UM1663S

UM1663S 36V Boost LED Driver with PWM and single wire interface dimming UM1663S SOT23-6 General Description The UM1663S is a highly integrated LED driver IC capable of driving 10 WLEDs in series. It is composed of a current mode boost converter integrated with a 38V/1A power switch. The UM1663S supports a wide input voltage range from 2.8Vto 5.5V and runs at a fixed frequency of 1MHz. The LED current is set via an external resistor and the feedback voltage is regulated to 200mV. During operation, the LED current is controlled by the duty cycle of the ____________ SHDN input signal, which determines the feedback reference voltage. The UM1663S can modify dimming to support 64-step pulse dimming. More details are shown in the Timing Diagram section. The UM1663S also has internal overvoltage protection setting to prevent the output from exceeding the absolute maximum ratings during open LED conditions. It is available inGreenSOT23-6 package and operates over an ambient temperature range of -40°C to +85°C. Applications Features z z z z z z z Mobile Phone and Smart Phone Digital Camera and GPS Portable DVD Player z z z z z z High Output Voltage: Up to 36V Internal Soft-Start and Compensation 200mV Reference Voltage PWM Dimming and Frequency Range from 500Hzto 50kHz 64-Step Pulse Dimming Open LED Protection Internal Over Voltage Protection Setting Over Temperature Protection Current Limit Protection RoHS Compliant and Halogen Free Efficiency(%) Typical Application Circuit 90  85  80  75  70  65  60  55  50  Efficiency  Vs  Vcc Iout=30mA 6LEDS in series 2.8 3.2 3.6 4 4.4 4.8 5.2 5.6 Vcc（V） ________________________________________________________________________ http://www.union-ic.com Rev.01Sep.2019 1/16 UM1663S Pin Configurations Top View (Top View) M: Month Code UM1663S SOT23-6 Ordering Information Part Number Packaging Type Marking Code UM1663S SOT23-6 UDC Shipping Qty 3000pcs/7Inch Tape & Reel Pin Description Pin Number Symbol 1 SW 2 GND/PGND 3 FB 4 ____________ 5 OVP 6 VIN SHDN Function Switch pin. Connect the inductor and the Schottky diode to this pin. Ground. Feedback voltage pin. Chip enable and PWM/Pulse mode dimming pin Overvoltage protection pin. The pin is connected to an output capacitor to determine overvoltage of the chip. The default overvoltage threshold is 38V. Supply voltage pin. ________________________________________________________________________ http://www.union-ic.com Rev.01Sep.2019 2/16 UM1663S Absolute Maximum Ratings Over operating free-air temperature (unless otherwise noted) (Note 1) Symbol Parameter Value VIN VFB, V/SHDN VSW, VOVP PD Supply Voltage on VIN (Note 2) ____________ Voltages on FB, SHDN (Note 2) Voltages on SW, OVP (Note 2) Unit -0.3 to +6 V -0.3 to +6 V -0.3 to +42 V Power Dissipation at TA = 25°C 0.684 Power Dissipation at TA = 70°C 0.447 W θJA Package Thermal Resistance(Note 3) 190 °C/W TJ Operating Junction Temperature +155 °C TSTG Storage Temperature Range -65 to +150 °C Maximum Lead Temperature for Soldering TL +260 °C 10seconds Note1: Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under recommended operating conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. Note2: All voltage values are with respect to network ground terminal. Note3:Junction to Ambient thermal Resistance is highly dependent on PCB layout. Note4: θJAis measured in the convection at TA=25℃(or TA=70℃)on a High effective thermal conductivity test board of JESD51-7 thermal measurement standard Note5: The maximum recommended junction temperature (TJ) of the UM1663S is 155°C,the thermal resistance of the UM1663S is θJA=190°C/W, specified regulator operation is assured to a maximum ambient temperature TA of 25°C .there for the maximum power dissipation is calculated as below: PD(MAX)= (TJ(MAX) −TA) /θJA=(155 − 25) / 190 = 0.684W Note 6: The device is not guaranteed to function properly beyond absolute maximum ratings. ________________________________________________________________________ http://www.union-ic.com Rev.01Sep.2019 3/16 UM1663S Electrical Characteristics ____________ (VIN=3.7V,SHDN =VIN,TA= -40°Cto 85°C, typical value are atTA= 25°C,unlessotherwise noted) Symbol Parameter Test Conditions Min Typ Max Unit Input Voltage VIN 2.8 5.5 V Range Not switching, 600 μA Operating VFB=0.3V IQ Quiescent Current Switching, VFB=0.1V 1.2 3 mA ISD VUVLO Shutdown Current Under-voltage Lockout Threshold UVLO Hysteresis ____________ VIH SHDN