LM3414, LM3414HV www.ti.com SNVS678E – JUNE 2010 – REVISED MAY 2013 1A 60W Common Anode Capable Constant Current Buck LED Driver Requires No External Current Sensing Resistor Check for Samples: LM3414, LM3414HV FEATURES DESCRIPTION • The LM3414 and LM3414HV are 1A 60W (see Note below) common anode capable constant current buck LED drivers. They are exceptionally suitable to drive single string of 3W HBLED with up to 96% efficiency. They accept input voltages from 4.5VDC to 65VDC and deliver up to 1A average LED current with ±3% accuracy. The integrated low-side N-channel power MOSFET and current sensing element realize simple and low component count circuitry as no bootstrapping capacitor and external current sensing resistor are required. An external small-signal resistor to ground provides very fine LED current adjustment, analog dimming as well as thermal fold-back functions. 1 2 • • • • • • • • • • • Support LED Power up to 60W (see Note under Description): 18x 3W HBLEDs Requires NO External Current Sensing Resistor ±3% LED Current Accuracy Up to 96% Efficiency High Contrast Ratio (Minimum Dimming Current Pulse Width <10 µS) Integrated Low-Side N-Channel MOSFET Adjustable Constant LED Current From 350mA to 1000mA Support Analog Dimming and Thermal FoldBack Wide Input Voltage Range: – 4.5V to 42V (LM3414) – 4.5V to 65V (LM3414HV) Constant Switching Frequency Adjustable from 250 kHz to 1000 kHz Thermal Shutdown Protection Power Enhanced SOIC-8 or 3mm x 3mm WSON-8 Package APPLICATIONS • • • • Constant switching frequency operation eases EMI. No external loop compensation network is needed. The proprietary Pulse-Level-Modulation (PLM) control method benefits in high conversion efficiency and true average LED current regulation. Fast response time realizes fine LED current pulse fulfilling the 240 Hz 256-step dimming resolution requirement for general lighting. The LM3414 and LM3414HV are available in SOIC-8 and 3mm x 3mm WSON-8 packages. Note: Thermal de-rating applies according to actual operation conditions High Power LED Driver Architectural Lighting, Office Troffer Automotive Lighting MR-16 LED Lamp Simplified Application Schematic High power LED Array Vin D1 LM3414/14HV CVCC VCC PGND VIN 4.5V ± 42 VDC (LM3414) Iout = 1A CIN 4.5V ± 65 VDC (LM3414HV) GND L1 LX IADJ DIM GND FS PWM dimming signal GND RIADJ * DAP connect to GND RFS GND GND 1 2 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. All trademarks are the property of their respective owners. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2010–2013, Texas Instruments Incorporated LM3414, LM3414HV SNVS678E – JUNE 2010 – REVISED MAY 2013 www.ti.com Connection Diagram VCC 1 8 VIN PGND 2 7 LX DIM IADJ 3 6 DIM FS GND 4 5 FS VCC 1 8 VIN PGND 2 7 LX IADJ 3 6 5 EP GND 4 Top View 8-Lead Plastic SOIC-8 Package Number DDA EP Top View 8-Lead Plastic WSON-8 Package Number NGQ PIN DESCRIPTIONS Pin Name Description 1 VCC Application Information Internal Regulator Output Pin This pin should be bypassed to ground by a ceramic capacitor with a minimum value of 1µF. 2 PGND Power Ground Pin Ground for power circuitry. Reference point for all stated voltages. Must be externally connected to EP and GND. 3 IADJ Average Output Current Adjustment Pin Connect resistor RIADJ from this pin to ground to adjust the average output current. 4 GND Analog Ground Pin Analog ground connection for internal circuitry, must be connected to PGND external to the package. 5 FS Switching Frequency Setting Pin Connect resistor RFS from this pin to ground to set the switching frequency. 