MOS transistor switching circuit design knowledge oled module

1, MOS tube type and structure
FET is the MOSFET (the other one is JFET), may be manufactured or enhanced depletion type , P -channel or N-channel type of four kinds , but the practical application of only N -channel enhancement type MOS tubes and P -channel enhancement type MOS transistor , it is usually referred to NMOS, PMOS , or refers to two .

For both enhanced MOS, more commonly used is NMOS. The reason is that the on-resistance is small, and easy to manufacture . Therefore, the switching power supply and motor drive applications, typically using NMOS. The following presentation, also mostly NMOS based.
Parasitic capacitance exists between the three pins MOS transistor , which is not what we need, but because of the manufacturing process limitations arising . Parasitic capacitance makes the design or selection of the drive circuit will take some time , but there is no way to avoid back again in detail.
MOS tube can be seen on the schematic , there is a parasitic diode between the drain and the source . This is called the body diode , drive inductive loads ( such as motors ) ,Tsingtek lcd graphic display this diode is very important. Incidentally , only the body diode of the MOS transistor in the presence of a single , integrated circuit chip is usually not .
2, MOS conduction characteristics
A conduction switch means is equivalent to a closed switch .
The characteristics of NMOS , Vgs greater than a certain value becomes conductive , suitable for the case when the source is grounded ( low side driver ) , as long as the gate voltage reaches 10V 4V or on it.
Characteristics of the PMOS , Vgs less than a certain value is turned on, the situation is extremely suitable for the source when connected to VCC ( high drive ) . However, while the PMOS can be conveniently used as high-side driver , but the on- resistance is large , expensive, and less replacement types reasons, the high-side driver , it is usually used NMOS.
3, MOS switch losses
Regardless of the NMOS or PMOS, both the on-resistance conduction exists, so current will dissipate energy in this resistor, which is called the partial consumption of energy conduction losses . Choose a small on-resistance MOS tube reduces conduction losses. Now a small on-resistance power MOS usually around tens of milliohms , there are a few milliohms .
MOS is turned on and when the cut-off , certainly not instantaneous. There is a voltage drop across the MOS process , there is a current flowing in the process of rising , at this time, the loss of MOS tube is the product of voltage and current , called switching losses. Switching losses are usually much larger than the conduction losses and switching frequency , the faster , the greater the loss .
Conducting product of the instantaneous voltage and current is large, will cause great damage . Shorten the switching time ,Tsingtek Character OLED Display conduction loss can be reduced every time ; reduce the switching frequency , the switching frequency can be reduced per unit of time . Both approaches can reduce the switching losses.

Character LCD Modules screen products using LED backlight

You can adjust the backlight white balance, while ensuring the overall contrast . When the user's video source switching between your computer and a DVD player , you can easily adjust the white balance between 9600K and 6500K, but without sacrificing brightness and contrast.
Real-time color management. As the three colors red, green and blue light independently , it is easy to precisely control the current display color characteristics .
Brightness adjustment range. Tsingtek COG LCD Module The existence of a threshold minimum brightness CCFL , LED backlight control is very easy to achieve . Therefore, whether outdoors or in bright black interior , users are easy to adjust the brightness of the display device to the most appropriate own state.
Can provide a continuous source of large- area array size screen . A planar light source is LED , the basic unit 3 to the light emitting side of 5mm square package together very easily become established in the area of ​​the surface light source, with good brightness uniformity, if a backlit LCD TV source , the required auxiliary optical components can be made very simple, even better screen brightness uniformity.
Safety. LED using a 5 ~ 24V low-voltage power supply is very safe Tsingtek 160x160 lcd, power module design is quite simple .

Plasma and Character LCD Modules contrast

Contrast refers to the measurement of different brightness levels between light and dark areas in an image of the brightest white and the darkest black, the greater the difference between the representative of the greater range of contrast , the smaller the difference between the representative of the range of the smaller contrast ratio of 120 good : one can easily display vivid, rich color , when the ratio of up to 300:1 , you can support the color of each floor . However, the ratio of suffering and the plight of the same brightness , today there is no effective and equitable set of criteria to measure contrast ratio , so the best way is to rely on user identification eye .

