APA102 LEDs have problem At 24 MHz? You can try NS017S LEDs

  NS107S LEDs don't any trouble at 24 MHz.
  According to Paul Stoffregen's Articles on December 6, 2017December 7, 2017, we know the APA102 LEDs strips have the problem at 24 MHz, usually after 150 to 250 LEDs.  But why?  Here’s his attempt to investigate:

  One tempting explanation is signal quality problems due to horribly messy unterminated wiring carrying high speed signals, as in this photo!  But it turned out to be a more fundamental timing problem.

In this test, a Teensy 3.2 runs the FastLED “Cylon” example with this line:

 LEDS.addLeds<APA102,11,13,RGB,DATA_RATE_MHZ(24)>(leds,NUM_LEDS);

NUM_LEDs was set to 160, and I connected a strip of 144.  The oscilloscope traces are the signals which arrive at the end of the 144 LED strip.

First, I set the clock speed to only 2 MHz to see the “normal” waveforms output by the last APA102 LED.

  

  The main thing to observe here is the APA102 output changes its data line (blue) at the falling edge of the clock (red).  You might notice a slight delay from the falling edge of the clock to the change in data, but it’s tiny relative to the slow 2 MHz clock cycle.

At 24 MHz, the delay is much more significant.  In this case I measured approximately 15 ns delay from clock to the data changing.

  

  You might also notice the red trace doesn’t look like the 50% duty cycle SPI clock signal.  I believe this, together with the data delay, is the main cause of APA102 issues on long LED strips.

Here’s another measurement of the clock.

  Each APA102 LED is supposed to regenerate the clock signal.  Ideally this is supposed to allow a very long LED strip.  But it appears each APA102 lengthens the clock high time and shortens the clock low time slightly.  This might be internal to the APA102 control chip, or it could be simply due to the clock output driver having a faster fall time than rise time, causing the following APA102 to receive a slightly different clock high time.  Perhaps the APA102 controller chip has a better N-channel transistor for pulling the clock output low than the P-channel transistor for driving it high?

After 144 LEDs, the clock low time on this strip has shrunk from 20.83 ns to approximately 18 ns.

With the data output delayed 15 ns after the falling edge, this leaves only 3 ns before the next APA102 LED captures the data on the rising edge of the clock.  As the strip gets longer, each APA102 reduces the clock low time, until it’s shorter than the clock to data delay.

FastLED defaults to 12 MHz SPI clock for APA102 LEDs on Teensy 3.x, which should allow for several hundred LEDs before this clock duty cycle change becomes a problem.

This test was just one APA102 strip I purchased about a year ago.  The Chinese semiconductor manufacturers making these LEDs have a history of changing the silicon without any notice.  I also only tested at room temperature, using only 1 example program which doesn’t drive the LEDs anywhere near 100% duty cycle (more heating).  I powered the 144 LEDs with 5V from both ends, but didn’t make any measurements of the voltage near the middle of the strip.  Power supply voltage might matter.  In other words, your mileage may vary.

But hopefully this helps with understanding what’s really going on, why short APA102 LED strips work so well with the fast clock speeds, but fail when using very long strips, even though the LEDs are supposed to regenerate the clock and data as they pass it down the strip.

Newstar

SK6812 3535 RGBW P6 Addressable LED chip

This is Newstar's newest development sk6812 rgbw addressable led chip with 3535 size. before only have sk6812 5050 rgbw addressable led in the market. 

SK6812 3535 RGBW pixel leds will be widely applied.

Product Overview: 
  SK6812-3535RGBW is a smart LED control circuit and light emitting circuit in one controlled LED source, which has the shape of a 3535 LED chip. Each lighting element is a pixel, and the intensities of the pixels are contained within the intelligent digital interface input. The output is driven by patented PWM technology, which effectively guarantees high consistency of the color of the pixels. The control circuit consists of a signal shaping amplification circuit, a built-in constant current circuit,and a high precision RC oscillator.
  The data protocol being used is unipolar RZ communication mode. The 24-bit data is transmitted from the controller to DIN of the first element, and if it is accepted it is extracted pixel to pixel. After an internal data latch, the remaining data is passed through the internal amplification circuit and sent out on the DO port to the remaining pixels. The pixel is reset after the end of DIN. Using automatic shaping forwarding technology makes the number of cascaded pixels without signal transmission only limited by signal transmission speed.
  The LED has a low driving voltage (which allows for environmental protection and energy saving), high brightness, scattering angle, good consistency, low power, and long life. The control circuit is integrated in the LED above.