High Level Input Voltage ____________ VIL SHDN Low Level Input Voltage ____________ IL SHDN Input Leakage Current ____________ SHDN =GND 2 0.5 2 μA 2.2 2.45 V 0.1 VCC=3.7V 1.5 VCC=5V VCC=3.7V VCC=5V 1.8 V V 0.6 0.8 V 1 μA 50K Hz ____________ SHDN =GND or VIN 0.1 ____________ SHDN Dimming Frequency 500 ____________ SHDN Shut Down Delay Time ____________ VSW fOSC DMAX RDS(ON) ILIM VOUT VREF SHDN Pulse Dimming Time Maximum Switch Voltage OSC Frequency Maximum Duty MOSFET On-Resistance MOSFET Leakage Current MOSFET Current Limit Adjustable Output Voltage Range Internal Voltage Reference Over Voltage Protection Over Temp Protection OTP Hysteresis Logic High Logic Low 20 ms 0.5 0.5 μs μs VSW =38V 0.8 40 V 1 93 MHz % 550 mΩ 1 10 μA 1 1.2 A 36 V 210 mV VIN 2.5V≤VIN≤5.5V 190 200 36 V 155 ℃ 25 ℃ ________________________________________________________________________ http://www.union-ic.com Rev.01Sep.2019 4/16 UM1663S ESD AND LATCH UP PERFORMANCE I/O Pin ESD-Protection Voltage LatchUpPerform ance Human Body Model ±2 KV JEDEC Standard No.78E ±200 mA Pulse/PWM Dimming Timing Diagram For the UM1663S, dimming method is determined by the length of the initial pulse period. If initial pulse width≥2ms, the UM1663S will be set to PWM dimming. If initial pulse width≤1.5ms, then UM1663S will be set to Pulse dimming. ____________ For pulse dimming logic high time TIH of SHDN should＞0.5us，logic low time TIL should be between 0.5us～500us. ____________ If SHDN is logic low＞20ms,both in Pulse dimming and PWM dimming mode UM1663S is shutdown. PWM Dimming Figure 1. UM1663S PWM dimming Pulse Dimming Figure 2. UM1663S pulse dimming ________________________________________________________________________ http://www.union-ic.com Rev.01Sep.2019 5/16 UM1663S Typical Operating Characteristics Eff vs Iout 85.00 80.00 Eff(%) 75.00 70.00 Iout=10mA 65.00 Iout=20mA Iout=30mA 60.00 55.00 50.00 2.8 3.2 3.6 4 4.4 Vcc(V) 4.8 5.2 5.6 Efficiency Waveform（Vcc=3.6V 6 WLED String） Eff vs Vcc 90.00 80.00 Eff(%) 70.00 60.00 50.00 Iout=20mA 10 LEDs 40.00 Iout=20mA 6 LEDs 30.00 20.00 2.8 3.2 3.6 4 4.4 4.8 5.2 5.6 Vcc(V) Efficiency Waveform ________________________________________________________________________ http://www.union-ic.com Rev.01Sep.2019 6/16 UM1663S Typical Operating Characteristics PWM Diming Precision 200 180 160 VFB（mV） 140 120 100 80 60 VIN=3.7 PWM=1K… 40 20 0 0 10 20 30 40 50 60 70 80 90 100 Duty(%) PWM Dimming Pulse vs VFB Voltage Curve Vfb VS Pulse Step 200 180 160 140 VFB(mV) 120 100 80 60 VIN=3.7V 40 Pulse Step 20 0 0 8 16 24 32 40 48 56 64 Pulse Step Pulse Dimming Pulse Step vs VFB Voltage Curve ________________________________________________________________________ http://www.union-ic.com Rev.01Sep.2019 7/16 UM1663S Typical Operating Characteristics Rdson vs VCC 0.8 Rdson(Ω) 0.6 0.4 0.2 Rdson 0 2.5 3 3.5 4 4.5 Vcc(V) Internal Power NMOS Rds(on) Vs VCC Curve Power ON from EN Power OFF from EN ________________________________________________________________________ http://www.union-ic.com Rev.01Sep.2019 8/16 UM1663S Typical Operating Characteristics Vsw&IswWaveform(VCC=3.6V Iout=20mA 10 WLED String) PWM Dimming ________________________________________________________________________ http://www.union-ic.com Rev.01Sep.2019 9/16 UM1663S Pulse Dimming Function Block Diagram Figure 3. UM1663S function block diagram ________________________________________________________________________ http://www.union-ic.com Rev.01Sep.2019 10/16 UM1663S Functional Description The UM1663S uses PWM current-mode boost converter architecture to control the LED current by regulating the feedback voltage. Refer to functional block diagram. The beginning of each cycle turns on the Power MOSFET. A slope compensation ramp is added to the output of the current sense amplifier and the result is fed into the positive input of the comparator (COMP). When this voltage goes above the output voltage of the error amplifier (gM), the Power MOSFET is turned off. The voltage at the output of the gM block amplifies the difference between the reference voltage and the feedback voltage (VFB), so that FB pin voltage can be regulated to the reference voltage. The UM1663S has built-in soft start to limit the inrush current during startup and to limit the amount of overshoot on the output. Protection features ininclude internal over-voltage protection(OVP), cycle-by-cycle current limit protection and thermal shutdownprotection. OVP