Document Outline
- List of Figures
- Features
- Applications
- Description
- Connection Diagram
- Pin Descriptions
- Functional Description
- Design
- Terminating the Outputs
- Power Supplies
- Circuit Layout
- Manufacturing
- Performance Specifications Absolute Maximum Ratings
- Environmental Parameters
- Electrical Parameters
- Optical Parameters (40C to +85C)
- Fiber Parameters
- Drawing Dimensions
- Ordering Information
- Handling Precautions
406
Fiber Optic "Light to Logic"
Receiver with Clock Recovery
Preliminary Technical Data
RGR2622
Features
Light to Logic 20-Pin DIP
Receiver Offers ECL
Compatibility
Sensitivity:
31 dBm
Phase-Locked Loop (PLL)
Timing Recovery Circuit
Meets All SONET Jitter
Requirements
(CCITT G.958)
Single +5 V Supply,
Typically <1.00 W
SONET/SDH Compliant
Applications
Telecommunication
Networks
SONET OC12 and SDH
STM4 Compatible
Local and Metropolitan Area
Networks
ATM Single Mode Public
Network
Military Communications
and Control Systems
Digital Cable TV Networks
Description
The RGR2622 receiver provides
optical signal conversion and
processing. It converts 1200 nm
to 1600 nm wavelength lightwave
information into an electrical
signal at data rates of 622 Mb/s.
Each receiver contains an InGaAs
PIN photodiode, a high sensitiv-
ity, wide dynamic range transim-
pedance amplifier, capacitively
coupled to a PLL based clock
recovery circuit. The clock and
data outputs are retimed
complementary PECL.
A complementary CMOS
compatible low light alarm is also
provided.
Preliminary Product Disclaimer
This preliminary data sheet is provided to assist you in the evaluation of engineering samples of the product which is under development.
Until Hewlett-Packard releases this product for general sales, HP reserves the right to alter prices, specifications, features, capabilities,
function, manufacturing release dates, and even general availability of the product at any time.
(5/97)
407
Pins 12, 14, ALARM, ALARM:
These pins provide complemen-
tary ALARM and ALARM outputs.
This is the low light alarm.
ALARM goes to a logic low
(CMOS compatible) state when
the optical power drops below
the threshold level (insufficient
optical power).
The optical power must increase
to a higher level than the level
where the alarm went low before
ALARM will return to a logic
high. This difference is the alarm
hysteresis.
Pins 17, 18, 19, 20 NC:
These pins are not connected.
Connection Diagram
Top View
Pin Descriptions
Pins 1, 2, 3, 6, 8, 13, 15, 16,
GND:
These pins should be connected
to the circuit ground.
Pins 4, 5, CLOCK, CLOCK:
These pins provide
complementary PECL CLOCK
and CLOCK outputs.
Pins 7, 9, DATA, DATA:
These pins provide complemen-
tary PECL DATA and DATA
outputs.
The RGR2622 DATA output is
noninverting, an optical pulse
causes the DATA output to go to
the PECL logic high state (+4 V
nominal).
Pin 10, PD Bias:
This pin must be connected to
any voltage from 0 V (GND) to
5 V. This provides the photo-
diode bias. The current drawn is
directly proportional to the
average received photocurrent.
I = Responsivity x Mean Power.
The Responsivity will be between
0.8 A/W and 1.0 A/W.
Pin 11, +5 V:
This pin should be connected to
+5 V supply. The network shown
below should be placed as close
as possible to pin 11.
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
GND
GND
GND
CLOCK
CLOCK
GND
DATA
GND
DATA
PD BIAS
NC
NC
NC
NC
GND
GND
ALARM
GND
ALARM
+5 V
FIBER PIGTAIL
1 H
+5 V
100 nF
100 nF
10 F
PIN 11
408
Functional Description
Design
The receiver contains an InGaAsP
photodetector, transimpedance
amplifier and interface amplifier
circuit, including a clock recovery
and data retiming function. It is
designed with a multimode fiber
pigtail to allow maximum
flexibility in connector options.
The interface amplifier is ac
coupled to the preamplifier
circuit.
