01.08.28
♦ Features • Low voltage of +3.3 V single power supply • 6.5 kΩ high transimpedance • Typical 320 MHz broad bandwidth • 27 dB high gain • 0 dBm large optical input • Over 30 dB wide dynamic range • Differential output
F0100208B
3.3 V / 622 Mb/s Receiver
Transimpedance Amplifier
♦ Applications • Preamplifier of an optical receiver circuit for OC-12/STM-4 (622 Mb/s)
♦ Functional Description The F0100208B is a stable GaAs integrated transimpedance amplifier capable of 27 dB gain at a typical 320 MHz 3 dB-cutoff-frequency, making it ideally suited for a 622 Mb/s optical receiver circuit, for example, OC-12/STM-4, instrumentation, and measurement applications. The integrated feedback loop design provides broad bandwidth and stable operation. The F0100208B typically specifies a high transimpedance of 6.5 kΩ(Rs=RL=50Ω) with a wide dynamic range of over 30 dB. It also provides a large optical input overload of more than 0 dBm. Furthermore, it can operate with a low supply voltage of single +3.3 V. It features a typical dissipation current of 25 mA. Only chip-shipment is available for all product lineups of GaAs transimpedance amplifiers, because the packaged preamplifier can not operate with the maximum performance owing to parasitic capacitance of the package.
3.3 V / 622 Mb/s Transimpedance Amplifier
♦ Absolute Maximum Ratings
F0100208B
Ta=25 °C , unless specified
Parameter Supply Voltage Supply Current Ambient Operating Temperature Storage Temperature Symbol VDD IDD Ta Tstg Value VSS-0.5 to VSS+4.0 50 -40 to +90 -50 to +125 Units V mA °C °C
♦ Recommended Operating Conditions Ta=25 °C , VDD=+3.3 V, VSS=GND, unless specified
Value Parameter Supply Voltage Ambient Operating Temperature Symbol Min. VDD Ta 2.9 0 Max. 3.6 85 V °C Units
♦ Electrical Characteristics Ta=25 °C , VDD=3.3 V, VSS=GND, unless specified
Value Parameter Supply Current Gain(Positive) Gain(negative) -3dB High Frequency Cut-off (positive) -3dB High Frequency Cut-off (negative) Input Impedance Trans-Impedance(positive) Trans-Impedance(negative) Output Voltage(positive) Output Voltage(negative) Input Voltage
(R 1+50) 2
Symbol IDD S21P S21N FCP FCN RI ZTP ZTN VOP VON VI
×10 S21P,N 20
Test Conditions Min. DC PIN=-50dBm f=1MHz, RL=50Ω PIN=-50dBm f=1MHz, RL=50Ω PIN=-50dBm RL=50Ω PIN=-50dBm RL=50Ω f=1MHz *1, f=1MHz *1, f=1MHz DC DC DC 18 27 27 265 265 350 4.5 4.5 1.5 1.5 0.65 Typ. 35 28.5 28.5 340 320 450 6.5 6.5 2.4 2.4 0.88 Max. 45 32 32 600 600 550 2.9 2.9 1.05
Units mA dB dB MHz MHz Ω KΩ KΩ V V V
*1 ZTP = ,N
3.3 V / 622 Mb/s Transimpedance Amplifier
♦ Block Diagram
F0100208B
VDD
OUT Level Shift IN VSS Buffer OUT
Variable Feedback Resistance
♦ Die Pad Description
VDD VSS IN OUT OUT Supply Voltage Supply Voltage Input Output Output
3.3 V / 622 Mb/s Transimpedance Amplifier
♦ Die Pad Assignments
F0100208B
(13)
(12)
(11)
(10)
(9)
(14)
8)
(15)
(7)
(16)
(6)
(1)
(2)
(3)
(4)
(5)
No. (1) (2) (3) (4) (5) (6) (7) (8) (9)
Symbol VDD3.3 VDD5.0 VDD5.0 OUT VSS OUT VSS OUT VSS
Center Coordinates(µm) (75,75) (235,75) (395,75) (555,75) (715,75) (715,235) (715,395) (715,555) (715,715)
No. (10) (11) (12) (13) (14) (15) (16) O A
Symbol OUT VSS VDD3.3 VDD3.3 VSS IN VDD3.3
Center Coordinates(µm) (555,715) (396,715) (235,715) (75,715) (75,555) (75,395) (75,235) (0,0) (790,790)
3.3 V / 622 Mb/s Transimpedance Amplifier
♦ Test Circuits 1) AC Characteristics
F0100208B
50Ω Pin=-50 dBm f=300 kHz~3 GHz IN
Network Analyzer
50Ω
VDD DUT VSS Prober
OUT Switch OUT 50Ω
2) Sensitivity Characteristics
VPD
5V 0.022µF
E/O Converter
Optical Attenuater
VCC PD DUT
5V 0.022µF
Pulse Pattern Generator
CLK 0.022µF Comparator SEI F0300232Q
Bit Error Rate Tester
3.3 V / 622 Mb/s Transimpedance Amplifier
♦ Examples of AC Characteristics
F0100208B
(1) Gain (S21P) Ta=25 °C, VDD=+3.3 V, VSS=GND, Pin=-50 dBm, RL=50 Ω, 300 kHz-3 GHz
36 33 30 27
Gain[dB]
24 21 18 15 12 9 6 1M 10M 100M 1G Frequency[Hz]
(2) Gain (S21N) Ta=25 °C, VDD=+3.3 V, VSS=GND, Pin=-50 dBm, RL=50 Ω, 300 kHz-3 GHz
36 33 30 27
Gain[dB]
24 21 18 15 12 9 6 1M 10M 100M 1G Frequency[Hz]
3.3 V / 622 Mb/s Transimpedance Amplifier
F0100208B
(3) Input Noise Current Density & Transimpedance
INPUT NOISE CURRENT DENSITY & TRANSIMPEDANCE(Typical Vaiues) Freq. (MHz) 10 20 30 50 80 100 200 300 400 500 600 700 800 900 1000 Zt(Ω) (RF transimpedance) 8246 8281 8101 8263 8391 8120 7583 6884 5589 4016 2668 2006 1546 997 697 Ini(pA/√Hz) (Equivalent input noise currentdensity) 1.29 1.35 1.37 1.44 1.42 1.23 1.72 2.42 2.82 3.27 4.15 4.55 5.85 6.06 8.02
