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Polysilicon thin-film technology has become of great interest due to the demand for large area electronic devices. Active matrix liquid crystal displays (AMLCDs) and active matrix organic light emitting displays (AMOLEDs) are among the fields where polysilicon thin-film transistors (poly-Si TFTs) are most commonly used. Such devices, generally, req...
Context in source publication
Context 1
... reference input current ranged from 1µΑ to 100µΑ. The first design examined was the simple current mirror implemented with two poly-Si TFTs as shown in figure 4. The minimum supply voltage was found to be 10V and the relative error between reference input and output current was 16% for no variation of the threshold voltage. ...
Citations
... 2 Very few reports are published on CM 2-7 using oxide and LTPS TFTs. 8 CM circuit with amorphous silicon TFT (a-Si: H) has also been reported. 9 All these are investigated by TFTs with conventional single-gate (SG) TFTs. ...
... For a mirror gain of 8Â, this error rate even reaches 46.25%. 2 With the poly-Si TFT CM, this error rate accounts for 16%. 8 The CM with a-Si: H TFTs degrades more with an error of 50%. 9 Thanks to the very high output resistance, 4-TFT cascode CM shows the perfect 1:1 mirroring with no error. ...
In this brief report, we state current mirror (CM) circuit employed by coplanar amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs) with dual-gate structure. The 2-TFT conventional structure with different mirroring ratios and 4-TFT cascode type are investigated. We compared the CM circuit performances made of the dual-gate (DG) and single-gate (SG) TFTs. At higher mirror gain, the percentage of error increases due to the issues such as TFT performance uniformity and threshold voltage shift. It is found that the DG-based CM circuit shows excellent mirror gain even at 10Â with only 2% error.
Polysilicon thin-film technology has become of great interest due to the demand for large area electronic devices. Display applications, memories and optical copier are among the fields where polysilicon thin-film transistors (poly-Si TFTs) are most commonly used. However the design of analogue blocks, by using Poly-Si TFTs, with constant specifications is very difficult because of the large variation of the threshold voltage of the poly-Si TFT across the wafer and the kink effect makes. In this paper we propose a circuit that can sense the voltage difference between two TFTs. This voltage can be used in order to design an improved current mirror with cancellation of threshold voltage variation
