TPS92551EVM/NOPB

TPS92551, TPS92551EVM www.ti.com SNVS805C – MAY 2012 – REVISED MAY 2013 450mA 23W Constant Current Buck LED Driver Micro-Module Check for Samples: TPS92551, TPS92551EVM FEATURES DESCRIPTION • The TPS92551 Constant Current Buck LED Driver Micro-Module drives maximum 450mA LED current up to 16 LEDs in a single string (maximum 23W). It integrates all the power components including the power inductor. The TPS92551 provides a full turnkey, highly efficient solution for wide range of single string LED lighting applications with up to 95% power efficiency. It accepts an input voltage ranging from 4.5V to 60V and delivers a 350mA LED current as default. The LED current is adjustable from 300mA to 450mA by charging a single external resistor. 1 2 • • • • • • • • • • • • • • Integrated All Power Components Including the Power Inductor Wide Input Voltage Range : 4.5V - 60V Constant Switching Frequency at 800kHz High Contrast Ratio (Minimum Dimming Current Pulse width < 16µs) Drives up to 16 LEDs in series at 60V input ±3.5% Typical LED Current Accuracy LED Current Adjustable from 300mA to 450mA Up to 95% Efficiency TPS92551 Modules can be Connected in Parallel for Higher Current Operation Input Under-Voltage Lock-Out (UVLO) Compatible with Ceramic and Low ESR Capacitors Low Electro Magnetic Interference (EMI) Complies with EN55015 Standard (1) LED Open and Short Circuit Protections Thermal Shutdown and RoHS Compliant -40˚C to +125˚C Junction Temperature Range The module operates at constant switching frequency (800kHz) with low Electro Magnetic Interference(EMI) complying with EN55015 standard. The module has fast control loop to realize fine LED current pulse yielding 256–step PWM dimming resolution at 240Hz for general lighting. Protection features include thermal shutdown, input under-voltage lockout, LED open-circuit and short-circuit protections. The TPS92551 Micro-Module is available in 7-pin PFM power package. APPLICATIONS • • General Lighting, Desk Lamps – Cabinet Lamps – Decorative Lamps – Street Lamps Architecture Lighting, Recess Lights – Spot Lights – Underwater Lights (1) θ JA measured on a 1.705” x 3.0” four layer board, with one ounce copper , thirty five 12 mil thermal vias, no air flow, and 1W power dissipation. Figure 1. 7-Pin PFM Package 10.16 x 13.77 x 4.57 mm (0.4 x 0.39 x 0.18 in) θJA = 20°C/W, θJC = 1.9°C/W(1) RoHS Compliant PACKAGE HIGHLIGHTS • • • (1) 7-Lead Easy-to-Use Package (Similar to TO263) Single Exposed Die Attach Pad for Enhanced Thermal Performance 10.2 x 13.8 x 4.6 mm Package EN55015, refer to Figure 35 and Figure 36 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 © 2012–2013, Texas Instruments Incorporated TPS92551, TPS92551EVM SNVS805C – MAY 2012 – REVISED MAY 2013 www.ti.com System Performance 100 10LED EFFICIENCY (%) 95 14LED ILED(200mA/DIV) 16LED 6LED 90 85 VDIM(2V/DIV) 80 75 25 30 35 40 45 VIN(V) 50 55 60 4 s/DIV Figure 2. Efficiency vs VIN , ILED = Figure 3. Radiated Emissions (EN 350mA 55015) Figure 4. LED Current with PWM Dimming 16µs dimming pulse TYPICAL APPLICATION CIRCUIT TPS92551 EP 5 6 7 LED+ VREF GND DIM LED+ IADJ LED- 4 2 3 1 CIN ILED High Power LED String IIN VIN 2 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: TPS92551 TPS92551EVM TPS92551, TPS92551EVM www.ti.com SNVS805C – MAY 2012 – REVISED MAY 2013 CONNECTION DIAGRAM LED- 7 Exposed Pad Connect to GND 6 IADJ 5 VREF 4 GND 3 2 DIM LED+ 1 LED+ Figure 5. 