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EVB10803
Evaluation board for MLX10803
 Download EVB10803 Datasheet (PDF)
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EVB10803 General Description
High current power LED driver with noise reduction function.
This unit has a filter cap on the supply to reduce EMI and is
able to handle automotive test pulses.
EVB10803 Features and Benefits
- Adjustable peak current and driver off time
- LED currents from mA to 1.5A settable
- Connector for external NTC (temperature regulation)
- Dimmable by PWM
- Second light level input by voltage level
EVB10803 Environmental Information
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EVB10803 Frequently asked Questions
mlx10803
Question
Problem in making an LED driver for 1Amp LED which will be powered by 5V. Use the circuit schematic as shown on the datasheet of the evaluation board EVB10803. Here you can also find an XLS file to calculate component values. The data to enter:
Supply: 5V
LED threshold: 3,75V
Number of LEDs in channel: 1
Feed back diode threshold: 0,9 V
Rsense: 0,33 Ohm
Vpeak at Rsense: 340 mV
Tmonoflop: 1 uS L (the Coil): uH 47
Values for Rosc is 13K Ohm and RIref is 34K Ohm.
Answer
The choice of NTC resistor is precisely described in chapter 8.4 of EVB10803 Datasheet. This datasheet is available on Melexis' website.
Question
How to drive several Power LEDs using the Evaluation Board EVB10803?
How to expand an application to drive 8 or more Power LED's with Forward Voltage 3.4VDC @ 350mA, input voltage of 180 to 265VAC 50/60 Hz?
Answer
1. On the Melexis web-site EVB10803 and EVB10803mini are represented and these evaluation boards are targeted for the automotive applications with 6-32VDC input voltage.
2. The MLX10803 can also be used for HV applications as well.
In order to evaluate the behavior of the MLX10803 in the case described above it is suggested to download the Coil_calc software from the Melexis web-site. Then use the following values:
Supply voltage - 300V
Led threshhold - 3,4V
Number Led - 8
Rsense - 1 Ohm
Vpeak - 510 mV
Tmon - 17 us
L - 1500 uH
Coil_cal will generate the next info:
Rosc = 300 K
Riref = 51 K
You can use these values in the application.
Of course it needs to choose the HV transistor (400V) and flyback diode.
Answer
Use the EVB10803:
3W case :
Rosc = 120K
Riref = 36K
coil is the same : Wurth WE-PD, L type, 100uH
you can use the smaller MOSFET transistor in SOT-23 package as PMV213N.
5W case :
Rosc = 56K
Riref = 36K
coil is the same : Wurth WE-PD, type L, 100uH
you can use the smaller MOSFET transistor in SOT-23 package as PMV213N.
Ostar Lighting case ( 21V, 1A )
Rosc = 39K
Riref = 40K
coil is the same : Wurth WE-PD, type L, 100uH.
Answer
For this case use the next settings :
Rsense = 0,1 Ohm ( EVB10803 has 0,33Ohm)
Rosc = 100K
Riref = 43K
Coil's the Coilraft ( www.coilcraft.com) PCV-2 type, 180uH, you also have to use more powerful flyback diode.
For analog dimming purposes please adjust the value of Riref from 43K to down.
Buy EVB10803
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