MP3306EG-LF-Z

MP3306 30V, 700kHz Synchronous Step-Up White LED Driver DESCRIPTION FEATURES The MP3306 is a step-up converter designed for driving white LEDs from 3V to 12V power supply. The MP3306 uses current mode, fixed frequency architecture to regulate the LED current, which is measured through an external high-side current sense resistor. The low 202mV feedback voltage and synchronous rectification reduces power loss and improves efficiency.    The MP3306 is turned off if an over-voltage condition is present due to an open circuit condition. The output disconnect feature allows the output to be completely discharged. The MP3306 includes under-voltage lockout, current limiting, output short protection and thermal overload protection.   The MP3306 is available in small 12-pin QFN (2mm x 2mm) package.    3V~12V Input Voltage Analog Dimming and PWM Dimming Output-to-Input Disconnect in Shutdown Mode Programmable Open Load Shutdown Output Short Protection Low 202mV Feedback Voltage with +/-3% accuracy UVLO, Thermal Shutdown Available in 2mm x 2mm QFN12 Package APPLICATIONS    Smart Phone, MID, PDA Digital Still Cameras Small LCD Displays 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 MP3306 Rev.1.02 1/18/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 1 MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER ORDERING INFORMATION Part Number* Package Top Marking MP3306EG QFN12 (2x2mm) 3Y * For Tape & Reel, add suffix –Z (e.g. MP3306EG–Z). For RoHS Compliant packaging, add suffix –LF (e.g. MP3306EG–LF–Z) PACKAGE REFERENCE ABSOLUTE MAXIMUM RATINGS (1) VSW, VOUT, VFB....................................-0.5V to 35V VBST................................. ..................... VSW +6V VIN, VL, ............................................ -0.5V to 14V VEN, VOVP, VPWMI, VPWMO, VCC ........... -0.3V to 6.5V (2) Continuous Power Dissipation (TA = +25°C) ………………………………………………....1.6W Storage Temperature ............... -55C to +150C Recommended Operating Conditions (3) IN Supply Voltage VIN ........................ 3V to 12V Vsw ................................................ -0.5V to 30V Operating Junct. Temp (TJ) ...... -40C to +125C MP3306 Rev.1.02 1/18/2018 Thermal Resistance (4) θJA θJC QFN12 (2 x 2mm) ................... 80 ...... 16 ... C/W Notes: 1) Exceeding these ratings may damage the device. 2) 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 will cause excessive die temperature, and the regulator will go into thermal shutdown. Internal thermal shutdown circuitry protects the device from permanent damage. 3) The device is not guaranteed to function outside of its operating conditions. 4) Measured on JESD51-7, 4-layer PCB. www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 2 MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER ELECTRICAL CHARACTERISTICS VIN = VEN = 5V, TA = +25C, all voltages with respect to GND, unless otherwise noted. Parameters Symbol Operating Input Voltage Condition Min VIN Typ Max Units 12 V 3.7 3.9 4.1 V 300 550 0.1 380 690 93 1 460 830 µA µA kHz % 2.5 2.7 2.9 V 3 VCC Voltage VVCC VIN > 5.5V, VEN = 3V Supply Current (Shutdown) Supply Current (Quiescent) Switching Frequency Maximum Duty Cycle Under Voltage Lockout ISD IQS fSW DMAX VEN = 0V VEN = 5V, VOUT - VFB = 0.5V IN Under Voltage Lockout UVLO VIN Rising VFB = VOUT Under Voltage Lockout Hysteresis Protection OVP Threshold (5) SW Current Limit Thermal Shutdown 130 VOVP-TH 1.18 Duty Cycle = 60% (5) 1.22 1.8 mV 1.26 V A C 150 Enable EN OFF Threshold EN ON Threshold Dimming VENLO VENHI PWMI Low Threshold PWMI High Threshold PWMI Input Frequency VPWMI-LO VPWMI-HI FPWMI Minimum PWMO Dimming Threshold Maximum PWMO Dimming Threshold Feedback FB Voltage FB Input Bias Current Disconnect Switch On-Resistance Output Switch High-Side NMOS On-Resistance Low-Side NMOS On-Resistance (5) (5) 0.6 VPMWI Falling VPMWI Rising 0.8 0.1 1.1 V V 1.2 50 V V kHz VPWMO-MIN VFB = VOUT 25 mV VPWMO-MAX VOUT-VFB = 0.2V 850 mV VFB IFB (5) VEN Falling VEN Rising VEN = 3V VEN = 3V 196 3 202 7 208 11 mV µA RND-ON 0.5 Ω RNH-ON 0.6 Ω RNL-ON 0.6 Ω Notes: 5) Guaranteed by design MP3306 Rev.1.02 1/18/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 3 MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER PIN FUNCTIONS Pin # 1 2 3 4 5 6 7 Name Pin Function IN Input Supply Pin. It provides the power for internal driver and logic circuit. Must be locally bypassed. The Internal Linear Regulator Output. VCC provides power supply for the internal MOSFET switch gate driver and the internal control circuitry .Bypass VCC to GND with a ceramic capacitor. EN Control Input. A voltage greater than 1.1V turns the part on and less than 0.6V turns the EN part off. Apply a PWM signal on this pin for brightness control. This signal is uniformed and filtered at PWMI PWMO pin with an internal 100kΩ resistance. With a capacitor at PWMO pin, the duty cycle from 0% to 100% at PWMI pin is converted to 0V to 1.2V DC voltage at PWMO pin. PWM Filter Output. Connect a capacitor from PWMO to GND. The voltage on this pin range 0V to 1.2V linearly controls the feedback voltage from 0V to 0.2V. PWMO To use PWM dimming, connect the PWM input signal to PWMI pin. To use analog dimming, connect the analog input voltage to PWMO pin. Over Voltage Protection Pin. Use one external resistor voltage divider to program OVP OVP threshold. When the OVP pin voltage reaches the shutdown threshold 1.22V, the IC will be turned off and latch up until EN is toggled again. Feedback Input. The MP3306 regulates the voltage across the current sense resistor FB between FB and VOUT. Connect a current sense resistor from VOUT to the LED string. Connect the anode of the LED string to FB. The regulation voltage is 202mV. VCC 8 GND 9 SW 10 OUT 11 BST 12 L MP3306 Rev.1.02 1/18/2018 Ground. Power Switch Node. SW is the drain of the internal low side MOSFET switch. Connect the power inductor to SW. The OUTPUT terminal. Connect the output cap on this pin, the output capacitor must be ceramic type and be placed as short as possible between OUT pin and GND pin. Bootstrap. A capacitor is connected between SW and BST pins to form a floating supply to drive the high side MOSFET. Power input pin. L is the source of internal disconnection MOSFET. Connect the inductor to this pin. www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 4 MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER TYPICAL PERFORMANCE CHARACTERISTICS VIN=5V, VEN=5V, 8 LEDs in series, 20mA, unless otherwise noted. MP3306 Rev.1.02 1/18/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 5 MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER FUNCTION DIAGRAM L M1 IN 12 1 10 OUT 11 BST 9 SW 8 GND 6 OVP OTP EN 3 PWMI 4 VCC 2 Enable Dimming Control Level Shift Regulator Regulator UVLO Soft-Start M3 OSC 700kHz RAMP Compensation PWMO 5 CONTROL LOGIC M2 Reference RSENSE FB 7 ERROR AMPLIFIER PWM COMPARATOR CURRENT SENSE AMPLIFIER 1.22V Figure 1—Functional Block Diagram MP3306 Rev.1.02 1/18/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 6 MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER OPERATION The MP3306 uses a constant frequency, peak current mode step up regulator architecture to regulate the current flowing through series string of white LEDs. The operation of the MP3306 can be understood by referring to the block diagram of Figure 1. At the start of each oscillator cycle the low side FET (M2) is turned on through the control circuitry. To prevent sub-harmonic oscillations at duty cycles greater than 50 percent, a stabilizing ramp is added to the output of the current sense amplifier and the result is fed into the positive input of the PWM