6 DIM PWM Dimming Control Pin Apply logic level PWM signal to this pin controls the intend brightness of the LED string. 7 LX Drain of N-MOSFET Switch Connect this pin to the output inductor and anode of the schottky diode. 8 VIN Input Voltage Pin The input voltage should be in the range of 4.5V to 42V (LM3414) or 4.5V to 65V (LM3414HV). EP EP Thermal Pad (Power Ground) Used to dissipate heat from the package during operation. Must be electrically connected to PGND external to the package. These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. Absolute Maximum Ratings (LM3414) (1) VIN to GND -0.3V to 42V VIN to GND (Transient) 45V (500 ms) LX to PGND -0.3V to 42V LX to PGND (Transient) -3V(2 ns) to 45V (500 ms) FS, IADJ to GND -0.3V to 5V DIM to GND -0.3V to 6V ESD Rating. Human Body Model (2) 2kV Storage Temp. Range -65°C to 125°C Soldering Information Lead Temperature (Soldering 10s) 260°C Infrared/Convection Reflow (20sec) 235°C (1) (2) 2 Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions under which operation of the device is intended to be functional. For ensured specifications and test conditions, see the Electrical Characteristics. The human body model is a 100pF capacitor discharged through a 1.5 kΩ resistor into each pin. Submit Documentation Feedback Copyright © 2010–2013, Texas Instruments Incorporated Product Folder Links: LM3414 LM3414HV LM3414, LM3414HV www.ti.com SNVS678E – JUNE 2010 – REVISED MAY 2013 Operating Ratings (LM3414) VIN 4.5V to 42V −40°C to +125°C Junction Temperature Range Thermal Resistance θJA SOIC-8 Package 45°C/W WSON-8 Package 54°C/W Absolute Maximum Ratings (LM3414HV) (1) (2) VIN to GND -0.3V to 65V VIN to GND (Transient) 67V (500 ms) LX to PGND -0.3V to 65V LX to PGND (Transient) -3V(2 ns) to 67V (500 ms) FS, IADJ to GND -0.3V to 5V DIM to GND -0.3V to 6V ESD Rating, Human Body Model (3) 2kV Storage Temp. Range -65°C to 125°C Soldering Information Lead Temperature (Soldering 10s) 260°C Infrared/Convection Reflow (20sec) 235°C (1) (2) (3) Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions under which operation of the device is intended to be functional. For ensured specifications and test conditions, see the Electrical Characteristics. If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/Distributors for availability and specifications. The human body model is a 100pF capacitor discharged through a 1.5 kΩ resistor into each pin. Operating Ratings (LM3414HV) VIN 4.5V to 65V −40°C to +125°C Junction Temperature Range Thermal Resistance θJA SOIC-8 Package 45°C/W WSON-8 Package 54°C/W Electrical Characteristics (LM3414) VIN = 24V unless otherwise indicated. Typical and limits appearing in plain type apply for TA=TJ= +25°C (1). Limits appearing in boldface type apply over full Operating Temperature Range. Datasheet min/max specification limits are obtained under device test mode and specified by design, test, or statistical analysis. Symbol Parameter Conditions Min Typ Max Units SYSTEM PARAMETERS IIN-DIM-HIGH Operating Current 4.5V ≤ Vin ≤ 42V RIADJ = 3.125 kΩ VDIM = High 2.2 3.2 3.5 mA IIN-DIM-LOW Standby Current 4.5V ≤ Vin ≤ 42V RIADJ = 3.125 kΩ VDIM = Low 0.8 1.15 1.4 mA ILX-OFF LX Pin Current Main Switch Turned OFF VLX = VIN = 42V (1) 6 µA Typical specification represent the most likely parametric norm at 25°C operation. Electrical Characteristics (LM3414HV) Symbol Parameter Conditions Min Typ Max Units 4.5V ≤ Vin ≤ 65V RIADJ = 3.125 kΩ VDIM = High 2.2 3.3 3.6 mA SYSTEM PARAMETERS IIN-DIM-HIGH Operating Current Copyright © 2010–2013, Texas