MPM6010GQV-P

MPM6010 The Future of Analog IC Technology DESCRIPTION 36V, 1.5A, High-Efficiency Module, Synchronous, Step-Down LED Driver with Integrated Inductor AEC-Q100 Qualified FEATURES The MPM6010 is a synchronous, rectified, stepdown, LED driver with built-in power MOSFETs, inductor, and two capacitors. The MPM6010 offers a very compact solution with only four external components to achieve 1.5A of continuous output current with excellent load and line regulation over a wide input supply range. The MPM6010 uses synchronous mode operation to achieve high efficiency.    The MPM6010 eliminates design and manufacturing risks while improving the time to market dramatically.     Full protection features include over-current protection (OCP) and thermal shutdown. The MPM6010 is available in a space-saving QFN-17 (3mmx5mmx1.6mm) package.         Complete Switch Mode Power Supply Wide 4V to 36V Operating Input Range 85mΩ/50mΩ Low RDS(ON) Internal Power MOSFETs High-Efficiency Synchronous Mode Operation Default 2.2MHz Switching Frequency PWM Dimming (Min 100Hz Dimming Frequency) Forced Continuous Conduction Mode (CCM) 0.2V Reference Voltage Internal Soft Start Fault Indication for LED Short, Open, and Thermal Shutdown Over-Current Protection (OCP) with ValleyCurrent Detection Thermal Shutdown Available in a QFN-17 (3mmx5mmx1.6mm) Package Available Wettable Flank AEC-Q100 Grade1 APPLICATIONS  Automotive LED Lighting All MPS parts are lead-free, halogen-free, and adhere to the RoHS directive. For MPS green status, please visit MPS website under Quality Assurance. “MPS” and “The Future of Analog IC Technology” are registered trademarks of Monolithic Power Systems, Inc. TYPICAL APPLICATION 95 90 85 80 75 70 65 60 55 50 0 0.5 MPM6010 Rev. 1.0 www.MonolithicPower.com 7/7/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 1 1.5 1 MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE ORDERING INFORMATION Part Number* MPM6010GQV MPM6010GQV-AEC1 MPM6010GQVE-AEC1** Package QFN-17 (3mmx5mmx1.6mm) QFN-17 (3mmx5mmx1.6mm) QFN-17 (3mmx5mmx1.6mm) Top Marking See Below See Below See Below * For Tape & Reel, add suffix –Z (e.g. MPM6010GQV–Z) ** Wettable Flank TOP MARKING (MPM6010GQV & MPM6010GQV-AEC1) MP: MPS prefix Y: Year code W: Week code 6010: First four digits of the part number LLL: Lot number M: Module TOP MARKING (MPM6010GQVE-AEC1) MP: MPS prefix Y: Year code W: Week code 6010: First four digits of the part number LLL: Lot number E: Wettable lead flank M: Module MPM6010 Rev. 1.0 www.MonolithicPower.com 7/7/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 2 MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE PACKAGE REFERENCE TOP VIEW QFN-17 (3mmx5mmx1.6mm) ABSOLUTE MAXIMUM RATINGS (1) Thermal Resistance VIN ................................................... -0.3V to 40V VSW, VOUT............................... -0.3V to VIN + 0.3V VBST ...................................................... VSW + 6V (2) All other pins ................................ -0.3V to 6V (3) Continuous power dissipation (TA = +25°C) ................................................................... 2.7W Junction temperature ................................150°C Lead temperature .....................................260°C Storage temperature .................. -65°C to 150°C QFN-17 (3mmx5mmx1.6mm) ... 46 .... 10 ... °C/W Recommended Operating Conditions Supply voltage (VIN) ............................ 4V to 36V LED current (ILED) ............................... Up to 1.5A Operating junction temp. (TJ). .. -40°C to +125°C (4) θJA θJC NOTES: 1) Exceeding these ratings may damage the device. 2) For details on EN/DIM’s ABS MAX rating, please refer to the Enable Control section on page 14. 3) The maximum allowable power dissipation is a function of the maximum junction temperature TJ (MAX), the junction-toambient thermal resistance θJA, and the ambient temperature TA. The maximum allowable continuous power dissipation at any ambient temperature is calculated by PD (MAX) = (TJ (MAX)-TA)/θJA. Exceeding the maximum allowable power dissipation produces an excessive die temperature, causing the regulator to go into thermal shutdown. Internal thermal shutdown circuitry protects the device from permanent damage. 