Description:
● Top SMD internal integrated high quality external control line serial cascade constant current IC;
● control circuit and the RGB chip in SMD 3535 components, to form a complete control of pixel, color mixing uniformity and consistency;
●built-in data shaping circuit, a pixel signal is received after wave shaping and output waveform distortion will not guarantee a line;
●The built-in power on reset and reset circuit, the power does not work;
●gray level adjusting circuit (256 level gray scale adjustable);
● red drive special treatment, color balance;
● line data transmission;
● plastic forward strengthening technology, the transmission distance between two points over 10M;
●Using a typical data transmission frequency of 800 Kbps, when the refresh rate of 30 frames per sec

Mechanical Dimensions:

PIN configuration:

Recommended dimensions for PCB:

General description of product naming

more details, please check the datasheet.

Newstar

the difference of NS107S HD107S LC8823

NS107S HD107S LC8823 LEDs are same with each other, all with same IC but different factory make the LEDs, IC provided by Newstar.

APA102, APA107/NS107S and SK9822, The differences?

Do you know the difference of APA102, APA107/NS107S, and SK9822?
APA102: 20+ kHz PWM.
APA107: 9 kHz PWM.
NS107S: 26+ kHz PWM (the upgrade of APA107).
SK9822: 1.2 kHz PWM.
In conclusions, APA107/NS107S is one real product which can replace APA102.
If you want to know the price, please contact us.

Now let us introduce some different types of LEDs,

The AllPixel supports all the popular LED chipsets and a bunch of the not so popular ones. The most common ones you will see are:

WS2812: A 1-wire interface chipset, integrated directly into either an SMD5050 or 8-12mm through-hole LED. Typically the cheapest option, but slow data and PWM rate. There are many variants that all use the same protocol:
NeoPixel: Adafruit's brand name for all of this type of LED
WS2812B: The 4 pin variant of the SMD5050 package (which originally came with 6 pins as the WS2812).
WS2811: Bare-IC variant typically used for Christmas style lights and 12V strips (3 RGB LEDs per IC)
WS2811 400kHz: Original version of the chipset that runs at 400kHz, unlike all newer versions that run at 800kHz. You must use LED TYPE.WS2811_400 when using this variant. These are rare now.
SK6812: A knock-off, related to the APA102 but uses the WS2812B protocol.
APA107: Our current favorite and "New Kid on the Block". The chipset is integrated into an SMD5050 LED like the WS2812 but uses a 2-wire interface instead and supports up to 30Mbps and a whopping 9kHz PWM rate. Newstar's patent design.
NS107: the upgrade of APA107, with PWM refresh rate of +26 kHz. sold by Newstar.
LPD8806: Oldie but still a goody, this chipset is a 2 wire interface that can manage 20Mbps and high PWM rate. The downsides are that each IC controls 2 LEDs and it only has 7 bits per channel instead of 8 so it can only handle 1/8th as many colors.
WS2801: Mid-price, 2-wire interface with great 8-bit per channel color but only 1Mbps data rate and decent, 2.5kHz, PWM rate.
Those are the main chipsets that you'll come across on the market, if you are using one of the others supported by the AllPixel, you likely know exactly why you are using it over the other options.

The AllPixel provides 4 connection pins for hooking up your LEDs:

Note: Your LEDs may not have the same pin ordering!

• V+: Power output. Typically 5V but up to 12V supported for LEDs that require it. Required if powering via USB or the onboard power jack. But can be left disconnected if power is connected elsewhere.
• GND: Common ground. Even if not using USB or the power jack on the AllPixel for power, this connection is required so that the DATA and CLK pins have a ground reference.
• CLK: The clock pin for chipsets that require clocked data. Refer to the table below to know if your chipset requires it.
• DATA: The pixel data output pin and required by all chipsets.

