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AN2531

STEVAL-ILL009V3 load board

 35/40

Figure 23.

STEVAL-ILL009V3 schematic diagram

R_diss = U/I = 06 / 0.7 = 0.85 => 0.75 

 

U_r = Ud - Uf_red_max = 4 - 3.4 = 0.6 V

R2 = R3 = 1.5 

  R2 || R3 = 0.75 

5 V

4700 

NTC

1.263 V for 72 ˚C

R_ntc (72 ˚C) = 1588 

R3

1. 5 

R4

47 k

1

2

3

4

5

6

7

8

9

10

CONNEC TOR1

ICC

R1

0

0

R1

1

R1

2

G1

a

3

G1

a

4

G1

b

5

G1

b

6

B1

7

B1

8

R2

9

R2

10

G2

a

11

G2

a

12

G2

b

13

G2

b

14

B2

15

B2

16

NC

17

NC

18

GND

19

GND

20

NC

21

Vo

22

NC

23

Vcc

24

NC

25

NC

26

Vd

27

Vd

28

Vd

29

Vd

30

CONNECTOR2

ICC

R2

1. 5

AM00300

Summary of Contents for STEVAL-ILL009V1

Page 1: ...lates the color of the LED to generate multicolor light The LED over temperature protection is designed on this board and therefore the power delivered to the LED can be automatically limited to prevent LED overheating The STEVAL ILL009V1 is a mother board assembled without LEDs To evaluate light effect features it is necessary to order a load board additional board with assembled RGB LEDs Two loa...

Page 2: ...rotection 16 8 STEVAL ILL009V1 reference board 17 8 1 General description 17 8 2 Getting started 18 8 3 Schematic description 19 8 4 Bill of material 22 8 5 Design calculation 23 8 5 1 LED supply voltage 23 8 5 2 Temperature protection 23 8 5 3 SW PWM frequency calculation 25 8 6 Software 26 9 STEVAL ILL009V5 reference board 30 9 1 STEVAL ILL009V5 schematic diagram 31 9 2 Bill of material 32 10 ST...

Page 3: ...AN2531 Contents 3 40 11 STEVAL ILL009V4 load board 36 11 1 Schematic description 37 11 2 Bill of material 37 12 Reference and related materials 39 13 Revision history 39 ...

Page 4: ...1 22 Table 2 Temperature limit setting using STLM20 24 Table 3 Temperature limit setting using NTC 24 Table 4 STEVAL ILL009V5 bill of material 32 Table 5 STEVAL ILL009V3 bill of material 34 Table 6 STEVAL ILL009V4 bill of material 37 Table 7 Document revision history 39 ...

Page 5: ...ure 11 Components position on the STEVAL ILL009V1 18 Figure 12 STEVAL ILL009V1 schematics LED drivers part 20 Figure 13 STEVAL ILL009V1 power sources schematic 21 Figure 14 Send data time diagram 25 Figure 15 Main program flowchart 26 Figure 16 Blink function flowchart first part 27 Figure 17 Blink function flowchart second part 28 Figure 18 Manual color modulation 29 Figure 19 Blink function flow...

Page 6: ...hich sends data through serial peripheral interface SPI to the shift registers inside STP04CM596 The data are shifted bit by bit to the next drivers in a cascade with falling edge of the clock frequency the maximum communication frequency for this drivers is 25 MHz When all data are transmitted to the drivers through SPI the micro sets latch input terminal LE pin log 1 to rewrite the data to the s...

Page 7: ...ds time to send data to all drivers More information about this principle is described in Chapter 4 Color control software modulation If the request is to build up a high power light with many LEDs of the same color drivers can be connected in parallel as shown in Figure 4 Main advantages are a simpler solution and better PWM resolution because only four bits are sent through the SPI and it takes ...

Page 8: ... drive many LEDs AN2531 8 40 Figure 4 LED driver connection parallel configuration AM00287 Micro SPI LED supply voltage STP04CM596 Control and logic part STP04CM596 Control and logic part Parallel connection ...

Page 9: ...TP04CM596 Thanks to a common drain configuration the outputs can be connected together as shown in Figure 5 This increases the performance and current capability of this driver This configuration allows driving the whole range of HB LEDs available on the market For example this principle is also used in the STEVAL ILL009V1 presented in this application note because the board has maximum current ca...

Page 10: ...nges to 0101 This frame is sent until output 2 with blue LED 28 duty cycle should be turned OFF and when the frame 0001 is used Finally the output 4 with another LED usually second green LED is turned OFF with 98 duty cycle which means than 0000 is being sent until maximum time for one cycle is reached After that the entire period for all outputs can start again Figure 6 Software brightness modula...