4) Measured on JESD51-7, 4-layer PCB. MPM6010 Rev. 1.0 www.MonolithicPower.com 7/7/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 3 MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE ELECTRICAL CHARACTERISTICS VIN = 12V, VEN = 2V, TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TJ = +25°C. Parameter Supply current (shutdown) Symbol ISHDN Supply current (quiescent) IQ HS switch on resistance LS switch on resistance Inductor DC resistance Switch leakage Current limit (5) Reverse current limit Oscillator frequency Maximum duty cycle Minimum on time (5) HSRDS(ON) LSRDS(ON) LDCR SWLKG ILIMIT fSW DMAX TON MIN Feedback voltage VFB Feedback current IFB Condition VEN = 0V VEN = 2V, VFB = 1V, no switching VBST-SW = 5V VCC = 5V VEN = 0V, VSW = 12V Under 40% duty cycle Min 2.5 VFB = 100mV VFB = 100mV 1800 80 TA = +25°C TA = -40°C to +125°C VFB = 250mV 192 184 Typ 12 Max Units μA 0.6 0.8 mA 85 50 75 150 105 208 216 100 mΩ mΩ mΩ μA A A kHz % ns mV mV nA 4 1.2 2200 87 46 200 200 30 1 5.5 2600 EN/DIM rising threshold VEN_RISING 1.1 1.45 1.8 V EN/DIM falling threshold VEN_FALLING 0.7 1 1.3 V EN/DIM threshold hysteresis VEN_HYS EN/DIM input current IEN EN/DIM turn-off delay ENTd-off INUVVth VIN under-voltage lockout threshold rising VIN under-voltage lockout threshold hysteresis Over-voltage detection (/FAULT pulled low) Over-voltage detection hysteresis /FAULT delay /FAULT sink current capability /FAULT leakage current VCC regulator VCC load regulation Soft-start time (5) 450 VEN = 2V mV 5 10 μA 10 25 50 ms 3.2 3.5 3.8 V INUVHYS 400 mV FTth-Hi 140% VFB 20% VFB 10 μs FTTd VFT IFT-LEAK VCC tSS Sink 4mA ICC = 0mA ICC = 5mA 4.6 ILED = 1.5A, load = 2 series LED, ILED from 10% to 90% Thermal shutdown (5) Thermal hysteresis (5) 150 4.9 1.5 0.4 V 100 5.2 4 nA V % 0.9 ms 170 30 °C °C NOTE: 5) Not tested in production and guaranteed by over-temperature correlation. MPM6010 Rev. 1.0 www.MonolithicPower.com 7/7/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 4 MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE PIN FUNCTIONS Package Pin # Name 1 /FAULT 2 EN/DIM 3 FB 4 VCC 5 AGND 6, 7, 8, 12 SW 9, 10, 11 OUT 13 BST 14, 15 PGND 16 IN 17 NC Description Fault indicator. /FAULT is an open drain output. /FAULT is pulled low when the LED is short, open, or when thermal shutdown is occurring. Enable/dimming control. Pull EN/DIM high to enable the MPM6010. Apply a 100Hz to 2kHz external clock to EN/DIM for PWM dimming. LED current feedback input. Internal 4.9V LDO output. Internal circuits integrate an LDO output capacitor, so there is no need to add an external capacitor to VCC. Analog ground. AGND is the reference ground of the logic circuit. AGND is connected to PGND internally. There is no need to add external connections to PGND. Switch output. Connection is not needed for these SW pins, but a large copper plane is recommended (especially on pin 6, 7, and 8) for better heat sinking. Power output. Connect LED+ to OUT. An output capacitor is needed on OUT. Bootstrap. A bootstrap capacitor is integrated internally. External connections are not required on BST. Power ground. PGND is the reference ground of the power device. PGND requires extra care during PCB layout. For best results, connect PGND with copper pours and vias. Supply voltage. IN supplies power for the internal MOSFET and regulator. The MPM6010 operates from a +4V to +36V input rail. A low ESR and low-inductance capacitor is required to decouple the input rail. Place the input capacitor very close to IN and connect it with wide PCB traces and multiple vias. No connection. NC must be left floating. MPM6010 Rev. 1.0 www.MonolithicPower.com 7/7/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 5 MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE TYPICAL CHARACTERISTICS 0.66 3.6 0.64 3.5 0.62 3.4 0.60 3.3 0.58 3.2 0.56 3.1 0.54 -50 -30 -10 10 30 50 70 90 110130 3.0 -50 -30 -10 10 30 50 70 90 110130 0.2010 0.2008 0.2006 0.2004 0.2002 0.2000 0.1998 0.1996 0.1994 0.1992 0.1990 0.1988 -50 -30 -10 10 30 50 70 90 110130 4.3 4.2 4.1 4.0 3.9 3.8 3.7 3.6 -50 -30 -10 10 30 50 70 90 110130 MPM6010 Rev. 1.0 www.MonolithicPower.com 7/7/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 6 MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE TYPICAL PERFORMANCE CHARACTERISTICS VIN = 12V, Load = 2 series LED, VLED+ - VLED- = 2x3.0V @1.5A, FSW = 2.2MHz, TA = +25°C, unless otherwise noted. 