Basically, all chipsets will either have 3 or 4 connections. 2 are always for ground and power. If there are 3 total wires, only DATA is required but if there are 4 wires, both DATA and CLK are required. See the following table for details on which pins are required, which LED TYPE to use with the BiblioPixel software library, and other chipset specifications. Note the R6 and R7 designations on DATA and CLK these are the resistor/jumper pads mentioned in the Optional Components section. If there is a check in the column than that resistor must be installed or the pad must be jumped. The resistors are intended mainly for the WS2812 chipset but we've found there's no harm in installing them for all chipsets.

Chipset	type = LEDTYPE.	DATA (R6)	CLK (R7)	Color Bits	Data Rate	PWM Rate
LPD8806	LPD8806	√	√	7	1-20Mbps	4kHz
WS2801	WS2801	√		8	1Mbps	2.5kHz
WS2812	WS2812	√		8	800kbps	400Hz
APA107	APA107	√	√	8	30Mbps	9kHz
NS107S	NS107S	√	√	8	30Mbps	+26khz
APA102	APA102	√	√	8	24Mbps	+20khz
TM1803	TM1803	√		8	400kbps	400Hz
TM1804	TM1804	√		8	800kbps	400Hz
UCS1903	UCS1903	√		8	400kbps	?
P9813	P9813	√	√	8	1-15Mbps	4.5kHz
SM16716	SM16716	√	√	8	?	?
LPD1886	LPD1886	√		12†	16Mbps	400Hz

† The LPD1886 chipset supports 12 bits per channel, but the AllPixel is limited to 8 bits.

Chipset Choice Considerations

For a lot of projects, just about any chipset will do and you can go with the cheaper WS2812 or APA102. But certain applications require making the right choice.

First, note that maximum frame-rate will depend on the number of pixels you are trying to control. All chipsets can achieve 100+ FPS if only controlling a few pixels, but if you are using the maximum of 700 that the AllPixel supports, that can drop to < 20 FPS for some of the chipsets with lower data rates. If pushing as many frames as possible is a concern, APA102, LPD8806 and P9813 are great choices because they all support data rates greater than 1Mbps.

Second, if your display will be moving or you want to use it in the persistence of vision display, like our POVStick project then you need a chipset that supports a high PWM rate. Lower rates will be visible as a flicker when the display is in motion. LPD8806, WS2801, P9813, and especially APA102 are all good options for this. WS2801 won't be able to have as high of a frame-rate, but won't show flicker. LPD8806 and APA102 are by far the best options for this application.

Power

Most LEDs will require 5V and, in general, you can calculate the maximum current draw as 60mA per LED when lit up full white. But that is just a maximum that you should design for when choosing a power supply. In practice, it's rare that the draw ever reaches that theoretical maximum, as the power draw heavily depends on what is currently being displayed. There are 3 main ways you can provide power to your display:

• DC Barrel Jack: Using the optional DC Barrel Jack you can provide up to 5A of current directly from the AllPixel using any power supply with a 2.1mm, positive-tip, connector. Using this jack it is possible to power LEDs requiring up to 12V as long as they still support 5V logic. Note, however, that there is a voltage drop over the length of LED strips and a good rule to follow is to inject power a least every 5 meters or 5A of current draw, whichever will likely come first. Using the AllPixel PowerTap is a great way to do this.
• Manual Hookup: You can "roll your own" and wire power to your display however necessary. But just remember that you must always connect the GND pin on the AllPixel to the ground of whatever power supply you are using.
• USB: For 5V strips, it is possible to power a small number of LEDs directly from the USB connection. Depending on the animation, this could be as many as 100 pixels. To do so, you must install the USB Power Diode. This will allow you to source up to a little over 400mA to the LEDs (the AllPixel requires about 65mA itself). If you go over this limit, the built-in poly-fuse will automatically trip before any damage could be done to your computer. If this happens, just unplug the AllPixel and the fuse will reset within a few minutes. To help decrease the current draw when using this power method, we recommend decreasing the master brightness in software like so:

led = LEDStrip(driver)
led.setMasterBrightess(64) //set to 25% brightness (0-255 is valid)

