Properly Aligned Comma Character
Am79761
P R E L I M I N A R Y
RCLK
RCLKN
COM_DET
RXD[0:9]
K28.5
TChar
TChar
TChar
K28.5
TChar
Potentially Corrupted
21560A-5
Figure 19.
Receiving Two Consecutive K28.5 + TCharacter Transmission Words
Am79761
11
P R E L I M I N A R Y
ABSOLUTE MAXIMUM RATINGS
OPERATING RANGES
Storage Temperature . . . . . . . . . . . .-65° C to +150° C
Temperature (TA) 0° C to +70° C for 14 x 14 mm PQFP
Ambient Temperature Under Bias . .-55° C to +125° C
. . . . . . . . . . . . . 0° C to +50° C for 10 x 10 mm PQFP
Power Supply Voltage (VDD) . . . . . . . -0.5 V to +4.0 V
Power Supply Voltage (DVDD) . . . . . . . . . +3.3 V ±5%
DC Voltage (PECL Inputs) . . . . . .-0.5 V to VDD +0.5 V
Operating ranges define those limits between which
functionality of the device is guaranteed.
DC Voltage (TTL Inputs). . . . . . . . . . . -0.5 V to +5.5 V
Output Current (TTL Outputs) . . . . . . . . . . . . -±50 mA
Output Current (PECL Outputs) . . . . . . . . . . . -±50 mA
Maximum Input ESD (Human Body Model) . . . 1500 V
Stresses above those listed under Absolute Maximum
Ratings may cause per manent device failure.
Functionality at or above these limits is not implied.
Exposure to absolute maximum ratings for extended
periods may affect device reliability.
DC CHARACTERISTICS (over recommended operating conditions)
Symbol
Parameter Description
Test Conditions
Min
Typ
Max
Unit
VIH
Input HIGH voltage (TTL)
2.0
—
5.5
V
VIL
Input LOW voltage (TTL)
0
—
0.8
V
IIH
Input HIGH current (TTL)
VIN =2.4 V
—
50
500
µA
IIL
Input LOW current (TTL)
VIN =0.5 V
—
—
-500
µA
VOH
Output HIGH voltage (TTL)
IOH = -1.0 mA
2.4
—
—
V
VOL
Output LOW voltage (TTL)
IOL = +1.0 mA
—
—
0.5
V
∆VOUT75
TX Output differential peak-topeak voltage swing
75 Ω to VDD – 2.0 V
1200
—
2200
mVp-p
∆VOUT50
TX Output differential peak-topeak voltage swing
50 Ω to VDD – 2.0 V
1200
—
2200
mVp-p
∆VIN
Receiver differential peak-topeak Input Sensitivity RX
Internally biased to VDD/2
400
—
3200
mVp-p
IDD
Supply Current
Outputs open,
VDD = VDD max
—
210
290
mA
PD
Power dissipation
Outputs open,
VDD = VDD max
—
700
1000
mW
12
Am79761
P R E L I M I N A R Y
DVDD
DVDD
INPUT
Current
Limit
INPUT
R
INPUT
All Resistors
R
3.3K
DVSS
DVSS
REFCLK and TTL Inputs
High Speed Differential Input
(RX±)
A
B
Figure 20.
21560A-6
Input Structures
Am79761
13
P R E L I M I N A R Y
KEY TO SWITCHING WAVEFORMS
WAVEFORM
INPUTS
OUTPUTS
Must be
Steady
Will be
Steady
May
Change
from H to L
Will be
Changing
from H to L
May
Change
from L to H
Will be
Changing
from L to H
Don’t Care,
Any Change
Permitted
Changing,
State
Unknown
Does Not
Apply
Center
Line is HighImpedance
“Off” State
KS000010-PAL
AC CHARACTERISTICS
REFCLK
T1
TXD[0:9]
10 Bit Data
Symbol
Data Valid
T2
Data Valid
Data Valid
21560A-7
Figure 21.
Transmit Timing Waveforms
Table 21.