7-Pin PFM (Top View) See NDW0007A Package PIN DESCRIPTIONS Pin Numbe r Name 1, 2 LED+ Anode of LED string Supply input and rail connection to the anode of the LED string. 3 DIM Dimming signal input Dimming control signal input. Open to enable or apply logic level PWM signal to control the brightness of the LED string. 4 GND Ground Reference point for all stated voltages. Connect to the exposed pad of the package externally. 5 VREF Voltage reference Internal voltage reference output. 6 IADJ LED current adjustment Fine tunning of the LED current by connecting a resistor between this pin and ground. Connect this pin to ground for factory preset current. 7 LED- Cathode of LED string The current return pin of the LED string, connect to the cathode of the LED string. EP Exposed Pad Description Function Exposed thermal pad Used to dissipate heat from the package during operation. Must connect to GND directly. Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: TPS92551 TPS92551EVM Submit Documentation Feedback 3 TPS92551, TPS92551EVM SNVS805C – MAY 2012 – REVISED MAY 2013 www.ti.com 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 (1) If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/ Distributors for availability and specifications. VALUE / UNITS LED+, LED– to GND -0.3V to 67V DIM to GND -0.3V to 6V IADJ, VREF to GND ESD Susceptibility -0.3V to 5V (2) ±2 kV (All Pins Except Pin 6) Power Dissipation Internally Limited Junction Temperature 150°C Storage Temperature Range 0°C to 150°C Peak Reflow Case Temperature (30 sec) (1) (2) 245°C 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 100 pF capacitor discharged through a 1.5 kΩ resistor into each pin. The Pin 6 ( IADJ pin) pass ± 1kV.Test method is per JESD22-AI14S. RECOMMENDED OPERATING CONDITIONS (1) VALUE / UNITS LED+, LED- 4.5V to 60V DIM 0V to 5.5V IADJ 0V to 0.2V Junction Temperature (TJ) (1) 4 –40°C to 125°C 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. Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: TPS92551 TPS92551EVM TPS92551, TPS92551EVM www.ti.com SNVS805C – MAY 2012 – REVISED MAY 2013 ELECTRICAL CHARACTERISTICS Limits in standard type are for TJ = 25°C unless otherwise stated; limits in boldface type apply over the operating junction temperature range TJ of -40°C to 125°C. Minimum and maximum limits are specified through test, design, or statistical correlation. Typical values represent the most likely parametric norm at TJ = 25°C, and are provided for reference purposes only. Unless otherwise stated the following conditions apply: VIN =48 V, ILED = 350mA. VIN is the voltage applied across LED+ and GND. IIN is the input current flowing into the LED+ node. ILED is a LED current flowing into the LED- pin. VLED is the voltage applied across LED+ and LED-. VDIM is the voltage applied across the DIM pin to ground. Resistor RIADJ connect from IADJ pin to ground. Resistor RVREF connect from VREF pin to ground. Symbol Parameter Conditions Min (1) Typ (2) Max (1) Units SYSTEM PARAMETERS IIN Input Current VLED = 0V, 4.5V ≤ VIN ≤ 60V, VDIM = 0V 2.1 2.65 3.0 mA ILED LED Current VLED = 24V , RIADJ = 0Ω, RVREF = open, TJ = 25°C 340 350 364 mA VLED = 24V, RIADJ = 0Ω, RVREF = open, TJ = 25°C to 125°C 337 350 364 VLED = 24V, RIADJ = 0Ω , RVREF = open, TJ = -40°C to 125°C 337 350 371 VIN = 60V, VLED = 36V, RIADJ = 0Ω RVREF = open, TJ = 