THL6518_Rev.1.01_E THL6518 8 channels LED Driver Description Features THL6518 is a 8 channels LED driver. THL6518 has a built-in boost converter, since back light system can consist of 1 chip. Soft start / Over current protection / Vout short circuit protection / Under voltage lock out protection / Over voltage protection / LED short protection / LED open protection / Thermal shut down are built in. Mounted area is reducible by 16-pin QFN. ・Input voltage range : 2.7V - 24V ・Boost converter Maximum output voltage : 40V Switching frequency range : 1MHz ・LED driver Up to 60mA per channel Current accuracy : +/-3% Current matching : +/-2.5% ・PWM dimming control : 100Hz - 30kHz ・Protection circuit Soft start Over current protection Vout short circuit protection Under voltage lock out protection Over voltage protection LED short protection LED open protection Thermal shut down ・3mm x 3mm QFN 16pin package Application ･Mobile phone display backlight ・Car Navigator display backlight ･Laptop/Netbook/Tablet PC display backlight Pin Configuration Block Diagram EN OUT8 OUT7 OUT6 16 15 14 13 VIN VCC PGND 1 12 LX Regulator OUT5 EN Boost PGND Protect circuit OVP OSC LX 2 11 SS PWM 8 OUT1 Exposed Thermal Pad VCC PWM (Top view) 3 10 17 GNDEXP OUT2 REXT AGND OUT3 OUT4 OSC OSC Current driver OUT5 OUT6 OVP 4 9 OUT4 OUT7 OUT8 5 6 7 8 REXT OUT1 OUT2 OUT3 AGND Copyright© 2013 THine Electronics, Inc. All rights reserved. 1/9 THine Electronics, Inc. THL6518_Rev.1.01_E Absolute Maximum Ratings Parameter Symbol VCC VH1 VH2 VL Pd Tj Tstg VCC voltage LX voltage OUT[8:1] voltage EN, PWM voltage Power dissipation Junction temperature (*1) Storage temperature range Rating 27 45 40 27 2.33 -40 to +125 -55 to +150 Units V V V V W ℃ ℃ *1. The operating temperature range should perform a thermal design, after consulting the thermal characteristic. Please use it in the range which does not exceed junction temperature. Recommended Operating Conditions Parameter Min 2.7 3 0.1 VCC voltage OUT[8:1] voltage LED output current PWM dimming control Typ - Max 24 40 60 30 Units V V mA kHz Pin Description Number 1 Name PGND 2 LX 3 VCC 4 OVP 5 10 REXT OUT1 to OUT4 AGND 11 PWM 12, 13, 14, 15 OUT5 to OUT8 16 EN Enable pin. 17 GNDEXP Back side. 6, 7, 8, 9 Function Power ground. Boost converter switching output pin. Input supply voltage pin. Over voltage protection input pin. LED current set pin. LED current sink regulation input pins. Analog ground. PWM dimming control input pin. LED current sink regulation input pins. Description Power ground pin of boost converter. This pin is switching output of boost converter. Power supply pin. This pin is the over voltage protection circuit setting input of the boost converter for LED driver. This pin is controlled by external resistance. LED current is set by the value of the external resistor. These pins are the constant current output. The constant current is determined by REXT resistor. Analog ground of LED driver. This pin is control input to LED dimming. These pins are the constant current output. The constant current is determined by REXT resistor. If low level voltage is impressed, the LED driver is shutdown. GND EXP should be soldered to GND to improve the thermal characteristics. Copyright© 2013 THine Electronics, Inc. All rights reserved. 2/9 THine Electronics, Inc. THL6518_Rev.1.01_E Power Dissipation Power Dissipation [mW] 2500 2000 1500 1000 500 0 -40 -20 0 20 40 60 80 100 120 140 Operating Temperature [ ℃ ] Copyright© 2013 THine Electronics, Inc. All rights reserved. 3/9 THine Electronics, Inc. THL6518_Rev.1.01_E Electrical Characteristics Parameter （at VCC＝12V , Ta=25℃, unless otherwise noted） Symbol Input quiescent Current １ Standby current Icc1 Ist Test Conditions Vpc=0V(No switching) EN>1.9V Typ Max Units - 2 3 mA - - 18 uA 2.4 2.5 2.6 V - 0.15 - V Rpwm_en - 800 - kΩ Vpwm_h 1.9 - - V Vpwm_l - - 0.8 V Tmin_pulse - 0.5 - us Fosc 0.8 1 1.2 MHz Maximum duty cycle Dmax - 92 - % Minimum ON-time Dmin - 12.5 - % UVLO threshold voltage Vuvlo UVLO hysteresis voltage dVuvloh PWM/EN pull down resistance PWM/EN input high voltage PWM/EN input low voltage PWM/EN minimum pulse Boost converter switching frequency LX ON-resistance EN<0.8V Min VCC rising Ron LX current limit - 0.2 0.45 Ω Ilim1 VIN>3.3V 2.2 2.8 - A Ilim2 VIN=2.6V - - A VCC>2.7V, CHx>0.7V 30 - - VCC>4.5V, CHx>1V 60 - - - - 3 LED current per channel Iled_max OUTx pin leakage current Ileak VOUT=36V OUTx pin regulation threshold Vout Rrext=62kΩ REXT pin voltage Vrext 0.6 - V 1.229 1.253 V 19.4 20.0 20.6 mA - 1 2.5 % Vovp 1.198 1.229 1.260 V Vscp - - 75 mV Vled_s 7.2 8 8.8 V LED current matching Dled short circuit threshold LED short protection protection uA - Iled OVP mA 1.204 LED current accuracy Over voltage protection threshold 0.5 x Ilim1 Irext = 20 uA Rrext=62kΩ (Imax-Imin)/Iave Copyright© 2013 THine Electronics, Inc. All rights reserved. 