3.3 V / 622 Mb/s Transimpedance Amplifier
♦ Typical Bit Error Rate
F0100208B
PRBS 223-1, Ta=25 °C, VDD=3.3 V, VSS=GND, RL=50 Ω
10-3
25 °C/3.0V 25 °C/3.3V 25 °C/3.6V
10-4
Bit Error Ratio
10 10
-5
-6
10-7 10
-8
10-9 10 10-11 -12 10 -38
-10
-36
-34
-32
-30
-28
Optical Input Power (dBm)
3.3 V / 622 Mb/s Transimpedance Amplifier
♦ General Description
F0100208B
A transimpedance amplifier is applied as a pre-amplifier which is an amplifier for a faint photo-current from a PIN photo diode (PD). The performance in terms of sensitivity, bandwidth, and so on, obtained by this transimpedance amplifier strongly depend on the capacitance brought at the input terminal; therefore, “typical”, “minimum”, or “maximum” parameter descriptions can not always be achieved according to the employed PD and package, the assembling design, and other technical experts. This is the major reason that there is no product lineup of packaged transimpedance amplifiers. Thus, for optimum performance of the transimpedance amplifier, it is essential for customers to design the input capacitance carefully. Hardness to electro-magnetic interference and fluctuation of a power supply voltage is also an important point of the design, because very faint photo-current flows into the transimpedance amplifier. Therefore, in the assembly design of the interconnection between a PD and a transimpedance, noise should be taken into consideration.
♦ Low Voltage Operation The F0100208B features a single 3.3 V supply operation, which is in great demand recently, because most of logic IC’s operate with the supply voltage of 3.3 V. The analog IC’s with a single 3.3 V supply for use in fiber optic communication systems are offered by only SEI. ♦ Recommendation SEI basically recommends the F08 series PINAMP modules for customers of the transimpedance amplifiers. In this module, a transimpedance amplifier, a PD, and a noise filter circuit are mounted on a TO-18-can package hermetically sealed by a lens cap, having typically a fiber pigtail. The F08 series lineups are the best choice for customers to using the F01 series transimpedance amplifiers. SEI’s F08 series allows the customers to resolve troublesome design issues and to shorten the development lead time. ♦ Noise Performance The F0100208B based on GaAs FET’s shows excellent low-noise characteristics compared with IC’s based on the silicon bipolar process. Many transmission systems often
3.3 V / 622 Mb/s Transimpedance Amplifier
F0100208B
demand superior signal-to-noise ratio, that is, high sensitivity; the F0100208B is the best choice for such applications. The differential circuit configuration in the output enable a complete differential operation to reduce common mode noise: simple single ended output operation is also available. ♦ Die-Chip Description The F0100208B is shipped like the die-chip described above. The die thickness is typically 280 µm ± 20 µm with the available pad size uncovered by a passivation film of 95 µm square. The material of the pads is TiW/Pt/Au and the backside is metalized by Ti/Au. ♦ Assembling Condition SEI recommends the assembling process as shown below and affirms sufficient wirepull and die-shear strength. The heating time of one minute at the temperature of 310 °C gave satisfactory results for die-bonding with AuSn performs. The heating and ultrasonic wire-bonding at the temperature of 150 °C by a ball-bonding machine is effective. ♦ Quality Assurance For the F01 series products, there is only one technically inevitable drawback in terms of quality assurance which is to be impossible of the burn-in test for screening owing to dieshipment. SEI will not ship them if customers do not agree on this point. On the other hand, the lot assurance test is performed completely without any problems according to SEI’s authorized rules. A microscope inspection is conducted in conformance with the MIL-STD883C Method 2010.7. ♦ Precautions Owing to their small dimensions, the GaAs FET’s from which the F0100208B is designed are easily damaged or destroyed if subjected to large transient voltages. Such transients can be generated by power supplies when switched on if not properly decoupled. It is also possible to induce spikes from static-electricity-charged operations or ungrounded equipment.
Electron Device Department