Page 11: ...e number of driven LEDs is the same as number of bits sent BITS LEDS Equation 4 The maximum number of used LEDs is assumption BITS LEDS Equation 5 Note The above calculation is only valid only when the data are sent to the driver through the SPI without any delay This means the data BYTES are sent thought the SPI and at the end of this communication the next data BYTES are immediately sent etc In ...

Page 12: ...river family The current flowing through each channel of the LED driver is constant and so power dissipation depends on the voltage on each channel which is the difference between the supply voltage DC bus and the forward voltage drop on the LEDs Therefore it is recommended to keep the supply voltage as low as possible but always above the maximum LED forward voltage Figure 7 shows the RGB LED con...

Page 13: ...l the red LED has a lower forward voltage and therefore the power dissipation on the red LED channel is the highest There is quite simple way to decrease this power dissipation by using a serial resistor with the red LED Calculation example is shown in Section 10 1 and 11 1 AM00290 STP04CM596 Rext I REG Vo Vo Vo Vf_red Vc Vf_blue Vf_green Vo Vf_green ...

Page 14: ... when the driver is turning off the LEDs and it can be dangerous for the STP04CM596 as it can exceed the maximum output voltage rating Generally higher current and higher parasitic inductance long cable means higher voltage peaks Therefore over voltage protection is very important for high brightness LEDs in case of long connections between the driver and LEDs Figure 8 Over voltage on STP04CM596 A...

Page 15: ...des are connected between the LED supply voltage DC bus and driver s channel and so limit the voltage on the channels The third solution is the most cost effective and uses only a single Zener diode which protects all channels It can be used only if the connection between the LED driver and LED cathodes is a quite short and if the connection between LED supply voltage and anodes is long This prote...

Page 16: ...n NTC resistor directly assembled on the aluminum LED board OSTAR projection module The STEVAL ILL009V4 has assembled the STLM20 temperature sensor in the middle of LEDs on the PCB The microcontroller checks the voltage from the sensors and sets the correct output PWM signal on the OE pin of the LED drivers The microcontroller can increase the duty cycle of the PWM signal 0 duty cycle is max brigh...

Page 17: ...x 64 x 64 SW startup implemented 200 ms Over voltage protection implemented using clamp Schottky diodes BAT46 6 different light MODES available Input over voltage protection done by Transil SMAJ33A Over temperature signalization ICC connector for SW evaluation and change 8 1 General description Figure 11 shows components position on the STEVAL ILL009V1 On the left side there is DC DC converter wit...

Page 18: ...or the application 3 If the application is supplied the green LED D8 is lighted ON It shows that there is a supply voltage for the micro and the drivers Also LED D5 is turned ON at the start up as the Automatic Color Control mode is set Color automatically changes from blue to green green to red and red to blue During this mode the brightness of all LEDs can be changed by potentiometer P2 but the ...

Page 19: ...rature protection Set full brightness by potentiometer P2 in White Color Control mode and wait approximately 3 minutes with STEVAL ILL009V3 board with heatsink or 1 minutes with STEVAL ILL009V4 board without heatsink Temperature on LEDs is increased and if the over temperature is detected LED D6 is turned ON and the PWM duty cycle is increased and the brightness decreased overcoming the potentiome...

Page 20: ... 2 G1a 3 G1a 4 G1b 5 G1b 6 B1 7 B1 8 R2 9 R2 10 G2a 11 G2a 12 G2b 13 G2b 14 B2 15 B2 16 NC 17 NC 18 GND 19 GND 20 NC 21 Vo 22 NC 23 V CC 24 NC 25 NC 26 Vd 27 Vd 28 Vd 29 Vd 30 S1 Switch LE 5 OUT0 6 OUT1 7 NC 8 NC 9 OUT2 10 OUT3 11 NC 12 OE 13 SDO 14 R_ext 15 16 GND 1 GND 2 SDI 3 CLK 4 IO3 STP04CM596 GND 1 SDI 2 CLK 3 LE 4 OUT0 5 OUT1 6 OUT2 7 OUT3 8 16 R EXT 15 SDO 14 OE 13 OUT7 12 OUT6 11 OUT5 10...

Page 21: ... C21 100 nF V OUT 1 V IN 8 GND 2 GND 3 GND 6 GND 7 INHIB 5 IO5 L78L05ACD C20 22 nF C2 C11 100 nF C9 100 nF C16 2 7 nF D10 STPS5L60 R10 9 1 kΩ C13 470 µF 35 V C18 100 nF C19 220 pF C15 100 nF D9 SMAJ33A TR R9 1 3 kΩ C14 4700 µF 10 V R8 20 kΩ D8 Green LED C17 100 nF R7 390 Ω GND 4 OSC 1 OUT 3 OUT 2 GND 5 GND 6 GND 7 GND 14 GND 15 GND 16 GND 17 BOOT 10 VFB 13 8 V CC 9 SS 19 V3 3 18 INH 11 COMP 12 SYN...

