Ji-Chen Huang

High-Responsivity Photodetector in Standard SiGe BiCMOS Technology

For high-speed optoelectronic applications such as fiber-optic data communication systems, photodetectors (PDs) with high responsivity in Si-related processes are required. In this letter, a result of the effort along this line is reported. A novel device named phototransistor PD (PTPD) was realized in a commercial 0.35-mum SiGe BiCMOS technology. The device combines a surface PD (SPD) and a conventional SiGe heterojunction PT (HPT). It was shown that the SPD enhanced light absorption and the PTPD showed significant performance improvement over HPT. Responsivities of 5.2 A/W for an 850-nm light and 9.5 A/W for a 670-nm light were achieved in the PTPD, with floating base and SPD terminals.

Design and Properties of Phototransistor Photodetector in Standard 0.35-

In this paper, without altering any step of the commercial 0.35-mum SiGe BiCMOS process, a novel photodetector named phototransistor photodetector (PTPD) has been realized and demonstrated. The PTPD shows high photoresponsivity and its structure relaxes the tradeoff between sensitivity and speed. Responsivities of 9.5 A/W for 670 nm light and of 5.2 A/W for 850 nm light were achieved. The operation details of the PTPD are introduced in this paper. The device can be readily integrated with other on-chip circuits to form a high-performance optoelectronic IC. The low cost, the high performance, and the flexibility in optical-electrical design allow the SiGe PTPD to be used in many demanding applications.

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Wireless time signal broadcast system is an essential platform for the operation of radio watches. It is also a good system for broadcasting other civil information such as disaster warning. To obtain wide coverage area, the carrier frequency is usually as low as tens of kHz. When designing receiver front-end ICs in this low-frequency range, noise consideration is critical. In this paper, the design of a low-power, low-noise receiver front-end IC in 0.35 μm SiGe BiCMOS technology for low frequency time signal broadcast system is reported. The front-end IC tolerates wide input dynamic range of 106 dB and has high sensitivity. With 3.3 V supply voltage, the IC only consumes 0.343 mW when working. Stand-by mode has been implemented to save even more energy. The chip area is only 1300 μm × 908 μm, including ESD protection and bonding pads.

m SiGe BiCMOS Technology

This paper provides a SiGe optical receiver using new high performance differential active Miller capacitor (DAMC) circuits to replace off-chip capacitors. The fully integrated design can avoid off-chip noise interference. The 4.25 Gbit/s optical receiver was realized in a commercial 0.35 µm SiGe BiCMOS process. The measured results of the receiver demonstrate a differential output swing of 530 mV with 50 Ω output loads, a crossing percentage of 51.6%, a peak-to-peak jitter (jitterp–p) of 23.9 ps, and an input sensitivity of -13.8 dBm, respectively, at a bit error rate (BER) of 10-12 with a 231-1 pseudo random binary sequences (PRBS) test pattern. The total circuit dissipates 105.6 mW under a 3.3 V supply, and the chip size is 945 ×980 µm2.

Design of low-power receiver front-end IC for low-frequency wireless time signal broadcast system

In this work, the high performance phototransistor photodetector (PTPD) in commercial 0.35 µm SiGe bipolar junction transistor complementary metal oxide semiconductor (BiCMOS) process without altering any process step is demonstrated and analyzed. The device combines a surface photodetector (SPD) and a conventional SiGe heterojunction transistor (HBT). It is shown that the SPD enhances light absorption, especially for the blue light. With the proper bias configuration, the PTPD shows acceptable dark current and a bias voltage that can be as low as 0.3 V. The Emitter and SPD areas can be respectively designed to meet electrical and optical requirements without increasing the device capacitance. Besides, high responsivities of 5.69/9.47/7.11 A/W for 450/670/780 nm lights were achieved in the PTPD, which makes the device suitable for many applications.

A Fully Integrated SiGe Optical Receiver Using Differential Active Miller Capacitor for 4.25 Gbit/s Fiber Channel Application

Low frequency (LF) broadcast system is not only an essential platform for the operation of radio watches but also a potential system for various applications such as disaster warning. The front-end IC in the LF receivers is a key component. A low-power, low-noise receiver front-end IC realized in SiGe BiCMOS technology for low frequency (77.5 kHz) time signal broadcast system is presented in this work. The receiver exhibits wide input dynamic range and high sensitivity. For the use at LF, flicker noise usually dominates the system noise floor. The receiver designed in this work uses SiGe HBT to reduce flicker noise. The receiver also incorporates a variable gain amplifier (VGA) with wide gain range from −44 dB to 62 dB. Under 3.3 V power supply, the receiver only consumes 0.343 mW when working. Stand-by mode has been implemented to save even more energy. The chip occupies an area of 1300 μm × 908 μm.

A High Performance Photodetector Suitable for Visible Light and Near Infrared Applications

This paper presents a 10 Gbit/s SiGe optical receiver analog front-end (AFE) using input parasitic capacitance immunization technique to enhance bandwidth performance. The broadband technique can strongly reduce the total input capacitance of the optical receiver AFE. The 10 Gbit/s optical receiver AFE was realized in a standard 0.35 µm SiGe bipolar junction transistor complementary metal oxide semiconductor (BiCMOS) process. The measured performance results of the receiver AFE demonstrate a differential output swing of 600 mV under 50 Ω instrument loads, a peak-to-peak jitter (jitterp–p) of 28.28 ps, a root-mean-square jitter (jitterrms) of 4.47 ps, and an input sensitivity of -12.1 dBm, respectively, at a bit error ratio (BER) of 10-12 under a 10 Gbit/s 231-1 pseudo random binary sequences (PRBS) test pattern. The total circuit dissipates 180 mW under a 3 V supply, and the chip size is 700 ×760 µm2.

A receiver in SiGe BiCMOS technology for wireless low frequency time signal broadcast system

A novel high performance integrated PTPD is proposed. The device incorporates a standard phototransistor (PT) and a surface photodetector (SPD) to frilly utilize the incident light energy. Samples in standard 0.35mum SiGe BiCMOS technology were fabricated and characterized. Compared with reference PT of the same size, the PTPD exhibits one order of magnitude improvement in responsivity