MLX10803_05

IC specification Automotive high power LED driver Features VREF 1 2 3 4 8 VS/PWM MLX10803 General • • • • • Low cost power LED driver for external n-channel MOSFET switching transistor 6V to 32V DC input range Applications from mA to several Ampere LED current Possible temperature dependent regulation using external Negative Temperature Coefficient (NTC) resistor Small package allows compact module design with minimised wire runs and short connections to achieve improved EMC performance Built-in randomizer for improved EMC performance High temperature operation capable Load dump protected to 80V ROSC IREF1 IREF2 10803 (SO8) 7 DRVGATE 6 GND 5 RSENSE • • • LED driver • • • • High energy efficiency PWM dimming via VS/PWM pin Light output has minimized dependency on supply and temperature variations LED regulation parameters set with external resistors Ordering Information Part Nr MLX10803 Temperature Code K (-40°C to 125°C) Package Code DC (SOIC8) General Description The MLX10803 is a multi-purpose LED driver for high power LEDs designed for automotive applications. Numerous adjustment possibilities allow for the design of different LED applications using only a few external components. The circuit is load dump protected for a 80V load dump pulse. 3901010803 Author: ALX, VAR Page 1/25 revised: TFR/VAR Rev 018 28/SEP/05 IC specification Automotive high power LED driver MLX10803 Table of contents Features………………………………………………………………………………………. 1 Ordering Information……………………………………………………………………........ 1 General Description………………………………………………………………………….. 1 Block diagram………………………………………………………………………………… 2 1. Typical application data…………………………………………………………….. 4 1.1. LED driver applications…………………………………………………………. 4 1.1.1. 1.1.2. 1.1.3. 1.1.4. Principle complete schematic LED driver diagram…………………………………4 Principle minimum schematic LED driver diagram…………………………………4 Principle soft start up LED driver diagram…………………………………………..5 LED driver application notes………………………………………………………….5 2. 3. 4. 5. 6. Application pins…………………………………………………………………….... 7 Absolute maximum ratings……………………………………………………….... 7 Electrical characteristics………………………………………………………….... 8 ESD/EMI recommendations for MLX10803…………………………………….... 11 Automotive test pulses………………………………………………………………12 6.1. Test pulse definition……………………………………………………………… 13 7. LED driving principle…………………………………………………………………16 7.1. General……………………………………………………………………………..16 7.2. The principle in detail……………………………………………………………..17 7.3. Switching frequency considerations and constant light output……………… 20 8. Temperature regulation.……………………………………………………………. 21 9. Load dump protection………………………………………………………………. 21 10. Mechanical Data……………………………………………………………………… 22 10.1. Mechanical data of the MLX10803 package………………………………….. 22 11. Melexis standard soldering information………………………………………… 23 12. History record………………………………………………………………………… 24 13. Disclaimer……………………………………………………………………………... 25 3901010803 Author: ALX, VAR Page 2/25 revised: TFR/VAR Rev 018 28/SEP/05 IC specification Automotive high power LED driver MLX10803 Block diagram VS/PWM Regulator VDD 5.0 V ± 10 % VDD POR Power on Reset Trim Logic (incl. Zener Zaps) RSENSE Reference Currents Debouncing 300 ns COMP VDD ... Iref_x COMP VDD ROSC RC Oscillator tunable: 0.5 MHz to 5 MHz frequ. tolerance: ± 20 % VDD IREF2 Start OFF Start ON divider 1/5 divider 1/10 Minimal voltage selection IREF1 VREF Monoflop with pseudo random generator OFF Timer 4.2 µs (average value) at fOSC = 2.5 MHz ON Timer 23.4 us (average value) at fOSC = 2.5MHz COMP VS/PWM 20mV Clamping max. 12 V GND OFF FF ON DRVGATE 3901010803 Author: ALX, VAR Page 3/25 revised: TFR/VAR Rev 018 28/SEP/05 IC specification Automotive high power LED driver MLX10803 1. Typical application data 1.1. LED driver applications 1.1.1. Principle complete schematic LED driver diagram Cap for EMC directly on the connector 100nF...1uF VBAT 100nF PWM RS_SET VREF ROSC IREF1 IREF2 NTC VS/PWM DRVGATE GND RSENSE GND Figure 1: Application with dimming via PWM/VS pin, a second light output set by an analogue voltage on input VREF and temperature regulation 1.1.2. Principle minimum schematic LED driver diagram Cap for EMC directly on the