ETC 78P2252-IGT

78P2252
STM-1/OC-3
Transceiver
JUNE 2002
DESCRIPTION
FEATURES
The 78P2252 is a transceiver IC designed for
155.52Mbit/s (OC-3 or STM-1) transmission. It is
used at the interface to a fiber optic module.
Interface to digital framer circuits is accomplished via
a serial PECL or parallel CMOS interface.
•
Compliant with ITU-T G.958 jitter tolerance,
Telcordia TR-NWT-00253, ANSI T1.105.031994, and ANSI T1.105.05-1994
•
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
•
Integrated Clock Multiplier PLL
•
Advanced BiCMOS Process
•
Available in 64TQFP Package
The 78P2252 is built in a BiCMOS technology
allowing for high performance with low power
operation. The device automatically adjusts for
operations with either a 3.3V or 5V power supply
and is packaged in a 64-pin TQFP.
CKIN
Crystal
Oscillator
8BIT/$BIT
PAR/SER
HUB/HOST
XTAL2
XTAL1
BLOCK DIAGRAM
Clock
Generator
TXCK
TXCKP,N
RLBACK
TXDTP,N
TXDT[7:0]
ECLOUTP
ECLOUTN
RXDTP,N
RXDT[7:0]
Clock
Recovery
ECLINP
ECLINN
RXCKP,N
RXCK
LLBACK
LF
RFO
Bias
78P2252
STM-1/OC-3
Transceiver
FUNCTIONAL DESCRIPTION
RECEIVER OPERATION
The 78P2252 contains all the necessary transmit
and receive circuitry for connection between
155.52Mbit/s signals and digital Framer/Deframer
ICs.
The receiver accepts NRZ coded, serial data at
155.52Mbit/ from the fiber optic module via the ECL
inputs, ECLINP and ECLINN. A clock signal is
recovered using a low jitter PLL circuit.
DIGITAL INTERFACE
In serial mode, the received data is output on the
RXDTP and RXDTN pins and the recovered clock is
output on the RXCKP and RXCKN pins at the line
rate frequency.
The digital interface of the 78P2252 can operate as
a Serial PECL, 4-bit Parallel CMOS, or 8-bit Parallel
CMOS interface. These modes are controlled by the
PAR/SER and 8BIT/$BIT pins as shown in the
following table.
Mode
PAR/
SER
8BIT/
$BIT
Data pins
Clock pins
Clock Frequency
(MHz)
Serial
0
X
TXDTP,N
RXDTP,N
TXCKP,N
RXCKP,N
155.52
4-bit
Parallel
1
0
TXDT[3:0]
RXDT[3:0]
TXCK
RXCK
38.88
8-bit
Parallel
1
1
TXDT[7:0]
RXDT[7:0]
TXCK
RXCK
19.44
In parallel mode, the received data is converted to
either eight bit or four bit parallel formats,
determined by the state of the 8BIT/$BIT pin. The
first bit received will arrive on the most significant
output pin, RXDT[7] in eight bit mode and RXDT[3]
in four bit mode. In parallel mode, the recovered
clock in output on the RXCK pin at either one-eighth
or one-fourth the line rate frequency, depending on
the state of the 8BIT/$BIT pin.
TRANSMITTER OPERATION
The transmitter accepts serial or parallel data and
generates an NRZ coded PECL signal for
transmission to a fiber optic module.
When set to serial mode via PAR/SER pin, serial
data is input from the digital Framer/Deframer IC to
the 78P2252 on the TXDTP and TXDTN pins at
PECL levels. The data is clocked in with a line rate
frequency clock generated by the 78P2252 on the
TXCKP and TXCKN pins.
When set to parallel mode, parallel data is input from
the digital Framer/Deframer IC to the 78P2252 on
the TXDT[7:0] pins. Eight bits or four bits of data are
used depending the setting of the 8BIT/$BIT pin.
o
In eight bit parallel mode, data is read on
pins TXDT[7:0].
o
In four bit parallel mode, data is read on pins
TXDT[3:0].
The parallel input data is clocked in with the
generated clock output TXCK. The TXCK
automatically adjusts to either one-eighth or onefourth the standard line rate frequency, depending
on the state of the 8BIT/$BIT pin.
2
78P2252
STM-1/OC-3
Transceiver
The HUB/HOST pin selects the source of the
reference signal used for the internal transmit clock
generator.
When in Remote (Digital) Loopback mode
(RLBACK logic high), the received data is internally
routed onto the transmitter inputs. Note that any
input data on the TXDTP,N pins or TXDT[7:0] pins is
ignored in remote loopback mode.
