Proceedings ArticleDOI
A High Precision Constant Current Source Applied in LED Driver
Hongtao Mu,Li Geng,Jun Liu +2 more
- pp 1-4
Reads0
Chats0
TLDR
In this article, a constant current source was proposed to improve the accuracy of the LED current, which consists of a reference current generator, a current mirror, and a current regulator.Abstract:
LED is generally driven by constant current because the color and brightness of LED are directly related to their forward current. The current accuracy is a very important index for a high performance LED driver. In this paper, a constant current source applied in LED driver is proposed to improve the accuracy of the LED current. The constant current source consists of a reference current generator, a current mirror and a current regulator. An accurate current mirror with high impedance is utilized which eliminates the channel length modulation effect of the MOSFETs. A new current regulator in which MOSFET operates in linear region instead of saturation region is proposed to improve the current accuracy and the driver's efficiency. The proposed circuit is based on chartered 0.35μm 3.3/5 V process and has been simulated by Cadence spectre. The output current is 150 mA. Simulation results show that current accuracy of +/-0.5% for a wide output voltage range from 0.35 V to 13 V is obtained.read more
Citations
More filters
Journal ArticleDOI
Analysis and design of a multi-channel constant current light-emitting diode driver based on high-frequency AC bus
TL;DR: In this paper, a multi-channel constant current LED driver based on high-frequency AC bus is proposed, which is composed of one resonant inverter followed by passive resonant rectifiers according to the number of LED strings.
Journal ArticleDOI
Prognostics for lithium-ion batteries using a two-phase gamma degradation process model
Chun Pang Lin,Man Ho Alpha Ling,Javier Cabrera,Fangfang Yang,Denis Y. W. Yu,Kwok-Leung Tsui,Kwok-Leung Tsui +6 more
TL;DR: In this article, a two-phase gamma process model with a fixed change-point for modeling the voltage-discharge curves of battery cycle aging under a constant current is presented, which can be applied to estimate the state of charge and the remaining useful discharge time (RUT) in a cycle with consideration of the effect of cycle aging.
Journal ArticleDOI
Reliability study of LED driver – a case study of black box testing
TL;DR: Pseudo Black Box testing is applied to the reliability study of a commercial LED driver and the circuit degradation model is built.
Proceedings ArticleDOI
High-Performance Megahertz-Frequency Resonant DC-DC Converter for Automotive LED Driver Applications
Mausamjeet Khatua,Ashish Kumar,Vahid Yousefzadeh,Alihossein Sepahvand,Montu Doshi,Dragan Maksimovic,Khurram K. Afridi +6 more
TL;DR: In this paper, the authors proposed a megahertz-frequency resonant dc-dc converter that inherently achieves a load-independent output current while maintaining high efficiency across a wide output voltage range.
Journal ArticleDOI
High-Performance Megahertz-Frequency Resonant DC–DC Converter for Automotive LED Driver Applications
Mausamjeet Khatua,Ashish Kumar,Vahid Yousefzadeh,Alihossein Sepahvand,Montu Doshi,Dragan Maksimovic,Khurram K. Afridi +6 more
TL;DR: In this paper, the authors proposed a megahertz-frequency resonant dc-dc converter that inherently achieves a load-independent output current while maintaining high efficiency across a wide output voltage range.
References
More filters
Journal ArticleDOI
Characterisation and modeling of mismatch in MOS transistors for precision analog design
TL;DR: In this paper, a characterization methodology is presented that accurately predicts the mismatch in drain current over a wide operating range using a minimum set of measured data and the physical causes of mismatch are discussed in detail for both p- and n-channel devices.
Proceedings ArticleDOI
A novel LED driver with adaptive drive voltage
Yuequan Hu,Milan M. Jovanovic +1 more
TL;DR: This paper presents an LED driver circuit consisting of a voltage pre-regulator and multiple linear current regulators with an adaptively-controlled supply voltage that provides consistent illumination and optimal operating efficiency at low cost.
Proceedings ArticleDOI
An analysis of current accuracies in peak and hysteretic current controlled power LED drivers
TL;DR: In this paper, the authors provided an analysis result of current control accuracy in driving power LEDs from widely varied DC input voltage and discussed how to improve current accuracy by using large a inductor size with PCC in Buck converter over wide input voltage variations.
Journal ArticleDOI
High-Efficiency Current-Regulated Charge Pump for a White LED Driver
Chi-Hao Wu,Chern-Lin Chen +1 more
TL;DR: This brief presents a high-efficiency current-regulated charge pump for a white light-emitting diode driver that incorporates no series current regulator, unlike conventional voltage charge pump circuits.
Proceedings ArticleDOI
Accurate current mirror with high output impedance
TL;DR: A novel feedback gain stage is used to increase the output impedance and matching accuracy significantly and the proposed new current mirror has an output swing similar to the traditional two-stage cascode current mirror.