comparator. When this voltage equals the output voltage of the error amplifier the power FET is turned off. Then the inductor current flows into the output capacitor and LED load through internal high side N-channel MOSFET (M3), which forces the inductor current to decrease. thus increasing the power charged in inductor and delivered to the output. MP3306 provides the analog and PWM dimming solution, the internal resistor and external capacitor one PWMO pin filters the PWM dimming signal on PWMI pin to DC level that program the internal reference to accomplish the analog dimming function. When floating the PWMO pin, PWM dimming function works. Open Load protection shuts off the MP3306 if the output voltage goes too high. In some cases an LED may fail, this results in the feedback voltage always being zero. The part then runs at maximum duty cycle boosting the output voltage up. If the output ever exceeds the programmable OVP threshold, the MP3306 will shut down. The part does not switch again until the EN pin or VIN is toggled. The voltage at the output of the error amplifier is an amplified version of the difference between the 200mV reference voltage and the feedback voltage. In this way the LED current is regulated accurately. During Shutdown mode when EN is low, the IC keeps the internal high-side N-channel MOSFET (M1) off to disconnect the output from input. If the feedback voltage starts to drop, the output of the error amplifier increases. This result in more current flowing through the high side power FET, MP3306 has cycle by cycle current limit to protect the load and IC from over current. And the internal MOSFET (M1) limits the input current to prevent system damage when short VOUT condition occurs. MP3306 Rev.1.02 1/18/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 7 MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER APPLICATION INFORMATION Figure 2—3V~12V Input, Typical Application Driving 8 WLEDs in series Figure 2 shows a typical application circuit that can drive up to 8 white LEDs with 20mA. A 0.22~2.2µF output capacitor is sufficient for most applications. The inductor with low DC inductor resistance (DCR) will improve efficiency. Two 4.7μF ceramic capacitors provide sufficient input decoupling. Setting the LED Current The LED current is controlled by the current setting resistor, R1. The current through the LEDs is given by: ILED = 202mV/R1. Table 1 shows the selection of resistors for a given LED current. Table 1—ILED vs. R1 RSET Selecting the Inductor The inductor forces a higher output voltage driven from a lower input voltage. A larger inductor value results in less ripple current, a lower peak inductor current, and reduces stress on the internal N-Channel MOSFET. However, larger-value inductor has a larger physical footprint, higher series resistance, and lower saturation current. Choose an inductor that does not saturate under the worst-case load conditions. Calculate the required inductance value using the following equations: L η  VOUT  D  (1 D)2 2  fSW  ILOAD D  1 VIN VOUT Where VIN and VOUT are the input and output voltages, fSW is the switching frequency, ILOAD is the LED load current, and η is the efficiency. MP3306 Rev.1.02 1/18/2018 ILED (mA) 1 5 10 20 60 180 200 R1 (Ω) 200 40 20 10 3.33 1.11 1 The internal ramped compensation voltage added to the current sense amplifier reduces the maximum output current as the duty cycle increases. As more LEDs are added, the output voltage rises but the maximum current delivered to the load falls as well. Figure 3 shows the current limit curve, and the max LED current is gotten as the formula. ILOAD(max)  (IPK  VIN  D )  (1  D)  0.8 2  L  fSW Where, IPK is the peak current corresponding duty cycle from current limit curve, the L is inductor, the 0.8 means the margin