Page 22: ...STPS5L60 ST diode STPS5L60 15 8 D11 D12 D13 D14 D15 D16 D17 D18 BAT46 ST Schottky diode BAT46JFILM 16 1 IO1 ST7FLITE09 ST microcontroller ST7FLITE09Y0M6 17 2 IO2 IO3 STP04CM596 ST LED driver STP04C596XTTR 18 1 IO4 STP08CL596 ST LED driver STP08CL596TTR 19 1 IO5 L78L05 ST voltage regulator L78L05ACD 20 1 IO6 L4973D3 3 ST DC DC converter L4973D3 3 21 1 J1 CON3 Input connector 22 1 L1 150 µH Coilcraf...

Page 23: ... an ambient temperature of 25 C More information about the STLM20 is described in the datasheet refer to Chapter 12 point 9 A simple linear transfer function with good accuracy near 25 C is expressed as Equation 10 If the sensor temperature is 50 C the output voltage is 1 263 V resulting from Equation 10 This analog voltage is then sensed by the 8 bit ADC with an input voltage range 0 to 5 V insid...

Page 24: ...70 and 80 C and so it is very easy to change the temperature limit see Table 3 Note The software implemented in the STEVAL ILL009V1 sets the integer number to 65 This means that the temperature is limited to 50 C for the board using STLM20 STEVAL ILL009V4 and to 72 C for the board using OSRAM module with NTC resistor STEVAL ILL009V3 Table 2 Temperature limit setting using STLM20 Temperature C Sens...

Page 25: ...even 100 Hz is observed as a still color without any flickering and also a PWM resolution higher than 6 bit 64 LEVELS Figure 14 shows the waveform of SPI clock frequency that explains why the 6 bit resolution of the PWM signal and frequency 100 Hz was designed The time for sending data is 156 µs but the SPI communication takes only 4 µs 8 bit times 0 5 µs SPI clock is 2 MHz and the rest 152 µs is ...

Page 26: ...sent through SPI or not If not the data are missed and the program waits for next interrupt 156 µs but it is only some kind of backup protection The second interrupt is a SPI interrupt which informs that data single byte have been already sent The last interrupt is an external input interrupt which detects that button was pressed Figure 15 Main program flowchart The heart of the software is a blin...

Page 27: ... the application starts Figure 16 Blink function flowchart first part Figure 17 shows the second part of the blink function the brightness setting based on value read on P2 in first part and mode selection mode is selected by pressing button S2 MODE 1 MODE 2 and MODE 3 sets the brightness for the red green and blue LEDs where the brightness level 0 to 64 is obtained from the potentiometer P1 after...

Page 28: ... basic colors MODE 5 represents automatic color changing The principle of the automatic color change is similar to manual color control because the color level is not adjusted by potentiometer P1 0 252 but automatically using the 156 µs time base generated by the auto reload timer Note In order to demonstrate the best lighting effects the application automatically starts in MODE 5 automatic color ...

Page 29: ... the LEDs are turned ON which produce the pure white color Figure 19 describes this last part Figure 19 Blink function flowchart third part AM00299 Return Blink procedure starts again 4 Default Counter_SW 64 MODE 6 Y N Y N Set WHITE color Counter_SW 0 Set DATA_blink1 Set DATA_blink2 Write to the SPI Register SPIDR DATA_blink1 SPIDR DATA_blink2 ...

Page 30: ... 2 MHz The high switching frequency allows the use of tiny SMD external components while the integrated synchronous rectifier eliminates the need for a Schottky diode The ST1S10 provides excellent transient response and is fully protected against thermal overheating switching over current and output short circuit For more information see the ST1S10 Datasheet The STP04CM05 is a high power LED drive...

Page 31: ...hing DC DC converter ST1S10 The diode D10 protects the application against input voltage reversion and Transil D9 protects the ST1S10 against over voltage The schematic diagram with LED drivers and microcontroller is not shown in this chapter because it was already introduced in Figure 12 There is only small difference because the new LED drivers STP04CM05 and STP08CP05 instead the STP04CM596 and ...

Page 32: ...9 SMAJ15A TR ST Transil SMAJ15A TR 12 1 D10 STPS340U ST diode STPS340U 13 8 D11 D12 D13 D14 D15 D16 D17 D18 BAT46 ST Schottky diode BAT46JFILM 14 1 IO1 ST7FLITE09 ST microcontroller ST7FLITE09Y0M6 15 2 IO2 IO3 STP04CM05 ST LED driver STP04CM05XTTR 16 1 IO4 STP08CP05 ST LED driver STP08CP05TTR 17 1 IO5 L78L05 ST voltage regulator L78L05ACD 18 1 IO6 ST1S10 ST DC DC converter ST1S10PHR 19 1 J1 CON3 I...

