ETC 78P2253-IGT

78P2253
E4/STM-1/STS-3/OC-3
Transceiver
Advanced Information
November 2000
DESCRIPTION
FEATURES
The 78P2253 is a transceiver IC designed for
139.264Mbit/s (E4) or 155.52Mbit/s (OC-3, STS-3 or
STM-1) transmission. It is used at the interface to a
75Ω coaxial cable using CMI coding or a fiber optic
module. Interface to digital framer circuits is
accomplished via a serial PECL or parallel CMOS
interface.
•
139.264Mbit/s or 155.52Mbit/s interface for
CMI coded transmission using 75Ω coaxial
cable
•
Compliant with ITU-T G.703, G.823 jitter
tolerance, Telcordia TR-NWT-00253
•
Integrated Clock Recovery Unit (CRU)
•
Serial PECL Interface
•
Four and Eight bit Parallel CMOS Interfaces
•
PECL Interfaces for connection to Fiber
Optic Modules for SONET OC3 applications
•
Adaptive Equalization
•
Integrated Clock Multiplier PLL
•
Advanced BiCMOS Process
The transmitter includes a PLL to multiply the
reference clock to the transmission frequency. The
receiver provides adaptive equalization for accurate
clock and data recovery. The 78P2253 is built in a
BiCMOS technology for high performance and low
power operation. It operates with a 3.3V or 5V power
supply and is packaged in a 64-pin TQFP.
CKIN
Crystal
Oscillator
CM I/ECL
8BIT/$BIT
HUB/HOST
PAR/SER
E4/SONET
XTAL2
XTAL1
BLOCK DIAGRAM
Clock
Generator
CMIOUTP
CMIOUTN
Binary
to CMI
TXCK
ECLOUTP
ECLOUTN
TXCKP,N
RLBACK
TXDTP,N
TXDT[7:0]
RXDTP,N
RXDT[7:0]
ECLINP
ECLINN
CMI to
Binary
Clock
Recovery
CMIINP
CMIINN
Adaptive
Equalizer
RXCKP,N
RXCK
LLBACK
LF
RFO
LOS
Signal
Detector
Bias
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
FUNCTIONAL DESCRIPTION
matching resistors. In CMI mode the transmitter
shapes the transmit pulses to meet the appropriate
template and the adaptive equalizer corrects the
received signal for dispersive attenuation. The
ECLOUTP and ECLOUTN pins are inoperative and
should be left open.
The 78P2253 contains all the necessary transmit
and receive circuitry for connection between
139.264Mbit/s or 155.52Mbit/s signals and digital
Framer/Deframer ICs.
Operating Rate
When the CMI/ECL pin is low the chip is in ECL
mode and a fiber optics transceiver is used. The
output data signal from the pins ECLOUTP and
ECLOUTN have PECL levels. In this mode, the CMI
pins are inoperative and should be left open. The
CMI encoder and decoder are disabled.
The 78P2253 has a variety of operating modes and
rates. They are summarized in the tables below.
More detailed descriptions can be found in the
sections that follow.
Standard
E4/SONET
CMI/ECL
Rate
(Mbit/s)
Reference
Frequency
Active I/O
TRANSMITTER OPERATION
(MHz)
OC-3
0
0
155.52
19.44
ECL
0
1
155.52
19.44
CMI
1
0
139.264
17.408
ECL
1
1
139.264
17.408
CMI
The transmitter section generates an analog signal
for transmission through a transformer onto the
coaxial cable or fiber optic module.
STM1 optic
STS-3
STM-1 Coax
E4
When the PAR/SER pin is low the chip is in serial
mode. Serial data is input to the 78P2253 on the
TXDTP and TXDTN pins at PECL levels. The data is
timed with the clock generated by the 78P2253 on
the TXCKP and TXCKN pins. In this mode the
8BIT/$BIT pin is ignored.
The digital interface of the 78P2253 can be either
Serial PECL, 4-bit Parallel CMOS or 8-bit Parallel
CMOS.
Mode
PAR/SER
8BIT/BIT
Data pins
Clock
pins
Clock
Frequency
(MHz)
Serial
0
X
TXDTP,N
TXCKP,N
155.52(Sonet)
RXDTP,N
RXCKP,N
139.264 (E4)
4-bit
Parallel
1
0
TXDT[3:0]
TXCK
38.88(Sonet)
RXDT[3:0]
RXCK
34.816(E4)
8-bit
Parallel
1
TXDT[7:0]
TXCK
19.44(Sonet)
RXDT[7:0]
RXCK
17.408(E4)
1
When the PAR/SER pin is high the chip is in parallel
mode. Parallel data is in put to the 78P2253 on the
TXDT[7:0] pins. The input data is timed with the
clock output from TXCK. When 8BIT/$BIT is high all
eight bits of TXDT[7:0] are used and the clock
frequency at TXCK is one-eighth the standard
frequency. When 8BIT/$BIT is low the lower four
bits, TXCK[3:0] are used and TXCK is one-fourth the
standard frequency.
