A sub-1-V 15-ppm/°C CMOS bandgap voltage reference withoutrequiring low threshold voltage device

A sub-1-V CMOS bandgap voltage reference requiring no low threshold voltage device is introduced in this paper. In a CMOS technology with V_thn ≈ |V_thp| ≈ 0.9 V at 0°C, the minimum supply voltage of the proposed voltage reference is 0.98 V, and the maximum supply current is 18 μA. A temperature coefficient of 15 ppm/°C from 0°C to 100°C is recorded after trimming. The active area of the circuit is about 0.24 mm²     

A CMOS bandgap reference circuit with sub-1-V operation

This paper proposes a CMOS bandgap reference (BGR) circuit, which can successfully operate with sub-1-V supply, In the conventional BGR circuit, the output voltage V_ref is the sum of the built-in voltage of the diode V_f and the thermal voltage V_T of kT/q multiplied by a constant. Therefore, V_ref is about 1.25 V, which limits a low supply-voltage operation below 1 V. Conversely, in the proposed BGR circuit, V_ref has been converted from the sum of two currents; one is proportional to V_f and the other is proportional to V_T. An experimental BGR circuit, which is simply composed of a CMOS op-amp, diodes, and resistors, has been fabricated in a conventional 0.4-μm flash memory process. Measured V_ref is 518±15 mV (3σ) for 23 samples on the same wafer at 27-125°C     

A low supply voltage high PSRR voltage reference in CMOS process

This paper describes a bandgap voltage reference circuit that operates with a 3 V power supply and is compatible with a digital CMOS process. The use of a simple circuit topology results in a small silicon area of 0.07 mm², a power consumption of 1 mW and a high power supply rejection over a wide frequency band. The circuit realizes a temperature coefficient of 85 ppm/°C and a standard deviation of 20 mV without trimming     

A resistorless CMOS bandgap reference with low temperature coefficient and high PSRR

A novel bandgap reference (BGR) with low temperature and supply voltage sensitivity without any resistor, which is compatible with standard CMOS process, is presented in this article. The proposed BGR utilises a differential amplifier with an offset voltage proportional to absolute temperature to compensate the temperature drift of emitter–base voltage. Besides, a self-biased current source with feedback is used to provide the bias current of the BGR core for reducing current mirror errors dependent on supply voltage and temperature further. Verification results of the proposed BGR implemented with 0.35?µm CMOS process demonstrate that a temperature coefficient of 10.2?ppm/°C is realised with temperature ranging from ?40°C to 140°C, and a power supply rejection ratio of 58?dB is achieved with a maximum supply current of 27?µA. The active area of the presented BGR is 160?×?140?µm².     

A sub-1 V high-precision CMOS bandgap voltage reference

A third-order, sub-1 V bandgap voltage reference design for low-power supply, high-precision applications is presented. This design uses a current-mode compensation technique and temperature-dependent resistor ratio to obtain high-order curvature compensation. The circuit was designed and fabricated by SMIC 0.18 μm CMOS technology. It produces an output reference of 713.6 mV. The temperature coefficient is 3.235 ppm/℃ in the temperature range of -40 to 120 ℃, with a line regulation of 0.199 mV/V when the supply voltage varies from 0.95 to 3 V. The average current consumption of the whole circuit is 49 μA at the supply voltage of 1 V.     

On-chip high voltage charge pump in standard low voltage CMOS process

An on-chip high voltage tolerant 4VDD charge pump with symmetrical architecture in a standard low voltage 1.8 V 0.18 /spl mu/m CMOS process is presented. For a 250 k/spl Omega/ load, circuit efficiency of the charge pump is approximately 71%. All the MOS transistors satisfy typical voltage stress related reliability requirements for standard low voltage CMOS devices.     