95 90 85 95 90 90 85 85 80 75 80 80 75 75 70 70 65 60 55 65 70 60 65 60 0 0.5 1 1.5 55 50 0 0.5 1 1.5 50 45 40 0 0.5 1 1.5 2.3 5 2.1 4.5 1.9 1.7 4 1.5 3.5 1.3 3 0 20 40 60 80 100 1.1 18 19 20 21 22 23 24 25 26 27 28 MPM6010 Rev. 1.0 www.MonolithicPower.com 7/7/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 7 MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, Load = 2 series LED, VLED+ - VLED- = 2x3.0V @1.5A, ILED = 1.5A, FSW = 2.2MHz, with EMI (6) filters, TA = +25°C, unless otherwise noted. CISPR25 Class 5 Peak Radiated Emissions (150kHz - 30MHz) 0.15 5.15 10.15 15.15 20.15 Frequency (MHz) Amplitude (dBuV/m) 100 200 300 400 500 600 700 800 0 400 500 600 700 800 900 100 200 300 400 500 600 Frequency (MHz) 700 1000 50 45 40 35 30 25 20 15 10 5 0 -5 -10 -15 Amplitude (dBuV/m) Amplitude (dBuV/m) 300 Frequency (MHz) 25.15 800 900 1000 CISPR25 Class 5 Average Radiated Emissions (Horizontal, 30MHz - 1GHz) Class 5 Avg 200 20.15 Data Class 5 Peak Class 5 Avg 900 1000 Data Class 5 Peak 100 15.15 50 45 40 35 30 25 20 15 10 5 0 -5 -10 -15 CISPR25 Class 5 Peak Radiated Emissions (Horizontal, 30MHz - 1GHz) 0 10.15 CISPR25 Class 5 Average Radiated Emissions (Vertical, 30MHz - 1GHz) Frequency (MHz) 50 45 40 35 30 25 20 15 10 5 0 -5 -10 -15 5.15 Frequency (MHz) Data Class 5 Peak Class 5 Avg 0 Data Class 5 Peak Class 5 Avg 0.15 25.15 CISPR25 Class 5 Peak Radiated Emissions (Vertical, 30MHz - 1GHz) 50 45 40 35 30 25 20 15 10 5 0 -5 -10 -15 Amplitude (dBuV/m) Data Class 5 Peak Class 5 Avg 50 45 40 35 30 25 20 15 10 5 0 -5 -10 -15 Amplitude (dBuV/m) Amplitude (dBuV/m) 50 45 40 35 30 25 20 15 10 5 0 -5 -10 -15 CISPR25 Class 5 Average Radiated Emissions (150kHz - 30MHz) Data Class 5 Peak Class 5 Avg 0 100 200 300 400 500 600 700 Frequency (MHz) 800 MPM6010 Rev. 1.0 www.MonolithicPower.com 7/7/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 900 1000 8 MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, Load = 2 series LED, VLED+ - VLED- = 2x3.0V @1.5A, ILED = 1.5A, FSW = 2.2MHz, with EMI (6) filters, TA = +25°C, unless otherwise noted. CISPR25 Class 5 Peak Conducted Emissions (150kHz -108MHz) CISPR25 Class 5 Average Conducted Emissions (150kHz - 108MHz) 80 80 70 70 60 60 50 40 Grenzwertlinie Leitungsgebunden B NN EN 55025 P eak Klasse 5 30 Grenzwertlinie Leitungsgebunden B NN EN 55025 QP Klasse 5 Pegel indBµV Pegel indBµV 50 40 Grenzwertlinie Leitungsgebunden B NN EN 55025 QP Klasse 5 20 20 10 10 0 0 -10 -10 150k 300 400500 8001M 2M 3M 4M5M 6 8 10M 20M 30M 40 50 60 80 108M Grenzwertlinie Leitungsgebunden B NN EN 55025 P eak Klasse 5 30 150k 300 400500 8001M Frequenz in Hz 2M 3M 4M5M 6 8 10M 20M 30M 40 50 60 80 108M Frequenz in Hz NOTE: 6) The EMC test results are based on the application circuit with EMI filters as shown in Figure 9. MPM6010 Rev. 1.0 www.MonolithicPower.com 7/7/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 9 MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, Load = 2 series LED, VLED+ - VLED- = 2x3.0V @1.5A, FSW = 2.2MHz, TA = +25°C, unless otherwise noted. VSW 5V/div. VSW 5V/div. VOUT/AC 10mV/div. VOUT/AC 10mV/div. IL 500mA/div. IL 1A/div. VIN 5V/div. VOUT 5V/div. VIN 5V/div. VOUT 5V/div. VSW 5V/div. VSW 5V/div. IL 500mA/div. IL 2A/div. VIN 5V/div. VOUT 5V/div. VSW 5V/div. IL 500mA/div. VIN 5V/div. VOUT 5V/div. VSW 5V/div. IL 1A/div. VEN 2V/div. VOUT 10V/div. VEN 2V/div. VOUT 5V/div. VEN 2V/div. VSW 5V/div. VSW 5V/div. VSW 5V/div. IL 1A/div. IL 2A/div. IL 2A/div. VOUT 5V/div. MPM6010 Rev. 1.0 www.MonolithicPower.com 7/7/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 10 MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, Load = 2 series LED, VLED+ - VLED- = 2x3.0V @1.5A, FSW = 2.2MHz, TA = +25°C, unless otherwise noted. VEN 2V/div. VEN 2V/div. FAULT 5V/div. FAULT 5V/div. VSW 5V/div. VSW 5V/div. IL 2A/div. IL 2A/div. FAULT 2V/div. VOUT 2V/div. VSW 5V/div. IL 2A/div. FAULT 2V/div. FAULT 5V/div. VOUT 10V/div. VOUT 5V/div. FAULT 5V/div. VOUT 10V/div. VSW 5V/div. VSW 5V/div. VSW 5V/div. IL 2A/div. IL 2A/div. VOUT 5V/div. FAULT 5V/div. IL 5A/div. VSW 5V/div. VIN 5V/div. VSW 10V/div. VOUT 5V/div. VIN 5V/div. VSW 5V/div. VOUT 2V/div. IL 2A/div. IL 2A/div. IL 2A/div. MPM6010 Rev. 1.0 www.MonolithicPower.com 7/7/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 11 MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, Load = 2 series LED, VLED+ - VLED- = 2x3.0V @1.5A, FSW = 2.2MHz, TA = +25°C, unless otherwise noted. FAULT 5V/div. VEN 2V/div. VEN 2V/div. VSW 5V/div. VOUT 2V/div. VSW 5V/div. VOUT 2V/div. IL 2A/div. IL 2A/div. IL 2A/div. FAULT 5V/div. VSW 10V/div. VSW 10V/div. FAULT 5V/div. FAULT 5V/div. ILED 1A/div. ILED 1A/div. IL 1A/div. IL 1A/div. VSW 5V/div. VOUT 5V/div. IL 2/div. VOUT 5V/div. VSW 5V/div. MPM6010 Rev. 1.0 www.MonolithicPower.com 7/7/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 12 MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE BLOCK DIAGRAM Figure 1: Functional Block Diagram MPM6010 Rev. 1.0 www.MonolithicPower.com 7/7/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 13 MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE OPERATION The MPM6010 is a high-frequency, synchronous, rectified, step-down, switch-mode, white LED driver with built-in power MOSFETs, integrated inductor, and two capacitors. The MPM6010 offers a very compact solution that achieves 1.5A of continuous output current with excellent load and line regulation over a 4V to 36V input supply range. The MPM6010 operates in a fixed-frequency, peak-current-control mode to regulate the output current. An internal clock initiates a pulse-width modulation (PWM) cycle. The integrated high-side power MOSFET (HS-FET) turns on and remains on until its current reaches the value set by the COMP voltage (VCOMP). When the power switch is off, it remains off until the next clock cycle starts. If the current in the power MOSFET does not reach the current value set by VCOMP within 87% of one PWM period, the power MOSFET is forced off. Internal Regulator A 4.9V internal regulator powers most of the internal circuitries. This regulator takes VIN as the input and operates in the full VIN range. When VIN exceeds 4.9V, the output of the regulator is in full regulation. When VIN is less than 4.9V, the output decreases following VIN. The MPM6010 integrates an internal decoupling capacitor, so there is no need to add an external VCC output capacitor. CCM Operation The MPM6010 uses continuous conduction mode (CCM) to ensure that the part works with fixed frequency from a no-load to full-load range. The advantage of CCM is the controllable frequency and lower output ripple at light load. Frequency Foldback The MPM6010 enters frequency foldback when the input voltage is higher than about 21V. The frequency decreases to half the nominal value and changes to 1.1MHz. Error Amplifier (EA) The error amplifier compares the FB voltage to the internal 0.2V reference (VREF) and outputs a current proportional to the difference between the two. This output current then charges or discharges the internal compensation network to form VCOMP, which controls the power MOSFET current. The optimized internal compensation network minimizes the external component count and simplifies the control loop design. Under-Voltage Lockout (UVLO) Under-voltage lockout (UVLO) protects the chip from operating at an insufficient supply voltage. The UVLO comparator monitors the output voltage of the internal regulator (VCC). The UVLO rising threshold is about 3.5V, while its falling threshold is about 3.1V. Enable Control (EN/DIM) EN/DIM is a control pin that turns the regulator on and off. Drive EN/DIM high to turn on the regulator; drive EN/DIM low to turn off the regulator. An