In Hub mode (HUB/HOST logic high), the transmit
clock reference is derived from either a crystal
oscillator applied to the XTAL1 and XTAL2 pins or a
reference clock input applied at the CKIN pin. The
reference frequency should be one-eighth the line
rate frequency at 19.44MHz and should be applied
in one of the following configurations.
XTAL2
XTAL1
Crystal
Oscillator
CKIN
8BIT/$BIT
Remote and Local Loopback modes in the 78P2252
are controlled by the RLBACK and LLBACK pins
respectively.
PAR/SER
REFERENCE CLOCK
HUB/HOST
LOOPBACK OPERATION
Hub Mode Configurations
Remote (Digital)
Loopback
Clock
Generator
TXCK
TXCKP,N
RLBACK
TXDTP,N
TXDT[7:0]
XTAL1
XTAL1
XTAL2
XTAL2
CKIN
CKIN
ECLOUTP
ECLOUTN
Clock
Recovery
RXDTP,N
RXDT[7:0]
ECLINP
ECLINN
RXCKP,N
RXCK
LLBACK
LF
RFO
Bias
Using crystal
CKIN
Crystal
Oscillator
LLBACK RLBACK
Local (Analog)
Loopback
Clock
Generator
-- or --
TXCK
TXCKP,N
HUB/HOST
HOST
Reference Clock
0
0
1
CKIN or
XTAL1,2
1
0
1
CKIN or
XTAL1,2
X
1
1
Recovered Rx
Clock
X
X
0
Recovered Rx
Clock
RLBACK
TXDTP,N
TXDT[7:0]
ECLOUTP
ECLOUTN
Clock
Recovery
RXDTP,N
RXDT[7:0]
ECLINP
ECLINN
RXCKP,N
RXCK
LLBACK
LF
Bias
RFO
Using external clock
In Host mode (HUB/HOST logic low), the transmit
clock reference is derived from the recovered receive
clock. Note that the recovered receive clock is also
used as the reference clock when Remote Loopback
is enabled.
8BIT/$BIT
PAR/SER
HUB/HOST
XTAL1
XTAL2
When in Local (Analog) Loopback mode
(LLBACK logic high), the transmit output signals are
internally routed to the receiver inputs. Note that
Local Loopback mode is disabled when HUB/HOST
is low or RLBACK is high.
3
78P2252
STM-1/OC-3
Transceiver
PIN DESCRIPTION
LEGEND
TYPE
DESCRIPTION
TYPE
A
Analog Pin
PI
PECL Digital Input
CI
CMOS Digital Input
PO
PECL Digital Output
CO
CMOS Digital Output
S
DESCRIPTION
Supply Pin
TRANSMIT PINS
NAME
PIN
TXDTP
19
TXDTN
20
TXCKP
22
TXCKN
23
TXDT[7:0]
TYPE
DESCRIPTION
PI
Transmit Data Inputs - Serial Mode.
PO
Transmit Clock Output - Serial Mode.
11-18
CI
TXCK
10
CO
ECLOUTP
56
ECLOUTN
55
PO
Transmit Data Inputs – Parallel Mode.
TXDT[7:4] are ignored in 4 bit mode.
Reference Clock Output – Serial mode.
Transmit Clock Output – Parallel Mode.
Transmit Outputs.
RECEIVE PINS
NAME
PIN
TYPE
ECLINP
ECLINN
52
51
PI
RXCKP
25
RXCKN
26
RXCK
38
RXDTP
27
RXDTN
28
RXDT[7:0]
30-37
DESCRIPTION
Receiver inputs.
PO
Recovered Receive Clock – Serial Mode.
CO
Recovered Receive Clock – Parallel Mode.
PO
Receive data – Serial Mode.
CO
Receive data – Parallel Mode. In 4 bit mode RXDT[3:0] are used and
RXDT[7:4] are pulled low.
REFERENCE CLOCK PINS
NAME
PIN
XTAL1
5
XTAL2
6
CKIN
9
TYPE
A
CI
DESCRIPTION
Crystal Pins.
These pins should be left floating if using reference clock input CKIN.
Reference clock input.
This pin should be grounded if using the crystal oscillator inputs.
4
78P2252
STM-1/OC-3
Transceiver
PIN DESCRIPTION (continued)
CONTROL AND STATUS PINS
NAME
PIN
TYPE
RLBACK
41
CI
DESCRIPTION
Remote (Digital) Loopback Enable.
When logic high, loops receiver output data to transmitter inputs.
Local (Analog) Loopback Enable.