protects in the event where an LED fails open, which forces the feedback voltage to zero. This causes the boost converter to operate in maximum duty cycle mode, ramping up the output voltage. Switching will stop when the output reaches the OVP threshold. The OVP feature protects the IC from damaging itself by exceeding the voltage rating on LX pins. Typical Application Circuit The UM1663S could drive different WLED topology.For example Figure4 shows the 3*7 WLEDS and the current is equal to 90mA.The total WLEDS current could be set by the Rset which is equal to following equation: Itotal = 200mV/R1 Figure 4. UM1663S driving 7 in series and 3 in parallel LEDS ________________________________________________________________________ http://www.union-ic.com Rev.01Sep.2019 11/16 UM1663S Low input voltage application In application that have low input voltage range(Figure5),such as those powered from 1AA cells, the UM1663S may still be used if there is a suitable system supply (such as 3.3V) avaieable to power the controller.In such an application,the inductor maybe connected directly Figure 5. Using UM1663S to drive LED strings power from 1AA Cell High input voltage application In applications that UM1663S have high input voltage range(Figure6),such as those power form a series connected Li-ion batteries. The UM1663S could be used if there is a suitable system supply available (such as 3.3V) to power the controller,or use high input voltage LDO such as UM1460-33 to generate a 3.3V power supply from Li-ion battery. In such cases, the inductor could be connected directly to the battery while the UM1663S power is Supply by the system supply or output of LDO UM1460-33. Figure 6. UM1663S based LED driver circuit powered from high input voltage ________________________________________________________________________ http://www.union-ic.com Rev.01Sep.2019 12/16 UM1663S Applications Information Soft-Start The UM1663S includes a soft-start function to avoid high inrush current during start up. LED Current The loop control of the boost converter keeps VFB equal to a reference voltage, VREF. Therefore, when RSET is connected between the FB pin and GND, the LED current will be determined by the current through RSET, which is equal to VFB / RSET. Pulse/PWM Dimming For the UM1663S, dimming method is determined by the length of the initial pulse period. If initial period ≤1.5ms , the UM1663S will be set to pulse dimming. If initial period ≥2ms , the UM1663S will be set to PWM dimming. The detail operation of brightness dimming is shown in the Figure 1&Figure 2. ____________ When adding the PWM signal to the SHDN pin, the UM1663S is turned on or off by the PWM signal, so the LEDs operate at either zero or full current. The average LED current increase proportionally with the duty cycle of the PWM signal. The magnitude of the PWM signal should ____________ be higher than the maximum enable voltage of the SHDN pin, in order to let the dimming control perform correctly. The recommended frequency range of the PWM signal is from500Hz to 50kHz. Once selection has been made, the dimming method may not be changed until system shutdown, even if the dimming frequency is modified. Current Limiting The current flowing through the inductor during a charging period is detected by a current sensing circuit. If the value is over the current limit, the N-MOSFET will be turned off. The inductor will then be forced to leave charging stage and enter discharging stage. Therefore, the inductor current will not increase over the current limit. Shutdown Delay ____________ When the SHDN voltage is in logic low for 20ms (min.) during pulse dimming, the system will enter shutdown. OVP/UVLO/OTP When the output voltage is higher than a specified value or input voltage is lower than a specified value, the IC will enter protection mode. If the die temperature > 155°C, the IC will also enter protection mode. During protection mode, the P-MOSFET is turned off to prevent abnormal operation. Inductor Selection The recommended Inductor value for 10 WLEDs applications is4.7μH. Small size and better efficiency are the major concerns for portable devices, such as for mobile phone. The inductor should have low core loss at1MHzand low DCR for better efficiency. The inductor saturation current rating must be greater than the inductor peak current. Capacitor Selection 10μF input ceramic capacitor and 2.2μF output ceramic