25°C 342 350 367 VIN = 60V, VLED = 36V, RIADJ = 0Ω, RVREF = open, TJ = 25°C to 125°C 338 350 367 VIN = 60V, VLED = 36V, RIADJ = 0Ω, RVREF = open, TJ = -40°C to 125°C 338 350 374 VLED = 24V, RIADJ = 0Ω, RVREF = 10.5kΩ, TJ = 25°C 442 450 471 VLED = 24V, RIADJ = 0Ω, RVREF = 10.5kΩ, TJ = 25°C to 125°C 437 450 471 VLED = 24V, RIADJ = 0Ω, RVREF = 10.5kΩ, TJ = -40°C to 125°C 437 450 483 VLED = 24V, RIADJ = 500Ω, RVREF = open, TJ = 25°C 288 300 309 VLED = 24V, RIADJ = 500Ω, RVREF = open, TJ = 25°C to 125°C 282 300 309 VLED = 24V, RIADJ = 500Ω, RVREF = open, TJ = -40°C to 125°C 282 300 316 800 920 1020 mA 1.2 µA 800 920 kHz 1.0 1.3 V ILED–60V ILED-ADJ1 ILED-ADJ2 LED Current at VIN = 60V Adjusted LED Current Adjusted LED Current ILED-SHORT LED Short Circuit Current at VIN = 60V VLED = 0V, VIN = 60V, DIM = open ILED-LEAK “LED-” pin leakage current VLED = 0V, VIN = operating max, DIM = 0V fSW Switching Frequency VLED = 24V, RIADJ = 0Ω, RVREF = open VDIM DIM Pin Threshold VDIM Increasing VDIM-HYS DIM Pin Hysteresis 720 mA mA mA 0.25 V THERMAL CHARACTERISTICS TSD Thermal Shutdown Temperature TJ Rising 170 °C TSD-HYS Thermal Shutdown Temp. Hysteresis TJ Rising 10 °C Junction to Ambient (3) 4 Layer JEDEC Printed Circuit Board, 100 vias, No air flow 19.3 °C/W 2 Layer JEDEC PCB, No air flow 21.5 No air flow 1.9 θJA θJC (1) (2) (3) Junction to Case °C/W Min and Max limits are 100% production tested at an ambient temperature (TA) of 25°C. Limits over the operating temperature range are specified through correlation using Statistical Quality Control (SQC) methods. Limits are used to calculate Average Outgoing Quality Level (AOQL). Typical numbers are at 25°C and represent the most likely parametric norm. θ JA measured on a 1.705” x 3.0” four layer board, with one ounce copper , thirty five 12 mil thermal vias, no air flow, and 1W power dissipation. Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: TPS92551 TPS92551EVM Submit Documentation Feedback 5 TPS92551, TPS92551EVM SNVS805C – MAY 2012 – REVISED MAY 2013 www.ti.com TYPICAL PERFORMANCE CHARACTERISTICS Unless otherwise specified, the following conditions apply: VIN = 48V, CIN is a 2.2µF 100V X7R ceramic capacitor for driving 5–13 power LEDs with ILED = 350mA. Single LED forward voltage used is 3.2V. TA = 25°C for efficiency curves and waveforms. Efficiency vs VIN, ILED = 350mA ILED Regulation vs VIN, ILED = 350mA 100 3 2 90 ILEDREGULATION (%) EFFICIENCY (%) 95 4LED 85 3LED 80 2LED 75 1LED 70 1 2LED 4LED 1LED -1 -2 65 60 -3 0 10 20 VIN(V) 30 40 0 10 20 VIN(V) Figure 6. Efficiency vs VIN, ILED = 350mA ILED Regulation vs VIN, ILED = 350mA 10LED 16LED 14LED 2 ILEDREGULATION (%) EFFICIENCY (%) 40 3 95 6LED 90 85 80 1 6LED 10LED 14LED 16LED 0 -1 -2 75 -3 25 30 35 40 45 VIN(V) 50 55 60 25 30 35 Figure 8. 40 45 VIN(V) 50 55 60 Figure 9. Efficiency vs VIN, ILED = 450mA ILED Regulation vs VIN, ILED = 450mA 100 3 95 2 90 ILEDREGULATION (%) EFFICIENCY (%) 30 Figure 7. 100 4LED 85 3LED 80 2LED 75 70 1LED 3LED 1 1LED 0 4LED -1 2LED -2 65 60 -3 0 10 20 VIN(V) 30 40 0 Figure 10. 6 3LED 0 Submit Documentation Feedback 10 20 VIN(V) 30 40 Figure 11. Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: TPS92551 TPS92551EVM TPS92551, TPS92551EVM www.ti.com SNVS805C – MAY 2012 – REVISED MAY 2013 TYPICAL PERFORMANCE CHARACTERISTICS (continued) Unless otherwise specified, the following conditions apply: VIN = 48V, CIN is a 2.2µF 100V X7R ceramic capacitor for driving 5–13 power LEDs with ILED = 350mA. Single LED forward voltage used is 3.2V. TA = 25°C for efficiency curves and waveforms. Efficiency vs VIN, ILED = 450mA ILED Regulation vs VIN, ILED = 450mA 3 100 EFFICIENCY (%) 16LED 14LED 2 ILEDREGULATION (%) 10LED 95 6LED 90 85 80 1 10LED 0 6LED -1 16LED -2 75 -3 25 30 35 40 45 VIN(V) 50 55 60 25 30 35 Figure 12. Efficiency vs VIN, ILED = 300mA 50 55 60 ILED Regulation vs VIN, ILED = 300mA 3 95 2 ILEDREGULATION (%) EFFICIENCY (%) 40 45 VIN(V) Figure 13. 100 4LED 90 85 3LED 2LED 80 75 1LED 70 1 4LED 0 1LED -1 2LED 3LED -2 65 60 -3 0 10 20 VIN(V) 30 40 0 10 Figure 14. Efficiency vs VIN, ILED = 300mA 30 40 ILED Regulation vs VIN, ILED = 300mA 3 14LED 16LED 2 ILEDREGULATION (%) 10LED 95 20 VIN(V) Figure 15. 100 EFFICIENCY (%) 14LED 6LED 90 85 80 6LED 1 10LED 14LED 16LED 0 -1 -2 75 -3 25 30 35 40 45 VIN(V) 50 55 60 25 Figure 16. 30 35 40 45 VIN(V) 50 55 60 Figure 17. Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: TPS92551 TPS92551EVM Submit Documentation Feedback 7 TPS92551, TPS92551EVM SNVS805C – MAY 2012 – REVISED MAY 2013 www.ti.com TYPICAL PERFORMANCE CHARACTERISTICS (continued) Unless otherwise specified, the following conditions apply: VIN = 48V, CIN is a 2.2µF 100V X7R ceramic capacitor for driving 5–13 power LEDs with ILED = 350mA. Single LED forward voltage used is 3.2V. TA = 25°C for efficiency curves and waveforms. LED Current with PWM Dimming VDIMRising LED Current with PWM Dimming VDIMFalling ILED(200mA/DIV) ILED(200mA/DIV) VDIM(2V/DIV) VDIM(2V/DIV) 2 s/DIV 2 s/DIV Figure 18. Figure 19. LED Current with PWM Dimming 16µs dimming pulse IIN vs VIN VDIM = 0V 3.0 TJ=25°C ILED(200mA/DIV) 2.5 IIN(mA) 2.0 TJ=-40°C TJ=125°C 1.5 1.0 VDIM(2V/DIV) 0.5 0.0 0 10 20 4 s/DIV Figure 20. 50 60 ILED vs VIN 6LED 4.0 450 TJ=25°C 3.5 400 TJ=-40°C 350 3.0 300 TJ=-40°C 2.5 ILED(mA) IIN(mA) 40 Figure 21. IIN vs VIN LED = open , DIM = open TJ=125°C 2.0 1.5 TJ=25°C 250 200 TJ=125°C 150 1.0 100 0.5 50 0.0 0 0 10 20 30 VIN(V) 40 50 60 0 Figure 22. 8 30 VIN(V) Submit Documentation Feedback 10 20 30 VIN(V) 40 50 60 Figure 23. Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: TPS92551 TPS92551EVM TPS92551, TPS92551EVM www.ti.com SNVS805C – MAY 2012 – REVISED MAY 2013 TYPICAL PERFORMANCE CHARACTERISTICS (continued) Unless otherwise specified, the following conditions apply: VIN = 48V, CIN is a 2.2µF 100V X7R ceramic capacitor for driving 5–13 power LEDs with ILED = 350mA. Single LED forward voltage used is 3.2V. TA = 25°C for efficiency curves and waveforms. ILED vs VIN VLED = 0V, DIM = open IIN vs VIN VLED = 0V, DIM = open 1000 100 TJ=-40°C 80 TJ=25°C 600 IIN(mA) ILED(mA) 800 TJ=125°C 400 TJ=125°C 60 TJ=-40°C 40 TJ=25°C 200 20 0 0 0 10 20 30 40 VIN(V) 50 60 0 10 Figure 24. 20 30 VIN(V) 40 50 60 Figure 25. ILED vs Dimming Duty Ratio ILED vs Dimming Duty Ratio 100 1.0 90 VIN=48V(8LED) 80 0.8 VIN=36V(6LED) 60 ILED(%) ILED(%) 70 50 40 VIN=48V(8LED) 0.6 0.4 30 20 VIN=60V(11LED) 0.2 10 VIN=60V(11LED) VIN=36V(6LED) 0 0.0 0 10 20 30 40 50 60 70 80 90 100 DIM DUTY RATIO (%) 0.0 0.2 0.4 0.6 0.8 DIM DUTY RATIO (%) Figure 26. Figure 27. Frequency Deviation vs VIN (800kHz) ILED Regulation vs Temperature 3 3 2 2 TJ=-40°C 1 ILEDREGULATION (%) FREQUENCY DEVIATION (%) 1.0 TJ=25°C 0 -1 -2 VIN=48V(8LED) 1 0 -1 V =60V(11LED) IN -2 TJ=125°C VIN=36V(6LED) -3 -3 20 25 30 35 40 45 VIN(V) 50 55 60 -50 Figure 28. -25 0 25 50 75 TEMPERATURE (°C) 100 125 Figure 29. Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: TPS92551 TPS92551EVM Submit Documentation Feedback 9 TPS92551, TPS92551EVM SNVS805C – MAY 2012 – REVISED MAY 2013 www.ti.com TYPICAL PERFORMANCE CHARACTERISTICS (continued) Unless otherwise specified, the following conditions apply: VIN = 48V, CIN is a 2.2µF 100V X7R ceramic capacitor for driving 5–13 power LEDs with ILED = 350mA. Single LED forward voltage used is 3.2V. TA = 25°C for efficiency curves and waveforms. ILED vs RIADJ RVREF = open ILED vs RVREF RIADJ =0Ω 450 350 425 ILED(mA) ILED(mA) 340 330 320 400 375 310 300 350 0 100 200 300 RIADJ( ) 400 500 0 Figure 30. 10 Submit Documentation Feedback 20 40 60 RVREF(k ) 80 100 Figure 31. Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: TPS92551 TPS92551EVM TPS92551, TPS92551EVM www.ti.com SNVS805C – MAY 2012 – REVISED MAY 2013 BLOCK DIAGRAM 1,2 LED+ Voltage Regulator 1 PF 47 PH 7 LED- High power LED Array 0.33 PF VCC VIN 4.5V to 60V CIN 4 EP Switch Control logic 4 GND 6 IADJ 3k 5 VREF VCC 3 DIM + - 1.2V OPERATION DESCRIPTION The TPS92551 is a high power floating buck LED driver with wide input voltage range. It requires no external current sensing elements and loop compensation network. The integrated power switch enables high output power up to 23W with 450mA LED current. High speed dimming control input allows precision and high resolution brightness control for applications which require fine brightness adjustment. Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: TPS92551 TPS92551EVM Submit Documentation Feedback 11 TPS92551, TPS92551EVM SNVS805C – MAY 2012 – REVISED MAY 2013 www.ti.com APPLICATION INFORMATION SETTING THE LED CURRENT The TPS92551 requires no external current sensing resistor for LED current regulation. The average LED current of the TPS92551 is adjustable from 300mA to 450mA by varying the resistance of the resistor according to the following equation and table. For RVREF = open and RIADJ = 10.5kΩ ILED 1050 3k / /R VREF (2) Table 1. Example for ILED Setting RIADJ(Ω) RVREF(Ω) ILED(mA) 499 OPEN 300 SHORT OPEN 350 SHORT 10.5k 450 TPS92551 EP 6 7 IADJ LED- VREF GND DIM LED+ 5 LED+ 4 2 3 1 RIADJ RVREF CIN ILED High Power LED String IIN VIN Figure 32. TPS92551 Application Schematic for ILED Setting Minimum Switch On-Time The on-time of the internal switch should be no shorter than 400ns. The number of LED (typical forward voltage at 3.2V) to input voltage is constrained by that as shown in the following table. 12 Submit Documentation Feedback No. of LED Max. VIN(V) 1 10 2 20 3 30 4 40 5 50 6 – 16 60 Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: TPS92551 TPS92551EVM TPS92551, TPS92551EVM www.ti.com SNVS805C – MAY 2012 – REVISED MAY 2013 Peak Switch Current Limit The TPS92551 features an integrated switch current limiting mechanism to prevent the LEDs from being overdriven. The switch current limiter is triggered when the switch current is three times exceeding the current level set by resistor. Once the current limiter is triggered, the internal power switch turn OFF for 3.6µs to discharge the inductor until inductor current reduces back to normal level. The current limiting feature is exceptionally important to avoid permanent damage of the TPS92551 application circuit due to short circuit of LED string. PWM Dimming Control The DIM pin of the