AL8806_13 DIODES | Alldatasheet
Document overview
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Technical content
Features
LED driving current up to 1.5A Better than 5% accuracy High efficiency up to 98% Operating input voltage from 6V to 36V High switching frequency up to 1MHz PWM/DC input for dimming control Built-in output open-circuit protection MSOP-8EP: Available in “Green” Molding Compound (No Br, Sb) with lead Free Finish/ RoHS Compliant Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. “Green” Device (Note 3) Pin Assignments AL8806 SET GND GND CTRL VIN N/C SW SW AL8806 SET GND GND CTRL VIN N/C SW SW MSOP-8EP
Applications
High Power MR16 Lamps General Illumination Lamps Multi-Die LED Driver Notes: 1. No purposely added lead. Fully EU Directiv e 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant. 2. See http://www.diodes.com/quality/lead_free.html for more in formation about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green" and Lead-free. 3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and <1000ppm antimony compounds. Typical Applications Circuit AL8806VIN SET CTRL SW GND 1µF RSET 0R089 450µF D2 D3 D4 D5 12VAC 33µH L1 Multi- die LED DFLS230LH DFLS230LH
Document number: DS35144 Rev. 5 - 2 2 of 15 www.diodes.com July 2013 © Diodes Incorporated AL8806 Pin Descriptions Pin Name Pin Number Function MSOP-8EP SW 5, 6 Switch Pin. Connect inductor/freewheeling diode here, minimizing track length at this pin to reduce EMI. GND 2, 3 GND Pin CTRL 4 Dimming and On/Off Control Input. Leave floating for normal operation. (VCTRL = VREF = 2.5V giving nominal average output current IOUTnom = 0.1/RS) Drive to voltage below 0.4V to turn off output current Drive with DC voltage (0.5V < V CTRL < 2.5V) to adjust output current from 20% to 100% of IOUTnom A PWM signal (low level ≤ 0.4V and high level > 2.6; transition times less than 1us) allows the output current to be adjusted below the level set by the resistor connected to SET input pin. SET 1 Set Nominal Output Current Pin. Configure the output current of the device. VIN 8 Input Supply Pin. Must be locally decoupled to GND with > 2.2µF X7R ceramic capacitor – see applications section for more information. EP EP Exposed pad: Connect to GND and thermal mass for enhanced thermal impedance. It should not be used as electrical ground conduction path. N/C 7 no connection Functional Block Diagram
Document number: DS35144 Rev. 5 - 2 3 of 15 www.diodes.com July 2013 © Diodes Incorporated AL8806 Absolute Maximum Ratings (@TA = +25°C, unless otherwise specified.) Symbol Parameter Ratings Unit ESD HBM Human Body Model ESD Protection 2.5 kV ESD MM Machine Model ESD Protection 200 V VIN Continuous V IN pin voltage relative to GND -0.3 to +40 V VSW SW voltage relative to GND -0.3 to +40 V VCTRL CTRL pin input voltage -0.3 to +6 V ISW-RMS DC or RMS switch current 1.65 A ISW-PK Peak switch current (<10%) 3 A TJ Junction Temperature 150 °C TLEAD Lead Temperature Soldering 300 °C TST Storage Temperature Range -65 to +150 °C Caution: Stresses greater than the 'Absolute Maximum Ratings' sp ecified above, may cause permanent damage to the device. These are stress ratings only; functional operation of the device at these or any other conditions exceeding those indicated in this specification is not implied. Device reliability may be affected by exposure to absolute maximum rating conditions for extended periods of time. Semiconductor devices are ESD sensitive and may be damaged by exposure to ESD events. Suitable ESD precautions should be taken when handling and transporting these devices. Recommended Operating Conditions (@TA = +25°C, unless otherwise specified.) Symbol Parameter Min Max Unit VIN Operating Input Voltage relative to GND 