Typically contrast ratio LCD TVs LCD display indicator is higher , ranging between 600:1 to 1500:1 .Tsingtek OLED Display Module However, we sometimes see some of the products will be advertised in the publicity when the parameters of ultra-high 10,000:1 dynamic contrast ratio and the like, so that consumers mistakenly think that the product than other similar technology a couple of notches higher , this is a playing with the concept of the place of text . Misunderstanding the concept that "dynamic" above the word , dynamic contrast ratio refers to the contrast of the LCD TV value under certain circumstances measured , such as one by one test each area of ​​the screen , the contrast maximum contrast value area , as the contrast parameters of the product . Method for measuring different manufacturers are not the same dynamic contrast ratio , usually with a dynamic contrast ratio of the value of the product is 3-5 times the contrast even higher . Therefore, a so-called ultra-high "dynamic" contrast ratio of the actual contrast TV does not necessarily higher than other products , and the contrast of Tsingtek TFT LCD Displays TVs currently has about 1500:1 is the limit.

Plasma are reached 1000:1 contrast ratio generally above , there are some products up to 10,000:1 or more, more than enough to meet the general needs of 2000:1 buy most occasions. NeoPDP using a newly developed phosphor technology , to enhance the contrast 40000:1 .

And other dynamic definition plasma and Character LCD Modules

Dynamic definition refers to the dynamic image playback screen resolution, sharpness , dynamic screen presence embodied in the "tail " , the impact of presence and overlapping . This depends mainly on the TV itself, the response rate, response speed of the LCD TV because the basic 8 milliseconds or less , which will produce significant smearing . The response speed plasma TVs up to 2-3 microseconds , 1-3 microseconds with traditional CRT flat , beyond the range of the human eye can recognize completely negligible in terms of the dynamic image viewing , plasma become the first choice of consumers flat-screen TVs .

LCD TVs rely on rotating LCD panel in LCD control light by forming an image , rotate LCD (ie pixels from dark to bright or dim the lights ) There is a process that requires a reaction time. Response speed of LCD TVs generally slower , so the performance of the screen when there is a lag dynamic picture of the phenomenon , the so-called liquid crystal "tail " phenomenon. Values ​​greater response speed , screen appears tailing phenomenon more serious image overlay . From the current perspective of the development of Tsingtek Lcd display module technology , the response rate has improved ( horizontal scanning improved vertical still did not improve ) , but by the principle of limited , tailing problem difficult to eradicate.

Currently more fashionable LED LCD TV , has been strengthened in terms of dynamic definition , but because LED LCD TV LCD TV is still using the principles of manufacturing , so in terms of response time is still not completely ignored .

Response speed plasma TVs up to 2-3 microseconds , 1-3 microseconds with traditional CRT flat , beyond the range of the human eye can recognize completely negligible . The latest chip technology can be a dynamic industry's highest resolution 1080 lines .

April 22, 2008 released by the China Video Industry Association, the " dynamic definition plasma digital TV test method " standard, the measuring method: a dynamic display screen on the established dynamic resolution measurement mode to 4.5PPF ( per Course number of pixels ) of the speed , that is about 8.5 seconds per frame to move again , and then determine whether the picture is clearly visible by visual inspection , after the speed change to 5.0PPF, also by visual inspection to determine whether the picture is clearly visible.Tsingtek Character LCD Modules These two dynamic resolution measurement data is averaged. The eye of the flat panel display dynamic performance of real feeling , it can be evaluated by the measurement . 4.5PPF ( picture from left to right lateral movement of about 8.5 seconds ) and 5.0PPF ( picture from left to right lateral movement of about 7.7 seconds ) , more than twice the average number of lines for the TV test .