Instruments Incorporated Product Folder Links: LM3414 LM3414HV Submit Documentation Feedback 3 LM3414, LM3414HV SNVS678E – JUNE 2010 – REVISED MAY 2013 www.ti.com Electrical Characteristics (LM3414HV) (continued) Symbol Parameter Conditions Min Typ Max Units IIN-DIM-LOW Standby Current 4.5V ≤ Vin ≤ 65V RIADJ = 3.125 kΩ VDIM = Low 0.8 1.2 1.45 mA ILX-OFF LX Pin Current Main Switch Turned OFF VLX = VIN= 65V 6.5 µA Electrical Characteristics (LM3414/LM3414HV) Symbol Parameter Conditions Min Typ Max Units RIADJ = 3.125 kΩ TA = 25°C 0.97 1 1.03 A RIADJ = 3.125 kΩ TA = –40°C to 125°C 0.95 1 1.05 A VCC Decreasing 3.60 3.75 3.90 SYSTEM PARAMETERS ILED Average LED Current VCC-UVLO Vcc UVLO Threshold VCC-UVLO-HYS Vcc UVLO Hysteresis VIADJ IADJ Pin voltage VDIM DIM Pin Threshold VDIM-HYS DIM Pin Hysteresis fSW Switching Frequency Range fSW-TOL Switching Frequency Tolerance tON-MIN Minimum On-time 300 1.230 VDIM Increasing 1.255 1.280 V 1.0 1.2 V 100 RFS = 40 kΩ V mV mV 250 500 1000 kHz 420 500 580 kHz 400 ns 6.0 V INTERNAL VOLTAGE REGULATOR VCC Regulator Output Voltage (1) VCC CVCC = 1µF, No Load to IVCC = 2mA 4.7 5.4 Vin = 4.5V, 2 mA Load 3.8 4.2 V MAIN SWITCH RLX Resistance Across LX and GND Main Switch Turned ON 1.8 Ω THERMAL PROTECTION TSD Thermal Shutdown Temperature TJ Rising 170 °C TSD-HYS Thermal Shutdown Temperature Hysteresis TJ Falling 10 °C SOIC-8 package 45 °C/W WSON-8 package 54 °C/W THERMAL RESISTANCE θJA (1) (2) 4 Junction to Ambient, 0 LFPM Air Flow (2) VCC provides self bias for the internal gate drive and control circuits. Device thermal limitations limit external loading to the pin. Tested on a 4 layer JEDEC board. Four vias provided under the exposed pad. See JESD51-5 and JESD51-7. The value of the θJA for the WSON package is specifically dependent on the PCB trace area, trace material, and the number of layers and thermal vias. For improved thermal resistance and power dissipation for the WSON package, refer to Application Note AN-1187 (SNOA401). Submit Documentation Feedback Copyright © 2010–2013, Texas Instruments Incorporated Product Folder Links: LM3414 LM3414HV LM3414, LM3414HV www.ti.com SNVS678E – JUNE 2010 – REVISED MAY 2013 Typical Performance Characteristics All curves taken at VIN = 48V with configuration in typical application for driving twelve power LEDs with ILED = 1A shown in this datasheet. TA = 25°C, unless otherwise specified. IOUT vs VIN, (4 - 8 LED) LM3414HV IOUT vs VIN, (10 - 18 LED) LM3414HV Figure 1. Figure 2. Efficiency vs VIN, (4 - 8 LED) LM3414HV Efficiency vs VIN, (10 - 18 LED) LM3414HV Figure 3. Figure 4. IOUT vs Temperature (TA) (6 LED, VIN = 24V), LM3414HV IOUT vs Temperature (TA) (12 LED, VIN = 48V), LM3414HV Figure 5. Figure 6. Copyright © 2010–2013, Texas Instruments Incorporated Product Folder Links: LM3414 LM3414HV Submit Documentation Feedback 5 LM3414, LM3414HV SNVS678E – JUNE 2010 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics (continued) All curves taken at VIN = 48V with configuration in typical application for driving twelve power LEDs with ILED = 1A shown in this datasheet. TA = 25°C, unless otherwise specified. 