Transmit AC Characteristics
Parameter Description
Test Conditions
Min
Max
Unit
T1
Measured between the valid data
TXD[0:9] Setup time to the rising
level of TXD[0:9] to the 1.4 V point of
edge of REFCLK
REFCLK
1.5
—
ns
T2
TXD[0:9] hold time after the rising
edge of REFCLK
1.0
—
ns
TSDR,TSDF
TX± rise and fall time
—
300
ps
TLAT
Latency from rising edge of
REFCLK to TXD0 appearing on
TX±-
11bc - 1ns
—
—
14
20% to 80%, 75 Ω load to VSS, Tested
on a sample basis
bc = Bit clocks
ns = Nano second
Am79761
P R E L I M I N A R Y
AC CHARACTERISTICS (Continued)
T4
T3
RCLK
RCLKN
T1
RXD[0:9]
Data Valid
T2
Data Valid
Data Valid
21560A-8
Figure 22.
Table 22.
Symbol
Receive Timing Waveform
Receive AC Characteristics
Parameter Description
Test Conditions
Min
Max
Unit
T1
Data or COM_DET Valid prior
to RCLK/RCLKN rise
3.0
—
ns
T2
Data or COM_DET Valid after
RCLK or RCLKN rise
Measured between the 1.4 V
point of RCLK or RCLKN and a
valid level of RXD[0:9]. All
outputs driving 10 pF load.
2.0
—
ns
-500
500
ps
Whether or not locked to serial
data
-1.0
1.0
%
Between VIL(MAX) and VIH(MIN),
into 10 pf load.
—
2.4
ns
15 bc + 2 ns
34 bc + 2 ns
—
—
2.0
µs
—
40
ps
T3
Deviation of RCLK rising edge
to RCLKN rising edge delay
Nominal delay is 10 bit times.
from nominal.
Tested on sample basis
f
delay = ----------- ± T 3
10
baud
Deviation of RCLK, RCLKN
frequency from nominal.
T4
f REFCLK
- ± T4
f RCLK = ------------------2
TR, TF
RXD[0:9], COM_DET, RCLK,
RCLKN rise and fall time
Rlat
Latency from RX± to RXD[0:9]
TLOCK
Data acquisition lock time @
1.25 Gbps
8B/10B IDLE pattern.
Receive Data Jitter Power
dBc, RMS for 10-12 Bit Error
Ratio Tested on a sample basis
Receive Data
Jitter
1
-------------------------------2 × BitTime
∫
bc = Bit clock
ns = Nano second
Tested on a sample basis
PhaseNoise
100KHz
Am79761
15
P R E L I M I N A R Y
REFERENCE CLOCK REQUIREMENTS
TL
TH
Vih (min)
Vil (max)
REFCLK
Figure 23.
Table 23.
Symbol
REFCLK Timing Waveform
Reference Clock Requirements
Test Conditions
Min
Max
Units
Frequency Range
Range over which both transmit and
receive reference clocks on any link may be
centered
123
127
MHz
FO
Frequency Offset
Maximum frequency offset between
transmit and receive reference clocks on
one link
-200
200
ppm
DC
REFCLK duty cycle
Measured at 1.5 V
30
70
%
TRCR,TRCF
REFCLK rise and fall time
Between VIL(MAX) and VIH(MIN)
—
1.0
ns
FR
16
Parameter Description
21560A-9
Am79761
P R E L I M I N A R Y
MEASUREMENTS
Serial Input Rise and Fall Time
TTL Input and Output Rise and Fall Time
80%
Vih(min)
20%
Vil(max)
Tf
Tr
Tf
Tr
Receiver Input Eye Diagram Jitter Tolerance Task Mask
Bit Time
Amplitude
Eye Width%
Parametric Test Load Circuit
Serial Output Load
TTL AC Output Load
10 pF
75Ω
Z0 = 75W
VDD – 2.0 V
Figure 24.