internal resistor from EN/DIM to GND allows EN/DIM to be floated to shut down the MPM6010. EN/DIM is clamped internally using a 6.5V series Zener diode (see Figure 2). Connecting EN/DIM through a pull-up resistor to VIN limits the EN/DIM input current to less than 100µA. For example, with 12V connected to VIN, RPULLUP ≥ (12V - 6.5V) ÷ 100µA = 55kΩ. Connecting EN/DIM to a voltage source directly without a pull-up resistor requires limiting the amplitude of the voltage source to ≤6V to prevent damage to the Zener diode. EN/DIM EN/DIM Figure 2: 6.5V Zener Diode Connection Drive EN/DIM low for more than 25ms to shut down the IC. Frequency foldback also occurs during soft start and short-circuit protection. MPM6010 Rev. 1.0 www.MonolithicPower.com 7/7/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 14 MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE PWM Dimming Apply an external, 100Hz to 2kHz, PWM waveform to EN/DIM for PWM dimming. The average LED current is proportional to the PWM duty. The minimum amplitude of the PWM signal is 1.8V. If a dimming signal is applied before the chip starts up, the on time of the dimming signal must be longer than 2ms to ensure that the soft start is finished so the output current can be built. If the dimming signal is applied after the soft start is finished, the 2ms limit is not required. Internal Soft Start (SS) Soft start (SS) prevents the converter output voltage from overshooting during start-up. When the chip starts up, the internal circuitry generates a soft-start voltage (VSS). When VSS is lower than the internal reference (VREF), VSS overrides VREF, so the error amplifier uses VSS as the reference. When VSS exceeds VREF, the error amplifier uses VREF as the reference. Fault Indicator (/FAULT) The MPM6010 has fault indication (/FAULT). /FAULT is the open drain of a MOSFET and should be connected to VCC or another voltage source through a resistor (e.g. 100kΩ). /FAULT is pulled high during normal operation. LED short, open, or thermal shutdown pull /FAULT down to indicate a fault status. Over-Current Protection (OCP) The MPM6010 has cycle-by-cycle, peakcurrent-limit protection with valley-current detection. The inductor current is monitored during the HS-FET on state. If the inductor current exceeds the current limit value set by the COMP high-clamp voltage, the HS-FET turns off immediately. Then the low-side MOSFET (LS-FET) turns on to discharge the energy, and the inductor current decreases. The HS-FET remains off unless the inductor valley current is lower than a certain current threshold (the valley current limit), even though the internal clock pulses high. If the inductor current does not drop below the valley current limit when the internal clock pulses high, the HS-FET misses the clock, and the switching frequency decreases to half the nominal value. Both the peak and valley current limits assist in keeping the inductor current from running away during an overload or short-circuit condition. Thermal Shutdown Thermal shutdown prevents the chip from operating at exceedingly high temperatures. When the die temperatures exceeds 170°C, the entire chip shuts down. When the temperature drops below its lower threshold (typically 140°C), the chip is enabled again. Floating Driver and Bootstrap Charging An internal bootstrap capacitor powers the floating power MOSFET driver. A dedicated internal regulator charges and regulates the bootstrap capacitor voltage to ~5V (see Figure 3). When the voltage between the BST and SW nodes drops below regulation, a PMOS pass transistor connected from VIN to BST turns on. The charging current path is from VIN to BST to SW. The external circuit should provide enough voltage headroom to facilitate charging. As long as VIN is higher than SW significantly, the bootstrap capacitor remains charged. When the HS-FET is on, VIN ≈ VSW, so the bootstrap capacitor cannot be charged. When the LS-FET is on, VIN - VSW reaches its maximum for fast charging. When there is no inductor current, VSW = VOUT, so the difference between VIN and VOUT can charge the