ANADIGICS ATA121302

ATA121302
1.25Gb/s Transimpedance Amplifier
ADVANCED PRODUCT INFORMATION - Rev 0.1
FEATURES
·
1.25 Gb/s Differential Output TIA
·
Automatic Gain Control
·
Single +5V Supply
·
1100 MHz Bandwidth
·
-28 dBm typical sensitivity
·
On-Chip PIN Photodiode Bias Voltage
APPLICATIONS
·
Gigabit Ethernet (1.250 Gb/s)
·
Fibre Channel (1.0625 Gb/s)
D1C
PRODUCT DESCRIPTION
The ANADIGICS ATA121302 is a +5V low noise
transimpedance amplifier designed to be used in
Gigabit Ethernet and Fiber Channel fiber optic links.
The device is used in conjunction with a
photodetector (PIN diode or avalanche photodiode)
to convert an optical signal into a differential output
voltage. The ATA121302 offers a bandwidth of
1100MHz, a dynamic range in excess of 28dB and
an on-chip bias voltage for PIN photodetectors. It is
manufactured in a GaAs MESFET process and is
available in bare die form.
VDD
4K
VOUT
IIN
VOUT
AGC
US Patent: 5047728, 5602510
Charge
Pump
VN
6.5 GHz
Osc
US Patent Pending
GND
The photodetector cathode must be connected to IIN
and the anode can be connected to VN or ground for
proper AGC operation.
Figure 1: ATA121302 Equivalent Circuit
08/2001
2-1
ATA121302
Figure 2: Bonding Pad Layout
Table 1: ATA121302 Pad Description
PAD
D ESC R IPTION
C OMMEN T
VD D
Posi ti ve Supply Voltage
+ 5 Volts
IIN
TIA Input
C onnect to detector cathode for proper operati on
VN
Negati ve Voltage for Photodi ode
Bi asi ng
C onnect to detector anode for opti mum performance
VOUT
TIA Output Voltage (Non-Inverted)
Logi cal '1' wi th opti cal i nput
VOUT
TIA Output Voltage (Inverted)
Logi cal '0' wi th opti cal i nput
ELECTRICAL CHARACTERISTICS
Table 2: Absolute Maximum Ratings
V DD
7.0V
II N
3.5mA
TS
Storage Temp. -65 0C to 125 0C
Stresses in excess of the absolute ratings may cause
permanent damage. Functional operation is not implied under
these conditions. Exposure to absolute ratings for extended
periods of time may adversely affect reliability.
2
ADVANCED PRODUCT INFORMATION - Rev 0.1
08/2001
ATA121302
Table 3: Electrical Specifications (1) (TA= 25 OC, VDD =+5.0V + 10%)
PAR AMETER
Small Si gnal D i fferenti al (RL = 100 )
Transresi stance (2)
Bandwi dth
Low Frequency C utoff
MIN
TYP
MAX
-
2.8
-
KW
1000
1100
-
MHz
-
800
-
kHz
Input Resi stance
U N IT
W
100
Output Resi stance
-
40
-
W
Input Offset Voltage
-
1.4
-
V
Output Offset Voltage
-
2.2
-
V
-5
-
V
-
dB m
Photodi ode Bi asi ng Voltage (VN)
Opti cal Overload
(1), (3)
-3
Opti cal Sensi ti vi ty (1), (3)
-
Input Noi se C urrent
-
D i fferenti al Output Voltage (4), (5)
-
TRISE & TFALL ( 20 - 80% ) (5), (6)
- 28
dB m
280
nA r ms
350
-
mV
-
280
-
ps
D uty C ycle D i storti on (4), (7)
-
4
-
%
RMS Ji tter (4), (7), (8)
-
20
-
ps
-
100
-
ps
-
35
-
mA
+4.5
+5.0
+5.5
V
0
-
85
Total Ji tter (pk-pk)
(4), (7), (9)
Supply C urrent
Operati ng Voltage Range
Operati ng Temperature Range
o
C
Notes:
1. Measured with a photodiode having a maximum capacitance of 0.6 pF
and a minimum responsivity of 0.8 A/W.