6.0 36 V VCTRLH Voltage High for PWM dimming relative to GND 2.6 5.5 V VCTRLDC Voltage range for 20% to 100% DC dimming relative to GND 0.5 2.5 V VCTRLL Voltage Low for PWM dimming relative to GND 0 0.4 V ISW DC or RMS switch current 1.5 A fOSC Switching Frequency 1 MHz TJ Junction Temperature Range -40 +125 °C Electrical Characteristics (@VIN = 12V, TA = +25°C, unless otherwise specified.) Symbol Parameter Conditions Min Typ Max Unit VINSU Internal regulator start up threshold VIN rising 5.9 V VINSH Internal regulator hysteresis threshold VIN falling 100 300 mV IQ Quiescent current Output not switching (Note 4) 350 µA IS Input supply Current CTRL pin floating f = 250kHz 1.8 5 mA VTH Set current Threshold Voltage VCTRL ≥ 2.6V or floating. 95 100 105 mV VTH-H Set threshold hysteresis ±20 mV ISET SET pin input current VSET = VIN-0.1 16 22 µA RCTRL CTRL pin input resistance Referred to internal reference 50 k Ω VREF Internal Reference Voltage 2.5 V RDS(on) On Resistance of SW MOSFET ISW = 1A 0.18 0.35 Ω ISW_Leakage Switch leakage current VIN =36V 0.5 μA JA Thermal Resistance Junction-to-Ambient (Note 5) MSOP-8EP (Note 6) 69 C/W JC Thermal Resistance Junction-to-Case (Note 5) MSOP-8EP (Note 6) 4.3 Notes: 4. AL8806 does not have a low power standby mode but current consumption is reduced when outp ut switch is inhibited: VSENSE = 0V. Parameter is tested with V CTRL ≤ 2.5V 5. Dominant conduction path via exposed pad. Refer to figure 5 for the device derating curve. 6. Measured on an FR4 51x51mm PCB with 2oz copper standing in still air with minimum recommended pad layout on top layer and thermal vias to bottom layer maximum area ground plane. For better thermal performance, larger copper pad for heat-sink is needed.
Document number: DS35144 Rev. 5 - 2 4 of 15 www.diodes.com July 2013 © Diodes Incorporated AL8806 Typical Performance Characteristics 100 150 200 250 300 350 400 0 5 10 15 20 25 30 V ( V ) Supply Current (not switching) vs. Input Current IN I ( µ A )IN V = 0 V V = V T = 2 5 C CTRL SE T IN A ° 100 200 300 400 500 600 700 800 900 012345 V( V ) Switching Frequency vs. V CTR L CTRL V = 1 2 V
1 LED
R = 1 5 0 m T = 25°C IN SE T A Frequency (kHz) L = 33µH L = 6 8µH L = 100 µH 0.2 0.4 0.6 0.8 1.2 1.4 1.6 T = 25°CA L =68µH CTRL VOLTAGE (V) LED Current vs. VCTRL LED CURRENT (A) R = 68mSET R = 100mSET R = 150mSET -60 -40 -20 V = V = 12V T = 2 5 C SE T IN A I ( µ A )CTRL V ( V ) I v s V CTRL CTRL CTRL 0.5 1.5 2.5 0 5 10 15 20 25 30 CTRL A V= O p e n T = 2 5 C SE T INV = V V ( V ) V vs. Input Voltage (CTRL pin open circuit) IN CTRL V ( V )CTRL 2.48 2.49 2.50 2.51 2.52 -40 -15 10 35 60 85 110 Ambient T emperature (°C) V vs. TemperatureCTRL V = O p e n V = V = 12V CTRL SE T IN V ( V )CTRL
Document number: DS35144 Rev. 5 - 2 5 of 15 www.diodes.com July 2013 © Diodes Incorporated AL8806 Typical Performance Characteristics (cont.) 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 PWM Duty Cycle I vs. PWM Duty CycleLED 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 V = 1 2 V R = 150m L = 68µH IN SE T LED Current Error (%) LED Current (A) LED Current Error ILED 100 120 140 160 180 200 05 1 0 1 5 20 25 30 R ( m )DS(ON) V ( V ) R vs. Input Voltage IN DS(ON) V = Open V = V 12V T = 2 5 C CTRL SET IN A 100 120 140 160 180 200 220 240 260 -40 -15 10 35 60 85 110 AMBIENT TEMPERATURE (°C) SW R vs. TemperatureDS(ON) V = Open V = V 1 2 V CTRL SET IN R (m )DS(ON) 100 105 11 0 11 5 120 125 130 024 68 Time (µs) SW Output Switching Characteristics VSW V ( m V )SENSE R = 150m L = 68µH SE T V = 1 2 V
1 LED Load
10% 20% 30% 40% 50% 60% 70% 80% 90% 100 6 9 12 15 18 21 24 27 30 Input Voltage (V) Duty Cycle vs. Input Voltage L = 33µH R = 150m T = 2 5 C SE T A
2 LED