APA107/NS107S LED CHINA

EC15 pixel led - Ultra-small SK6812 LED with 1.5x1.5mm size

1, EC15 is one ultra-small SK6812 pixel led chip with 1.5x1.5mm size, it is an embedded control type LED light source integrating control circuit and light-emitting circuit. It contains intelligent digital interface data latch signal shaping and amplifying drive circuit, power supply voltage regulator circuit, built-in constant current circuit and high precision RC oscillator. The output driver adopts the patented PWM technology, which effectively ensures the high color consistency of the light in the pixel.
  The data protocol being used is unipolar RZ communication mode. The 24-bit data is transmitted from the controller to DIN of the first element, and if it is accepted it is extracted pixel to pixel. After an internal data latch, the remaining data is passed through the internal amplification circuit and sent out on the DO port to the remaining pixels. The pixel is reset after the end of DIN. Using automatic shaping forwarding technology makes the number of cascaded pixels without signal transmission only limited by signal transmission speed.
  The LED has a low driving voltage (which allows for environmental protection and energy saving), high brightness, scattering angle, good consistency, low power, and long life. The control circuit is integrated into the LED above.

2. Main Features :
● Easy to design
● Easy to build
● Easy to program

3. Description:
● EC LED internal integrated high-quality external control line serial cascade constant current IC;
●built-in data shaping circuit, a pixel signal is received after wave shaping and output waveform distortion will not guarantee a line;
●The built-in power-on reset and reset circuit, the power does not work;
●gray level adjusting circuit (256 level grayscale adjustable);
● red drive special treatment, color balance;
● line data transmission;
● plastic forward strengthening technology, the transmission distance between two points over 10M;
●Using a typical data transmission frequency of 800 Kbps, when the refresh rate of 30 frames per sec

4. Mechanical Dimensions:

5. PIN configuration

Notes:

1. All dimensions are in millimeters.

2. Tolerance is ±0.1mm unless otherwise noted

5. Product welding plate size

7. General Information

8. Absolute Maximum Ratings (Ta=25℃,VSS=0V)

9. Electrical/Optical Characteristics:

10. The electrical parameters (unless otherwise specified, TA=-20 ~ +70 ℃, VDD=4.5 ~ 5.5V, VSS=0V):

11. The dynamic parameters (Ta=25 ℃):

12. The data transmission time :

1. The protocol uses a unipolar zeroing code. Each symbol must have a low level. Each

symbol in this protocol starts with a high level. The high time width determines the "0" or

"1" code. .

2. When writing programs, the minimum symbol period is 1.2μs.

3. The high time of “0” code and “1” code should be in accordance with the

stipulated range in the above table. The low time requirement of “0” code and “1”code is less than 1.2μs.

13. Timing wavefrom:

        Input code:

         Connection mode:

14. The method of data transmission:

Note: the D1 sends data for MCU, D2, D3, D4 for data forwarding automatic shaping cascade circuit.

15. The data structure of 24bit:

    Note: high starting, in order to send data (G7 - G6 - ...... ..B0)

16. The typical application circuit:

Product signal input and output must be connected in series Protection resistor R1, R1 depends on the size of the cascade lamp beads, the greater the number of cascade, the smaller R1, the general recommended value between 200-2KΩ, usually recommended Worth about 500 euros;

16. Standard LED Performance Graph:

More details, please contact us.

Newstar

www.newstar-ledstrip.com

WS2815 compare GS8208, 12V pixel LED SMD

  Now 12V pixel LED is more popular, can be more widely used than 5v pixel led. nowadays there are two mature products, one is WS2815 DC12V pixel LED, another one is GS8208 12v pixel LED, actually WS2815 12v led came out earlier than GS8208, and has been updated several times, now ws2815 is more stable and mature than before. About the GS8208, it is a clone led of WS2815, but with more interesting features. just like the SK9822, one clone led of APA102/APA107.

so what is the different of WS2815 and GS8208? 