Transmit timing is derived from either the reference
clock (the crystal oscillator or CKIN), or the
recovered receive clock. LLBACK and RLBACK
control the local and remote loopback modes
respectively.
LLBACK
RLBACK
HUB/HOST
Transmit Clock derived from
0
0
1
Reference
1
0
1
Reference
X
1
1
Receiver
X
X
0
Receiver
The first bit output from the ECL/CMI interface is the
most significant bit on the parallel interface, TXDT7
in eight bit mode, TXDT3 in four bit mode.
The clock is generated by a phase-locked oscillator
(PLO). The PLO is locked to a crystal oscillator
operating at one-eighth of the standard clock
frequency, 19.44MHz for OC-3, STS-3 and STM-1
and 17.408MHz for E4. This is shown in Figure 1a.
An external clock signal at CKIN may also be
substituted for a crystal as the reference frequency
for the chip. In this mode, XTL1 and XTL2 must be
configured as shown in Figure 1b. Note that the chip
can be in either ECL or CMI mode when using either
an external clock or a crystal for the reference. In
serial mode the reference clock is output from
TXCK. In parallel mode, the parallel transmit clock is
output from TXCK.
Medium Choices
The CMI/ECL pin selects one of two media for
transmission.
When the CMI/ECL pin is high, the chip is in CMI
mode and a 75Ω coaxial cable is used as the
transmission medium. In this mode, the CMIOUTP
and CMIOUTN pins are active. They connect the
chip to the coaxial cable through a transformer and
2
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
TRANSMITTER OPERATION (continued)
RECEIVER OPERATION
XTAL2
The receiver accepts serial, CMI coded data, at
155.52Mbit/s or 139.264Mbit/s from either the CMI
or the ECL inputs. In CMI mode, the inputs CMIINP
and CMIINN receive the input signal from a coaxial
cable that is transformer-coupled to the chip. The
ECL pins should be left open. In ECL mode, the pins
ECLINP and ECLINN receive the input signal.
CKIN
In CMI mode, the received signal is equalized for
dispersive cable attenuation and decoded in the CMI
to binary decoder.
XTAL1
A clock signal is recovered using a low jitter PLL
circuit.
FIGURE 1A: USING CRYSTAL
The data is converted to binary by the CMI to Binary
decoder.
In serial mode, the received data is output on the
RXDTP and RXDTN pins and the recovered clock is
output on the RXCKP and RXCKN pins.
XTAL1
In parallel mode, the received data is converted to
parallel, eight bits if 8BIT/$BIT is high and four if it is
low. The first bit received will arrive on the most
significant output pin, RXDT[7] in eight bit mode and
RXDT3 in four bit mode.
XTAL2
17.283 MHz (E4)
19.440 MHz (Sonet)
CKIN
The LOS pin goes high when the signal detector
detects a loss-of-signal condition.
LOOPBACK OPERATION
FIGURE 1B: USING EXTERNAL CLOCK
The 78P2253 is capable of performing signal
loopback in two ways The RLBACK pin selects the
remote loopback mode. In this mode, the received
signal is “looped back” and sent out of transmitter in
place of the transmit input signal.
In ECL mode the data signal is converted to CMI
code by the Binary to CMI encoded.
The HUB/HOST input changes the reference signal
for the clock generator. In the hub mode (HUB/HOST
high), the transmit clock reference is derived from
either the crystal oscillator or CKIN. In host mode
(HUB/HOST low), the transmit clock reference is
derived from the recovered receive clock.
The LLBACK pin selects the local loop-back mode,
and causes the receiver to use the transmitter output
signal as its input. Local loopback is disabled when
HUB/HOST is low or RLBACK is high.
3
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
PIN DESCRIPTION
LEGEND
TYPE
DESCRIPTION
A
Analog Pin
CI
CMOS Digital Input
CO
CMOS Digital Output
TYPE
PI
PO
S
DESCRIPTION
PECL Digital Input
PECL Digital Output
Supply Pin
TRANSMIT PINS
NAME
PIN
TYPE
TXDTP
19
PI
Transmit Data Inputs - Serial Mode.
TXDTN
20
TXCKP
22
PO
Transmit Clock Output - Serial Mode.
TXCKN
23
11-18
CI
Transmit Data Inputs – Parallel Mode. TXDT[7:4] are ignored in 4 bit
mode.
10
CO
Reference Clock Output – Serial mode.
TXDT[7:0]
TXCK
DESCRIPTION
Transmit Clock Output – Parallel Mode.