4/9 THine Electronics, Inc. THL6518_Rev.1.01_E power supply is inputted, the voltage difference of input Function voltage and output voltage becomes the largest at the Input voltage / Output voltage moment of Under voltage lock out protection (UVLO) If the difference of input voltage and output voltage being canceled. becomes large, the ON duty cycle (Don) will become In this condition, most much current flows from an input. small. Depending on the conditions of input and output When input voltage is inputted slowly, the over-current voltage, the pulse width below the minimum pulse width, protection circuit is operated for the above-mentioned 125nsec is needed. In this case, a pulse is skipped and reason. In that case, please input into VCC after inputting frequency is decreased. Please decide the input and EN input or PWM input. In inputting into VCC, please output voltage condition with considering a maximum use the conditions that it does not become an duty cycle and the minimum pulse width. over-current. Moreover, if the input voltage is unstable, please connect R-C filter to the input line. When input voltage rises steeply, by the capacitive coupling of Boost converter the inside transistor of IC, excess voltage may be The boost converter for an LED drive is built in. The built over the low resisting pressure element voltage of an LED constant current output OUTn pin is inside IC, and it may become a cause of failure. If feedback, and the suitable voltage for the anode of LED input voltage rises sharply, excess voltage is is supplied. added to a low resisting pressure element by the capacitive coupling of the inside transistor of IC. Thereby, it may become a cause of failure. It Enable recommends inserting the filter (Fig. 1) of 10ohm The standby function is carried. When a low level signal / 1uF in a VCC pin. is inputted into EN pin, it will be in a standby state. And a boost converter and an LED constant current output are VIN suspended. The consumed current is set to less than 18uA in a standby state. EN does not have restriction of an input sequence. If inputted into EN before the input of 10Ω 1uF Fig. 1 VCC, there is no problem. VCC Filter setup of VCC input PWM dimming The dimming function is carried. It is possible to control <<Notes>> ON/OFF of the constant current output for LED by This product contains the over current protection inputting in a PWM signal. An LED output becomes destruction of IC from the active when a PWM signal is a high level. Please input a output abnormality of a boost converter. Please refer to dimming signal in 30 kHz from 100 Hz. The minimum Over current protection (OCP) for details. duty cycle DPWMmin which can be set up by a PWM circuit in order to protect After a Copyright© 2013 THine Electronics, Inc. All rights reserved. 5/9 THine Electronics, Inc. THL6518_Rev.1.01_E dimming function is determined by the following 2.5V input voltage. And a boost converter carries out formula from PWM minimum pulse width and the LEDs constant current drive, after starting soft start frequency fPWM of PWM. operation. D PWM min [%] 0.5[ sec] f PWM [ MHz ] 100 Soft start (SS) When not use a dimming function, please input the The boost converter carries the soft start function in signal of a high level to PWM pin. If a dimming signal order to prevent the rush current at a start up. This which is less than 100Hz is inputted, a boost converter is function is to raise output voltage slowly. It is because stopped and it performs the same operation as EN. PWM overshooting and rush current occur when input voltage does not have restriction of an input sequence. If inputted is inputted. into PWM before the input of VCC, there is no problem. Over voltage protection (OVP) LED constant current output setup Over voltage protection is built in. If LED is LED current is determined by resistance connected to a disconnecting, the output voltage of a boost converter is REXT pin. Please use it according to the following stopped and destruction of IC is prevented. In formula in the range from, 3mA/ch to 60mA/ch. consideration of the threshold voltage of an OVP pin, OVP sets up in the range below a boost converter output. 1229 I LED [mA] 1000 R EXT VOVP V 1.229 (1 R2 ) R1 Boost converter output LED constant current output Please connect LED constant current output OUT1-8 to the cathode of LED. The constant current is supplied to R2 LEDs decided by REXT. If the current needs more than Over voltage 60mA, please connect each output pin. If there is an LED protection pin R1 output which is not used, please connect with GND. Fig. 2 Over voltage protection setup Protection circuits Under voltage lock out protection (UVLO) Over current protection (OCP) The UVLO function is carried in order to prevent In order to restrict the over-current by the abnormalities malfunction in the state where input voltage is low. A of load, etc., the over current protection circuit is built in. boost converter and an LED constant current output are Over-current detection of pulse-by-pulse system is suspended to the power supply voltage which can carry adopted. An output transistor is turned off if the current out operational stability. UVLO is released by more than which flows into an output transistor reaches boost Copyright© 2013 THine Electronics, Inc. All rights reserved. 