#dimmer control

[mcdonlv-blog]

Intersil mere digital sensor simplifies dimmer control

Intersil Company claims to introduce 2 sections of new light - digital sensor. ISL29001 and ISL29002 can respond to the visible light ' 380nm ~ 770nm) ,And can transform luminous intensity into simple and convenient 15 apt to use - the location, I2C standard digital outcoming signal.

These new device integrated current amplifiers, using for dispelling artificial and mere and flashing 50Hz/60Hz suppression filter and 15 - location ADC (analog-to-digital converter) . These integrated type light - digital sensor realizes the most high degree of sensitivity, can reach people's ophthalmic degree of sensitivity, have low power consumption, lengthen in a poor light to control the intersection of battery and life-span and faceplate visibility employ.

"ISL29001/2 light of Intersil - digital sensor is very suitable for the application that those characteristic, flexibility and small dimension are extremely key, " Manager Oleg Steciw of market of product division says the display unit of Intersil Company. "These devices are highly Integrated, offer the single chip solution to user, can transform luminous intensity into 15 - location, the intersection of I2C and digital outcoming signal, signal this can feed a walkie employ, one to in the in a poor light umbilical control device directly. "

Photoinduction of simulation with digital simple and convenient ease of use

To shine subject brightness range 0.3 Lux to 10,000 Lux, to shine subject brightness range 1 Lux to 100,000 Lux ISL29002 ISL29001 of Intersil. Spectrum of these devices wavelength degree of sensitivity and people wavelength degree of sensitivities ophthalmic ( The maximum of 550nm is responded to) Very close. Efficiency extremely high ISL29001 and ISL29002 also has power down modes, have further saved the power consumption. Last framework double diode that utilized Intersil,these device can autocompensation crystal plate temperature. ISL29001 adopts space-saving 2.0 mm x 2.1 mm unleadedly to capsulate, operating temperature range (- 40 ℃~ +85 ℃) Very extensive. ISL29002 adopts 8- lead wire, 3.0 mm x 3.0 mm (operating temperature range: 0 ℃~ +70 ℃) Capsulate, have 3 address selection pins, allow to install 8 sensors on bus line of a I2C.

Price and supply the situation

ISL29001 adopts 6 - lead wire DFN to capsulate now, pricing is 1.30 dollars; ISL29002 adopts 8 - lead wire DFN to capsulate now, pricing is 1.39 dollars. The pricing of the two regards 1,000 as the unit. Understand more information of ISL29001, please log on websites: http://www.intersil.com/cda/deviceinfo/0,1477,ISL29001,0.html

[pedese-blog]

Automatic brightness control in LED display screen

LED by a lot of mutual independent picture element a bit in electronic display screen ' Shiny yuan) Arranged it, the separation property clicked because of picture element, it is determined that it was luminous to control and drove and can only go on in digital way. The shiny state that the picture element is lighted is controlled synchronously by the control device, self-powered. The real color display of the video means the luminance to be clicked to every picture element is controlled separately, and finish wanting the internal synchronization in specified sweep time. Large screen a bit constituent with tens of thousands of picture element, this make complexity of system reveal large screen than two value and speech increase greatly, and proposed more high requirement to the total data transmission speed. It is obviously unrealistic to click and set up a regular D/A for every picture element, can look for one high limit reduce the system complexity and solution as high as possible of the characteristic.

Know by visual principle, people can depend on bright it / kill duty ratio to the intersection of picture element and average brightness sensation a bit. That is to say, so long as light / kill the duty ratio to regulate, can realize the control on luminance picture element. As to LED electronic display screen, this means that so long as will change into picture element and click luminous time (D/T will be changed) on behalf of the figure like some plain luminance ,Namely has realized D/A of the luminance changes.

Set cycle that the screen data break as, control any data like some plain luminance to be n a binary number

D =Bi2i (bi among them =0 or 1)

Ton to shiny time of D, picture element light then / in duty ratio killed:

d=Ton/Ts=D =bi2i

Expression this can with can preset backward counter, realize, but every picture element mix, make display circuit to be unusually complicated by one counter a bit. It is rewritten that aboving: Ton =Ts bi2i, this means dividing Ton into several time quantums, act as enough hour, several separate time quantum composite Ton the same in visual effect their in the same as total length serial Ton. Then, generally have, as to n location binary data D =Bi2i, will divide Ts as section n, and choose the appropriate time division function f(i) ,Make section i Ti =Tsf(i) ,Among them 0Tibi=Ts f(i) Bi,  d at this moment =Ton/ Ts=Tibi/Ts=f(i) bi

The intersection of picture element and showing / killing duty ratioing a bit this. Because of the function f(i) It can be common as to some of all picture element, aboving shows, so long as use f(i) Control each picture element a bit, can realize the whole the intersection of screen and all the intersection of picture element and a bit separate synchronous D/T change in unison. Can realize as to single picture element aboving with circuit of 1 Fig. a bit. SFR is 8 shift registers in the picture, the picture is the function f(i) of time division Waveform.

The driving circuit of large screen display is usually adopted " Serial shift + latch + drive " Structural,in the hope of trying hard by command line on reduction. Want the whole screen realize aboving at the same time, so long as signal unified from f(i) all ST Control. Prerequisite that do it in this way certainly to require power and position that it deposits in the shift register to be in the each picture element some control data, and this can be accomplished through the data processing in advance.