Page 33: ... current flowing through each channel is set to 350 mA but because 700 mA is needed to drive the OSTAR module two outputs are connected in parallel Figure 23 Resistor R4 represents together with the NTC resistor the voltage divider for the temperature sensing described in detail in Chapter 8 5 2 The software has a preset temperature limitation 50 C for Golden DRAGON LEDs using STLM20 temperature s...

Page 34: ... of material Item Quantity Reference Part Note Ordering code 1 1 OSTAR projection module OSRAM OSTAR Projection Module LE ATB A2A 2 1 Cable with connector 10 lines cable SHR 10V S B JST 3 1 Heatsink SEMIC Trade 8150 50 N 4 1 Connector1 10 pins 5 1 Female Connector1 10 pins 6 1 Connector2 30 pin connector 7 1 R1 0 8 2 R2 R3 1 5 Ω Through hole 0 6 W 9 1 R4 4 7 kΩ Through hole 0 6 W ...

Page 35: ...R3 1 5 Ω R2 R3 0 75 Ω 5 V 4700 Ω NTC 1 263 V for 72 C R_ntc 72 C 1588 Ω R3 1 5 Ω R4 47 kΩ 1 2 3 4 5 6 7 8 9 10 CONNECTOR1 ICC R1 0 0 R1 1 R1 2 G1a 3 G1a 4 G1b 5 G1b 6 B1 7 B1 8 R2 9 R2 10 G2a 11 G2a 12 G2b 13 G2b 14 B2 15 B2 16 NC 17 NC 18 GND 19 GND 20 NC 21 Vo 22 NC 23 Vcc 24 NC 25 NC 26 Vd 27 Vd 28 Vd 29 Vd 30 CONNECTOR2 ICC R2 1 5 5 Ω AM00300 ...

Page 36: ... 12 point 2 used with a maximum forward current of 350 mA As described in Chapter 8 the STEVAL ILL009V1 can drive eight Golden DRAGON LEDs To demonstrate the driving capability of the STP04CM596 only four LEDs are used on the load board In fact this means that one STP04CM596 driver is not used The STLM20 temperature sensor is assembled in the middle of the LEDs to protect against overheating as de...

Page 37: ...g the following equation Equation 16 Equation 17 11 2 Bill of material 1 4V 2 6 4 V V V F_RED_MAX d R 4Ω 0 35 1 4 I V R RED_LED R Table 6 STEVAL ILL009V4 bill of material Item Quantity Reference Part Note Ordering code 1 2 G1a G1b LTW5SM HZ 3 OSRAM Golden DRAGON Green LED Q65110A5876 2 1 R1 LRW5SM HY 1 OSRAM Golden DRAGON Red LED Q65110A4386 3 1 B1 LBW5SM FX 3 OSRAM Golden DRAGON Blue LED Q65110A4...

Page 38: ...35 4 Ω 3 3 Ω used R4 R5 R6 U_r U_d U_f_red 4 2 6 1 4 V R5 10 R5 10 C7 100 nF R1 1 R1 2 G1a 3 G1a 4 G1b 5 G1b 6 B1 7 B1 8 R2 9 R2 10 G2a 11 G2a 12 G2b 13 G2b 14 B2 15 B2 16 NC 17 NC 18 GND 19 GND 20 NC 21 Vo 22 NC 23 V CC 24 NC 25 NC 26 Vd 27 Vd 28 Vd 29 Vd 30 CONNECTOR2 ICC R6 10 R6 10 R4 10 V 4 NC 1 Vo 3 GND 2 GND 5 IO5 STLM20 AM00301 ...

Page 39: ...gulators Datasheet www st com 8 STMicroelectronics AN938 Designing with L4973 3 5 A high efficiency DC DC converter www st com 9 STMicroelectronics STLM20 Ultra low Current 2 4 V precision analog temperature sensor Datasheet www st com 10 STMicroelectronics STP04CM05 4 bit constant current for power LED sink driver data sheet www st com 11 STMicroelectronics STP08CP05 8 bit constant current for LE...

Page 40: ...ANTIES OF MERCHANTABILITY FITNESS FOR A PARTICULAR PURPOSE AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION OR INFRINGEMENT OF ANY PATENT COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT UNLESS EXPRESSLY APPROVED IN WRITING BY AN AUTHORIZED ST REPRESENTATIVE ST PRODUCTS ARE NOT RECOMMENDED AUTHORIZED OR WARRANTED FOR USE IN MILITARY AIR CRAFT SPACE LIFE SAVING OR LIFE SUSTAINING APPLICATIONS...

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