一种体输入式1V低电源电压带隙基准电路

本文设计了一种电源电压低于1v的体输入式带隙基准电路.在电路的核心电路部分采用了体输入方式以使电路在低电源电压条件下仍能保持较大的共模输入范围.同时,在本设计中舍弃了传统的用镜像电路采集温度补偿电流的方式,而设计了一种新的采集电路结构以避免传统采集方式在低电源电压情况下出现的镜像误差问题.采用CSMC 0.6um工艺的仿真结果表明,在-40-80℃的温度范围内,输出基准电压的温度系数为20ppm/℃,电源电压抑制比(PSRR)在1KHz时可达到60dB.     

A very high precision 500-nA CMOS floating-gate analog voltage reference

A floating gate with stored charge technique has been used to implement a precision voltage reference achieving a temperature coefficient (TC) <1 ppm//spl deg/C in CMOS technology. A Fowler-Nordheim tunnel device used as a switch and a poly-poly capacitor form the basis in this reference. Differential dual floating gate architecture helps in achieving extremely low temperature coefficients, and improving power supply rejection. The reference is factory programmed to any value without any trim circuits to within 200 /spl mu/V of its specified value. The floating-gate analog voltage reference (FGAREF) shows a long-term drift of less than 10 ppm//spl radic/1000 h. This circuit is ideal for portable and handheld applications with a total current of only 500 nA. This is done by biasing the buffer amplifier in the subthreshold region of operation. It is fabricated using a 25-V 1.5-/spl mu/m E/sup 2/PROM CMOS technology.     

A high speed,precision voltage buffer in a submicron CMOS process

A new buffer architecture was introduced by Comer and Comer (1998, International Journal of Electronics, 84, 345). This buffer uses an active feedback network based on a transconductance amplifier. An implementation of the new buffer was done in a CMOS process. The buffer was intended for the output stage of a 10-bit video digital-to-analogue converter. The circuit was fabricated on the American Microsystems 0.6 μm process. Design specifications called for a gain accuracy of 0.1%, an offset voltage shift of no more than 1mV over a commonmode input range of 50% of supply voltage and a bandwidth of 500MHz. The actual circuit showed a gain error of less than 0.1%, a common-mode offset variation of less than 2mV, and a bandwidth of 450MHz.     

低成本多路输出CMOS带隙基准电压源设计

在传统Brokaw带隙基准源的基础上,提出一种采用自偏置结构和共源共栅电流镜的低成本多路基准电压输出的CMOS带隙基准源结构,省去了一个放大器,并减小了所需的电阻阻值,大大降低了成本,减小了功耗和噪声。该设计基于华虹1μm的CMOS工艺,进行了设计与仿真实现。Cadence仿真结果表明,在-40～140℃的温度范围内,温度系数为23.6ppm/℃,静态电流为24μA,并且能够产生精确的3V,2V,1V和0.15V基准电压,启动速度快,能够满足大多数开关电源的设计需求与应用。     

A low power CMOS voltage reference generator with temperature and process compensation

A low power CMOS voltage reference with process compensation is presented in TSMC 0.18-μm standard CMOS technology. Detailed analysis of the process compensation technique is discussed. The circuit is simulated with Spectre. Simulation results show that, without any trimming procedure, the output voltage achieves a maximum deviation of 0.35 % across different process corners. The temperature coefficient of the proposed circuit is 12.7 ppm/°C in a temperature range from ?40 to 85 °C and the line sensitivity is 0.036 mV/V with a supply voltage range from 1.2 to 2.5 V under typical condition. The maximum supply current is 390.4 nA at maximum supply voltage and ?40 °C. The power supply rejection ratio is ?68.3 dB at 100 Hz and 2.5 V without any filtering capacitor.     

