SE1050W
LightCharger
TM
10 Gb/s Transimpedance Amplifier
Final
45-DST-01
Rev 1.5
May 24/02
1 of 11
Applications
SONET/SDH-based transmission systems, test
equipment and modules
OC-192 fibre optic modules and line termination
10 Gigabit Ethernet
Fibre Channel
Serial data systems up to 10.7 Gb/s
Features
Single +5 V power supply
Power dissipation = 430 mW (typ)
Input noise current = 1.4
A rms when used with
a 0.2 pF detector
Transimpedance gain = 1.2 k
into a 50
load
(differential)
Input current overload = 2.3 mA pk (+1.1 dBm for
0.9 A/W responsivity - meets 10 Gigabit Ethernet
specification)
Wide linear dynamic range of 17 dB (typ)
50
single-ended or 100
differential wire bond
selectable outputs
Bandwidth (-3 dB) = 9.8 GHz
Operates at OC-192 / STM-64 up to 10.7 Gb/s
NRZ rates
Power supply rejection for both single ended and
differential modes of operation
Optimized for PIN photodetectors
Minimal external components, supply decoupling
only
Operating junction temperature range = -40
C to
+100
C
Equivalent to Nortel Networks AE99
Ordering Information
Type
Package
Remark
SE1050W
Bare Die
Shipped in
Waffle Pack
Product Description
SiGe Semiconductor offers a portfolio of optical
networking ICs for use in high-performance optical
transmitter and receiver functions, from 155 Mb/s up
to 12.5 Gb/s.
SiGe Semiconductor's SE1050W is a fully integrated
silicon bipolar transimpedance amplifier, providing
wideband, low noise preamplication of signal current
from a PIN photodetector. It features differential
outputs. A decoupling capacitor on the supply is the
only external component required. A system block
diagram is shown after the functional description, on
page 3.
Noise performance is optimized for 10 Gb/s operation,
with a calculated rms noise based sensitivity of
20 dBm for 10
-10
bit error rate, using a detector with
0.20 pF capacitance and a responsivity of 0.9 A/W,
with an infinite extinction ratio source.
Functional Block Diagram
VCC or +ve supply
SE1050
TzAmp
10 Gb/s
Tz Amp
Output
Driver
TZ_IN
Input
Current
OUTP
OUTN
50
50
R
f
1.29 V
ACGND
Bandgap
Reference
Power
Supply
Rejection
Wire bond option for single-ended operation
50
SE1050W
LightCharger
TM
10 Gb/s Transimpedance Amplifier
Final
45-DST-01
Rev 1.5
May 24/02
2 of 11
Bondpad Diagram
Top
View
VCC2
VCC2
GND
VCC1
VCC1
GND
TZ_IN
OUTN
OUTP
1
2
10
9
8
6
5
4
3
7
13
11
12
1
GND
GND
ACGND
GND
Bondpad Description
Pad No.
Name
Description
1
GND
Negative supply (0V).
2
GND
Negative supply (0V).
3
TZ_IN
Input pad (connect to photodetector anode).
4
GND
Negative supply (0V).
5
GND
Negative supply (0V).
6
GND
Negative supply (0V).
7
VCC1
Positive supply (+5 V).
8
VCC1
Positive supply (+5 V).
9
VCC2
Positive supply (+5 V) Note: This is a separate supply for the output driver stage
only.
10
VCC2
Positive supply (+5 V) Note: This is a separate supply for the output driver stage
only.
11
OUTN
Negative differential voltage output; leave unconnected for single-ended operation.
12
OUTP
Positive differential or single-ended voltage output.
13
ACGND
Bond option: Connected to external capacitor to ground for single-ended operation
(recommended 1 nF); unconnected for differential operation.
SE1050W
LightCharger
TM
10 Gb/s Transimpedance Amplifier
Final
45-DST-01
Rev 1.5
May 24/02
3 of 11
Functional Description
Amplifier Front-End
The transimpedance front-end amplifies the current
from a PIN photodetector, anode connected to pad
TZ_IN, to produce a differential output voltage with
the feedback resistor Rf determining the level of
amplification (see the functional block diagram on
page 1).
The input pad TZ_IN is biased at nominally 1.29 V
above ground, allowing the photodetector to have a
wide reverse-bias by connecting the cathode to VCC.
This enables single rail operation and normally
ensures that the PIN operates in its constant, low-
capacitance region.
The output stage has its own supply connection
VCC2 (+5 V) to maintain integrity of the high-speed
signal path. The output stage shares the GND (0 V)
connection with the remainder of the circuitry, which
has a separate supply connection VCC1 (+5 V).