2. f = 50 MHz
3. Measured at 10–10 BER with a 27-1 PRBS, 1.25 Gb/s.
4. Input optical power = -3 dBm, RL = 100 W (differential)
5. Measured with a 625 MHz, 50% duty cycle square wave.
6. Measured differentially at -14dBm optical input power.
7. Measured with a 27-1 PRBS.
8. 1s about the center eye crossing.
9. 6s about the center eye crossing.
ADVANCED PRODUCT INFORMATION - Rev 0.1
08/2001
3
ATA121302
Scribe streets are 37.5mm wide
Figure 3: ATA 121302 Typical Bonding Diagram
PERFORMANCE DATA
Figure 4: Frequency Response
(Typical Characteristics measured with a photodiode)
35
Amplitude (dB)
30
25
20
15
10
5
0
0
500
1000
1500
2000
2500
Frequency (MHz)
4
ADVANCED PRODUCT INFORMATION - Rev 0.1
08/2001
3000
3500
ATA121302
100mV/Div
Figure 5: Eye Diagram with an Optical Input Power of –3dB
200ps/Div
50mV/Div
Figure 6: Eye Diagram with an Optical Input Power of –17 dBm
200ps/Div
ADVANCED PRODUCT INFORMATION - Rev 0.1
08/2001
5
ATA121302
Figure 7: Supply Current vs. Case Temperature
Figure 8: Bandwidth vs. Case Temperature
1160
45
1140
40
4.5V
5.0V
5.5V
30
Bandwidth (MHz)
Supply Current (mA)
1120
35
4.5V
5.0V
5.5V
1100
1080
25
1060
1040
20
0
10
20
30
40
50
60
70
80
0
90
10
20
30
40
50
60
70
80
90
Case Temperature (C)
Case Temperature (C)
Figure 10: Sensitivity vs. Case Temperature
Figure 9: Differential Responsivity vs. Temperature
3750
-27.00
-27.20
3500
-27.60
3250
4.5V
5.0V
5.5V
3000
Sensitivity (dBm)
Differential Responsivity (V/W)
-27.40
-27.80
4.5V
5.0V
5.5V
-28.00
-28.20
-28.40
2750
-28.60
2500
-28.80
0
10
20
30
40
50
60
Case Temperature (C)
6
70
80
90
0
10
20
30
40
50
Case Temperature (C)
ADVANCED PRODUCT INFORMATION - Rev 0.1
08/2001
60
70
80
90
ATA121302
APPLICATION INFORMATION
V DD
0.1uF
2
4K
OUT
0.1uF
1
CF
OUT
3
RO
0.1uF
AGC
Charge
Pump
LIMITING
AMPLIFIER
6.5 GHz
OSC
4
Figure 11: Application Schematic
CF is an optional single pole noise filter
CF =
1
2π fcR
fc is the desired cutoff frequency
R = 50 W
RO is required with high input resistance limiting amplifiers
RO = 100 W
ADVANCED PRODUCT INFORMATION - Rev 0.1
08/2001
7
ATA121302
ORDERING INFORMATION
PAR T N U MB ER
ATA121302D 1C
PAC K AGE OPTION
D1
PAC K AGE D ESC R IPTION
Die
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
Mktg@anadigics.com
IMPORTANT NOTICE
ANADIGICS, Inc. reserves the right to make changes to its products or to discontinue any product at any time without
notice. The product specifications contained in Advanced Product Information sheets and Preliminary Data Sheets are
subject to change prior to a product’s formal introduction. Information in Data Sheets have been carefully checked and are
assumed to be reliable; however, ANADIGICS assumes no responsibilities 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.
ADVANCED PRODUCT INFORMATION- Rev 0.1
08/2001
8