LLBACK
42
CI
When logic high, loops transmitter output to receiver input.
Note: Disabled when HUB/HOST is low or RLBACK is high.
HUB/HOST
2
CI
8BIT/$BIT
63
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.
When in parallel mode, logic high selects 8-bit mode and logic low
selects 4-bit mode.
Ignored in serial mode.
PAR/SER
62
CI
Selects parallel mode when high, serial mode when low.
NAME
PIN
TYPE
RFO
46
A
External reference resistor.
section for more info.
LF
44
A
PLL loop filter capacitor. See APPLICATION INFORMATION section
for more info.
ANALOG PINS
DESCRIPTION
See APPLICATION INFORMATION
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
3, 8, 24,
40, 43,
53, 54,
57
S
Power Supply.
GND
1, 4, 7,
21, 29,
39, 45,
47, 48,
50, 58,
59, 60,
61, 64
S
Ground.
5
78P2252
STM-1/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 (VCC+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)
Icc
Supply Current (Serial Mode)
Icc
CONDITIONS
NOM
MAX
Vcc = 3.3V
140
165
Vcc = 5.0V
150
175
Vcc = 3.3V
210
245
Vcc = 5.0V
280
330
6
MIN
UNIT
mA
mA
78P2252
STM-1/OC-3
Transceiver
ELECTRICAL SPECIFICATIONS (continued)
DIGITAL INPUT CHARACTERISTICS
Pins of type CI
PARAMETER
SYMBOL
CONDITIONS
MIN
NOM
Input Voltage Low
Vil
Input Voltage High
Vih
Vcc/2 + 0.9
Iil, Iih
-10
Input Current
Input Capacitance
MAX
UNIT
Vcc/2 - 0.9
V
V
10
Cin
µA
10
pF
Pins of type PI
PARAMETER
SYMBOL
CONDITIONS
MIN
Input Voltage Low
Vil
Relative to Vcc
Input Voltage High
Vih
Relative to Vcc
-1.1
CONDITIONS
MIN
NOM
MAX
UNIT
-1.5
V
V
DIGITAL OUTPUT CHARACTERISTICS
Pins of type CO
PARAMETER
SYMBOL
Output Voltage Low
Vol
Output Voltage High
Voh
Transition Time
Below Vcc
Tt
NOM
MAX
UNIT
0.6
0.7
V
0.6
0.7
V
3.5
ns
Pins of type PO
PARAMETER
Output Voltage Low
SYMBOL
Vol
CONDITIONS
Vcc Reference
biased at Vcc -1.5V
with 50 ohm
MIN
-1.7
NOM
-1.4
MAX
-1.3
UNIT
V
Output Voltage High
Voh
Vcc Reference
biased at Vcc -1.5V
with 50 ohm
-1.1
-0.9
-0.7
V
Rise Time
Tr
1
3
ns
Fall Time
Tf
1
3
ns
7
78P2252
STM-1/OC-3
Transceiver
ELECTRICAL SPECIFICATIONS (continued)
DIGITAL TIMING CHARACTERISTICS
Transmit Interface – Serial Mode
TXCKP TXCKN
TXDTP TXDTN
TSUs
PARAMETER
SYMBOL
THs
CONDITIONS
MIN
NOM
MAX
UNIT
Transmit Setup Time
TSUs
Serial Mode
1.5
ns
Transmit Hold Time
THs
Serial Mode
1.5
ns
TXCKP,N Duty Cycle
40
60
%
MAX
UNIT
Transmit Interface – 8-bit Parallel Mode
TXCK
TXDT[7:0]
TSUp
PARAMETER
THp
SYMBOL
CONDITIONS
MIN
Transmit Setup Time
TSUp
Parallel Mode
3.5
ns
Transmit Hold Time
THp
Parallel Mode
2.5
ns
TXCK Duty Cycle
40
8
NOM
60
%
78P2252
STM-1/OC-3
Transceiver
ELECTRICAL SPECIFICATIONS (continued)
DIGITAL TIMING CHARACTERISTICS
Receive Interface – Serial Mode
RXCKP RXCKN
RXDTP RXDTN
PARAMETER
Receive Propagation Delay
SYMBOL
TPROPs
TPROPs
CONDITIONS
MIN
Serial Mode
RXCKP,N Duty Cycle
NOM
MAX
UNIT
2.4
3.0
ns
60
%
NOM
MAX
UNIT
4.0
6.0
ns
60
%
40
Receive Interface – 8-bit Parallel Mode
RXCK
RXDT[7:0]
TPROPp
PARAMETER
Receive Propagation Delay
SYMBOL
CONDITIONS
TPROPps
Parallel Mode
RXCKP,N Duty Cycle
MIN
40
9
78P2252
STM-1/OC-3
Transceiver
ELECTRICAL SPECIFICATIONS (continued)
REFERENCE CLOCK INTERFACE
CKIN
TXCKP TXCKN
PARAMETER
CKIN to TXCKP/N Delay
SYMBOL
TPROPs
TPROPs
CONDITIONS
MIN
NOM
MAX
UNIT
Serial Mode
3.1
4.6
5.6
ns
CONDITIONS
MIN
NOM
MAX
UNIT
Parallel 8 bit Mode
1.6
3.7
5.7
ns
CKIN
TXCK
T
PARAMETER
CKIN to closes phase of TXCK
Delay
SYMBOL
TPROPp
PROPp
10
78P2252
STM-1/OC-3
Transceiver
ELECTRICAL SPECIFICATIONS (continued)
TRANSMITTER OUTPUT JITTER
The transmit jitter specification ensures compliance with ITU-T G.958 and ANSI T1.105.03-1994 for STM-1 and
OC-3 rates. The corner frequency of the transmit PLL is nominally 3.0 MHz.