21560A-10
Parametric Measurement Information
Am79761
17
P R E L I M I N A R Y
MEASUREMENTS (Continued)
Random Jitter Measurement
BERT
Pattern
Generator
DATA
DATA
CLK = 1.25 GHz
DATA = 00000 0000011111 11111
125 MHz
Trigger
Digitizing
Scope
125 MHz
Am79761
RJ
-K28.7
0011111000
-K28.7
0011111000
REFCLK
TXD[0:9]
TX+
TX-
1.25 Gbps
Single-Ended Measurement
Random jitter (RJ) measurements performed according to Fibre Channel 4.3 Annex A, Test Methods, Section
A.4.4. Measure standard deviation of all 50% crossing points. Peak to peak RJ is ±7 sigma of distribution.
Deterministic Jitter Measurement
BERT
Pattern
Generator
DATA
PAT SYNC
CLK = 1.25 GHz
DATA = 00000 0000011111 11111
125 MHz
Trigger
Digitizing
Scope
125 MHz
Am79761
DJ
-K28.5
0011111010
K28.5
1100000101
REFCLK
TXD[0:9]
TX+
TX-
1.25 Gbps
Single-Ended Measurement
TRIGGER
DATA
20 bit time
19 bit time
18 bit time
17 bit time
12 bit time
10 bit time
9 bit time
8 bit time
7 bit time
Deterministic jitter (DJ) measurements
performed according to Fibre Channel
4.3 Annex A, Test Methods, Section A.4.3.
Measure time of all the 50% points of
all ten transitions. DJ is the range of
the timing variation from expected.
21560A-11
2 bit time
Figure 25.
Transmitter Jitter Measurement Method
Transmitter Output Jitter Allocation
Trj
Serial data output random jitter
(RMS)
RMS, tested on a sample basis
TDJ
Serial data output deterministic
jitter (p-p)
Peak to peak, tested on a sample
basis (refer to Figure 8)
18
(refer to Figure 8)
Am79761
—
20
ps
—
100
ps
P R E L I M I N A R Y
THERMAL CONSIDERATIONS
The Am79761 is packaged in a 14-mm or a 10-mm
conventional PQFP with an internal heat spreader. These
packages use an industry-standard EIAJ footprint, but
have been enhanced to improve thermal dissipation. The
construction of the packages are as shown in Figure 26.
Plastic Molding Compound
Lead
Copper Heat Spreader
Figure 26.
21560A-12
Package Cross Section
Table 24.
Symbol
Die
Bond Wire
Thermal Resistance
Description
10 mm Value
14 mm Value
Units
θjc
Thermal resistance from junction to case
10.0
9.5
oC/W
θca
Thermal resistance from case to ambient in still air including
conduction through the leads.
50.8
29
oC/W
θca-100
Thermal resistance from case to ambient with 100 LFM airflow
41.2
26.1
oC/W
θca-200
Thermal resistance from case to ambient with 200 LFM airflow
36.9
23.8
oC/W
θca-400
Thermal resistance from case to ambient with 400 LFM airflow
31.8
20.5
oC/W
θca-600
Thermal resistance from case to ambient with 600 LFM airflow
27.8
17.9
oC/W
The Am79761 is designed to operate with a junction
temperature up to 105oC. The user must guarantee
that the temperature specification is not violated. With
the Thermal Resistances shown above, the 10x10
PQFP can operate in still air ambient temperatures of
50oC, while the 14x14 PQFP can operate in still air ambient temperatures of 72oC. If the ambient air temperature exceeds these limits then some form of cooling
through a heatsink or an increase in airflow must be
provided.
Notes:
1. 50oC=110oC-1W*(10oC/W+50.8oC/W)
2. 72oC=110oC-1W*(95oC/W+29oC/W)
Am79761
19
P R E L I M I N A R Y
PHYSICAL DIMENSIONS
PDH064
64-Pin (measured in millimeters)
Trademarks
Copyright © 1998 Advanced Micro Devices, Inc. All rights reserved.
AMD, the AMD logo, and combinations thereof are trademarks of Advanced Micro Devices, Inc.
GigaPHY is a trademark of Advanced Micro Devices, Inc.
Product names used in this publication are for identification purposes only and may be trademarks of their respective companies.
20
Am79761