Output Driver Stage
The output driver acts as a buffer stage, capable of
swinging up to 1.1 V pk-pk differential into a 100
load.
The output can be configured in a differential or
single-ended mode. For differential operation, the pad
ACGND is not wire bonded and the circuit provides a
fully balanced 100
output, on the pins OUTP and
OUTN. For single-ended operation, the ACGND pad
is required to be wire bonded to an external capacitor
to ground (recommend 1 nF). Under these
circumstances, OUTP operates as a single-ended
50
output. In both cases, increasing optical input
level gives a positive-going output signal on the
OUTP pin.
Power Supply Rejection
An on-chip power supply rejection circuit is used to
achieve both single-ended and differential rejection
from the +5 V VCC rail. This rejection ensures that
performance is not degraded by noise on the power
supply. The circuit achieves a power supply rejection
on the outputs of 38 dB for single-ended and 24 dB
for differential operation, up to 100 kHz. The use of
external decoupling will help to remove any unwanted
signals at higher frequencies.
System Block Diagram
Receiver Module
Data
Post
Amplifier
2
PIN
SE1050W
2
SE1250
TZ
Amplifier
Clock
CDR &
Demux
Data
Mux
Ck In
LOS
Laser
Driver
SE1150/51/52
SE1050W
LightCharger
TM
10 Gb/s Transimpedance Amplifier
Final
45-DST-01
Rev 1.5
May 24/02
4 of 11
Absolute Maximum Ratings
These are stress ratings only. Exposure to stresses beyond these maximum ratings may cause permanent damage
to, or affect the reliability of the device. Avoid operating the device outside the recommended operating conditions
defined below.
Symbol
Parameter
Min
Max
Unit
VCC
Supply Voltage
0.7
6.0
V
V
IO
Voltage at any input or output
0.5
VCC+0.5
V
I
IO
Current sourced into any input or output except
TZ_IN
20
20
mA
I
IO
Current sourced into pin TZ_IN
5
5
mA
V
ESD
Electrostatic Discharge (100 pF, 1.5 k
) except
TZ_IN and ACGND
2
2
kV
V
ESD
Electrostatic Discharge (100 pF, 1.5 k
) pins
TZ_IN and ACGND
0.25
0.25
kV
Tstg
Storage Temperature
65
150
C
Recommended Operating Conditions
Symbol
Parameter
Min
Typ
Max
Unit
VCC
Supply Voltage
4.7
5.0
5.3
V
Tj
Operating Junction Temperature
40
100
C
DC Electrical Characteristics
Symbol
Parameter
Min
Typ
Max
Unit
ICC
Supply Current
86
130
mA
Vin
Input Bias Voltage
1.28
1.29
1.34
V
Vout
Output Bias Voltage
3.0
V
Rout
Output Resistance
38
50
62
SE1050W
LightCharger
TM
10 Gb/s Transimpedance Amplifier
Final
45-DST-01
Rev 1.5
May 24/02
5 of 11
AC Electrical Characteristics
Symbol
Parameter
Min
Typ
Max
Unit
BW (3dB)
Small Signal Bandwidth at 3dB point
8
9.8
13
GHz
Tz
Differential Transimpedance (50
on each output,
f = 100 MHz)
0.75
1.2
1.8
k
Dri
Input Data Rate
10.7
Gb/s
Voutmax
Maximum Differential Output Voltage
1.1
V pk-pk
Flf
Low Frequency Cut-off
37
47
kHz
PSRR
Power Supply Rejection Ratio (differential) up to
100 kHz
16
24
dB
PSRR
Power Supply Rejection Ratio (single-ended) up to
100 kHz
30
38
dB
Olim
Onset of Limiting (mean input current from
photodetector)
290
460
A mean
DR
Linear Dynamic Range (sensitivity to onset of
limiting)
17
dB
l
OL
Input Current before overload (10 Gb/s NRZ data)
2300
A pk-pk
Pol
Optical Overload
+1.1
dBm
Nrms
Input Noise Current (in 10 GHz)
1.4
2.0
A rms
DC and AC electrical characteristics are specified under the following conditions:
Supply Voltage (VCC).........................................4.7 V to 5.3 V
Junction Temperature (Tj)..................................40
C to 100
C
Load Resistor (R
L
)...............................................50
AC coupled via 100 nF, for each output
Photodetector Capacitance (Cd)......................0.2 pF
Input bond wire inductance (Li) ........................1.1 nH
(Must comply with recommended bonding arrangement that will be provided as an application note)
Photodetector responsivity ................................0.9 A/W
Photodetector series resistance........................10
max
Transimpedance (Tz) measured with 0 > lin < 580
A pk-pk, at 100 MHz
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