Firstly, let us see the WS2815.

WS2815 is an intelligent control LED light source that the control circuit and RGB chip are integrated in a package of 5050 components. Its internal includes intelligent digital port data latch and signal reshaping amplification drive circuit.

Dual-signal wires version, signal break-point continuous transmission. Any pixel’s failure won't affect signal transfer and total emitting effect. The data transfer protocol uses a single NZR communication mode. After the pixel power-on reset, the DIN port receives data from the controller, the first pixel collects initial 24bit data then sent to the internal data latch, the other data which

reshaping by the internal signal reshaping amplification circuit sent to the next cascade pixel through the DO port. After transmission for each pixel, the signal to reduce 24bit. Every pixel adopts auto-reshaping transmit technology, making the pixel cascade numbers are not limited to the signal transmission, only relate to the speed of signal transmission.

The BIN receives the data signal, and then compare the data with the DIN side after phagocytosis of 24bit data, if DIN do NOT receive the signal, then switching to BIN for receiving the input signal, which ensures that any the IC's damage does not affect the signal cascade transmission and make the BIN in state of receiving signal until restart after power-off.

Refresh Frequency updates to 2KHz, Low Frame Frequency, and no Flicker appear in HD Video Camera.

RESET time>280μs, it won’t cause the wrong reset while interruption, it supports the lower frequency and inexpensive MCU.

Integrated circuit chips enable the circuit control simpler, neater and more reliable while NO extra components needed.

Mechanical Dimensions

PIN Configuration

PIN Function

Absolute Maximum Ratings

Electrical Characteristics (TA=-20～+70℃, VDD=4.5～5.5V, VSS=0V)

Switching Characteristics (TA=-20～+70℃, VDD=4.5～5.5V, VSS=0V)

LED Characteristics

Data Transfer Time

Data Transmission Method

                                                 Note: D1 is the data from MCU, and D2, D3, D4 are from Cascade Circuits
The composition of 24bit data

                                                 Note: Data transmit in order of GRB, high bit data is first.

Typical application circuit

1. Recommended application circuit

Remarks: C1 is bypass filter capacitor, its value of 100NF.

2. For complicated wiring & space-saving

So what is GS8208? 

  The GS8208 is a 3-channel constant current LED driver with resumable data transfers and internal display patterns. There are three open-drain constant current outputs, with a built-in PWM of grayscale. The range of input power is from 9VDC to 15VDC, and voltage-endurance of LED port is +12VDC. there is a built-in 12bits GAMMA correction module. PWM maximum refresh frequency is 8kHz. The GS8208 use the e-Rz (extended return to zero code) as the signal transmission mode, which can control the output current channel by channel and cascade infinitely. GS8208 provides two signal data input as redundant control, which ensures the transmission of the signal if any single chip damages. In the absence of signal input, GS8208 displays the built-in display patterns that are suitable for those applications without a controller. there is the built-in power-on the power-off protection in the driver, which can enhance the service life of the chip. It also has the automatic test function while power on, which is convenient for the customer to test. The GS8208 provides SOP8 packaging, the working environment is from -° 40° C to + 85C.

Features

-12V operating supply voltage with 7805 module inside

-Default 17.5mA constant current output, the minimum is 11mA.

-Use e-Rz code, serial data frequency 800kHz.

-8bits data transfer, 12bits build-in GAMMA correction of PWM display.

-Built-in PWM technology, supports 8kHz PWM refresh rate.

-With resumable data transfer function, single chip damage does not infect data transmission.

-Built-in automatic test mode, power-on and power-off protection.

-ESD: 2KV.

Typical Applications:

Block Diagram

PIN

PIN Description

Equivalent Circuits of Input and Output

Maximum Ratings

(1) Stresses above there ratings may cause permanent damage. Exposure to absolute maximum condition for extended periods may degrade device reliability. These are stress ratings only and functional operation of the device at these or any other condition beyond those specified is not supported.

(2) All voltage values are with respect to the ground terminal.