Jitter
Detector
Measured Jitter
Amplitude
20dB/decade
Transmitter
Output
500 Hz
PARAMETER
CONDITION
Transmitter Output Jitter
200 Hz to 3.5 MHz
1.3 MHz
MIN
11
NOM
MAX
UNIT
0.075
UIpp
78P2252
STM-1/OC-3
Transceiver
ELECTRICAL SPECIFICATIONS (continued)
RECEIVER JITTER TOLERANCE
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 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
PARAMETER
Receiver Jitter Tolerance
Note 1: Not tested in production
1.E-02
1.E-01
1.E+00
1.E+01
1.E+02
1.E+03
1.E+04
1.E+05
CONDITION
MIN
12µHz to 178µHz
2800
1.6mHz to 15.6mHz
311
125mHz to 19.3 Hz
39
500Hz to 6.5kHz
1.5
65kHz to 3.5MHz
0.15
12
1.E+06
1.E+07
NOM
MAX
UNIT
UI
78P2252
STM-1/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.
The corner frequency of the PLL is approximately 100 kHz. These specifications are not tested in production.
0
-1
-2
-3
-4
-5
-6
-7
-8
-9
-10
1.00E+03
1.00E+04
1.00E+05
PARAMETER
CONDITION
Receiver Jitter transfer function
below 100 kHz
1.00E+06
MIN
Jitter transfer function roll-off
NOM
20
Note 1: Not tested in production
13
1.00E+07
MAX
UNIT
0.1
dB
dB per
decade
78P2252
STM-1/OC-3
Transceiver
APPLICATION INFORMATION
EXTERNAL COMPONENTS:
COMPONENT
PIN(S)
VALUE
UNITS
TOLERANCE
Reference Resistor
RFO
31.6
kΩ
1%
Filter Capacitor
LF1
470
nF
5%
VALUE
UNITS
TOLERANCE
19.44
MHz
+/- 20ppm
27
pF
CRYSTAL SPECIFICATIONS:
COMPONENT
Center Frequency
Load Capacitor – XTAL1 to ground; XTAL2 to ground
Please check datasheet of crystal manufacturer for
optimal load capacitor values.
SCHEMATICS
The latest typical application schematics are available in the form of Application Notes and/or Demo Board
Manuals. Please contact TDK Semiconductor for more information.
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.
RTERM
RBIAS
RBIAS
FIGURE 1. PECL INTERFACE
14
78P2252
STM-1/OC-3
Transceiver
MECHANICAL SPECIFICATIONS
64-TQFP (JEDEC LQFP)
Mechanical Specification
15
78P2252
STM-1/OC-3
Transceiver
PACKAGE PIN DESIGNATIONS
GND
ECLINN
ECLINP
VCC
VCC
ECLOUTN
ECLOUTP
VCC
GND
GND
GND
GND
PAR/SER
8BIT/$BIT
GND
GND
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
GND
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
LLBACK
VCC
8
41
RLBACK
CKIN
9
40
VCC
TXCK
10
39
GND
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
RXTDN
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)
78P2252-IGT
ORDERING INFORMATION
PART DESCRIPTION
ORDER NUMBER
PACKAGING MARK
78P2252
64- Pin Thin Quad Flatpack
78P2252-IGT
78P2252-IGT
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
2002 TDK Semiconductor Corporation
6/13/02- Rev. H
16