A 1-V, 8-bit successive approximation ADC in standard CMOS process

A 1-V 8-bit 50-kS/s successive approximation analog-to-digital converter (ADC) implemented in a conventional 1.2-μm CMOS process is presented. Low voltage, large signal swing sample-and-hold, and digital-to-analog conversion are realized based on inverting op-amp configurations with biasing currents added to the op-amp negative input terminal so that the op-amp input common-mode voltages can be biased near ground to minimize the supply voltage. At the same time, the input and output quiescent voltages can be set at half of the supply rails. A low-voltage latched comparator is realized based on the current-mode approach. The entire ADC including all the digital circuits consumes less than 0.34 mW. An effective number of bits of 7.9 was obtained for a 1-kHz 850-mV peak-to-peak input signal     

A 1-V 1.25-GS/S 8-Bit Self-Calibrated Flash ADC in 90-nm Digital CMOS

We present an 8-bit 1.25-GS/s flash analog-to-digital converter (ADC) in 90-nm digital CMOS with wide analog input bandwidth and low power dissipation. The ADC employs two key techniques: a self-biased track-and-hold amplifier which enhances the ADC full-scale voltage and enables the converter operating under a single 1-V supply; and an improved calibration scheme based on reference pre-distortion to enhance the ADC linearity without sacrificing its sampling speed. The prototype converter thus achieves 7-, 6.9-, 6.5–bit ENOB at 1.25 GS/s for input signal frequencies of 10 MHz, 600 MHz, and 1.3 GHz, respectively, and better than 52-dB SFDR across the full Nyquist-band, while dissipating 207 mW from a single 1-V supply.      

基于标准CMOS的低压高效正向注入型Si-LED阵列研究

基于标准CMOS工艺的n⁺源/漏区和p-sub,设计 了一种楔形n^+pn+ 结构的硅基发光二极管(Si-LED)阵列,并经UMC 0.18μm 1P6M CMO S工艺制备。 测试结果表明, 设计的Si-LED 在 0.9~1.5V范围内正常工作,与CMOS电路的电源电压兼容,其发光 峰值波长在1100nm附近;注 入电流为390mA时,器件的发光功率可达1800nW,平均功率转换效率为3.5×10－6 。由于工作电压低、发光功率高,设计的LED器件有望在光互连领域得到广泛应用。     

90纳米CMOS工艺下带改进RC网络的电源轨静电泄放箝位电路

An electrostatic discharge(ESD) detection circuit with a modified RC network for a 90-nm process clamp circuit is proposed.The leakage current is reduced to 4.6 nA at 25℃.Under the ESD event,it injects a 38.7 mA trigger current into the P-substrate to trigger SCR,and SCR can be turned on the discharge of the ESD energy.The capacitor area used is only 4.2μm~2.The simulation result shows that the proposed circuit can save power consumption and layout area when achieving the same trigger efficiency,compared with the previous circuits.     

A 1-V 140-/spl mu/W 88-dB audio sigma-delta modulator in 90-nm CMOS

A single-loop third-order switched-capacitor /spl Sigma/-/spl Delta/ modulator in 90-nm standard digital CMOS technology is presented. The design is intended to minimize the power consumption in a low-voltage environment. A load-compensated OTA with rail-to-rail output swing and gain enhancement is chosen in this design, which provides higher power efficiency than the two-stage OTA. To lower the power consumption further, class-AB operation is also adapted in the OTA design. Due to the relatively low threshold voltage of the advanced technology, no clock bootstrapping circuits are needed to drive the switches and the power consumption of the digital circuits is reduced. All the capacitors are implemented using multilayer metal-wall structure, which can provide high-density capacitance. The modulator achieves 88-dB dynamic range in 20-kHz signal bandwidth with an oversampling ratio of 100. The power consumption is 140 /spl mu/W under 1-V supply voltage and the chip core size is 0.18 mm/sup 2/.     

A 2-V, low distortion, 1-GHz CMOS up-conversion mixer

A 1 GHz, very linear, CMOS up-conversion mixer is presented. The circuit is able to operate at a 2-V power supply. The topology has a true single-ended output stage which avoids the use of any balun. The total power consumption in both the mixers and the output stage is only 22 mW at 2 V. A profound analysis of the origins of distortion in the mixer has been performed. This study has resulted in the optimization of the linearity of the realized up-conversion mixer. The low power consumption, the low supply voltage, the high frequency performance, and the relatively large amplitude and low distortion single-ended off-chip output signal make the presented topology very suitable for wireless applications     