TPS92551 is an input with internal pull-up that accepts logic signals for average LED current control. Applying a logic high (above 1.3V) signal to the DIM pin or leaving the DIM pin open will enable the device. Applying a logic low signal (below 0.7V) to the DIM pin will disable the switching activity of the device but maintain operation of the VCC regulator active. The TPS92551 operation of high speed dimming and very fine dimming control as shown in Figure 33. Figure 33. Shortened Current Slew up Time of the TPS92551 To ensure normal operation of the TPS92551, it is recommended to set the dimming frequency not higher than 1/10 of the switching frequency. The dim pulse on time is tested down to 16µs. In applications that require high dimming contrast ratio, low dimming frequency should be used. Parallel Operation When a load current higher than 450mA is required by the application, TPS92551 can be used in parallel to deliver higher current. With common VINs and GNDs, the TPS92551 will operate as independent asynchronous current sinks driving the same LED load. The total DC current of the modules will be additive; however, low frequency sub-harmonic current ripple may be present and its frequency and magnitude will depend upon the phase relationship between the internal clocks as there is no provision for synchronizing driver clocks. It is suggested to have minimum 2.2μF COUT located close the module to filter out the current ripple , and the resultant LED current will become DC. Current sharing modules should have a local CIN capacitor of minimum 2.2μF located as close to VIN and GND as possible. Refer to Figure 33 for the TPS92551 parallel operation circuit schematic. Refer to Figure 35 for the TPS92551 parallel operation results ILED vs VIN. Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: TPS92551 TPS92551EVM Submit Documentation Feedback 13 TPS92551, TPS92551EVM SNVS805C – MAY 2012 – REVISED MAY 2013 www.ti.com VIN ILED1 COUT IADJ 6 LED- 7 VREF 5 DIM 3 LED+ 1 LED+ 2 COUT LED- 7 VREF 5 IADJ 6 DIM 3 GND 4 GND 4 EP EP LED+ 1 LED+ 2 ILED TPS92551 High Power LED String TPS92551 ILED2 CIN CIN Figure 34. Parallel Operation Circuit Schematic for ILED = 900mA 1.0 0.9 9LED 0.8 1LED 16LED ILED(A) 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 0 10 20 30 VIN(V) 40 50 60 Figure 35. Parallel Operation Results for ILED = 900mA, ILED vs VIN PC Board Layout Considerations The overall performance of the LED driver is highly depends on the PCB layout. Poor board layout can disrupt the performance of the TPS92551 and surrounding circuitry by contributing to EMI, ground bounce and resistive voltage drop in the traces. These can send erroneous signals to the LED driver resulting in poor regulation and stability. Good layout can be implemented by following a few simple design rules. 1. Place CIN as close as possible to the VIN pin and GND exposed pad (EP). 2. Place COUT (optional for reduction of LED current ripple and EMI compliance) as close as possible to the VLED+ pin and VLED- pin. 3. The exposed pad (EP) must connect to the GND pin directly. EMI Design Considerations From an EMI reduction standpoint, it is imperative to minimize the di/dt current paths (refer to Figure 36). Therefore, it is essential to connect an 2.2µF capacitor (COUT) across the LED+ pin and LED- pin. This will minimize the ripple current so that it can reduce radiated EMI (refer to Figure 37 and Figure 38). 