capacitor are recommended for driving 10 WLEDs applications. For better voltage filtering, ceramic capacitors with low ESR are recommended. X5R and X7R types are suitable because of their wide voltage and temperature Diode Selection Using a schottky diode is recommended in UM1663 application because of its low forward ________________________________________________________________________ http://www.union-ic.com Rev.01Sep.2019 13/16 U UM1663S voltagge drop and fast reversee recovery tiime .The cu urrent raring of the schoottky diode should exceedd the peak current of thee boost convverter. The voltage v ratingg should alsoo exceed thee target outputt voltage. ut Consideraation Layou PCB layout is verry important for high freequency swittching regulaators in ordeer to keep th he loop c to the IC to get th he best stable and minimiize noise. Thhe input cappacitor should be very close a output caapacitor shouuld be kept as a short decouppling. The path of the innductor, schoottky diode and as posssible to minnimize noise and ringingg. FB is a sen nsitive node and it shouuld be kept separate from the t SW switcching node inn the PCB layyout. mal Consideration Therm For coontinuous opperation, do not n exceed absolute a max ximum junctiion temperatuure. The maximum powerr dissipation depends onn the thermaal resistancee of the IC package, PC CB layout, rate of surrouunding airfloow, and diffeerence betweeen junction n and ambiennt temperatuure. The max ximum powerr dissipation can be calcuulated by the following fo ormula: PD(MAXX) = (TJ(MAX) −TA) / θJA where TJ(MAX) is thhe maximum m junction tem mperature, TA is the ambbient temperaature, and θJAA is the junctioon to ambiennt thermal ressistance. For reecommendedd operating condition c sppecifications of the UM1663S, the m maximum ju unction temperrature is 1555℃and TA is the am mbient tempeerature. The junction too ambient thermal t resistaance, θJA, is layout dependdent. The maximum m pow wer dissipatiion depends on the operaating ambiennt temperature for fixed TJ(MAX) and thhermal resistaance, θJA. _____________________________________________ ______________________________ _____ http:// //www.union n-ic.com Revv.01Sep.20119 14/16 U UM1663S Pack kage Inforrmation UM1663S: SO OT23-6 Outline Drawing Symb bol A A1 A2 b c D E E1 e e1 L L1 θ DIMENSION D NS MILL LIMETERS Min Max 1.050 1.250 0.000 0.100 1.050 1.150 0.300 0.500 0.100 0.200 2.820 3.020 1.500 1.700 2.650 2.950 0.9950REF 1.800 2.000 0.6600REF 0.300 0.600 0° 8° INCHE ES Min Max 0.041 0.049 0 0.000 0.004 0 0.041 0.045 0 0.012 0.020 0 0.004 0.008 0 0.111 0.119 0 0.059 0.067 0 0.104 0.116 0 0.037R REF 0.071 0.079 0 0.023R REF 0.012 0.024 0 0° 8° Land d Pattern NOTES S: 1. Com mpound dimennsion:2.92×11.60； 2. Unit: mm; 3. Gen neral tolerancce ±0.05mm m unless oth herwise speciified; 4. The layout is justt for referencce. O n Tape and Reel Orientation _____________________________________________ ______________________________ _____ http:// //www.union n-ic.com Revv.01Sep.20119 15/16 UM1663S GREEN COMPLIANCE Union Semiconductor is committed to environmental excellence in all aspects of its operations including meeting or exceeding regulatory requirements with respect to the use of hazardous substances. Numerous successful programs have been implemented to reduce the use of hazardous substances and/or emissions. All Union components are compliant with the RoHS directive, which helps to support customers in their compliance with environmental directives. For more green compliance information, please visit: http://www.union-ic.com/index.aspx?cat_code=RoHSDeclaration IMPORTANT NOTICE The information in this document has been carefully reviewed and is believed to be accurate. Nonetheless, this document is subject to change without notice. Union assumes no responsibility for any inaccuracies that may be contained in this document, and makes no commitment to update or to keep current the contained information, or to notify a person or organization of any update. Union reserves the right to make changes, at any time, in order to improve reliability, function or design and to attempt to supply the best product possible. Union Semiconductor, Inc Add: Unit 606, No.570 Shengxia Road, Shanghai 201908 Tel: 021-51093966 Fax: 021-51026018 Website: www.union-ic.com ________________________________________________________________________ http://www.union-ic.com Rev.01Sep.2019 16/16