ANADIGICS ATA7601D1 5.0v 10gb/s tia Datasheet

ATA7601
5.0V 10 Gb/s TIA
Preliminary Data Sheet - Rev 1
FEATURES
·
10 Gb/s Differential Output TIA
·
+5V Power Supply
·
Low Group Delay
·
Small Size: 0.85mm x 0.914mm
·
325mW (typ) power dissipation
GND
GND
VCC
VOUT
IIN
VOUT
GND
APPLICATIONS
·
SONET OC-192
·
10 Gb/s DWDM
·
10 Gb/s Ethernet
CEXT
GND
GND
D1 Package
Product Description
The ANADIGICS ATA7601D1 is a 5V high-speed
transimpedance amplifier (TIA) for 10 Gb/s
applications available in bare die form and
manufactured using an InGaP HBT process.
The device is used in conjunction with a photodetector
to convert an optical signal into a differential voltage
that must be AC coupled to a post amplifier. With its
low input noise, a sensitivity of better than -19dBm
(BER <10-10) can be achieved with the ATA7601D1.
Figure 1: Circuit Block Diagram
VCC
VBIAS
VOUT
IIN
VOUT
CEXT
ATA7601
Absolute Maximum Ratings
V CC
7.0V
IIN
4mApp
TS
Storage Temp -65 °C to 125 °C
Recommended Operating Conditions
PAR AMETER
Operati ng Voltage Range
Operati ng Temperature Range(1)
MIN
TYP
MAX
U N IT
+4.75
+5.0
+5.25
V
-40
85
C
O
1. Defined at the interface between the die and the substrate.
DC Characteristics
PAR AMETER
MIN
TYP
MAX
U N IT
Input Offset Voltage
1.35
V
Output Offset Voltage
3.0
V
Supply C urrent
65
95
mA
Power D i ssi pati on
325
500
mW
AC Characteristics (2)
PAR AMETER
MIN
TYP
Small Si gnal D i fferenti al Transresi stance (RL - 100W)
900
1100
W
Bandwi dth (-3dB)
8.0
9.0
GHz
30
kHz
Low Frequency C utoff
(3)
Group D elay (1MHz to 8GHz)
-25
Opti cal Sensi ti vi ty (4)
+25
-19.5
Input Noi se C urrent (RMS) (5)
Opti cal Overload
MAX
-3
Input C urrent at whi ch Output Li mi ts
(6)
Maxi mum D i fferenti al Output Voltage
Output Return Loss (1MHz to 10GHz)
dB m
350
mA
400
10
Preliminary Data Sheet - Revision 1
03/01
mA
-2
2. The specifications are based upon the use of a PIN photodetector with a responsivity
at 1550nm of 0.85A/W and a capacitance of CDIODE + CSTRAY = 0.3pF max connected
to IIN via a 0.8nH bond wire.
3. With the use of an external capacitor.
4. Measured at 10-10 BER with a 223 -1 PRBS at 10Gb/s.
5. 11GHz bandwidth.
6. Defined as 80% of the maximum output voltage.
2
ps
dB m
1.8
(4)
U N IT
mV
dB
ATA7601
Pad Description
PAD
D ESC R IPTION
C OMMEN T
V CC
Posi ti ve Supply Voltage
+5.0V
IIN
TIA Input
Photocurrent i nput
C EXT
C onnecti on for an external C apaci tor
Sets the low frequency cutoff
VOUT
TIA Output Voltage (Non-i nverted)
Logi cal '1' wi th opti cal i nput
VOUT
TIA Output Voltage (i nverted)
Logi cal '0' wi th opti cal i nput
Figure 2: Die Size and Layout
245µm
292µm
GND
GND
VCC
Die Size: 850µm x 914µm
189µm
Pad Size: 114µm x 114µm
unless otherwise noted
VOUT
Pad Pitch: 150µm
unless otherwise noted
VOUT
IIN
GND
225µm
CEXT
GND
GND
353µm
183µm
Preliminary Data Sheet - Revision 1
03/01
3
ATA7601
Figure 3: External Capacitor Required for Low Frequency Cutoff
10000
Cext (pF)
1000
100
10
0
50
100
150
200
250
300
350
400
Low Frequency Cutoff (kHz)
Figure 4: Eye Diagram with an Optical Input Power of -19dBm
10mV/Div.