CMIOUTP
60
CMIOUTN
59
ECLOUTP
56
ECLOUTN
55
A
Transmit Output in CMI mode.
No signal is output in ECL mode.
PO
Transmit Outputs for ECL mode.
No signal is output in CMI mode.
RECEIVE PINS
NAME
PIN
TYPE
CMIINP
50
A
CMIINN
49
DESCRIPTION
Receive inputs in CMI mode.
Transformer coupled from the coaxial cable.
Ignored in ECL mode.
ECLINP
ECLINN
52
51
PI
Receiver inputs in ECL mode.
Ignored in CMI mode.
RXCKP
25
PO
Recovered Receive Clock – Serial Mode.
RXCKN
26
RXCK
38
CO
Recovered Receive Clock – Parallel Mode.
RXDTP
27
PO
Receive data – Serial Mode.
RXDTN
28
CO
Receive data – Parallel Mode. In 4 bit mode RXDT[3:0] are used and
RXDT[7:4] are pulled low.
RXDT[7:0]
30-37
4
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
PIN DESCRIPTION (continued)
REFERENCE CLOCK PINS
NAME
PIN
TYPE
DESCRIPTION
XTAL1
5
A
Crystal Pins. Connect as in Figure 1a.
XTAL2
6
CKIN
9
CI
Reference clock input. The crystal oscillator connections should be
left open.
CONTROL AND STATUS PINS
NAME
PIN
TYPE
RLBACK
41
CI
Loopback receiver output to transmitter input.
LLBACK
42
CI
Loopback transmitter output to receiver input. Disabled when
HUB/HOST is low or RLBACK is high.
HUB/HOST
2
CI
In HUB mode (input high) the transmit reference clock is derived from
the CKIN pin or the crystal oscillator. In HOST mode (input low) the
transmit reference clock is derived from the recovered receive clock.
CMI/ECL
1
CI
Selects CMI (input high) or ECL (input low) modes.
E4/SONET
64
CI
When high, E4 (139.264 Mbit/s) operation is selected. When low,
STM-1/STS-3/OC-3 (155.52Mbit/s) operation is selected.
CI
Selects 8 bit parallel data when high and 4 bit parallel mode when
low. In serial mode this pin is ignored.
39
CO
High during a loss-of-signal condition.
PIN
TYPE
RFO
46
A
External reference resistor.
LF
44
A
PLL loop filter capacitor.
8BIT/$BIT
LOS
DESCRIPTION
ANALOG PINS
NAME
DESCRIPTION
POWER SUPPLY PINS
It is recommended that all VCC pins be connected to a single power supply plane and all GND pins be connected
to a single ground plane.
NAME
PIN
TYPE
DESCRIPTION
VCC
43
S
Power Supply.
GND
4, 7, 21,
29, 45,
47, 48,
58, 61
S
Ground.
5
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
ELECTRICAL SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS
Operation beyond these limits may permanently damage the device.
PARAMETER
Supply Voltage
Storage Temperature
Pin Voltage
Pin Current
RATING
7 VDC
-65 to 150° C
-0.3 to (V CC+0.3) VDC
±100 mA
RECOMMENDED OPERATING CONDITIONS
Unless otherwise noted all specifications are valid over these temperatures and supply voltage ranges.
PARAMETER
RATING
DC Voltage Supply, VCC
3.3 ± 0.3 VDC; 5 ± 0.5 VDC
Ambient Operating Temperature
-40 to 85°C
DC CHARACTERISTICS:
PARAMETER
SYMBOL
Supply Current (Parallel Mode)
Supply Current
(Serial Mode)
Icc
Icc
CONDITIONS
MIN
NOM
MAX
UNIT
Vcc = 3.3V
140
165
mA
Vcc = 5.0V
150
175
VCC = 3.3V
210
245
VCC = 5.0V
280
330
NOM
MAX
UNIT
0.8
V
mA
DIGITAL INPUT CHARACTERISTICS
Pins of type CI
PARAMETER
SYMBOL
CONDITIONS
MIN
Input Voltage Low
Vil
Input Voltage High
Vih
2.0
Iil, Iih
-10
Input Current
Input Capacitance
Cin
V
10
10
µA
pF
Pins of type PI
PARAMETER
SYMBOL
CONDITIONS
Input Voltage Low
Vil
Relative to Vcc
Input Voltage High
Vih
Relative to Vcc
6
MIN
-1.1
NOM
MAX
UNIT
-1.5
V
V
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
ELECTRICAL SPECIFICATIONS (continued)
DIGITAL OUTPUT CHARACTERISTICS