Document number: DS35144 Rev. 5 - 2 6 of 15 www.diodes.com July 2013 © Diodes Incorporated AL8806 Typical Operating Performance Characteristics (cont.) 1.5A Nominal LED Current 1.0A Nominal LED Current
2 LEDs
3 LEDs
4 LEDs
5 LEDs
6 LEDs
7 LEDs 8 LEDs
-10% -8% -6% -4% -2% 10% 6 9 12 15 18 21 24 27 30 INPUT VOLTAGE (V) T = 25°C L = 33µH R = 6 6 . 6 7 m A S % ERROR
6 LEDs 7 LEDs
8 LEDs
-10% -8% -6% -4% -2% 6 9 12 15 18 21 24 27 30 INPUT VOLTAGE (V) T = 25°C L = 33µH R = 100m A S DEVIATION
2 LEDs 3 LEDs 4 LEDs 5 LEDs 6 LEDs 7 LEDs 8 LEDs
INPUT VOLTAGE (V) T = 2 5 ° C L = 33µH R = 66.67m A S SWITCHING FREQUENCY (kHZ) 700 600 500 400 300 200 100
2 LEDs 3 LEDs 4 LEDs 5 LEDs 6 LEDs 7 LEDs
INPUT VOLTAGE (V) T = 2 5 ° C L = 33µH R = 1 0 0 m A S SWITCHING FREQUENCY (kHz)
4 LEDs 5 LEDs 6 LEDs 7 LEDs 8 LEDs
75% 80% 85% 90% 95% 100% 6 9 12 15 18 21 24 27 30 INPUT VOLTAGE (V) T = 25°C L = 33µH R = 66.67m A S
5 LEDs 6 LEDs 7 LEDs 8 LEDs
75% 80% 85% 90% 95% 100% 6 9 12 15 18 21 24 27 30 INPUT VOLTAGE (V) T = 2 5 ° C L = 33µH R = 100m A S EFFICIENCY
Document number: DS35144 Rev. 5 - 2 7 of 15 www.diodes.com July 2013 © Diodes Incorporated AL8806
Application Information
In normal operation, when voltage is applied at V IN, the AL8806 internal switch is turned on. Curr ent starts to flow through sense resistor R SET, inductor L1, and the LEDs. The current ramps up linearly, and the ramp rate is determined by the input voltage VIN and the inductor L1. 33µH AL8806VIN SET CTRL SW GND 1µF RSET 0R082 100nF Multi- die LED DFLS230LH 4.7µF 12V GND AL8806VIN SET CTRL SW GND 1µF RSET 0R082 100nF Multi- die LED DFLS230LH 4.7µF 12V GND Figure 1 Typical Application Circuit This rising current produces a voltage ramp across R SET. The internal circuit of the AL8806 senses the voltage across R SET and applies a proportional voltage to the input of the internal comparator. When this voltage reaches an internally se t upper threshold, the internal switch is turned off. The inductor current continues to flow through R SET, L1, the LEDs and the schottky diode D1, and back to the supply rail, but it decays, with the rate of decay determined by the fo rward voltage drop of the LEDs and the schottky diode. This decaying current produces a falling voltage at R 1, which is sensed by the AL8806. A volt age proportional to the sense voltage across R SET is applied at the input of the internal comparator. When this voltage falls to the internally set lower threshold, the internal switch is turned on again. This switch-on-and-off cycle continues to provide the average LED current set by the sense resistor RSET. LED Current Control The LED current is controlled by the resistor RSET in Figure 1. Connected between VIN and SET the nominal average output current in the LED(s) is defined as: SET THD LED R VI If the CTRL pin is driven by an external voltage (higher than 0.4V and lower than 2.5V), the average LED current is: SET THD REF CTRL LED R V V VI For example for a desired LED current of 1.33A and a default voltage VCTRL=2.5V the resulting resistor is: m 755 . 2 5 . 2 33 . 1 1 . 0 V V I VR REF CTRL LED THD SET DC Dimming The CTRL pin can be driven by an external DC voltage (V CTRL), to adjust the output current to a val ue below the nominal average value defined by RSET. The LED current decreases linearly with the CTRL voltage when 0.5V ≤ VCTRL ≤ 2.5V, as shown on page 4 for 4 different current levels. Note that 100% brightness setting corresponds to V CTRL = VREF, nominally 2.5V. For any voltage applied on the CTRL pin that is higher than V REF, the device will not overdrive the LED current and will still set the current according to the equation VCTRL = VREF. When the CTRL voltage falls below the threshold, 0.4V, the output switch is turned off which allows PWM dimming.