connector 100nF...1uF VBAT 100nF VREF ROSC IREF1 IREF2 VS/PWM DRVGATE GND RSENSE GND Figure 2: Basic application without dimming and temperature regulation 3901010803 Author: ALX, VAR Page 4/25 revised: TFR/VAR Rev 018 28/SEP/05 IC specification Automotive high power LED driver MLX10803 1.1.3. Principle soft start up LED driver diagram Cap for EMC directly on the connector 100nF...1uF VBAT 100nF VREF ROSC IREF1 IREF2 VS/PWM DRVGATE GND RSENSE GND Figure 3: Application with gradual increase of light intensity after power up (soft start) 1.1.4. LED driver application notes The MLX10803 is optimised for the use of low cost coils and n-channel MOSFETs. For a standard application with 1 LED and an average current of 350mA, a coil of about 100µH…220µH and ≤ 1Ω DC resistance should be chosen. The sense resistor should have a value between 0.27Ω…0.47Ω / 250mW. As a general rule: the higher the load current, the lower the inductance of the coil as higher currents lengthen the charging time of the coil. Thus, switching frequencies may become lower than 20kHz which is often not desired. It is possible to set the peak current and the average current of the LED by variation of the RSENSE resistor, the coil value and the internal oscillator frequency (ROSC resistor). The flyback diode that carries the load current during the passive state (driver OFF) should be a fast switching and low intrinsic capacitance diode like ES1D or BYG80 in order to avoid parasitic spikes on RSENSE. The diode must be able to carry the LED current flowing during the OFF time of the driver. The n-channel MOSFET should have low intrinsic capacitances, a drain-source voltage suitable for the application and must be able to carry the current flowing through the LED(s) during the ON time. To decrease the time of transistor switching and to improve the thermal behaviour of the module, the lines between transistor and IC should me minimized. For applications that use an NTC resistor for temperature sensing, the NTC value has to be selected according to the application requirements. For most applications, a NTC value up to 470kΩ will be suitable. In case of longer lines between the IC and the coil (which should be avoided because of EMI), a capacitor might be placed in parallel to RSENSE to avoid crosstalk and parasitic switching. Well chosen parameters for external components can help to avoid such conditions. The goal should be to unload the coil as much as possible during the selected off time (see also chapter 7). 3901010803 Author: ALX, VAR Page 5/25 revised: TFR/VAR Rev 018 28/SEP/05 IC specification Automotive high power LED driver The schematic diagram under 1.1.1 is used in applications where the LED is controlled by external control electronics. A PWM with a frequency between 30Hz..5kHz can be applied to the VS/PWM pin in order to dim the light output. This frequency is limited by the time needed for recharging the coil and monoflop time selected by the resistor connected to ROSC as well as by the IC settling time after POR. This function can be used to achieve different light outputs or also be used in a temperature down regulation. It is recommended to have the PWM frequency at least 5-10 times lower than the selected driver switching frequency. The minimum schematic diagram under Figure 1: is sufficient for all applications with a constant light output. We also recommend to compare with our other circuits in the MLX108xx family and study these application notes for suitable solutions. MLX10803 3901010803 Author: ALX, VAR Page 6/25 revised: TFR/VAR Rev 018 28/SEP/05 IC specification Automotive high power LED driver 2. Nr. 1 2 3 4 5 6 7 8 MLX10803 Application pins Name VREF ROSC IREF1 IREF2 RSENSE GND DRVGATE VS/PWM Function CMOS input, peak current reference External resistor sets internal Oscillator frequency. Sets the average discharge time of the coil External NTC resistor for temperature down regulation External resistor sets the temperature breakpoint when the NTC resistor starts down regulation External sense resistor pin for peak current detection Ground Pin driving the gate of the switching transistor Supply Voltage / PWM signal 3. Absolute maximum ratings