6 VCC vs Temperature (TA) LM3414HV VIADJ vs Temperature (TA) LM3414HV Figure 7. Figure 8. IOUT and VLX LM3414HV ILX and VDIM LM3414HV Figure 9. Figure 10. LED Current with PWM Dimming (VDIM Rising) LM3414HV LED Current with PWM Dimming (VDIM Falling) LM3414HV Figure 11. Figure 12. Submit Documentation Feedback Copyright © 2010–2013, Texas Instruments Incorporated Product Folder Links: LM3414 LM3414HV LM3414, LM3414HV www.ti.com SNVS678E – JUNE 2010 – REVISED MAY 2013 Typical Performance Characteristics (continued) All curves taken at VIN = 48V with configuration in typical application for driving twelve power LEDs with ILED = 1A shown in this datasheet. TA = 25°C, unless otherwise specified. LED Current with PWM Dimming (9µs dimming pulse), LM3414HV Figure 13. Copyright © 2010–2013, Texas Instruments Incorporated Product Folder Links: LM3414 LM3414HV Submit Documentation Feedback 7 LM3414, LM3414HV SNVS678E – JUNE 2010 – REVISED MAY 2013 www.ti.com Block Diagram Operation Description OVERVIEW The LM3414/14HV is a high power floating buck LED driver with wide input voltage ranges. It requires no external current sensing elements and loop compensation networks. The integrated power N-MOSFET enables high output power with up to 1000 mA output current. The combination of Pulse Width Modulation (PWM) control architecture and the proprietary Pulse Level Modulation (PLM) ensures accurate current regulation, good EMI performance and provides high flexibility on inductor selection. High speed dimming control input allows precision and high resolution brightness control for applications require fine brightness adjustment. 8 Submit Documentation Feedback Copyright © 2010–2013, Texas Instruments Incorporated Product Folder Links: LM3414 LM3414HV LM3414, LM3414HV www.ti.com SNVS678E – JUNE 2010 – REVISED MAY 2013 APPLICATION INFORMATION SETTING THE SWITCHING FREQUENCY Both the LM3414 and LM3414HV are PWM LED drivers that contain a clock generator to generate constant switching frequency for the device. The switching frequency is determined by the resistance of an external resistor RFS in the range of 250 kHz to 1 MHz. Lower resistance of RFS results in higher switching frequency. The switching frequency of the LM3414/14HV is governed by the following equation: fSW = 20 x 106 kHz RFS (1) Figure 14. Switching Frequency vs RFS Table 1. Examples for fSW Settings fSW (kHz) RFS (kΩ) 250 80 500 40 1000 20 To ensure accurate current regulation, the LM3414/14HV should be operated in continuous conduction mode (CCM) and the on time should not be shorter than 400 ns under all operation condition. SETTING LED CURRENT The LM3414/14HV requires no external current sensing resistor for LED current regulation. The average output current of the LM3414/14HV is adjustable by varying the resistance of the resistor, RIADJ that connects across the IADJ and GND pins. The IADJ pin is internally biased to 1.255V. The LED current is then governed by the following equation: ILED = 3125 x 103 mA RIADJ where • 350 mA < ILED < 1A (2) Copyright © 2010–2013, Texas Instruments Incorporated Product Folder Links: LM3414 LM3414HV Submit Documentation Feedback 9 LM3414, LM3414HV SNVS678E – JUNE 2010 – REVISED MAY 2013 www.ti.com 1.4 1.2 ILED(A) 1.0 0.8 0.6 0.4 0.2 0.0 0 1 2 3 4 5 6 RIADJ(k ) 7 8 9 Figure 15. LED Current vs RIADJ Table 2. Examples for IOUT Settings IOUT (mA) RIADJ (kΩ) 350 8.93 500 6.25 700 4.46 1000 3.13 The LED current can be set to any level in the range from 350 mA to 1A. In order to provide accurate LED current, RIADJ should be a resistor with no more than 0.5% tolerance. If the IADJ pin is accidentally shorted to GND (RIADJ = 0), the output current will be limited to avoid damaging the circuit. When the over current protection is activated, current regulation cannot be maintained until the over-current condition is cleared. MINIMUM SWITCH ON-TIME As the LM3414 features a 400 ns minimum ON time, it is essential to make sure the ON time of the internal switch is not