14 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: TPS92551 TPS92551EVM TPS92551, TPS92551EVM www.ti.com SNVS805C – MAY 2012 – REVISED MAY 2013 High power LED Array COUT di/dt Loop 2 VIN LED+ LED- TPS92551 CIN Loop1 GND Figure 36. Current Loops Figure 37. Complies with EN55015 Radiated Emissions (HORI. / HEIGHT=3.0m / RANGE=10m) CIN = 2.2uF, COUT = 2.2µF, VIN = 60V, ILED = 350mA, No. of LED = 16 Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: TPS92551 TPS92551EVM Submit Documentation Feedback 15 TPS92551, TPS92551EVM SNVS805C – MAY 2012 – REVISED MAY 2013 www.ti.com Figure 38. Complies with EN55015 Radiated Emissions (VERT. / HEIGHT=1.0m / RANGE=10m) CIN = 2.2uF, COUT = 2.2µF, VIN = 60V , ILED = 350mA, No. of LED = 16 TPS92551 Application Circuit Schematic and BOM High power LED Array U1 VIN 1,2 7 LED+ LED- TPS92551 CIN 2.2 PF 100V 3 PWM Dimming Signal DIM IADJ 6 GND 4,EP VREF 5 Table 2. Bill of Materials, VIN = 48V , ILED = 350mA, No. of LED = 5 –13 16 Designator Description Case Size Manufacturer U1 CIN LED Micro-Module Driver PFM 2.2 µF, 100V, X7R 1210 Submit Documentation Feedback Manufacturer P/N Quantity Texas Instruments TPS92551TZ 1 Murata GRM32ER72A225KA35L 1 Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: TPS92551 TPS92551EVM TPS92551, TPS92551EVM www.ti.com SNVS805C – MAY 2012 – REVISED MAY 2013 High power LED Array COUT 2.2 PF 100V U1 VIN 1,2 7 LED+ LED- TPS92551 CIN 2.2 PF 100V 3 PWM Dimming Signal DIM IADJ 6 GND 4,EP VREF 5 Table 3. Bill of Materials, VIN = 60V , ILED = 350mA , No.of LED = 16, Complies with EN55015 Radiated Emissions Designator Description Case Size Manufacturer Manufacturer P/N Quantity U1 LED Micro-Module Driver PFM Texas Instruments TPS92551TZ 1 CIN 2.2 µF, 100V, X7R 1210 Murata GRM32ER72A225KA35L 1 COUT 2.2 µF, 100V, X7R 1210 Murata GRM32ER72A225KA35L 1 Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: TPS92551 TPS92551EVM Submit Documentation Feedback 17 TPS92551, TPS92551EVM SNVS805C – MAY 2012 – REVISED MAY 2013 www.ti.com PCB Layout Diagrams The PCB design is available in the TPS92551 product folder at www.ti.com. Figure 39. Top Layer and Top Overlay Figure 40. Bottom Layer and Bottom Overlay 18 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: TPS92551 TPS92551EVM TPS92551, TPS92551EVM www.ti.com SNVS805C – MAY 2012 – REVISED MAY 2013 Figure 41. Top Overlay Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: TPS92551 TPS92551EVM Submit Documentation Feedback 19 TPS92551, TPS92551EVM SNVS805C – MAY 2012 – REVISED MAY 2013 www.ti.com REVISION HISTORY Changes from Revision B (May 2013) to Revision C • 20 Page Changed layout of National Data Sheet to TI format .......................................................................................................... 19 Submit Documentation Feedback Copyright © 2012–2013, Texas Instruments Incorporated Product Folder Links: TPS92551 TPS92551EVM PACKAGE OPTION ADDENDUM www.ti.com 16-Jul-2020 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (°C) Device Marking (3) (4/5) (6) TPS92551TZ/NOPB ACTIVE TO-PMOD NDW 7 250 RoHS Exempt & Green SN Level-3-245C-168 HR -40 to 125 TPS92551 TZ TPS92551TZX/NOPB ACTIVE TO-PMOD NDW 7 500 RoHS Exempt & Green SN Level-3-245C-168 HR -40 to 125 TPS92551 TZ (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) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of