Symbol vs vsmax Iprot Condition Min DC -0.3 max 0.5s In case of maximum supply ratings 32 -10 Max 32 80 10 Unit V V mA Parameter Power supply (VS/PWM) Power supply, non operational function (off) max. 0.5s (Load dump) Maximum input current in protection circuitry on any pin Maximum input voltage on RSENSE Maximum input voltage on IREF2, IREF1, VREF Maximum input voltage on ROSC Maximum junction temperature Lifetime Dynamic Storage temperature Ambient temperature range Thermal resistance junction to ambient virsense Vihv vdrvgatmax Tjunc with load -0.3 -0.3 -0.3 -40 -40 -55 11 80 Vdd+0.3 140 150 150 125 120 (SO8) V V C tambient rth -40C C K/W 3901010803 Author: ALX, VAR Page 7/25 revised: TFR/VAR Rev 018 28/SEP/05 IC specification Automotive high power LED driver 4. Electrical characteristics MLX10803 Following characteristics are valid - for the full temperature range of T = -40°C to +125°C, - a supply range of 32V ≥ VS/PWM > 6V unless other conditions noted. With 6V ≥ VS/PWM > vporh analogue parameters can not be guaranteed. Note: The correct operation of the MLX10803 as a switching mode power supply for voltages lower than the nominal supply voltage is dependent on the forward bias voltage of the used LED. The user must ensure that at low supply voltage the peak current threshold voltage on the RSENSE pin can be reached in order to keep the switching principle working. If several pins are charged with transients above VS/PWM and below GND, the sum of all substrate currents of the influenced pins should not exceed 10mA for correct operation of the device. Normal operating supply voltage is supposed to be 13.8V. Parameter Symbol Conditions Min Maximum current during 80V load dump Normal supply current at highest DC voltage Normal supply current ihv inomdch inom Global parameters VS/PWM=80V VS/PWM=32V VS/PWM=13.8V IC settling time IC settling time after power on reset tsettle 30 µs Limits Typ Units Max 10 2 700 mA mA uA Oscillator related parameters The min/max specification influences directly all derived timings in the same direction Min oscillator frequency foscmin For a selected 0.4 0.5 0.6 MHz external resistor of 440k and room temperature Max oscillator frequency foscmax For a selected 4.0 5.0 6.0 MHz external resistor of 40k and room temperature 3901010803 Author: ALX, VAR Page 8/25 revised: TFR/VAR Rev 018 28/SEP/05 IC specification Automotive high power LED driver MLX10803 Power on reset level, if VS/PWM is ramped up Internal supply voltage range RESET related parameters (Reset is 3.0 connected to the internal VDD, but vporh is measured on pin VS/PWM) VDD related parameters (VDD used internally only) vdd VS/PWM=13.8V 4.5 vporh 4.0 V 5.5 V Monoflop related parameters Minimum OFF time due to toffmin1mhz Oscillator is set to 7 µs the implemented jitter 1 MHz, in case the oscillator is put to an other frequency, toffmin1MHz scales accordingly Maximum OFF time due toffmax1mhz Oscillator is set to 14 µs to the implemented jitter 1 MHz, in case the osc is put to an other frequency, toffmax 1MHz scales accordingly Average monoflop time ton1mhz Oscillator is set to 58.5 µs for ON state of transistor 1 MHz RSENSE related parameters Input leakage current ileakrsense -20 20 µA Debounce time after tdeb 200 400 ns switching on Threshold voltage on vrsensethr Minimum value of voltage on pins IREF2, RSENSE IREF1 and VREF divided by 5 IREF1 related parameters Output current for iiref1 47.5 52.5 µA temperature measurement Temperature drift of the iiref1drift -0.1 %/C current Voltage range viref1rng VS/PWM=13V 0 3.8 V 3901010803 Author: ALX, VAR Page 9/25 revised: TFR/VAR Rev 018 28/SEP/05 IC specification Automotive high power LED driver IREF2 related parameters Voltage on IREF2 47.5 lower than (VDD – Vthr) -5 -0.1 VS/PWM=13V 0 DRVGATE related parameters Load current 1uA 10.0 to GND VREF related parameters -2 15 VS/PWM=13V 0 ROSC related parameters 1.2 tbd tbd tbd 440 tbd 40 3.8 14.0 100 20 25 3.8 1.3 tbd tbd tbd kΩ MLX10803 Output current Difference of output current comparing with iiref1 Temperature drift of the current Voltage range Max output voltage in ON state Max output resistance. iiref2 idiferiref1 iiref2drift viref2rng vmaxdrv