shorter than 400 ns when setting the LED driving current. If the switching ON time is shorter than 400 ns, the accuracy of the LED current may not maintain and exceed the rated current of the LEDs. The ratio of the LED forward voltage to input voltage is restricted by the following restriction: VLED t 400 nS x fSW VIN (3) PEAK SWITCH CURRENT LIMIT The LM3414/14HV features an integrated switch current limiting mechanism that protects the LEDs from being overdriven. The switch current limiter will be triggered when the switch current is three times exceeding the current level set by RIADJ. Once the current limiter is triggered, the internal power switch turns OFF for 3.6 µs to allow the inductor to discharge and cycles repetitively until the over current condition is removed. The current limiting feature is exceptionally important to avoid permanent damage of the LM3414/14HV application circuit due to short circuit of LED string. 10 Submit Documentation Feedback Copyright © 2010–2013, Texas Instruments Incorporated Product Folder Links: LM3414 LM3414HV LM3414, LM3414HV www.ti.com SNVS678E – JUNE 2010 – REVISED MAY 2013 IL1 ILED = IL(AVERAGE) = Mid-point of ILX during tON ILX ILED Time 1/fSW tON Figure 16. Waveforms of a Floating Buck LED Driver with PLM INDUCTOR SELECTION To ensure proper output current regulation, the LM3414/14HV must operate in Continuous Conduction Mode (CCM). With the incorporation of PLM, the peak-to-peak inductor current ripple can be set as high as ±60% of the defined average output current. The minimum inductance of the inductor is decided by the defined average LED current and allowable inductor current ripple. The minimum inductance can be found by the equations shown below: Since: 'IL = VIN - VLED xDxT L (4) Thus: LMIN = VIN -VLED VLED 1 x x 1.2 x ILED VIN fSW (5) The LM3414/14HV can maintain LED current regulation without output filter capacitor. This is because the inductor of the floating buck structure provides continuous current to the LED throughout the entire switching cycle. When LEDs are driven without filter capacitor, the LED peak current must not set exceeding the rated current of the LED. The peak LED current is governed by the following equation: 'IL = (VIN -VLED) VLED + ILED(AVG) 2L x VIN x fSW (6) INTERNAL N_MOS POWER SWITCH The LM3414/14HV features an integrated N-channel power MOSFET that connects between the LX and GND pins for power switching. With the switch turned ON, the resistance across the LX and GND pins is 1.8Ω maximum. Copyright © 2010–2013, Texas Instruments Incorporated Product Folder Links: LM3414 LM3414HV Submit Documentation Feedback 11 LM3414, LM3414HV SNVS678E – JUNE 2010 – REVISED MAY 2013 www.ti.com INTERNAL VCC REGULATOR The LM3414/14HV features a 5.4V internal voltage regulator that connects between the VIN and VCC pins for powering internal circuitry and provide biases to external components. The VCC pin must be bypassed to the GND pin with a 1µF ceramic capacitor, CVCC that connected to the pins as close as possible. When the input voltage falls below 6V, the VCC voltage will drop below 5.4V and decrease proportionally as Vin decreases. The device will shutdown as the VCC voltage falls below 3.9V. When the internal regulator is used to provide bias to external circuitry, it is essential to ensure the current sinks from VCC pin does not exceed 2mA to maintain correct voltage regulation. CONTROL SCHEME The main control circuitry of the LM3414/14HV is generally a Pulse-Width-Modulated (PWM) controller with the incorporation of the