bootstrap capacitor. The floating driver has its own UVLO protection with a rising threshold of 2.2V and hysteresis of 150mV. Figure 3: Internal Bootstrap Charging Circuit MPM6010 Rev. 1.0 www.MonolithicPower.com 7/7/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 15 MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE Start-Up and Shutdown If both VIN and EN/DIM exceed their thresholds, the chip starts up. The reference block starts first, generating stable reference voltage and currents, and then the internal regulator is enabled. The regulator provides a stable supply for the remaining circuitries. Three events can shut down the chip: VIN low, EN/DIM low, and thermal shutdown. During the shutdown procedure, the signaling path is blocked first to avoid any fault triggering. VCOMP and the internal supply rail are then pulled down. The floating driver is not subject to this shutdown command. MPM6010 Rev. 1.0 www.MonolithicPower.com 7/7/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 16 MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE APPLICATION INFORMATION Setting the Output Current The output current is set by the external resistor (RFB) (see Figure 4). another lower-value capacitor (e.g. 0.1µF) in a small package (0603) to absorb high-frequency switching noise. Place the smaller capacitor as close to IN and GND as possible. Since CIN absorbs the input switching current, it requires an adequate ripple current rating. The RMS current in the input capacitor can be estimated with Equation (2): ICIN  ILED  RT ICIN  Figure 4: Feedback Network The feedback voltage is 0.2V. Calculate ILED with Equation (1): 0.2V R FB (1) RT is used to set the loop bandwidth. The lower RT is, the higher the bandwidth. However, a high bandwidth may cause insufficient phase margin, resulting in loop instability. A proper value of RT is needed to make a trade-off between bandwidth and phase margin. Table 1 lists the recommended feedback resistor and RT values for common outputs with a 1- or 2series LED. Table 1: Resistor Selection for Common Outputs ILED (A) 0.5 1 1.5 RFB (mΩ) 400 (1%) 200 (1%) 133 (1%) (2) The worst-case condition occurs at VIN = 2VOUT, shown in Equation (3): RFB ILED  VOUT V  (1  OUT ) VIN VIN RT (kΩ) 200 (1%) 150 (1%) 100 (1%) Selecting the Input Capacitor The input current to the step-down converter is discontinuous and therefore requires a capacitor to supply AC current to the converter while maintaining the DC input voltage. Use low ESR capacitors for the best performance. Ceramic capacitors with X5R or X7R dielectrics are highly recommended because of their low ESR and small temperature coefficients. For most applications, use a 4.7µF to 10µF capacitor. It is strongly recommended to use ILED 2 (3) For simplification, choose an input capacitor with an RMS current rating greater than half the maximum load current. The input capacitor can be electrolytic, tantalum, or ceramic. When using electrolytic or tantalum capacitors, add a small, high-quality, ceramic capacitor (e.g. 0.1μF) as close to the IC as possible. When using ceramic capacitors, ensure that they have enough capacitance to provide a sufficient charge to prevent excessive voltage ripple at input. The input voltage ripple caused by capacitance can be estimated with Equation (4): VIN  V V ILED  OUT  (1  OUT ) fSW  CIN VIN VIN (4) Selecting the Output Capacitor The output capacitor maintains the DC output voltage. Ceramic, tantalum, or low ESR electrolytic capacitors are recommended. For best results, use low ESR capacitors to keep the output voltage ripple low. The output voltage ripple can be estimated with Equation (5): VOUT  VOUT V 1  (1  OUT )  (RESR  ) (5) fSW  L VIN 8fSW  COUT Where L is the internal integrated inductor value (2.2µH), and RESR is the equivalent series resistance (ESR) value of the output capacitor. MPM6010 Rev. 1.0 www.MonolithicPower.com 7/7/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 17 MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE For ceramic capacitors, the capacitance dominates the impedance at