Rdrvgateout 52.5 5 µA % %/C V V Ω µA mV V V kΩ Leakage current Ileakvref Switch-off of external FET Vswoff voltage* Voltage range vvrefrng Output voltage irosc Resistance on pin to GND Roscmin for 0.5MHz Resistance on pin to GND Roscmid for 2.5MHz Resistance on pin to GND Roscmax for 5MHz * This parameter is also related to IREF1 and IREF2 pins because of triple reference derivation (minimum of Vvref, Viref1, Viref2) 3901010803 Author: ALX, VAR Page 10/25 revised: TFR/VAR Rev 018 28/SEP/05 IC specification Automotive high power LED driver 5. • • • • MLX10803 ESD/EMI recommendations for MLX10803 In order to minimise EMI, the PCB has to be designed according to EMI guidelines. Additional components may be needed, other than what is shown in the application diagrams, in order to comply with the EMI requirements. The MLX10803 is an ESD sensitive device and has to be handled according to EN100015 part 1. The MLX10803 will fulfil the requirements in the application according to the specification and to DIN 40839 part 1. The MLX10803 is designed with ESD protection >1000V HBM according to MIL883D. 3901010803 Author: ALX, VAR Page 11/25 revised: TFR/VAR Rev 018 28/SEP/05 IC specification Automotive high power LED driver 6. Automotive test pulses MLX10803 The following chapter is valid for a completely assembled module. That means that automotive test pulses are applied to the module and not to the single IC. In the recommended application according to chapter 1.1, the reverse polarity diode together with the capacitors on the supply and the load dump protected IC itself protect the module against the automotive test pulses listed below. The exact values of the capacitors for the application have to be figured out according to the automotive and EMI requirements. No damage occurs for any of the test pulses. A deviation of the IC’s characteristics is allowed during pulse 1, 2, 4; the module returns to normal operation after the pulse without any additional action. During test pulse 3a, 3b, 5 the module operates within characteristic limits. Parameter Test condition, Functional status Transient test pulses in accordance to ISO7637 part 2 & 3, module schematics according to application notes. Module acts as a single light source Test pulse #1 at module pin VBAT, GND vpulse1 -100 0 V 5000 pulses, functional state C Test pulse #2 at module pin VBAT, GND vpulse2 0 100 V 5000 pulses functional state C Test pulse #3a at module pin VBAT, GND vpulse3a -150 0 V 1h, functional state A Test pulse #3b at module pin VBAT, GND vpulse3b 0 100 V 1h, functional state A Test pulse #4 at module pin VBAT, GND vspulse4 -6 -4 V 1 pulse, vapulse4 -5 -2.5 V functional state C Test pulse #5 at module pin VBAT, GND vpulse5 26.5 80 V functional state C, Symbol Min Max Dim Description of functional status: A: All functions of the module are performed as designed during and after the disturbance. B: All functions of the module are performed as designed during and after the disturbance: However, one or more can deviate from specified tolerance. All functions return automatically to normal limits after exposure is removed. Memory functions shall remain class A. C: A function of the module is not performed as designed during disturbance but returns automatically to a normal operation after the disturbance. 3901010803 Author: ALX, VAR Page 12/25 revised: TFR/VAR Rev 018 28/SEP/05 IC specification Automotive high power LED driver 6.1. Test Pulse 1 Ri = 10 Ω V MLX10803 Test pulse definition 200ms Coil 2 Resistance 1 > Resistance 2 t Conclusion: In most cases the coil is driven in a combination of both ways. A trade off has to be made between EMI behaviour and maximum allowed LED current. By varying these parameters, an optimum can be found for every application. Below are some examples for typical parameter sets given for a 4A LED current and the following application data: • • • • RSENSE = 0.1R / 2 watt ROSC = 270K L = 47µH, 4A minimum, 0.05 Ω Normal nFET switch transistor, rds on < 0,01 Ω Remarks: • 4A and 0.05 Ω results in 0.8 watt power dissipation over the coil. • 4A and 0.1 Ω for the RSENSE resistor results in 1.6 watt, but only for 50% of the time in average. • The LED(s) with this current will dissipate 32 watt if they have 8V forward voltage. 