High-performance Current Mirror Research Articles

Low Power High Performance Current Mirror – A Review

In VLSI technology the circuit has small size. The efficient size gained due to decreasing chip design to nano-scale. But as chip size becomes very less the factor which adversely affects the design is maintaining constant current in CMOS integrated circuit. Current mirror replicates input current at the output. There is need to design current mirror circuit such that it works efficiently with low power requirement. In this work the survey of different CM circuits analysed and studies. Each CM has its advantages, limitations and research gap which is noted and applicable for further development.

Breaking the speed-power-accuracy trade-off in current mirror with non-linear CCII feedback

Design of analog integrated circuit is a matter of trade-offs. Elementary blocks as simple as current mirrors must balance power, speed and accuracy as soon as they have to face dynamic inputs. In this paper, we propose a new structure of high-performance current mirror that overcomes the classical speed-power-accuracy limits. The structure combines a precise cascode current mirror with a custom low-power current conveyor used as a current mode non-linear feedback circuit. It is particularly suitable for fast multipolar current sources with high driving capabilities and small step response time over a large current dynamic. Design method and practical implementation are discussed in details. The circuit realized in AMS CMOS 0.18 μm technology at 1.8 V supply exhibits a large output current dynamic ranging from 160 μA to 2 m A, an average relative current copy error of 0.3% for worst-cases, a maximal settling time of 730 ns for full range step and a maximum quiescent power consumption of 142 μW.

Current compensation techniques for low-voltage high-performance current mirror circuits

This paper presents two current mirror circuits for low-voltage applications. Unlike most current mirrors that use stacked transistors in the output branch to boost the output resistance, the proposed designs use current compensation techniques to achieve high output resistance. By avoiding stacked transistors in the output branch, the minimum output voltages of the proposed circuits are significantly lower compared to those of other current mirror circuits with comparable output resistance. Particularly, the first design emphasizes on reducing the minimum output voltage to an extremely low level of around 20 mV. The second design stresses minimizing implementation cost. Compared to a simple current mirror circuit, the second design requires only one additional transistor but boosts the output resistance by more than 10 times. Both circuit analysis and simulations are presented to examine the performance of the proposed designs.

High performance current mirrors using quasi-floating bulk

In this paper, a modified structure of standard MOSFET is proposed which offer high transconductance in comparison to its conventional architecture. The conventional MOSFET is a four terminal device whose fourth terminal, the bulk is connected to either negative/positive supply for N-channel/P-channel transistor respectively, or to their source terminal. In the proposed structure, instead of connecting bulk to supply rails or to source terminals, the bulk is configured in a quasi-floating state and then connected back to its gate terminal. The resultant is a gate driven quasi floating bulk MOSFET. Under DC analysis, the proposed structure operates as standard gate driven MOSFET whereas performing analysis in frequency domain the structure results in effective transconductance higher than that of standard MOSFET. Using the proposed structure, three high performance current mirrors are presented in this paper which showed improved performance over its conventional architectures. Performance of the proposed structure and the current mirror circuits are verified using HSpice simulations on 0.18µm mixed-mode twin-well technology at a supply voltage of ±0.5V.

A new wideband regulated cascode amplifier with improved performance and its application

This paper presents a new high frequency Regulated Cascode (RGC) amplifier with improved performance. The split-length compensation technique is used to increase both the bandwidth and output impedance, and decrease the input impedance of the conventional RGC. The bandwidth of the proposed RGC amplifier is 5.81GHz, which is about 2.7GHz larger than that of simple one. The improved performance of the introduced circuit is achieved with no additional passive element and DC power dissipation. In the paper, output impedance and bandwidth of the proposed circuit are derived by using small signal analysis and have also been compared with the traditional one. In addition, a wideband high performance current mirror is designed in the work as an application of the proposed RGC structure. The bandwidth extension ratio (BWER) of the modified wideband current mirror is 1.37. The proposed circuits are designed by using TSMC 0.18µm CMOS process and BSIM3 Level 49 device model. The circuits are simulated on Spectre simulator of Cadence to validate the analytical results obtained in the paper.