the switching frequency, and the capacitance causes the majority of the output voltage ripple. For simplification, the output voltage ripple can be estimated with Equation (6): VOUT  VOUT V  (1  OUT ) (6) 8  fSW  L  COUT VIN 2 For tantalum or electrolytic capacitors, the ESR dominates the impedance at the switching frequency. For simplification, the output ripple can be approximated with Equation (7): VOUT  VOUT V  (1  OUT )  RESR fSW  L VIN (7) The characteristics of the output capacitor also affect the stability of the regulation system. The MPM6010 can be optimized for a wide range of capacitance and ESR values. VIN UVLO Setting The MPM6010 has an internal, fixed, undervoltage lockout (UVLO) threshold. The rising threshold is about 3.5V, while the falling threshold is about 3.1V. For applications that require a higher UVLO point, an external resistor divider can be added between IN and EN/DIM to achieve a higher equivalent UVLO threshold (see Figure 5). VIN The UVLO threshold can be calculated with Equation (8) and Equation (9): INUVRISING  (1  R UP )  VEN_RISING 500k//R DOWN INUVFALLING  (1 RUP )  VEN_FALLING (9) 500k//R DOWN (8) Where VEN_RISING = 1.45V, and VEN_FALLING = 1V. When choosing RUP, ensure that it is large enough to limit the current flow into EN/DIM below 100μA. External Bootstrap Diode An external bootstrap diode can enhance the efficiency of the regulator when the duty cycle is high (>65%). A power supply between 2.5V and 5V can be used to power the external bootstrap diode. VCC or VOUT is recommended for this power supply in the circuit (see Figure 6). Figure 6: Optional External Bootstrap Diode to Enhance Efficiency The recommended external BST diode is IN4148. IN R UP EN/DIM RDOWN 500k Figure 5: Adjustable UVLO Using EN/DIM Divider MPM6010 Rev. 1.0 www.MonolithicPower.com 7/7/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 18 MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE PCB Layout Guidelines (7) Efficient PCB layout, especially of the input capacitor placement, is critical for stable operation. For best results, refer to Figure 7 and follow the guidelines below. A four-layer layout is strongly recommended to achieve better thermal performance. 1. Use a large ground plane on PGND. If the bottom layer is a ground plane, add vias near PGND. 2. Ensure that the high-current paths at PGND and IN have short, direct, and wide traces. 3. Place the ceramic input capacitor, especially the small package (0603) input bypass capacitor as close to IN and PGND as possible to minimize high-frequency noise. 4. Keep the connection of the input capacitor and IN as short and wide as possible. 5. Place the feedback resistors close to the chip to ensure the trace which connects to FB is as short as possible. 6. Use multiple vias to connect the power planes to the internal layers. Top Layer Inner Layer 1 Inner Layer 2 Bottom Layer Figure 7: Recommended PCB Layout NOTE: 7) The recommended layout is based on Figure 8. MPM6010 Rev. 1.0 www.MonolithicPower.com 7/7/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 19 MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE TYPICAL APPLICATION CIRCUITS Figure 8: Typical Application Circuit for ILED = 1.5A Figure 9: Application Circuit with EMI Filters for ILED = 1.5A MPM6010 Rev. 1.0 www.MonolithicPower.com 7/7/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 20 MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE PACKAGE INFORMATION QFN-17 (3mmx5mmx1.6mm) Non-Wettable Flank MPM6010 Rev. 1.0 www.MonolithicPower.com 7/7/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 21 MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE PACKAGE INFORMATION (continued) QFN-17 (3mmx5mmx1.6mm) Wettable Flank NOTICE: The information in this document is subject to change without notice. Users should warrant and guarantee that third party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS will not assume any legal responsibility for any said applications. MPM6010 Rev. 1.0 www.MonolithicPower.com 7/7/2017 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 22