Pins of type CO
PARAMETER
SYMBOL
CONDITIONS
Output Voltage Low
Vol
Iol = 2mA
Output Voltage High
Voh
Ioh = -2mA
Transition Time
MIN
Tt
NOM
MAX
UNIT
0.6
V
Vcc –
0.6
V
3.5
ns
Pins of type PO
PARAMETER
Output Voltage Low
SYMBOL
Vol
CONDITIONS
Relative to Vcc
MIN
NOM
-1.8
MAX
-1.6
UNIT
V
Output Voltage High
Voh
Relative to Vcc
-1.1
-0.8
V
Rise Time
Tr
1
ns
Fall Time
Tf
1
ns
DIGITAL TIMING CHARACTERISTICS:
Reference Clock Interface
CKIN
TXCK
TCK
PARAMETER
CKIN to TXCK Propagation
Delay
SYMBOL
CONDITIONS
TCK
MIN
NOM
20
7
MAX
UNIT
ns
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
ELECTRICAL SPECIFICATIONS (continued)
DIGITAL TIMING CHARACTERISTICS
Transmit Interface
TXCKP TXCKN
TXDTP TXDTN
TSUs
PARAMETER
SYMBOL
THs
CONDITIONS
MIN
NOM
MAX
UNIT
Transmit Setup Time
TSUs
Serial Mode
1.0
ns
Transmit Hold Time
THs
Serial Mode
-0.5
ns
TXCKP,N Duty Cycle
40
60
%
MAX
UNIT
TXCK
TXDT[7:0]
TSUp
PARAMETER
THp
SYMBOL
CONDITIONS
Transmit Setup Time
TSUp
Parallel Mode
2.5
ns
Transmit Hold Time
THp
Parallel Mode
0.1
ns
TXCK Duty Cycle
MIN
40
8
NOM
60
%
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
ELECTRICAL SPECIFICATIONS (continued)
DIGITAL TIMING CHARACTERISTICS
Receive Interface
RXCKP RXCKN
RXDTP RXDTN
PARAMETER
Receive Propagation Delay
SYMBOL
TPROPs
TPROPs
CONDITIONS
MIN
Serial Mode
RXCKP,N Duty Cycle
NOM
MAX
1.0
40
UNIT
ns
60
%
MAX
UNIT
RXCK
RXDT[7:0]
TPROPp
PARAMETER
Receive Propagation Delay
SYMBOL
TPROPs
CONDITIONS
MIN
Serial Mode
RXCKP,N Duty Cycle
4.0
40
9
NOM
ns
60
%
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
ELECTRICAL SPECIFICATIONS (continued)
TRANSMITTER OUTPUT JITTER
The transmit jitter specification ensures compliance with ITU-T G.823 and G.825 and ANSI T1.105.03-1994 for
all supported rates. The corner frequency of the transmit PLL is nominally 3.0 MHz.
Jitter
Detector
Measured Jitter
Amplitude
20dB/decade
Transmitter
Output
200 Hz
PARAMETER
CONDITION
Transmitter Output Jitter
200 Hz to 3.5 MHz
3.5 MHz
MIN
NOM
MAX
UNIT
0.075
UI
TRANSMITTER SPECIFICATIONS FOR CMI INTERFACE IN E4 MODE
Bit Rate: 139.264Mbit/s ± 15ppm
Code: coded mark inversion (CMI)
The following specifications are met with the external components for E4 operation, above, and configured with
a recommended 1:1 transformer as in Figure 10. With the coaxial output port driving a 75Ω load, the output
pulses conform to the templates in Figure 4 and Figure 5.
PARAMETER
CONDITION
MIN
Peak-to-peak Output Voltage
Template
0.9
Rise/ Fall Time
10-90%
Transition Timing Tolerance
Negative Transitions
NOM
MAX
UNIT
1.1
V
2
ns
-0.1
0.1
ns
Positive Transitions at Interval
Boundaries
-0.5
0.5
ns
Positive Transitions at midinterval
-0.35
0.35
ns
PARAMETER
CONDITION
MIN
MAX
UNIT
Return Loss
7MHz to 240MHz
TRANSMISSION PERFORMANCE
10
15
NOM
dB
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
ELECTRICAL SPECIFICATIONS (continued)
V
0.60
T = 7.18ns
(Note 1)
(Note 1)
Nominal
Pulse
0.55
0.50
0.45
0.40
1.795 ns
1ns
0.1ns
1ns
0.1ns
-0.05
-0.40
1ns
0.1ns
0.35ns
0.05
1.795 ns
0.1ns
0.35ns
Nominal
Zero Level
(Note 2)
1ns
1ns
1ns
-0.45
-0.50
-0.55
1.795 ns
1.795 ns
(Note 1)
(Note 1)
-0.60
Note 1 – The maximum “steady state” amplitude should not exceed the 0.55V limit. Overshoots and other transients are permitted to fall
into the shaded area bounded by the amplitude levels 0.55V and 0.6V, provided that they do not exceed the steady state level by more
than 0.05V.