Document number: DS35144 Rev. 5 - 2 9 of 15 www.diodes.com July 2013 © Diodes Incorporated AL8806 Application Information (cont.) Soft Start The AL8806 does not have in-built soft-start action – this provides very fast turn off of the output the stage improving PWM di mming accuracy; nonetheless, adding an external capacitor from the CTRL pin to ground will provide a soft-start delay. This is achieved by increasing the time taken for the CTRL voltage to rise to the turn-on threshold and by slowing down the rate of rise of the control voltage at the input of the comparator. Adding a capacitor increases the time taken for the output to reach 90% of its final value, this delay is 0.1ms/nF, but will im pact on the PWM dimming accuracy depending on the delay introduced. Figure 4 Soft Start with 22nF Capacitor on CTRL Pin (VIN = 36V, ILED = 667mA, 1 LED) Reducing Output Ripple Peak to peak ripple current in the LED(s) can be reduced, if r equired, by shunting a capacitor C2 across the LED(s) as shown al ready in the circuit schematic. A value of 1 μF will reduce the supply ripple current by a factor three (approx.). Proportionally lo wer ripple can be achieved with higher ca pacitor values. Note that the capacitor will not affect operating frequenc y or efficiency, but it will increase start-up delay, by reducing the rate of rise of LED voltage. By adding this capacitor the current waveform through the LED(s) changes from a triangul ar ramp to a more sinusoid al version without altering the mean current value.
Document number: DS35144 Rev. 5 - 2 13 of 15 www.diodes.com July 2013 © Diodes Incorporated AL8806 Application Information (cont.) AL8806EV6 BOM Count Designator Description Package Manufacturer Part Number
1 C1 Capacitor, 470uF, 25V Aluminium Electrolytic Radial,
10 x 12.5mm Rubycon 25ZLH470M 1 C2 Capacitor, 4.7µF 10% 50V X7R 1210 Kemet C1210X475K5RAC
3 C3, C9, C10 Capacitor, 100nF 10% 50V X7R 0805 Kemet
1 C4 Capacitor, 100nF 10% 50V X7R 1206 Kemet
4 C5 to C8 Capacitor, 1.5nF 10% 50V or 100V, COG 0805 generic 1 L1 Inductor, shielded, 15µH 20% 6.6 x 6.6mm Coilcraft NIC Würth MSS7341-153ML NPIS64D150MTRF 744777115
1 L2 Inductor, ferrite bead, 6A, 30ohms @100MHz 0805 TDK MPZ2012S300A
1 R1 Resistor, 0.15ohms 1% 250ppm 125mW 0805 generic 1 R2 Resistor, 0.2ohms 1% 250ppm 125mW 0805 generic
1 D1 Diode, schottky, 36V 2A DFLS230 (alternatives:
DFLS230L or LH) PowerDi123 Diodes Inc DFLS230-7
4 D2 to D5 Diode, Super Barrier Rectifier, 36V 2A SBR2U30 PowerDi123 Diodes Inc SBR2U30P1-7
1 U1 IC, LED Driver, AL8806 MSOP-8EP Diodes Inc AL8806MP8-13
The AL8806 guarantees high level of performance both with 12VAC and 12VDC power supply.
