power consumption

Linear voltage regulator switch voltage will face problem of power consumption, switch mode has the problems of noise, LED drive the choice of conversion depends on the application.

How to convert?

The linear regulator to convert the voltage will face the problem of power consumption, LED Spotlight this approach is more suitable for the need to avoid noise ( such as car audio ) and therefore cannot use switch mode converter. While the switch mode is characterized by a very high conversion efficiency, but it also has the problems of noise, LED Floodlight so the choice of conversion depends on the application.

Usually, the charge pump drive efficiency with the input voltage changes, the change in voltage range applications, its efficiency is quite low; and the voltage variation range of small applications, only when the input and output voltages are integral multiples of relations, its efficiency can reach the maximum, but this in battery powered applications it is difficult to achieve. The inductance of the conversion efficiency is not affected by voltage interference, application limits than the charge pump is less, so the current conversion circuit with inductance mode.

How to evaluate the performance?

Say objectively, evaluation of HB LED drive IC performance according to different applications, can lump together. Such as decorative lighting applications on the RGB color change control requirements, the performance becomes the main index, in monochrome application does not require the. And as the narrow space of application requirements is the heat capacity; LED Candle Bulb automotive lighting instead of application requirements of both the original circuit system and smooth combination of performance and high reliability is required; in NB and display applications, the string LED brightness balance control driver IC for each branch current is accurate control, such as MAXIM product control precision can reach 3%; projector application requires high efficiency driving circuit, the rapid adjustment of brightness and thermal protection capability; in alternative applications, performance more is reflected throughout the programme rather than a single driver on IC. In general, the integration of device, control volume, speed of response, fault diagnosis, heat-resistant are performance evaluation.

Usually, high integration aims to improve performance, but at high power, high integration as the meet the current will increase in chip area, increase the cost at the same time also faces the problem of heat dissipation, so, how to balance the power and integration is the relationship between the driver IC design task. Drive IC in improved chip technology to meet the cost at the same time, improve the package to solve the problem of heat dissipation.

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