Note 2 – For all measurements using these masks, the signal should be AC coupled, using a capacitor of not less than 0.01 µF, to the
input of the oscilloscope used for measurements. The nominal zero level for both masks should be aligned with the oscilloscope trace with
no input signal. With the signal then applied, the vertical position of the trace can be adjusted with the objective of meeting the limits of the
masks. Any such adjustment should be the same for both masks and should not exceed ±0.05V. This may be checked by removing the
input signal again and verifying that the trace lies with ±0.05V of the nominal zero level of the masks.
Note 3 – Each pulse in a coded pulse sequence should meet the limits of the relevant mask, irrespective of the state of the preceding or
succeeding pulses, with both pulse masks fixed in the same relation to a common timing reference, i.e. with their nominal start and finish
edges coincident. The masks allow for HF jitter caused by intersymbol interference in the output stage, but not for jitter present in the timing
signal associated with the source of the interface signal. When using an oscilloscope technique to determine pulse compliance with the
mask, it is important that successive traces of the pulses overlay in order to suppress the effects of low frequency jitter. This can be
accomplished by several techniques [e.g. a) triggering the oscilloscope on the measured waveform or b) providing both the oscilloscope
and the pulse output circuits with the same clock signal].
Note 4 – For the purpose of these masks, the rise time and decay time should be measured between –0.4V and 0.4V, and should not
exceed 2ns.
FIGURE 4 – MASK OF A PULSE CORRESPONDING TO A BINARY ZERO IN E4 MODE
11
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
ELECTRICAL SPECIFICATIONS (continued)
V
T = 7.18ns
0.60
0.55
(Note 1)
(Note 1)
0.50
0.45
1ns
0.40
0.1ns
1ns
0.5ns
0.1ns
0.5ns
Nominal
Pulse
0.05
Nominal
Zero Level
(Note 2)
-0.05
3.59ns
3.59ns
1.35ns
-0.40
-0.45
-0.50
1.35ns
1ns
1ns
1.795 ns
1.795 ns
-0.55
(Note 1)
-0.60
Note 1 – The maximum “steady state” amplitude should not exceed the 0.55V limit. Overshoots and other transients are permitted to fall into the
shaded area bounded by the amplitude levels 0.55V and 0.6V, provided that they do not exceed the steady state level by more than 0.05V.
Note 2 – For all measurements using these masks, the signal should be AC coupled, using a capacitor of not less than 0.01 µF, to the input of the
oscilloscope used for measurements. The nominal zero level for both masks should be aligned with the oscilloscope trace with no input signal. With
the signal then applied, the vertical position of the trace can be adjusted with the objective of meeting the limits of the masks. Any such adjustment
should be the same for both masks and should not exceed ±0.05V. This may be checked by removing the input signal again and verifying that the
trace lies with ±0.05V of the nominal zero level of the masks.
Note 3 – Each pulse in a coded pulse sequence should meet the limits of the relevant mask, irrespective of the state of the preceding or
succeeding pulses, with both pulse masks fixed in the same relation to a common timing reference, i.e. with their nominal start and finish edges
coincident. The masks allow for HF jitter caused by intersymbol interference in the output stage, but not for jitter present in the timing signal
associated with the source of the interface signal. When using an oscilloscope technique to determine pulse compliance with the mask, it is
important that successive traces of the pulses overlay in order to suppress the effects of low frequency jitter. This can be accomplished by several
techniques [e.g. a) triggering the oscilloscope on the measured waveform or b) providing both the oscilloscope and the pulse output circuits with the
same clock signal].
Note 4 – For the purpose of these masks, the rise time and decay time should be measured between –0.4V and 0.4V, and should not exceed 2ns.
Note 5 –The inverse pulse will have the same characteristics, noting that the timing tolerance at the level of the negative and positive transitions are
± 0.1ns and ±0.5ns respectively.
Figure 5 – Mask of a Pulse corresponding to a binary One in E4 mode.
12
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
ELECTRICAL SPECIFICATIONS (continued)
TRANSMITTER SPECIFICATIONS FOR CMI INTERFACE IN STS-3 (STM-1) MODE
Bit Rate: 155.52Mbit/s ± 20ppm
Code: coded mark inversion (CMI)
The following specifications are met with the external components for STS-1 operation configured with a
recpmmended 1:1 transformer as in Figure 10. With the coaxial output port driving a 75Ω load, the output
pulses conform to the templates in Figure 6 and Figure 7.
