Dynamic Slew-Rate Control for High Uniformity and Low Power in LCD Driver ICs

Choi, Sung-Pil; Lee, Mi-Ra; Jin, Jahoon; Kwon, Kee-Won; Chun, Jung-Hoon

doi:10.5573/jsts.2014.14.5.688

Cited by 3 publications

(1 citation statement)

References 7 publications

(9 reference statements)

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“…Recently, manufacturers begin to pay much attention on electromagnetic interface (EMI), power consumption, efficiency and reliability. The design of high efficiency display driver integrated circuit (IC) (Marano et al, 2010;Jeon et al, 2011;Choi et al, 2014) is important for a high performance of flat-display panels. The rapid development of the display driver IC requires a high frequency operation with a low EMI noise.…”

Section: Introductionmentioning

confidence: 99%

Application of cascode level shifter for EMI reduction in LCD driver IC

Kim

Choi

et al. 2015

Microelectronics International

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Purpose -This paper aims to design the circuit for electromagnetic interface (EMI) reduction in liquid crystal display (LCD). Design/methodology/approach -The cascode level shifter and segmented driver circuit are applied in LCD column driver integrated circuit (IC) for EMI reduction. Cascode current mirror is used in the proposed level shifter for DC voltage biasing and reduction of the driving current which passes through the level shifter. The on-off switching currents and transient times are measured and compared between the conventional and proposed level shifters. Additionally, a segmented data latch is obtained by the timing spread solution in data latch, and applied to split the large peak switching current into a number of smaller peak current. The timing spread-operation does not actually reduce the total power of the noise, instead, it spreads the noise power evenly over the frequency bandwidth. The optimal number of latch is dependent on the operating frequency and EMI allowance. The column driver IC and clock controller are integrated in 0.18 m CMOS technology with 1-poly and 4-metal process. Findings -The post-layout simulation shows that the proposed column driver circuit for LCD driver IC significantly reduces the peak switching current, and it results in the reduction of EMI noise level by more than 15 dB. It is obtained with 20 segmented operations in data latch at 40 MHz frequency. Originality/value -The advantage of the cascode current source is that it can provide a well-controlled bias current with an accurate current transfer ratio. To reduce the EMI noise in LCD driver circuit, the cascode current source is properly located for the DC bias block in the level shifter. The application is rarely done by others, and a significant EMI noise reduction is found. The well-controlled current source provides a high performance switching in the level shifter.

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Section: Introductionmentioning

confidence: 99%

Application of cascode level shifter for EMI reduction in LCD driver IC

Kim

Choi

et al. 2015

Microelectronics International

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Low Specific On-resistance SOI LDMOS Device with P⁺P-top Layer in the Drift Region

Yao¹,

Guo²,

Xu³

et al. 2014

JSTS:Journal of Semiconductor Technology and Science

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Abstract-In this paper, a novel low specific onresistance SOI LDMOS Device with P+P-top layer in the drift region is proposed and investigated using a two dimensional device simulator, MEDICI. The structure is characterized by a heavily-doped P + region which is connected to the P-top layer in the drift region. The P + region can modulates the surface electric field profile, increases the drift doping concentration and reduces the sensitivity of the breakdown voltage on the geometry parameters. Compared to the conventional D-RESURF device, a 25.8% decrease in specific on-resistance and a 48.2% increase in figure of merit can be obtained in the novel device. Furthermore, the novel P + P-top device also present cost efficiency due to the fact that the P + region can be fabricated together with the P-type body contact region without any additional mask.

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Temperature-Dependent Instabilities of DC characteristics in AlGaN/GaN-on-Si Heterojunction Field Effect Transistors

Keum

Choi²,

Kang³

et al. 2014

JSTS:Journal of Semiconductor Technology and Science

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Abstract-We have performed reverse gate bias stress tests on AlGaN/GaN-on-Si Heterostructure FETs (HFETs). The shift of threshold voltage (V th ) and the reduction of on-current were observed from the stressed devices. These changes of the device parameters were not permanent. We investigated the temporary behavior of the stressed devices by analyzing the temperature dependence of the instabilities and TCAD simulation. As the baseline temperature of the electrical stress tests increased, the changes of the V th and the on-current were decreased. The on-current reduction was caused by the positive shift of the V th and the increased resistance of the gate-to-source and the gate-to-drain access region. Our experimental results suggest that electrontrapping effect into the shallow traps in devices is the main cause of observed instabilities.

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Dynamic Slew-Rate Control for High Uniformity and Low Power in LCD Driver ICs

Cited by 3 publications

References 7 publications

Application of cascode level shifter for EMI reduction in LCD driver IC

Application of cascode level shifter for EMI reduction in LCD driver IC

Low Specific On-resistance SOI LDMOS Device with P⁺P-top Layer in the Drift Region

Temperature-Dependent Instabilities of DC characteristics in AlGaN/GaN-on-Si Heterojunction Field Effect Transistors

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Dynamic Slew-Rate Control for High Uniformity and Low Power in LCD Driver ICs

Cited by 3 publications

References 7 publications

Application of cascode level shifter for EMI reduction in LCD driver IC

Application of cascode level shifter for EMI reduction in LCD driver IC

Low Specific On-resistance SOI LDMOS Device with P+P-top Layer in the Drift Region

Temperature-Dependent Instabilities of DC characteristics in AlGaN/GaN-on-Si Heterojunction Field Effect Transistors

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Product

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About

Low Specific On-resistance SOI LDMOS Device with P⁺P-top Layer in the Drift Region