Terminating the Outputs
The data outputs of the RGR2622
are PECL compatible. Care
should be taken to match termin-
ation impedances to the intercon-
nect to minimize reflection
effects. In order to balance the
drive currents drawn from the
RGR2622 all serial data outputs
(DATA and DATA, CLOCK and
CLOCK) should be terminated
identically, even if only one
output is used.
This will lower the power supply
noise generated by the RGR2622
and improve performance at low
optical input power levels.
Power Supplies
The RGR2622 will operate to
specifications with a single +5 V
power supply (Pin 10 grounded).
The 5 V pin bias is provided to
maintain functional compatibility
with second sources.
Circuit Layout
The RGR2622 uses very high
bandwidth circuitry to achieve its
high level of performance. Care
must be taken to ensure stable
operation. The use of ground
planes and transmission line
interconnects is required. The use
of a standard evaluation board is
highly recommended for those
users who are not familiar with
these techniques.
Signal traces should conform to
ECL design rules to prevent
reflections and ringing from
degrading performance. Useful
guidelines are contained in ECL
manufacturer design manuals.
Manufacturing
The fiber pigtail on the device
requires normal fiber handling
considerations. Care should be
taken to avoid tight bends as well
as excessive tension on the fiber
pigtail.
The allowable temperature range
for the RGR2622 is limited by the
material used in the pigtail.
Exposure to temperatures over
+85
C is not recommended. Low
profile sockets or hand soldering
are recommended for this part.
Figure 1. Block Diagram.
MID
AMP
LOW PASS FILTER
PLL
CLOCK AND
DATA RECOVERY
VCC (+5 V)
GND (0 V)
ALARM
ALARM
DATA
DATA
CLOCK
CLOCK
VNEG
(-5 V OR GND)
TI
AMP
+5 V
0 V
409
Performance Specifications
Absolute Maximum Ratings
Absolute maximum limits mean that no catastrophic damage will occur if the product is subjected to these ratings for short periods, provided that
each limiting parameter is in isolation and all other parameters have values within the performance specification. It should not be assumed that
limiting values of more than one parameter can be applied to the product at the same time.
Parameter
Symbol
Minimum
Maximum
Units
Note
Supply Voltage
V
CC
0.5
+5.5
V
1
Supply Voltage
V
NEG
10
+0.5
V
1
Environmental Parameters
Parameter
Symbol
Minimum
Maximum
Units
Note
Operating Temperature
-
40
+85
C
-
Storage Temperature
-
40
+85
C
-
Humidity
-
-
85
%RH
-
Electrical Parameters
(40
C to +85
C)
Parameter
Symbol
Minimum
Maximum
Units
Note
Supply Voltage
V
CC
4.75
5.25
V
-
V
CC
Supply Current
-
-
250
mA
4
DATA Output Level (high)
-
3.8
4.15
V
2, 3
DATA Output Level (low)
-
3.1
3.5
V
2, 3
ALARM Output Level (high)
V off
4.5
5.0
V
3
ALARM Output Level (low)
V on
0
0.5
V
3
Notes:
1. On an RGR2622 V
CC
of 0.5 V and V
NEG
of +0.5 V may not be applied simultaneously.
2. Output terminated to (V
CC
-2) with 50
load or equivalent.
3. Output voltages are for V
CC
= 5.0 V.
4. Outputs not loaded.
410
Optical Parameters
(40
C to +85
C)
Parameter
Symbol
Minimum
Typical
Maximum
Units
Note
Wavelength
-
1200
-
1600
nm
-
Receiver Sensitivity
-
-
33.5
31
dBm
1
Maximum Input Power
-
4
-
-
dBm
-
Alarm ON
-
40
-
30
dBm
-
Hysteresis
-
1
-
6
dB
-
Alarm Response Time
-
-
-
600
S
-
Reliability Target
-
-
-
2000
FIT
-
Fiber Parameters
Fiber Pigtail
Typical
Units
Core Diameter
50
microns
Cladding Diameter
125
microns
Secondary Coating Diameter
900
microns
Jitter Tolerance
ITU G.958 Compliant
Jitter Transfer
ITU G.958 Compliant
Jitter Generation
ITU G.958 Compliant
Note:
1. At a BER of 1 x 10
-10
, 2
23-1
PRBS pattern NRZ data at the line rate with 10:1 extinction ratio. EOL.
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