PARAMETER
CONDITION
MIN
Peak-to-peak Output Voltage
Template
0.9
Rise/ Fall Time
10-90%
Transition Timing Tolerance
Negative Transitions
NOM
MAX
UNIT
1.1
V
2
ns
-0.1
0.1
ns
Positive Transitions at Interval
Boundaries
-0.5
0.5
ns
Positive Transitions at midinterval
-0.35
0.35
ns
PARAMETER
CONDITION
MIN
MAX
UNIT
Return Loss
7MHz to 240MHz
TRANSMISSION PERFORMANCE
13
15
NOM
dB
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
ELECTRICAL SPECIFICATIONS (continued)
V
0.60
0.55
T = 6.43ns
(Note 1)
(Note 1)
Nominal
Pulse
0.50
0.45
1ns
0.40
0.1ns
1.608ns
1ns
0.1ns
-0.05
-0.40
-0.45
-0.50
-0.55
-0.60
1ns
0.1ns
0.35ns
0.05
1.608ns
0.1ns
0.35ns
Nominal
Zero Level
(Note 2)
1ns
1ns
1.608ns
1ns
1.608ns
(Note 1)
(Note 1)
Note 1 – The maximum “steady state” amplitude should not exceed the 0.55V limit. Overshoots and other transients are permitted to fall into
the shaded area bounded by the amplitude levels 0.55V and 0.6V, provided that they do not exceed the steady state level by more than
0.05V.
Note 2 – For all measurements using these masks, the signal should be AC coupled, using a capacitor of not less than 0.01 µF, to the input
of the oscilloscope used for measurements. The nominal zero level for both masks should be aligned with the oscilloscope trace with no input
signal. With the signal then applied, the vertical position of the trace can be adjusted with the objective of meeting the limits of the masks. Any
such adjustment should be the same for both masks and should not exceed ±0.05V. This may be checked by removing the input signal again
and verifying that the trace lies with ±0.05V of the nominal zero level of the masks.
Note 3 – Each pulse in a coded pulse sequence should meet the limits of the relevant mask, irrespective of the state of the preceding or
succeeding pulses, with both pulse masks fixed in the same relation to a common timing reference, i.e. with their nominal start and finish
edges coincident. The masks allow for HF jitter caused by intersymbol interference in the output stage, but not for jitter present in the timing
signal associated with the source of the interface signal. When using an oscilloscope technique to determine pulse compliance with the mask,
it is important that successive traces of the pulses overlay in order to suppress the effects of low frequency jitter. This can be accomplished
by several techniques [e.g. a) triggering the oscilloscope on the measured waveform or b) providing both the oscilloscope and the pulse
output circuits with the same clock signal].
Note 4 – For the purpose of these masks, the rise time and decay time should be measured between –0.4V and 0.4V, and should not
exceed 2ns.
Figure 6 – Mask of a Pulse corresponding to a binary Zero in STS-3 mode.
14
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
V
0.60
0.55
6.43ns
(Note 1)
(Note 1)
0.50
0.45
0.40
1ns
0.1ns
1ns
0.5ns
0.1ns
0.5ns
Nominal
Pulse
0.05
Nominal
Zero Level
(Note 2)
-0.05
3.215ns
3.215ns
1.2ns
-0.40
-0.45
-0.50
1.2ns
1ns
1ns
1.608ns
1.608ns
-0.55
(Note 1)
-0.60
Note 1 – The maximum “steady state” amplitude should not exceed the 0.55V limit. Overshoots and other transients are permitted to fall into the
shaded area bounded by the amplitude levels 0.55V and 0.6V, provided that they do not exceed the steady state level by more than 0.05V.
Note 2 – For all measurements using these masks, the signal should be AC coupled, using a capacitor of not less than 0.01 µF, to the input of the
oscilloscope used for measurements. The nominal zero level for both masks should be aligned with the oscilloscope trace with no input signal.
With the signal then applied, the vertical position of the trace can be adjusted with the objective of meeting the limits of the masks. Any such
adjustment should be the same for both masks and should not exceed ±0.05V. This may be checked by removing the input signal again and
verifying that the trace lies with ±0.05V of the nominal zero level of the masks.
Note 3 – Each pulse in a coded pulse sequence should meet the limits of the relevant mask, irrespective of the state of the preceding or
succeeding pulses, with both pulse masks fixed in the same relation to a common timing reference, i.e. with their nominal start and finish edges
coincident. The masks allow for HF jitter caused by intersymbol interference in the output stage, but not for jitter present in the timing signal
associated with the source of the interface signal. When using an oscilloscope technique to determine pulse compliance with the mask, it is
important that successive traces of the pulses overlay in order to suppress the effects of low frequency jitter. This can be accomplished by several
techniques [e.g. a) triggering the oscilloscope on the measured waveform or b) providing both the oscilloscope and the pulse output circuits with
the same clock signal].
Note 4 – For the purpose of these masks, the rise time and decay time should be measured between –0.4V and 0.4V, and should not exceed 2ns.