coefficient. www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 8 MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER Layout Considerations Careful attention must be paid to the PCB board layout and components placement. Proper layout of the high frequency switching path is critical to prevent noise and electromagnetic interference problems. The loop of MP3306’s internal low side MOSFET, synchronous MOSFET, and output capacitor is flowing with high frequency ripple current, it must be minimized. So the output capacitor should be placed to IC as close as possible. Figure 3—Current Limit Curve Analog and PWM Dimming MP3306 provides 2 types of dimming solutions, analog dimming and PWM dimming. For analog, connect an external capacitor on PWMO pin to form the low pass filter with internal resistor R, the PWM dimming signal on PWMI pin is filtered to DC signal to set the internal reference to accomplish the analog dimming. The time constant should be ten times greater than a PWM waveform cycle: RC  10  TPWM For PWM dimming, floating PWMO pin and apply the PWM dimming signal on PWMI pin. Setting Over Voltage Protection Threshold Open Load protection will shut off the MP3306 if the output voltage goes too high. In some cases an LED may fail, this will result in the feedback voltage always being zero. The part boots the output voltage higher and higher. If the output voltage ever exceeds the programmed OVP threshold as the formula, VOVP =1.22  (1  R2/R3) The MP3306 will shut down. The part will not switch again until the power is recycled. MP3306 Rev.1.02 1/18/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 9 MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER TYPICAL APPLICATION CIRCUIT L1 15μH C3 10nF 2.7V~8.4V VIN IN C1 1μF L R4 100kΩ GND EN SW BST OUT R1 10Ω MP3306 EN 20mA PWMI R3 10kΩ LED4 VCC R2 130kΩ LED1 FB OFF ON C4 1μF C2 0.22μF GND PWMO OVP Figure 4— 4 LEDs in Series 20mA L1 15μH C3 10nF 2.7V~8.4V VIN C1 1μF GND IN L R4 100kΩ EN SW BST OUT MP3306 EN FB OFF ON VCC PWMO C2 0.22μF R2 130kΩ LED1 20mA PWMI C4 1μF R1 10Ω LED4 R3 10kΩ GND OVP Figure 5— 4 LEDs in Series 20mA MP3306 Rev.1.02 1/18/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 10 MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER L1 15μH C3 10nF 2.7V~8.4V L VIN SW IN BST OUT C1 1μF GND R1 10Ω C2 0.22μF MP3306 EN EN LED1 FB OFF ON 20mA DIM PWMI 100Hz~50kHz C4 1μF R3 10kΩ LED6 VCC R2 205kΩ GND OVP PWMO C5 1uF Figure 6— 6 LEDs in Series with PWM Dimming L1 15μH C3 10nF 5V~10V VIN IN C1 1μF L R4 100kΩ GND EN SW BST OUT C2 0.22μF MP3306 EN FB OFF ON VCC PWMO R2 95.3kΩ LED1 20mA PWMI C4 1μF R1 10Ω LED3 R3 10kΩ GND OVP Figure 7— 3 LEDs in Series 20mA with 5~10V Input Voltage MP3306 Rev.1.02 1/18/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 11 MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER L1 15uH 14V VIN C3 10nF R4 2kΩ C1 1uF GND L R5 8kΩ SW IN BST OUT C6 0.33uF R1 10Ω C2 0.22uF MP3306 EN EN FB OFF ON LED1 20mA DIM PWMI LED8 100Hz~50kHz VCC C4 1uF PWMO R2 232kΩ R3 10kΩ GND OVP C5 1uF Figure 8— The application when Vin>12V MP3306 Rev.1.02 1/18/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 12 MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER PACKAGE INFORMATION QFN12 (2x2mm) 1.90 2.10 0.35 0.45 0.30 0.40 PIN 1 ID MARKING 11 0.20 0.30 1.90 2.10 PIN 1 ID INDEX AREA PIN 1 ID 0.10X45º TYP. 12 10 1 7 4 0.50 BSC 6 TOP VIEW 5 BOTTOM VIEW 0.80 1.00 0.20 REF 0.00 0.05 SIDE VIEW NOTE: 1.90 0.70 1) ALL DIMENSIONS ARE IN MILLIMETERS. 2) EXPOSED PADDLE SIZE DOES NOT INCLUDE MOLD FLASH. 3) LEAD COPLANARITY SHALL BE 0.10 MILLIMETER MAX. 4) JEDEC REFERENCE IS MO-220, VARIATION VCCD. 5) DRAWING IS NOT TO SCALE. 0.25 1.90 0.50 RECOMMENDED LAND PATTERN 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. MP3306 Rev.1.02 1/18/2018 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 13