具有30dB增益和1-16GHz带宽的CMOS低噪声中频放大器

This paper presents a high-gain wideband low-noise IF amplifier aimed for the ALMA front end system using 90-nm LP CMOS technology.A topology of three optimized cascading stages is proposed to achieve a flat and wideband gain.Incorporating an input inductor and a gate-inductive gain-peaking inductor,the active shunt feedback technique is employed to extend the matching bandwidth and optimize the noise figure.The circuit achieves a flat gain of 30.5 dB with 3 dB bandwidth of 1-16 GHz and a minimum noise figure of 3.76 dB.Under 1.2 V supply voltage,the proposed IF amplifier consumes 42 mW DC power.The chip die including pads takes up 0.53 mm~2,while the active area is only 0.022 mm~2.     

A novel low voltage very low power CMOS class AB current output stage with ultra high output current drive capability

In this paper a novel low voltage (LV) very low power (VLP) class AB current output stage (COS) with extremely high linearity and high output impedance is presented. A novel current splitting method is used to minimize the transistors gate–source voltages providing LV operation and ultra high current drive capability. High linearity and very high output impedance are achieved employing a novel resistor based current mirror avoiding conventional cascode structures to be used. The operation of the proposed COS has been verified through HSPICE simulations based on TSMC 0.18 μm CMOS technology parameters. Under supply voltage of ±0.7 V and bias current of 5 μA, it can deliver output currents as high as 14 mA with THD better than ?53 dB and extremely high output impedance of 320 MΩ while consuming only 29 μW. This makes the proposed COS to have ultra large current drive ratio (I_outmax/I_bias or the ratio of peak output current to the bias current of output branch transistors) of 2800. By increasing supply voltage to ±0.9 V, it can deliver extremely large output current of ±24 mA corresponding to 3200 current drive ratio while consuming only 42.9 μW and exhibiting high output impedance of 350 MΩ. Interestingly, the proposed COS is the first yet reported one with such extremely high output current and a THD even less than ?45 dB. Such ultra high current drive capability, high linearity and high output impedance make the proposed COS an outstanding choice for LV, VLP and high drive current mode circuits. The superiority of the proposed COS gets more significance by showing in this work that conventional COS can deliver only ±3.29 mA in equal condition. The proposed COS also exhibits high positive and negative power supply rejection ratio (PSRR+/PSRR?) of 125 dB and 130 dB, respectively. That makes it very suitable for LV, VLP mixed mode applications. The Monte Carlo simulation results are provided, which prove the outstanding robust performance of the proposed block versus process tolerances. Favorably the proposed COS resolves the major limitation of current output stages that so far has prevented designing high drive current mode circuits under low supply voltages. In brief, the deliberate combination of so many effective novel methods presents a wonderful phenomenal COS block to the world of science and engineering.     

A 1.5-V multi-mode quad-band RF receiver for GSM/EDGE/CDMA2K in 90-nm digital CMOS process

A single chip quad-band multi-mode (GSM900/ DCS1800/PCS1900/CDMA2K) direct-conversion RF receiver with integrated baseband ADCs is presented. The fully integrated RF receiver is implemented in a 90-nm single poly, six level metal, standard digital CMOS process with no additional analog and RF components. The highly digital multi-mode receiver uses minimum analog filtering and AGC stages, digitizing useful signal, dynamic DC offsets and blockers at the mixer output. The direct-conversion GSM front-end utilizes resistive loaded LNAs with only two coupled inductors per LNA. The GSM front-end achieves a 31.5 dB gain and a 2.1 dB integrated noise figure with a 5 dB noise figure under blocking conditions. The CDMA2K front-end utilizes a self-biased common-gate input amplifier followed by passive mixers, achieving wideband input matching from 900 MHz up to 2.1 GHz with an IIP3 of +8 dBm. The GSM receiver consumes 38 mA from a power supply of 1.5 V and CDMA2K receiver consumes 16 mA in the low band and 21 mA in the high band. The multi-mode receiver, including LO buffers and frequency dividers, ADCs, and reference buffers, occupies 2.5 mm/sup 2/.