Note 5 –The inverse pulse will have the same characteristics, noting that the timing tolerance at the level of the negative and positive transitions
are ± 0.1ns and ±0.5ns respectively.
Figure 7 – Mask of a Pulse corresponding to a binary One in STS-3 mode
15
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
ELECTRICAL SPECIFICATIONS (continued)
RECEIVER SPECIFICATIONS
The following specifications are met with the external components.
PARAMETER
CONDITION
MIN
NOM
LOS Threshold
MAX
0.1
UNIT
V
RECEPTION PERFORMANCE
Return Loss
7MHz to 240MHz
15
dB
RECEIVER JITTER TOLERANCE
STS-3 and OC-3 jitter tolerance specifications are in ANSI T1.105.05-1994 and Telcordia TR-NWT-000253,
Issue 2, Dec. 1991. STM-1 specifications are in ITU-T G.825. They are identical except that STM-1 specifies
both jitter and wander. The E4 specifications are found in ITU-T G.823. The STM-1 specification is the tightest
and covers the largest frequency range.
10000
1000
100
STM-1
E4
10
1
0.1
0.01
1.E-06
1.E-05
1.E-04
1.E-03
1.E-02
1.E-01
1.E+00
1.E+01
1.E+02
1.E+03
1.E+04
1.E+05
1.E+06 1.E+07
PARAMETER
CONDITION
MIN
Receiver Jitter Tolerance
12µHz to 178µHz
2800
1.6mHz to 15.6mHz
Note 1: Not tested in production
311
125mHz to 19.3 Hz
39
500Hz to 6.5kHz
1.5
65kHz to 3.5MHz
0.15
16
NOM
MAX
UNIT
UI
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
ELECTRICAL SPECIFICATIONS (continued)
RECEIVER JITTER TRANSFER FUNCTION
The receiver clock recovery loop filter characteristics such that the receiver has the following transfer function.
0
-1
-2
-3
-4
-5
-6
-7
-8
-9
-10
1.00E+03
1.00E+04
1.00E+05
1.00E+06
1.00E+07
The corner frequency of the PLL is approximately 250 kHz.
PARAMETER
CONDITION
Receiver Jitter transfer function
below 250 kHz
MIN
Jitter transfer function roll-off
NOM
20
Note 1: Not tested in production
MAX
UNIT
0.1
dB
dB per
decade
17
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
ELECTRICAL SPECIFICATIONS (continued)
RECEIVER SPECIFICATIONS FOR CMI INTERFACE
The following specifications are met with the external components for E4 operation, above, and configured with
a 1:1 recommended. The input signal is assumed compliant with ITU-T G.703 and attenuated by the dispersive
loss of a cable. The minimum cable loss is 0dB and the maximum is shown in Figure 8.
The “Worst Case” line corresponds to the01 ITU-T G.703 recommendation. The “Typical” line corresponds to a
typical installation referred to in ANSI T1.102-1993. The receiver is tested using the cable model on page n. It is
a lumped element approximation of the “Worst Case” line.
30
Attenuation (dB)
25
20
15
10
5
0
1.00E+05
1.00E+06
1.00E+07
1.00E+08
Frequency (Hz)
Worst Case
Typical
Figure 8: Typical and worst-case Cable attenuation
18
1.00E+09
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
APPLICATION INFORMATION
EXTERNAL COMPONENTS:
COMPONENT
PIN(S)
VALUE
UNITS
TOLERANCE
Reference Resistor
RFO
31.6
kΩ
1%
Filter Capacitor
LF1
150
nF
10%
VALUE
UNITS
TOLERANCE
1:1
3%
TOLERANCE
TRANSFORMER SPECIFICATIONS:
COMPONENT
Turns Ratio
Suggested Manufacturer: Pulse, MiniCircuits
CRYSTAL SPECIFICATIONS:
E4 Operation
COMPONENT
VALUE
UNITS
Center Frequency
17.408
MHz
27
pF
VALUE
UNITS
19.44
MHz
27
pF
Load Capacitor – XTAL1 to ground; XTAL2 to ground
CRYSTAL SPECIFICATIONS:
OC-3, STM-1, STS-3 Operation
COMPONENT
Center Frequency
Load Capacitor – XTAL1 to ground; XTAL2 to ground
19
TOLERANCE
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
APPLICATION INFORMATION (continued)
RTERM
RBIAS
RBIAS
FIGURE 9. PECL INTERFACE
PECL INTERFACE COMPONENTS:
COMPONENT
Output Bias Resistor, RBIAS
VALUE
UNITS
TOLERANCE
VCC = 5v
250
Ω
5%
VCC = 3.3V
140
Ω
5%
100
Ω
5%
Termination Resistor, RTERM
When the PECL signals travel one inch or less, lower power operation can be achieved by increasing RBIAS and
eliminating RTERM.