Pulse-Level-Modulation (PLM) technology. PLM is a technology that facilitates true output average current control without the need to sense the output current directly. In the LM3414/LM3414HV, the PLM circuit senses the current of the internal switch through an integrated current sensing circuitry to realize average output current control. The use of PLM reduces the power losses on current sensor as it needs current information only when the switch is turned ON. In general, the LED drivers with current sensing resistor at the output, the power dissipation on the current sensing resistor is ILED2 x RISNS, where ILED is the average output current and RISNS is the resistance of the current sensing resistor. In the LM3414/LM3414HV, because of the incorporation of PLM, power dissipates on the RISNS only in ON period of the internal power switch. The power loss on RISNS becomes ILED2 x RISNS x D, where D is the switching duty cycle. For example, when the switching duty cycle, D of a converter is 0.5, the power loss on RISNS with PLM is half of those with conventional output current sensing. PULSE-LEVEL-MODULATION (PLM) OPERATION PRINCIPLES The Pulse-Level-Modulation is a patented method to ensure accurate average output current regulation without the need of direct output current sensing. Figure 16 shows the current waveforms of a typical buck converter under steady state, where, IL1 is the inductor current and ILX is the main switch current flowing into the LX pin. For a buck converter operating in steady state, the mid-point of the RAMP section of the main switch current is equal to the average level of the inductor current hence the average output current. In short, by regulating the mid-point of the RAMP section of the main switch current with respect to a precise reference level, PLM achieves output current regulation by sensing the main switch current solely. PWM DIMMING CONTROL The DIM pin of the LM3414/14HV is an input with internal pull-up that accepts logic signals for average LED current control. Applying a logic high (above 1.2V) signal to the DIM pin or leaving the DIM pin open will enable the device. Applying a logic low signal (below 0.9V) to the DIM pin will disable the switching activity of the device but maintain VCC regulator active. The LM3414/14HV allows the inductor current to slew up to the preset regulated level at full speed instead of charging the inductor with multiple restrained switching duty cycles. This enables the LM3414/14HV to achieve high speed dimming and very fine dimming control as shown in Figure 17 and Figure 18: 12 Submit Documentation Feedback Copyright © 2010–2013, Texas Instruments Incorporated Product Folder Links: LM3414 LM3414HV LM3414, LM3414HV www.ti.com SNVS678E – JUNE 2010 – REVISED MAY 2013 LE D cu rre nt s le ws up ILED ILED regulated Time 0 LED dimmed OFF ILED slew up time Figure 17. LED Current Slews up with Multiple Switching Cycle Copyright © 2010–2013, Texas Instruments Incorporated Product Folder Links: LM3414 LM3414HV Submit Documentation Feedback 13 LM3414, LM3414HV SNVS678E – JUNE 2010 – REVISED MAY 2013 www.ti.com LED c urrent s lews u p ILED ILED regulated Time 0 LED dimmed OFF ILED slew up time Figure 18. Shortened Current Slew up Time of the LM3414/14HV To ensure normal operation of the LM3414/14HV, it is recommended to set the dimming frequency not higher than 1/10 of the switching frequency. The minimum dimming duty cycle is limited by the 400 ns minimum ON time. In applications that require high dimming contrast ratio, low dimming frequency should be used. ANALOG DIMMING CONTROL The IADJ pin can be used as an analog dimming signal input. As the average output current of the LM3414 depends on the current being drawn from the IADJ pin, thus the LED current can be increased or decreased by applying external bias current to the IADJ pin. The simplified circuit diagram for facilitating analog dimming is as shown in Figure 19. 