3901010803 Author: ALX, VAR Page 19/25 revised: TFR/VAR Rev 018 28/SEP/05 IC specification Automotive high power LED driver MLX10803 7.3. Switching frequency considerations and constant light output As already shown, the switching frequency depends on the peak current as well as on the monoflop time for a given coil. Furthermore it depends on the coil inductance itself. Due to the principle of switch mode power supplies, the current through the LED is kept constant for any supply changes. The parameter that changes in order to keep the current constant is the switching frequency itself. The lower the supply voltage, the lower the switching frequency. Furthermore, the supply current is affected by supply changes: with an increasing supply voltage the average supply current decreases. The graph below shows the normalized luminous flux versus the power supply for a standard application with one white Luxeon III LED driven at 750mA . The parameters are optimized for the 24V board net. The luminous flux at 24V has been set to 100%. The graph indicates that the light output is minimally dependent on supply changes over the whole range from 16 to 32V. MLX10803 Normalized luminous flux Θv/Θv(24V) vs. supply voltage Θv/Θv(24V)=f(VBAT) 120.00 Iled=750mA, fsw=70kHz (@24V) 115.00 110.00 105.00 Θv/Θv(24V) [%] 100.00 95.00 90.00 85.00 80.00 16 18 20 22 24 VBAT [V] 26 28 30 32 3901010803 Author: ALX, VAR Page 20/25 revised: TFR/VAR Rev 018 28/SEP/05 IC specification Automotive high power LED driver MLX10803 8. Temperature regulation In normal mode the peak current threshold voltage is defined by the lowest voltage on pins VREF, IREF2 and IREF1. Usually the resistor connected to IREF2 pin has a small thermal coefficient and the resistor on IREF1 pin has a big negative temperature coefficient (but they also can be connected vice versa). Both of these pins have an output current of 50uA. When the voltage on pin IREF1 falls below the voltage on pin IREF2 or VREF, the voltage reference for the actual maximum current is taken from pin IREF1. This makes the value of the peak current sensitive to temperature and prevents overheating of LED or IC. When the voltage on pin IREF1 becomes higher than voltage on IREF2 or VREF, the reference switches back to IREF2 or VREF pin. The thermal behaviour of the system should be characterised during the design-in of the product by the user. For a system that is designed for thermal conditions, temperature down regulation may not be needed. In this case, It is enough to leave the IREF1 or IREF2 pin unconnected and the internal current source will pull it up to the voltage Vdd – Vthr. 9. Load dump protection The MLX10803 is protected against 80V load dump, in case the application proposals described under 1.1 are used. 3901010803 Author: ALX, VAR Page 21/25 revised: TFR/VAR Rev 018 28/SEP/05 IC specification Automotive high power LED driver 10. Mechanical Data 10.1. Mechanical data of the MLX10803 package Package of the MLX10803: SOIC8 in accordance to the JEDEC standard. MLX10803 DIMENSIONS MIN. A A1 A0 B C D E e H h L oc X .061 .004 .055 .0138 .0075 .189 .150 .230 .010 .016 0° .085 INCHES NOM. .064 .006 .058 .016 .008 .194 .155 .050 .236 .013 .025 5° .093 MILLIMETERS MAX .068 .0098 .061 .0192 .0098 .196 .157 .244 .016 .035 8° .100 Note MIN. 1.55 0.127 1.40 0.35 0.19 4.80 3.81 5.84 0.25 0.41 0° 2.16 NOM. 1.63 0.15 1.47 0.41 0.20 4.93 3.94 1.27 5.99 0.33 0.64 5° 2.36 MAX 1.73 0.25 1.55 0.49 0.25 4.98 3.99 6.20 0.41 0.89 8° 2.54 Degrees 3901010803 Author: ALX, VAR Page 22/25 revised: TFR/VAR Rev 018 28/SEP/05 IC specification Automotive high power LED driver MLX10803 11. Melexis standard soldering information This Melexis device is classified and qualified regarding soldering technology, solderability and moisture sensitivity level, as defined in this specification, according to following test methods: • • • • • • IPC/JEDEC J-STD-020 Moisture/Reflow Sensitivity Classification For Nonhermetic Solid State Surface Mount Devices (classification reflow profiles according to table 5-2) EIA/JEDEC JESD22-A113 Preconditioning of Nonhermetic Surface