25ps/Div.
Figure 5: Eye Diagram with an Optical Input Power of -9dBm
40mV/Div.
4
25ps/Div.
Preliminary Data Sheet - Revision 1
03/01
ATA7601
Figure 6: Eye Diagram with an Optical Input Power of -4dBm
70mV/Div.
25ps/Div.
Figure 7: Differential Output Voltage vs. Input Current
Output Voltage (mVpp)
400
350
300
250
200
150
100
50
0
0
100
200
300
400
500
600
700
800
Input Current (uApp)
Preliminary Data Sheet - Revision 1
03/01
5
ATA7601
Figure 8: Typical Bonding Diagram
Application Information
V BIAS
+5V
1nF
GND
V CC
GND
50Ω transmission lines
ATA7601D1
V OUT
I IN
V OUT
*
GND
50Ω
CEXT
GND
GND
1nF
* This ground bond can be omitted if it interferes with the
placement of the photodetector.
6
Preliminary Data Sheet - Revision 1
03/01
50Ω
ATA7601
Packaging
The ATA7601D1 is provided as bare die. For optimum performance, the die should be packaged in a
hermetic enclosure and a low inductance ground plane should be made available for power supply
bypassing and ground bonds. The bond wire from the photodetector to IIN should be made as short as
possible. As the inductance of this connection increases beyond 1nH, more gain peaking will occur
and the group delay performance will degrade.
Output Connections
The ATA7601D1 provides a differential output that must be AC coupled to the next stage of the receiver
as the output buffer is not designed to drive a DC coupled 50W load. For single-ended applications,
one output of the ATA7601D1 must be AC terminated to a 50W load.
CEXT Connection
In order to achieve the desired low frequency cutoff, an external capacitor is required. A low inductance
surface mount chip capacitor or MIM capacitor is recommended.
Sensitivity Measurement
The typical sensitivity, as specified in the AC characteristics, is –19.5dBm. This was measured at a
BER of 10-10 with a 10Gb/s, 223-1 PRBS, using a lensed single mode fiber with the photodetector and
TIA in an open test fixture under the following conditions:
Photodetector active area: 32mm
Photodetector capacitance: 0.2pF
Photodetector responsivity: 0.85A/W
Lensed fiber beam width: 13mm (86.5% of contained power)
Lensed fiber focal distance: 3mm
When the photodetector and TIA are packaged in a hermetic enclosure, with the fiber optimally aligned
to the active area of the photodiode, an improvement in sensitivity should be observed.
Device Modeling and Simulation
S-parameter files of the TIA are available on the Anadigics web site (http://www.anadigics.com) or upon
request. Also included on the web-site is a “virtual sample”. This is an encrypted model of the TIA that
can be downloaded into the ADS simulation environment.
Preliminary Data Sheet - Revision 1
03/01
7
ATA7601
ANADIGICS, Inc.
141 Mount Bethel Road
Warren, New Jersey 07059, U.S.A
Tel: +1 (908) 668-5000
Fax: +1 (908) 668-5132
http://www.anadigics.com
[email protected]
IMPORTANT NOTICE
ANADIGICS, Inc. reserves the right to make changes to its products or discontinue any product at any time without notice.
The Advanced Product data sheets and product specifications contained in this data sheet are subject to change prior to
a products formal introduction. The information in this data sheet has been carefully checked and is assumed to be reliable.
However, ANADIGICS assumes no responsibility for inaccuracies. ANADIGICS strongly urges customers to verify that the
information they are using is current before placing orders.
WARNING
ANADIGICS products are not intended for use in life support appliances, devices, or systems. Use of an ANADIGICS
product in any such application without written consent is prohibited.
Preliminary Data Sheet - Revision 1
03/01
8
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