6/9 THine Electronics, Inc. THL6518_Rev.1.01_E converter limit current (Ilim). The output transistor operates again in reset time in IC after that. An over Normal Operation current protection circuit detects the peak current of an inductor. Input and output voltage and not only LED Check if any working channel voltage > 7.2V constant current but ripple current is taken into consideration. If 8msec or more of over current states No Yes continue, IC is shut down. If 8mesc or more of the Turn off this channel over-current protection circuits operates, IC is shut down. No If all channels voltage Yes Turn off all channels and Reset the turn-off status (Turn on allthe channels) Short circuits protection (SCP) If the output of a boost converter connects with GND Fig. 3 LED short protection circuit function and, OVP pin is arrived at less than 75 mV, Short circuits protection is carried out. In that case, operation of a LED open protection boost converter is stopped. If a short state is canceled, it When an LED constant current output opens, the opened will return to normal operation. LED constant current output is separated from the feedback loop, and stops. The other LED constant current output connected continues normal operation. If LED short protection an open state is canceled, it will return to normal If LED line was shorted and the LED constant current operation. If all the LED constant current outputs output OUTn reaches more than 7.2V, an LED constant become open, the output voltage of a boost converter current output will be suspended. Even if the short state will be raised and the over voltage protection will is canceled, an LED constant current output holds a halt operate. condition. The LED constant current output which does not act as short continues normal operation. Short circuit of all the LED constant current outputs will stop Thermal shut down (TSD) operation of a boost converter. If the short state is In order to prevent destruction by heat, the thermal canceled, it returns to normal operation. (Fig. 3) shutdown circuit is built in. If the junction temperature Tj is 125oC or more, the thermal shutdown circuit will operate and it will stop switching operation. Moreover, the hysteresis of a thermal shutdown circuit is 15 oC. If Tj falls, output voltage will return. Copyright© 2013 THine Electronics, Inc. All rights reserved. 7/9 THine Electronics, Inc. THL6518_Rev.1.01_E Package Dimensions QFN 16-pin Recommend connecting Back Exposed Pad with GND for a thermal characteristic improvement. Copyright© 2013 THine Electronics, Inc. All rights reserved. 8/9 THine Electronics, Inc. THL6518_Rev.1.01_E Notices and Requests 1. The product specifications described in this material are subject to change without prior notice. 2. The circuit diagrams described in this material are examples of the application which may not always apply to the customer’s design. We are not responsible for possible errors and omissions in this material. Please note if errors or omissions should be found in this material, we may not be able to correct them immediately. 3. This material contains our copyright, know-how or other proprietary. Copying or disclosing to third parties the contents of this material without our prior permission is prohibited. 4. Note that if infringement of any third party's industrial ownership should occur by using this product, we will be exempted from the responsibility unless it directly relates to the production process or functions of the product. 5. This product is presumed to be used for general electric equipment, not for the applications which require very high reliability (including medical equipment directly concerning people's life, aerospace equipment, or nuclear control equipment). Also, when using this product for the equipment concerned with the control and safety of the transportation means, the traffic signal equipment, or various Types of safety equipment, please do it after applying appropriate measures to the product. 6. Despite our utmost efforts to improve the quality and reliability of the product, faults will occur with a certain small probability, which is inevitable to a semi-conductor product. Therefore, you are encouraged to have sufficiently redundant or error preventive design applied to the use of the product so as not to have our product cause any social or public damage. 7. Please note that this product is not designed to be radiation-proof. 8. Customers are asked, if required, to judge by themselves if this product falls under the category of strategic goods under the Foreign Exchange and Foreign Trade Control Law. 9. The product or peripheral parts may be damaged by a surge in voltage over the absolute maximum ratings or malfunction, if pins of the product are shorted by such as foreign substance. The damageｓ may cause a smoking and ignition. Therefore, you are encouraged to implement safety measures by adding protection devices, such as fuses. THine Electronics, Inc. [email protected] Copyright© 2013 THine Electronics, Inc. All rights reserved. 9/9 THine Electronics, Inc.