Ordering Information
MP8 : MSOP-8EP Packing 13 : 13” Tape & Reel AL8806 XXX - XX Package MP8 : MSOP-8EP Packing 13 : 13” Tape & Reel Part Number Package Code Packaging Tape and Reel Quantity Part Number Suffix AL8806MP8-13 MP8 MSOP-8EP 2500/Tape & Reel -13
Document number: DS35144 Rev. 5 - 2 14 of 15 www.diodes.com July 2013 © Diodes Incorporated AL8806 Marking Information MSOP-8EP Part Number Package AL8806MP8-13 MSOP-8EP Package Outline Dimensions (All dimensions in mm.) Please see AP02002 at http://www.diodes.com/datasheets/ap02002.pdf for latest version. Suggested Pad Layout Please see AP02001 at http://www.diodes.com/datasheets/ap02001.pdf for the latest version. MSOP-8EP Dim Min Max Typ A - 1.10 - A1 0.05 0.15 0.10 A2 0.75 0.95 0.86 A3 0.29 0.49 0.39 b 0.22 0.38 0.30 c 0.08 0.23 0.15 D 2.90 3.10 3.00 D1 1.60 2.00 1.80 E 4.70 5.10 4.90 E1 2.90 3.10 3.00 E2 1.30 1.70 1.50 E3 2.85 3.05 2.95 e - - 0.65 L 0.40 0.80 0.60 a 0° 8° 4° x - - 0.750 y - - 0.750 All Dimensions in mm Dimensions Value (in mm) C 0.650 G 0.450 X 0.450 X1 2.000 Y 1.350 Y1 1.700 Y2 5.300 D A E e y x Seating Plane Gauge Plane L D 8Xb See Detail C Detail C c a 4X10° 4X10° 0.25 G X C Y Y2 Y1
Document number: DS35144 Rev. 5 - 2 15 of 15 www.diodes.com July 2013 © Diodes Incorporated AL8806 IMPORTANT NOTICE DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION). Diodes Incorporated and its subsidiaries rese rve the right to make modifications, enhanc ements, improvements, corrections or ot her changes without further notice to this document and any product descri bed herein. Diodes Incorporated does not assume any liability arising out of the application or use of this document or an y product described herein; neither does Di odes Incorporated convey any license under its patent or trademark rights, nor the rights of others. Any Customer or us er of this document or products described herein in such applications shall assume all risks of such use and will agree to hold Diodes Incorporated and all the companies whose products are represented on Diodes Incorporated website, harmless against all damages. Diodes Incorporated does not warrant or accept any liability whatsoever in respect of any products purchased through unauthoriz ed sales channel. Should Customers purchase or use Diodes Inco rporated products for any unintended or una uthorized application, Customers shall i ndemnify and hold Diodes Incorporated and its representativ es harmless against all claims, damages, expenses, and attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized application. Products described herein may be covered by one or more United States, international or foreign patents pending. Product names and markings noted herein may also be covered by one or more United States, international or foreign trademarks. This document is written in English but may be translated into multiple languages for reference. Only the English version of t his document is the final and determinative format released by Diodes Incorporated. LIFE SUPPORT Diodes Incorporated products are specifically not authorized for use as critical component s in life support devices or systems without the express written approval of the Chief Executive Officer of Diodes Incorporated. As used herein: A. Life support devices or systems are devices or systems which: 1. are intended to implant into the body, or 2. support or sustain life and whose failure to perform when proper ly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in significant injury to the user. B. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or to affect its safety or effectiveness. Customers represent that they have all necessary expertise in the safety and regulatory ramifi cations of their life support dev ices or systems, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any use of Diodes Incorporated products in such safety-critical, life support devices or systems, notwithstanding any devices- or s ystems-related information or support that may be provided by Diodes Incorporated. Further, Customers must fully indemnify Diodes Incorporate d and its representatives against any damages arising out of the use of Diodes Incorporated products in such safety-critical, life support devices or systems. Copyright © 2013, Diodes Incorporated www.diodes.com