20
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
VCC
VCC
C18
C19
C20
0.1uF
0.01uF
C2
+
0.1uF
GND
U1
VCC
VCC
VCC
VCC
VCC
VCC
VCC
VCC
3
8
24
40
43
53
54
57
4.7uF
RX1
T1
1
5
1
50
R1 75 1%
LOS
CMIINP
2
2
49
R12
31.6K
ADT1-1WT
46
C8
VCC
9
0.1uF
C26
5
8
C1
0.1uF
27pF
Vcc
U2
1 ENA OUT 5
CKIN
XTAL1
CRYSTAL
Y1
GND
Can oscillator
or sigle crystal
4
Crystal Osc.
VCC
Isolated ground under
Transformer output
J2
TX1
C27
27pF
6
S1
1
2
3
4
5
6
7
8
1
2
62
63
64
42
41
T2
1
6
XTAL2
SW DIP-8
16
15
14
13
12
11
10
9
1
60
R2 301 1%
44
1uF
CMINN
RFO
CMI/ECL
HUB/HOST
PAR/SER
8BIT/4BIT
E4/SONET
LLBACK
RLBACK
D2 LED
1
2
R12
510
C28
LF
6
39
RXCK
RXDT7
RXDT6
RXDT5
RXDT4
RXDT3
RXDT2
RXDT1
RXDT0
TXDT7
TXDT6
TXDT5
TXDT4
TXDT3
TXDT2
TXDT1
TXDT0
TXCK
38
30
31
32
33
34
35
36
37
33
11
12
13
14
15
16
17
18
10
J1
13
25
12
24
11
23
10
22
9
21
8
20
7
19
6
18
5
17
4
16
3
15
2
14
1
CMIOUTP
C9
4
3
C3
ADT1-1WT
0.1uF
59
CMIOUTN
GND
GND
GND
GND
GND
GND
GND
GND
GND
2
2
4
7
21
29
45
47
48
58
61
0.1uF
78P2253
FIGURE 10: RECOMMENDED APPLICATION CIRCUIT, STM-1 COAX SERIAL INTERFACE
21
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
MECHANICAL SPECIFICATIONS
64-TQFP Mechanical Specification
22
78P2253
E4/STM-1/STS-3/OC-3
Transceiver
PACKAGE PIN DESIGNATIONS
CMIINN
CMIINP
ECLINP
VCC
VCC
ECLOUTN
ECLOUTP
VCC
GND
CMIOUTN
CMIOUTP
GND
PAR/ SER
8BIT/$BIT
E4/SONET
ECLINN
CAUTION: Use handling procedures necessary for
a static sensitive component.
(Top View)
64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49
CMI/ECL
1
48
GND
HUB/HOST
2
47
GND
VCC
3
46
RFO
GND
4
45
GND
XTAL1
5
44
LF
XTAL2
6
43
VCC
GND
7
42
LLBA CK
VCC
8
41
RLBACK
CKIN
9
40
VCC
TXCK
10
39
LOS
TXDT7
11
38
RXCK
TXDT6
12
37
RXDT0
TXDT5
13
36
RXDT1
TXDT4
14
35
RXDT2
TXDT3
15
34
RXDT3
TXDT2
16
33
RXDT4
RXDT5
RXTD6
RXDT7
GND
RXDTN
RXTDP
RXCKN
RXCKP
VCC
TXCKN
TXCKP
GND
TXDTN
TXDTP
TXDT0
TXDT1
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
64-Pin TQFP (JEDEC LQFP)
78P2253-I64GT
ORDERING INFORMATION
PART DESCRIPTION
ORDER NUMBER
PACKAGING MARK
78P2253
64- Pin Thin Quad Flatpack
78P2253-IGT
78P2253-IGT
Advanced Information: Indicates a product is either in prototype testing or undergoing design evaluation prior to full production release.
Specifications are based on design goals or preliminary evaluation and are not guaranteed. Small quantities are usually available and TDK
Semiconductor Corporation should be consulted for current information.
No responsibility is assumed by TDK Semiconductor Corporation for use of this product nor for any infringements of patents and trademarks
or other rights of third parties resulting from its use. No license is granted under any patents, patent rights or trademarks of TDK
Semiconductor Corporation and the company reserves the right to make changes in specifications at any time without notice. Accordingly, the
reader is cautioned to verify that you are referencing the most current data sheet before placing orders. To do so, see our web site at
http://www.tsc.tdk.com or contact your local TDK Semiconductor representative.
TDK Semiconductor Corporation, 2642 Michelle Drive, Tustin, CA 92780-7019, (714) 508-8800, FAX: (714) 508-8877
2000 TDK Semiconductor Corporation
11/08/00- rev. D
23