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 1010 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 [email protected] 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 products 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