A very high performance compact CMOS current mirror

This paper proposes a very high performance current mirror (CM), where output current accurately copies the input current without carrying any offset component. Compact implementation of Garimella et al. CM structure has been combined with super cascode configuration to achieve the proposed very high performance CM. The proposed CM offers extremely high output resistance, very low input resistance and high degree of copying accuracy over a wide operating current range. Small signal analysis is carried out to validate the performance characteristics of the circuit. The proposed CM is simulated by Mentor Graphics Eldospice in TSMC 0.18 µm CMOS, BSIM3 and Level 53 technology, using a single supply voltage of 1.5 V. The circuit is shown to have high current copying accuracy for a range of (0---500 µA) with an error less than 0.0016 % and has no offset current at the output side. The robustness of the proposed CM against the variations in device parameters and temperature changes has been reflected in simulations by carrying Monte Carlo and temperature analysis. The simulation results show that the proposed circuit provides very high output resistance of 55.76 G? and a very low input resistance of 0.07 ?.

High-Performance CMOS Current Mirrors: Application to Linear Voltage-to-Current Converter Used for Two-Stage Operational Amplifier

This paper presents two schemes of high performance CMOS current mirror, one of them is used for operational tran-sconductance amplifier (OTA) in analog VLSI systems. The linearity, output impedance, bandwidth and accuracy are the most parameters to determine the performance of the current mirror. Here a comparison of two architectures based on same architecture of the amplifier is presented. This comparison includes: linearity, output impedance, bandwidth and accuracy. These two circuits are validated with simulation in technology AMS 0.35 μm. An operational amplifier based on the adapted current mirror is proposed. Its frequency analysis with large bandwidth is validated with the same technology.

A novel ultra-high compliance, high output impedance low power very accurate high performance current mirror

In this paper a novel ultra-high compliance, low power, very accurate and high output impedance current mirror/source is proposed. Deliberately composed elements and a good combination (for a mutual auto control action) of negative and positive feedbacks in the proposed circuit made it unique in gathering ultra-high compliances, high output impedance and high accuracy ever demanded merits. The principle of operation of this unique structure is discussed, its most important formulas are derived and its outstanding performance is verified by HSPICE simulation in TSMC 0.18μm CMOS, BSIM3 and Level49 technology. Simulation results with 1V power supply and 8μA input current show an input and output minimum voltages of 0.058 and 0.055V, respectively, which interestingly provide the highest yet reported compliances for current mirrors implemented by regular CMOS technology. Besides an input resistance of 13.3Ω, an extremely high output resistance of 34.3GΩ and −3dB cutoff frequency of 210MHz are achieved for the proposed circuit while it consumes only 42.5μW and its current transfer error (at bias point) is the excellent value of 0.02%.

Compact implementation of high-performance CMOS current mirror

A high-performance compact current mirror implementation with very low input resistance, very high output resistance, high copying accuracy, low input and output voltage supply requirements and high bandwidth is proposed. The circuit characteristics are validated with simulations in 0.5 /spl mu/m CMOS technology and with experimental results.

Low voltage, low power, high performance current mirror for portable analogue and mixed mode applications

A novel current mirror (CM), suitable for operation at low voltage levels is presented. The mirror has high input and high output voltage swings. Adaptive current biasing is introduced for minimising the effects of offset current. A compensation technique has been used to increase the bandwidth. This makes the CM structure attractive for portable, high frequency circuit applications. P-SPICE simulations, based on models for 1.2 /spl mu/m technology, validate the operation of the proposed current mirror for currents from 1 to 500 /spl mu/A with 1.2 GHz bandwidth.

A low-voltage micropower JFET/bipolar operational amplifier

A single cell supply (operable down to 1.2 V) micropower operational amplifier using compatible low pinchoff voltage JFET's (V/SUB p/=0.4 V) in conjunction with standard bipolar technology has been developed. The subvolt pinchoff JFET's have proved useful in the common-mode feedback-assisted biasing of a simple p-n-p input stage to permit single supply operation, the design of a low-voltage high-performance current mirror and a differential to single-ended converter. The amplifier exhibits excellent ac performance (unity gain slew rate=0.25 V//spl mu/s, unity gain bandwidth=850 kHz) with low power dissipation (245 /spl mu/W).