Electrical Characteristics

Switching Characteristics

Typical Application

Data Format

  GS8208 adopts the extended return zero code (e-RZ) data transmission mode, 8bits data for a single channel, each IC support 3 channel for display. The transmission data is filtered internally to support the data anti-jitter function. The extension type is compatible with traditional RZ code. So it is suitable for most of RZ code controller in the market.

Single code with 1:3 duty cycle and a standard 800kHz transmission speed. The maximum frequency can reach 1MHz. GS8208 re-code the data before transmission. Data delay is less than 0.7us from chip to chip, meets the dynamic image needs.

Dual Channel redundant control

   Dual channel redundant control can be used to effectively avoid the failure of any single device damage, and reduce the damage rate of driving system to one millionth. The SDI signal is used as the default transmission channel while the system is power on. The transmission channel priority is switched between SDI and SDI2 when the transmission data is abnormal. The device will choose the clear transmission channel after data detection.

When the external control data is transmitted, SDI used the 1-24bits received data as the display data, meanwhile SDI2 will discard the 1-24bits data and use 25-48bits data as the display data.

Dual Channel status testing during production

  In the production process, any one of the abnormal data channel will not affect display because the chip uses dual SDI input. it is difficult to detect the problem data channel during the production process, which may cause the dual channel is equivalent to a single channel.

  In order to avoid this situation, the status of the data channel can be detected by using the test controller in the external control situation. While any channel appears weld, short, open or other abnormal communication, the chip will display in white to facilitate the detection of the problem position.

Working principle of series structure LED controller

  it is RGB LED series structure. Power supply voltage is 12V, and the LED constant current is 18mA. Different to the parallel architecture of 5v power supply and 54mA driver current, the series architecture can provide a better driver ability. The new architecture's total driver current is only 1/3 of the original one and Vds=4V. The power loading ability is better.

  In the series structure mode, when the internal MOS paralleling with the LED is open, the current flow into the LED and the LED lights. When the internal MOS paralleling with the LED is short, the current flow into the MOS device and the LED close. Switching the MOS device by PWM signal can lights on or off the LED.

Working principle of series structure LED controller

  In order to prevent the large power interference from the LED switching, reduce the power circuit voltage fluctuations, GS8208 has built-in output hysteresis function. OUT1, OUT2, OUT3 will work in accordance with 80ns interval sequence, to improve the system's anti-jamming performance. Meanwhile, the current peak output stagger will reduce the system EMI radiation, to meet environmental requirements.

MPWM (multi-PWM)

  In order to increase the refresh rate of PWM output, MPWM adopts a unique method of dispersibility to distribute the periodic N in the display time, as shown in the figure below. GS8208 adopts MPWM technology, and the PWM refresh rate increases to 8kHz, which shows the gentle effect and does not affect the accuracy of output current.

MPWM (multi-PWM)

  GS8208 gets into RGB test mode right after power on. If the device does not receive the external display data for a long time, the chip will go into the built-in display patterns mode. The pattern on a total of six categories of 32 series, including integral color jump, integral color gradient, meteors, waves, colorful gradient, color jump of water circulation. It is 10 minutes about, and the image refresh frequency is 100hz.

  Under the internal display mode, the first chip's SDI/SDI2 needs to be connected to GND.

Power dissipation

  When all the three output channels are turned on, the practical power dissipation is determined by the following equation:

(Vout represents the output terminal voltage when the current is turned on; Duty represents the ratio of the time at which the current is turned on)

                    PD(practical) VccxIccVoutA2xIoutA2xDutyA2...VoutD0xIoutD0xDutyD0

In secure operation conditions, the power consumption of an integrated chip should be less than the maximum permissible power dissipation which is determined by the package types and ambient temperature. The formula for maximum power dissipation is described as follows: 

The PD (max) declines as the ambient temperature rises. Therefore, suitable operating conditions should be designed with caution according to the chosen package and the ambient temperature. The following figure illustrates the relation between the maximum power dissipation and the ambient temperature of the SOP8 package.

If you don't know which one is more suitable to you, please contact us.

Newstar

www.newstar-ledstrip.com