14 Submit Documentation Feedback Copyright © 2010–2013, Texas Instruments Incorporated Product Folder Links: LM3414 LM3414HV LM3414, LM3414HV www.ti.com SNVS678E – JUNE 2010 – REVISED MAY 2013 VCC Current Mirror VEXT To LED current setting circuitry + - IEXT + - IADJ IIADJ 1.255V RIADJ LM3414/14HV Figure 19. Analog LED Current Control Circuit When external bias current IEXT is applied to the IADJ pin, the reduction of LED current follows the equations: 1.255 - IEXT x 2490 x 103 mA RIADJ ILED = (7) Provided that IEXT < 1.255 RIADJ (8) ILED decreases linearly as IEXT increases. This feature is exceptionally useful for the applications with analog dimming control signals such as those from analog temperature sensors and ambient light sensors. DESIGN EXAMPLE Figure 20 shows an example circuit for analog dimming control using simple external biasing circuitry with a variable resistor. Copyright © 2010–2013, Texas Instruments Incorporated Product Folder Links: LM3414 LM3414HV Submit Documentation Feedback 15 LM3414, LM3414HV SNVS678E – JUNE 2010 – REVISED MAY 2013 www.ti.com VCC VCC IEXT Q1 IADJ R2 R1 LM3414 RIADJ VR1 GND GND GND Figure 20. Example Analog Dimming Control Circuit In the figure, the variable resistor VR1 controls the base voltage of Q1 and eventually adjusts the bias voltage of current to the IADJ pin (IEXT). As the resistance of VR1 increases and the voltage across VR1 exceeds 1.255V + 0.7V, the LED current starts to decrease as IEXT increases. where VCC ± 1.955 IEXT = R2 R1 +1 VR1 R1 +1 VR1 mA (9) The analog dimming begins only when IEXT > 0. DESIGN CONSIDERATIONS The overall performance of the LED driver is highly depends on the PCB layout and component selection. To minimize connection losses and parasitic inductance of the traces, the best practice is to keep the copper traces connecting the inductor, power switch and rectifier short and thick . Long traces on critical power paths will introduce voltage and current spikes to the LM3414/LM3414HV. If the voltage spike level exceeds the absolute maximum pin voltage of the LM3414, it could damage the device and LEDs. To avoid physical damage of the circuit, a Transient Voltage Suppressor (TVS) can be added across VIN and GND pins to suppress the spike voltage. This also helps in absorbing the input voltage spike when the circuit is powered through physical switch upon power up. 16 Submit Documentation Feedback Copyright © 2010–2013, Texas Instruments Incorporated Product Folder Links: LM3414 LM3414HV LM3414, LM3414HV www.ti.com SNVS678E – JUNE 2010 – REVISED MAY 2013 Additional Application Circuit Vin Iout = 1000 mA (nom.) 100V 2.2 PF CIN CVCC 16V 1 PF LM3414 / LM3414HV VCC VIN PGND IADJ LED x 6 100V 2A D1 24V ± 42 VDC (LM3414) 24V - 65 VDC (LM3414HV) GND L1 47 PH LX U1 DIM GND FS GND RIADJ 3.24k * DAP connect to GND RFS 40.2k GND GND Figure 21. LM3414/14HV Design Example (IOUT = 500 mA) Table 3. Bill of Materials Designation Description Package Manufacture Part # Vendor U1 LED Driver IC LM3414 / LM3414HV SOIC-8 LM3414 / LM3414HV TI L1 Inductor 47 µH 8 x 8 x 4.9 (mm) MMD-08EZ-470M-SI Mag.Layers D1 Schottky Diode 100V 2.0A SMP SS2PH10-M3 Vishay CIN Cap MLCC 100V 2.2 µF X7R 