Character LCD Modules TV money saving four strokes

Not pursue large-size screen

Treatment to cure , if you pay attention to the LCD TV 's performance in energy efficiency , it should at the beginning of the purchase to buy a more energy-efficient , low -power products, and in addition to the application of energy-saving technology television itself , the TV screen Power consumption is also quite a lot for the size of the impact . We can understand that when using the phone, the phone standby time big screen is generally short . LCD TV is the same reason , the same paragraph TV screen size is larger, the power consumption is also greater. Therefore, we should choose for their own living room to watch TV models , but not unilateral pursuit of " big-screen enjoyment," too big screens either for consumption or for the perception will have damage.

When viewing the volume to moderate

Having impact on the power consumption of the screen , we look at the voice , now mostly use LCD TV built-in speaker design , for the average family is completely enough, but sound also depends on the size of the speaker 's own power , the greater the power the greater it sounds , power consumption also increases, so if we do not necessary, it is best not to open the TV volume too large , just listen to the clear enough , so that you can to achieve the purpose of saving , and secondly, it will not wake the neighbors a break , and you can extend the life of the TV speakers and then to a certain extent .

TV consumes very high brightness

Now we look at the brightness of the TV ,mini lcd module if determined , then we take a look at your own home TV screen brightness settings, this setting may seem simple, but in fact will cause a relatively large impact on the power consumption of the TV , the brightness of the more high power consumption will be. Of course , we do not regard the brightness of the TV so that we pick very dark , but we need reasonable adjustments , in general , the brightness of the LCD TV does not need to be set to 100 %, generally use 50 percent or slightly higher brightness you can, you know 100% brighter than the darkest brightness power consumption to increase more than 50% of the level seen how important the "Brightness" LCD TV for energy-saving effect is .

Standby power consumption is also

Note above finished watching television after saving techniques , and finally watch television after use . I believe there is a part of the habit of watching TV friends when turned off the TV with a remote control after walked away, but in fact we need to know if you do not press the power button, the TV is not real power, but only in standby mode , in this state the TFT Lcd Modules TV will still be a few watts of power consumption exist, though not high , when accumulated in the long run will also be considerable. After watching so we must remember to turn off the TV the TV's power , so as to better energy conservation, electricity saving for our next record monthly expenses.

Select only hard-screen Character LCD Modules TV Buying Guide

The first method , the black screen with a finger touches the screen , if there is no white flashes , it shows a hard screen, and vice versa is soft screen ; second method is in a moving picture , gently tap the LCD panel, if you will severe smearing the screen , the screen proved to be soft , otherwise it is hard screen . For a more professional friends , you can discern from the pixel structure of the LCD panel , it can be said more accurately foolproof. Technology , IPS wide viewing angle is the top technology, which uses a transparent ITO electrode layer , so the higher aperture ratio obtain higher light output , but expressive than soft pure black screen slightly inferior. We know that the LCD pixel which is composed of three primary colors , red, green , and blue. So in LCD TV , a full pixel is composed of red, Character LCD Module green and blue , and we need to see is this three-color pixel is what shape , as shown below , IPS hard screen panel scaly .

Insiders pointed out that , in fact, pick an LCD TV is also very simple, there is no best , only the most suitable, just remember that the main purpose of buying an LCD TV on it. The most important thing is to buy a TV , is always to look at . The survey shows that for consumers who have a flat- screen TV , watching movies, playing digital camera / camcorder content , playing games is to watch television programs in addition to their maximum use of features, Utah to see the movie for the most , reaching 70.6% . Thus , quality , clarity , LCD TV is undoubtedly the key to the selection of key indicators .

Talk function , depending on demand , just enough , but also to avoid unnecessary waste. In addition to the optional graphic lcd display module TV above described these " cheats " , there are other places to consider , such as the various configuration interfaces , etc., is always good LCD panel is important. I do not know read these , if you are into the store to buy time users can be aware of ? !