Mount Devices Prior to Reliability Testing (reflow profiles according to table 2) CECC00802 Standard Method For The Specification of Surface Mounting Components (SMDs) of Assessed Quality EIA/JEDEC JESD22-B106 Resistance to soldering temperature for through-hole mounted devices EN60749-15 Resistance to soldering temperature for through-hole mounted devices MIL 883 Method 2003 / EIA/JEDEC JESD22-B102 Solderability For all soldering technologies deviating from above mentioned standard conditions (regarding peak temperature, temperature gradient, temperature profile etc) additional classification and qualification tests have to be agreed upon with Melexis. The application of Wave Soldering for SMD's is allowed only after consulting Melexis regarding assurance of adhesive strength between device and board. Based on Melexis commitment to environmental responsibility, European legislation (Directive on the Restriction of the Use of Certain Hazardous substances, RoHS) and customer requests, Melexis has installed a Roadmap to qualify their package families for lead free processes also. Various lead free generic qualifications are running, current results on request. For more information on Melexis lead free statement see quality page at our website: http://www.melexis.com/html/pdf/MLXleadfree-statement.pdf 3901010803 Author: ALX, VAR Page 23/25 revised: TFR/VAR Rev 018 28/SEP/05 IC specification Automotive high power LED driver 12. Rev. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 MLX10803 History record No. 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Change Creation with MLX10801 specifications as base Gone through document VAR,ALX,RAH,LIW 4-th pin recast from TEST to VREF - linear dimming Revision of kick off meeting Revision before release RAH Improved packing information RAH Improved block diagram Design implementation review Updated schematic diagrams Pin order changed Temperature code changed to “K”, Vmaxdrv changed, Oscillator related parameters changed, VREF related parameters changed, ROSC related parameters changed Cosmetic changes Cosmetic changes VREF related parameters are changed Pins’ names changed: RE_REF VREF, NTC IREF1, SETNTC IREF2, VS VS/PWM. Corresponding parameters’ names changed. RSENSE related parameters changed LED driver applications changed Block diagram changed, Electrical characteristics: Global parameters, Monoflop related parameters, RSENSE related parameters, IREF1 related parameters, IREF2 related parameters, VREF related parameters changed, LED driving principle: The principle in detail changed Internal review Chapter 7.3. changed: graph added, cosmetic changes Cosmetic changes Date 25.07.04 02.08.04 07.08.04 7.10.04 15.01.05 16.01.05 3.02.05 13.06.05 17.06.05 21.06.05 12.07.05 3.08.05 18.08.05 21.09.05 2 18 1 2 23.09.05 23.09.05 28.09.05 3901010803 Author: ALX, VAR Page 24/25 revised: TFR/VAR Rev 018 28/SEP/05 IC specification Automotive high power LED driver 13. Disclaimer MLX10803 Devices sold by Melexis are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. Melexis makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. Melexis reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with Melexis for current information. This product is intended for use in normal commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical life-support or life-sustaining equipment are specifically not recommended without additional processing by Melexis for each application. The information furnished by Melexis is believed to be correct and accurate. However, Melexis shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interrupt of business or indirect, special incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of Melexis’ rendering of technical or other services. © 2005 Melexis NV. All rights reserved. For the latest version of this document, go to our website at: www.melexis.com Or for additional information contact Melexis Direct: Europe and Japan: Phone: +32 13 61 16 31 E-mail: sales_europe@melexis.com All other locations: Phone: +1 603 223 2362 E-mail: sales_usa@melexis.com QS9000, VDA6.1 and ISO14001 Certified 3901010803 Author: ALX, VAR Page 25/25 revised: TFR/VAR Rev 018 28/SEP/05