1210 GRM32ER72A225KA35L Murata CVCC Cap MLCC 16V 1.0 µF X5R 603 GRM39X5R105K16D52K Murata RIADJ Chip Resistor 3.24 kΩ 1% 603 CRCW06033241F Vishay RFS Chip Resistor 40.2 kΩ 1% 603 CRCW06034022F Vishay D1 LM3414 / LM3414HV CVCC VCC R1 PGND IADJ GND GND Q1 Analog temperature sensor GND VIN U1 GND CIN GND LX PWM dimming signal DIM FS * DAP connect to GND R2 L1 High power LED Array Vin VCC RFS GND RIADJ GND Figure 22. Application Circuit of LM3414/14HV with Temperature Fold-Back Circuitry and PWM Dimming Copyright © 2010–2013, Texas Instruments Incorporated Product Folder Links: LM3414 LM3414HV Submit Documentation Feedback 17 LM3414, LM3414HV SNVS678E – JUNE 2010 – REVISED MAY 2013 www.ti.com REVISION HISTORY Changes from Revision D (May 2013) to Revision E • 18 Page Changed layout of National Data Sheet to TI format .......................................................................................................... 17 Submit Documentation Feedback Copyright © 2010–2013, Texas Instruments Incorporated Product Folder Links: LM3414 LM3414HV PACKAGE OPTION ADDENDUM www.ti.com 19-Jul-2013 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan Lead/Ball Finish (2) MSL Peak Temp Op Temp (°C) Device Marking (3) (4/5) LM3414HVMR/NOPB ACTIVE SO PowerPAD DDA 8 95 Green (RoHS & no Sb/Br) CU SN Level-3-260C-168 HR -40 to 125 L3414 HVMR LM3414HVMRX/NOPB ACTIVE SO PowerPAD DDA 8 2500 Green (RoHS & no Sb/Br) CU SN Level-3-260C-168 HR -40 to 125 L3414 HVMR LM3414HVSD/NOPB ACTIVE WSON NGQ 8 1000 Green (RoHS & no Sb/Br) Call TI Level-1-260C-UNLIM -40 to 125 L249B LM3414HVSDX/NOPB ACTIVE WSON NGQ 8 4500 Green (RoHS & no Sb/Br) Call TI Level-1-260C-UNLIM -40 to 125 L249B LM3414MR/NOPB ACTIVE SO PowerPAD DDA 8 95 Green (RoHS & no Sb/Br) CU SN Level-3-260C-168 HR -40 to 125 L3414 MR LM3414MRX/NOPB ACTIVE SO PowerPAD DDA 8 2500 Green (RoHS & no Sb/Br) CU SN Level-3-260C-168 HR -40 to 125 L3414 MR LM3414SD/NOPB ACTIVE WSON NGQ 8 1000 Green (RoHS & no Sb/Br) Call TI Level-1-260C-UNLIM -40 to 125 L248B LM3414SDX/NOPB ACTIVE WSON NGQ 8 4500 Green (RoHS & no Sb/Br) Call TI Level-1-260C-UNLIM -40 to 125 L248B (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. Addendum-Page 1 Samples PACKAGE OPTION ADDENDUM www.ti.com (4) 19-Jul-2013 There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. 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Addendum-Page 2 PACKAGE MATERIALS INFORMATION www.ti.com 11-Oct-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant LM3414HVMRX/NOPB SO Power PAD DDA 8 2500 330.0 12.4 6.5 5.4 2.0 8.0 12.0 Q1 LM3414HVSD/NOPB WSON NGQ 8 1000 178.0 12.4 3.3 3.3 1.0 8.0 12.0 Q1 LM3414HVSDX/NOPB WSON NGQ 8 4500 330.0 12.4 3.3 3.3 1.0 8.0 12.0 Q1 LM3414MRX/NOPB SO Power PAD DDA 8 2500 330.0 12.4 6.5 5.4 2.0 8.0 12.0 Q1 LM3414SD/NOPB WSON NGQ 8 1000 178.0 12.4 3.3 3.3 1.0 8.0 12.0 Q1 LM3414SDX/NOPB WSON NGQ 8 4500 330.0 12.4 3.3 3.3 1.0 8.0 12.0 Q1 Pack Materials-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 11-Oct-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM3414HVMRX/NOPB LM3414HVSD/NOPB SO PowerPAD DDA 8 2500 367.0 367.0 35.0 WSON NGQ 8 1000 210.0 185.0 35.0 LM3414HVSDX/NOPB WSON NGQ 8 4500 367.0 367.0 35.0 LM3414MRX/NOPB SO PowerPAD DDA 8 2500 367.0 367.0 35.0 LM3414SD/NOPB WSON NGQ 8 1000 210.0 185.0 35.0 LM3414SDX/NOPB WSON NGQ 8 4500 367.0 367.0 35.0 Pack Materials-Page 2 MECHANICAL DATA DDA0008A MRA08A (Rev D) www.ti.com MECHANICAL DATA NGQ0008A SDA08A (Rev A) www.ti.com IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. 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