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MPM6010 36V, 1.5A, High-Efficiency Module, Synchronous, Step-Down LED Driver with Integrated Inductor AEC-Q100 Qualified MPM6010 Rev. 1.0 www.MonolithicPower.com 1 7/7/2017 MPS Proprietary Information. Patent Protec ted. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. The Future of Analog IC Technology
DESCRIPTION
The MPM6010 is a synchronous, rectified, step- down, 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.
FEATURES
Complete Switch Mode Power Supply Wide 4V to 36V Operating Input Range 85m Ω/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 Valley- Current 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 0 1 1.5 0.5
MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE MPM6010 Rev. 1.0 www.MonolithicPower.com 2 7/7/2017 MPS Proprietary Information. Patent Protec ted. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved.
ORDERING INFORMATION
Part Number* Package Top Marking MPM6010GQV QFN-17 (3mmx5mmx1.6mm) See Below MPM6010GQV-AEC1 QFN-17 (3mmx5mmx1.6mm) See Below MPM6010GQVE-AEC1** QFN-17 (3mmx5mmx1.6mm) 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 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE MPM6010 Rev. 1.0 www.MonolithicPower.com 3 7/7/2017 MPS Proprietary Information. Patent Protec ted. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. PACKAGE REFERENCE TOP VIEW QFN-17 (3mmx5mmx1.6mm) ABSOLUTE MAXIMUM RATINGS (1) Continuous power dissipation (TA = +25°C) (3) Recommended Operating Conditions Operating junction temp. (TJ). .. -40°C to +125°C Thermal Resistance (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 powe r dissipation is a function o f the maximum junction temperature T J (MAX), the junction-to- ambient thermal resistance θJA, and the ambient temperature TA. The maximum allowable cont inuous power dissipation at any ambient temperature is calculated by P D (MAX) = (T J (MAX)-TA)/θJA. Exceeding the maximum allowable powe r 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 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE MPM6010 Rev. 1.0 www.MonolithicPower.com 4 7/7/2017 MPS Proprietary Information. Patent Protec ted. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved.
ELECTRICAL CHARACTERISTICS
VIN = 12V, V EN = 2V, TJ = -40°C to +125°C, unless otherwise noted. Typical values are at T J = +25°C. Parameter Symbol Condition Min Typ Max Units Supply current (shutdown) I SHDN V EN = 0V 12 μA Supply current (quiescent) I Q VEN = 2V, VFB = 1V, no switching 0.6 0.8 mA HS switch on resistance HS RDS(ON) V BST-SW = 5V 85 150 m Ω LS switch on resistance LS RDS(ON) V CC = 5V 50 105 m Ω Inductor DC resistance L DCR 75 m Ω Switch leakage SW LKG V EN = 0V, VSW = 12V 1 μA Current limit (5) I LIMIT Under 40% duty cycle 2.5 4 5.5 A Reverse current limit 1.2 A Oscillator frequency f SW V FB = 100mV 1800 2200 2600 kHz Maximum duty cycle D MAX V FB = 100mV 80 87 % Minimum on time (5) T ON MIN 46 ns Feedback voltage V FB TA = +25°C 192 200 208 mV TA = -40°C to +125°C 184 200 216 mV Feedback current I FB V FB = 250mV 30 100 nA EN/DIM rising threshold V EN_RISING 1.1 1.45 1.8 V EN/DIM falling threshold V EN_FALLING 0.7 1 1.3 V EN/DIM threshold hysteresis V EN_HYS 450 mV EN/DIM input current I EN V EN = 2V 5 10 μA EN/DIM turn-off delay EN Td-off 10 25 50 ms VIN under-voltage lockout threshold rising INUVVth 3.2 3.5 3.8 V VIN under-voltage lockout threshold hysteresis INUVHYS 400 mV Over-voltage detection (/FAULT pulled low) FTth-Hi 140% V FB Over-voltage detection hysteresis 20% V FB /FAULT delay FT Td 10 μs /FAULT sink current capability VFT Sink 4mA 0.4 V /FAULT leakage current I FT-LEAK 100 nA VCC regulator V CC I CC = 0mA 4.6 4.9 5.2 V VCC load regulation I CC = 5mA 1.5 4 % Soft-start time (5) t SS ILED = 1.5A, load = 2 series LED, ILED from 10% to 90% 0.9 ms Thermal shutdown (5) 150 170 °C Thermal hysteresis (5) 3 0 ° C NOTE: 5) Not tested in production and guaranteed by over-temperature correlation.
MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE MPM6010 Rev. 1.0 www.MonolithicPower.com 5 7/7/2017 MPS Proprietary Information. Patent Protec ted. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. PIN FUNCTIONS Package Pin # Name Description 1 /FAULT Fault indicator. /FAULT is an open drain output. /FAULT is pulled low when the LED is short, open, or when thermal shutdown is occurring. 2 EN/DIM Enable/dimming control. Pull EN/DIM high to enable the MPM6010. Apply a 100Hz to 2kHz external clock to EN/DIM for PWM dimming. 3 FB LED current feedback input. 4 VCC Internal 4.9V LDO output. Internal circuits integrate an LDO output capacitor, so there is no need to add an external capacitor to VCC. 5 AGND 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. 6, 7, 8, 12 SW 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. 9, 10, 11 OUT Power output. Connect LED+ to OUT. An output capacitor is needed on OUT. 13 BST Bootstrap. A bootstrap capacitor is integrated inte rnally. External connections are not required on BST. 14, 15 PGND 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. 16 IN 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 ra il. Place the input capacitor very close to IN and connect it with wide PCB traces and multiple vias. 17 NC No connection. NC must be left floating.
MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE MPM6010 Rev. 1.0 www.MonolithicPower.com 6 7/7/2017 MPS Proprietary Information. Patent Protec ted. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. TYPICAL CHARACTERISTICS 0.54 0.58 0.56 0.60 0.62 0.64 0.66 -50 -30 -10 10 30 50 70 90 110130 -50 -30 -10 10 30 50 70 90 110130 3.0 3.1 3.2 3.3 3.4 3.5 3.6 -50 -30 -10 10 30 50 70 90 110130 -50 -30 -10 10 30 50 70 90 110130 3.6 3.7 3.8 3.9 4.0 4.1 4.2 4.3 0.1988 0.1990 0.1992 0.1994 0.1996 0.1998 0.2000 0.2002 0.2004 0.2006 0.2008 0.2010
MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE MPM6010 Rev. 1.0 www.MonolithicPower.com 7 7/7/2017 MPS Proprietary Information. Patent Protec ted. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. TYPICAL PERFORMANCE CHARACTERISTICS VIN = 12V, Load = 2 series LED, V LED+ - VLED- = 2x3.0V @1.5A, F SW = 2.2MHz, T A = +25°C, unless otherwise noted. 0 1 1.5 0.5 0 1 1.5 0.5 0 1 1.5 0.5 3.5 4.5 0 2 04 06 08 0 1 0 0 1.1 1.3 1.5 1.7 1.9 2.1 2.3 18 19 20 21 22 23 24 25 26 27 28
MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE MPM6010 Rev. 1.0 www.MonolithicPower.com 8 7/7/2017 MPS Proprietary Information. Patent Protec ted. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, Load = 2 series LED, V LED+ - VLED- = 2x3.0V @1.5A, I LED = 1.5A, F SW = 2.2MHz, with EMI filters, TA = +25°C, unless otherwise noted. (6) CISPR25 Class 5 Peak Radiated Emissions CISPR25 Class 5 Average Radiated Emissions (150kHz - 30MHz) (150kHz - 30MHz) -15 -10 Frequency (MHz) Amplitude (dBuV/m) Data Class 5 Peak C lass 5 Avg -15 -10 Frequency (MHz) Amplitude (dBuV/m) Data Class 5 Peak C lass 5 Avg CISPR25 Class 5 Peak Radiated Emissions CISPR25 Class 5 Average Radiated Emissions (Vertical, 30MHz - 1GHz) (Vertical, 30MHz - 1GHz) -15 -10 0 100 200 300 400 500 600 700 800 900 1000 Frequency (MHz) Amplitude (dBuV/m) Data Class 5 Peak Class 5 Avg -15 -10 0 100 200 300 400 500 600 700 800 900 1000 Frequency (MHz) Amplitude (dBuV/m) Data Class 5 Peak C lass 5 Avg CISPR25 Class 5 Peak Radiated Emissions CISPR25 Class 5 Average Radiated Emissions (Horizontal, 30MHz - 1GHz) (Horizontal, 30MHz - 1GHz) -15 -10 0 100 200 300 400 500 600 700 800 900 1000 Frequency (MHz) Amplitude (dBuV/m) Data Class 5 Peak C lass 5 Avg -15 -10 0 100 200 300 400 500 600 700 800 900 1000 Frequency (MHz) Amplitude (dBuV/m) Data Class 5 Peak Class 5 Avg
MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE MPM6010 Rev. 1.0 www.MonolithicPower.com 9 7/7/2017 MPS Proprietary Information. Patent Protec ted. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, Load = 2 series LED, V LED+ - VLED- = 2x3.0V @1.5A, I LED = 1.5A, F SW = 2.2MHz, with EMI filters, TA = +25°C, unless otherwise noted. (6) CISPR25 Class 5 Peak Conducted Emissions CISPR25 Class 5 Average Conducted Emissions (150kHz -108MHz) (150kHz - 108MHz) -1 0 1 50k 300 400500 8001 M 2M 3M 4M5M 6 8 1 0M 20M 30M 40 5060 80 10 8 M Pegel in dBµV Frequenz in Hz Grenzwertlinie Leitungsgebunden BNN EN 55025 Peak Klasse 5 Grenzwertlinie Leitungsgebunden BNN EN 55025 QP Klasse 5 -1 0 1 50k 300 400500 8001 M 2M 3M 4M5M 6 8 1 0M 20M 30M 40 5060 80 10 8 M Pegel i n dBµV Frequenz in Hz Grenzwertlinie Leitungsgebunden BNN EN 55025 Peak Klasse 5 Grenzwertlinie Leitungsgebunden BNN EN 55025 QP Klasse 5 NOTE: 6) The EMC test results are based on the application circuit with EMI filters as shown in Figure 9.
MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE MPM6010 Rev. 1.0 www.MonolithicPower.com 10 7/7/2017 MPS Proprietary Information. Patent Protec ted. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, Load = 2 series LED, V LED+ - VLED- = 2x3.0V @1.5A, F SW = 2.2MHz, T A = +25°C, unless otherwise noted. VOUT/AC 10mV/div. VSW 5V/div. IL 500mA/div. VOUT/AC 10mV/div. VSW 5V/div. IL 1A/div. VOUT 5V/div. VSW 5V/div. VIN 5V/div. IL 500mA/div. VOUT 5V/div. VSW 5V/div. VIN 5V/div. IL 500mA/div. VOUT 10V/div. VSW 5V/div. VEN 2V/div. IL 1A/div. VOUT 5V/div. VSW 5V/div. VEN 2V/div. IL 2A/div. VOUT 5V/div. VSW 5V/div. VIN 5V/div. IL 1A/div. VOUT 5V/div. VSW 5V/div. VIN 5V/div. IL 2A/div. VOUT 5V/div. VSW 5V/div. VEN 2V/div. IL 2A/div.
MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE MPM6010 Rev. 1.0 www.MonolithicPower.com 11 7/7/2017 MPS Proprietary Information. Patent Protec ted. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, Load = 2 series LED, V LED+ - VLED- = 2x3.0V @1.5A, F SW = 2.2MHz, T A = +25°C, unless otherwise noted. FAULT 5V/div. VSW 5V/div. IL 2A/div. VEN 2V/div. FAULT 2V/div. VSW 5V/div. IL 2A/div. VOUT 2V/div. FAULT 5V/div. VSW 5V/div. IL 5A/div. VOUT 10V/div. FAULT 5V/div. VSW 5V/div. IL 2A/div. VOUT 5V/div. VIN 5V/div. VSW 10V/div. IL 2A/div. VOUT 5V/div. FAULT 2V/div. VSW 5V/div. IL 2A/div. VOUT 10V/div. FAULT 5V/div. VSW 5V/div. IL 2A/div. VOUT 5V/div. FAULT 5V/div. VSW 5V/div. IL 2A/div. VEN 2V/div. VOUT 2V/div. VSW 5V/div. VIN 5V/div. IL 2A/div.
MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE MPM6010 Rev. 1.0 www.MonolithicPower.com 12 7/7/2017 MPS Proprietary Information. Patent Protec ted. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 12V, Load = 2 series LED, V LED+ - VLED- = 2x3.0V @1.5A, F SW = 2.2MHz, T A = +25°C, unless otherwise noted. VOUT 2V/div. VSW 5V/div. IL 2A/div. VEN 2V/div. VOUT 2V/div. VSW 5V/div. IL 2A/div. VEN 2V/div. FAULT 5V/div. VSW 5V/div. IL 2A/div. VOUT 5V/div. FAULT 5V/div. VSW 10V/div. IL 1A/div. ILED 1A/div. FAULT 5V/div. VSW 10V/div. IL 1A/div. ILED 1A/div. FAULT 5V/div. VSW 5V/div. IL 2/div. VOUT 5V/div.
MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE MPM6010 Rev. 1.0 www.MonolithicPower.com 13 7/7/2017 MPS Proprietary Information. Patent Protec ted. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. BLOCK DIAGRAM Figure 1: Functional Block Diagram
MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE MPM6010 Rev. 1.0 www.MonolithicPower.com 14 7/7/2017 MPS Proprietary Information. Patent Protec ted. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 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 COMP). 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 V COMP 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 V IN as the input and operates in the full V IN range. When V IN exceeds 4.9V, the output of the regulator is in full regulation. When V IN is less than 4.9V, the output decreases following V IN. 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. Frequency foldback also occurs during soft start and short-circuit protection. Error Amplifier (EA) The error amplifier compares the FB voltage to the internal 0.2V reference (V REF) and outputs a current proportional to the difference between the two. This output current then charges or discharges the internal compensation network to form V COMP, 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 V IN limits the EN/DIM input current to less than 100µA. For example, with 12V connected to V IN, 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.
MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE MPM6010 Rev. 1.0 www.MonolithicPower.com 15 7/7/2017 MPS Proprietary Information. Patent Protec ted. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 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 (V SS). When V SS is lower than the internal reference (V REF), V SS overrides V REF, so the error amplifier uses V SS as the reference. When V SS exceeds V REF, 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. 100k Ω). /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, peak- current-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 V IN to BST turns on. The charging current path is from V IN to BST to SW. The external circuit should provide enough voltage headroom to facilitate charging. As long as V IN is higher than SW significantly, the bootstrap capacitor remains charged. When the HS-FET is on, V IN ≈ V SW, so the bootstrap capacitor cannot be charged. When the LS-FET is on, V IN - V SW reaches its maximum for fast charging. When there is no inductor current, V SW = V OUT, so the difference between V IN 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 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE MPM6010 Rev. 1.0 www.MonolithicPower.com 16 7/7/2017 MPS Proprietary Information. Patent Protec ted. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 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: V IN low, EN/DIM low, and thermal shutdown. During the shutdown procedure, the signaling path is blocked first to avoid any fault triggering. V COMP and the internal supply rail are then pulled down. The floating driver is not subject to this shutdown command.
MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE MPM6010 Rev. 1.0 www.MonolithicPower.com 17 7/7/2017 MPS Proprietary Information. Patent Protec ted. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved.
APPLICATION INFORMATION
Setting the Output Current The output current is set by the external resistor (RFB) (see Figure 4). RFB RT Figure 4: Feedback Network The feedback voltage is 0.2V. Calculate I LED with Equation (1): FB LED R 0.2VI (1) RT is used to set the loop bandwidth. The lower R T is, the higher the bandwidth. However, a high bandwidth may cause insufficient phase margin, resulting in loop instability. A proper value of R T is needed to make a trade-off between bandwidth and phase margin. Table 1 lists the recommended feedback resistor and R T values for common outputs with a 1- or 2- series LED. Table 1: Resistor Selection for Common Outputs ILED (A) R FB (mΩ) R T (kΩ) 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 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 C IN 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): OUT OUT CIN LED IN IN VVII ( 1 ) VV (2) The worst-case condition occurs at V IN = 2VOUT, shown in Equation (3): LED CIN II 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. 0.1 μF) 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): OUT OUTLED IN SW IN IN IN VVIV( 1 )fCV V (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): OUT OUT OUT ESR SW IN SW OUT VV 1V( 1 ) ( R )fL V 8 fC (5) Where L is the internal integrated inductor value (2.2µH), and R ESR is the equivalent series resistance (ESR) value of the output capacitor.
MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE MPM6010 Rev. 1.0 www.MonolithicPower.com 19 7/7/2017 MPS Proprietary Information. Patent Protec ted. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. 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 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE MPM6010 Rev. 1.0 www.MonolithicPower.com 21 7/7/2017 MPS Proprietary Information. Patent Protec ted. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved.
PACKAGE INFORMATION
QFN-17 (3mmx5mmx1.6mm) Non-Wettable Flank
MPM6010 – 36V, 1.5A, SYNCHRONOUS, STEP-DOWN, LED MODULE NOTICE: The information in this document is subject to change wi thout notice. Users should warra nt and guarantee that third party Intellectual Property rights are not infringed upon w hen integrating MPS products into any application. MPS will not assume any legal responsibility for any said applications. MPM6010 Rev. 1.0 www.MonolithicPower.com 22 7/7/2017 MPS Proprietary Information. Patent Protec ted. Unauthorized Photocopy and Duplication Prohibited. © 2017 MPS. All Rights Reserved. PACKAGE INFORMATION (continued) QFN-17 (3mmx5mmx1.6mm) Wettable Flank