THV6511_Rev.1.00_E THV6511 Boost converter Description Features THV6511 is a 1 channel boost converter IC. Soft start / Over current protection / Under voltage lock out protection / Thermal shut down are built in. Mounted area is reducible by MSOP-8. ・Input voltage range : 2.5V – 5.5V ・Boost converter Maximum output voltage : 18V Switching limit current : 1.2A Feedback voltage accuracy : +/-1.5% Switching frequency : 640kHz / 1.2MHz ・Protection circuit Soft start Over current protection Under voltage lock out protection Thermal shut down ・MSOP-8pin package Application ･Mobile phone display ・Car Navigator display ･Laptop/Netbook/Tablet PC display Pin Configuration Block Diagram VLS VIN PC 1 8 SS FB 2 7 OSC EN 3 6 VCC GND 4 5 LX VCC EN LX PC UVLO SS Boost FB OSC GND Copyright© 2013 THine Electronics, Inc. All rights reserved. 1/9 OSC THine Electronics, Inc. THV6511_Rev.1.00_E Absolute Maximum Ratings Parameter Symbol VCC VH Pd Tj Tstg VCC voltage LX voltage Power dissipation Junction temperature (*1) Storage temperature range Rating 6.5 26 625 -40 to 125 -55 to +150 Units V V mW ℃ ℃ *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 2.5 - VCC voltage LX voltage Typ - Max 5.5 18 Units V V 0.5 0.4 0.3 0.2 0 0.1 Power Dissipation [W] 0.6 0.7 Power Dissipation -40 -20 0 20 40 60 80 100 120 140 160 Operating Temperature [℃] Copyright© 2013 THine Electronics, Inc. All rights reserved. 2/9 THine Electronics, Inc. THV6511_Rev.1.00_E Pin Description Number Name Function 1 PC Boost converter error amplifier output pin 2 FB 3 4 EN GND 5 LX 6 7 VCC OSC Boost converter feedback voltage sense input pin Enable pin. Ground pin Boost converter switching output pin Input supply voltage pin Oscillator set pin 8 SS Soft start set pin Description This pin is the boost converter error amplifier output. Please connect resistance and capacitor to GND for phase compensation. This pin is feedback input for boost converter. If low level voltage is impressed, PMIC is shutdown. Ground of PMIC. This pin is switching output of boost converter. Power supply pin. Low level voltage is 640kHz, high level voltage is 1.2MHz. This pin is set by soft start for boost converter. Please connect capacitor to GND for soft start time. Copyright© 2013 THine Electronics, Inc. All rights reserved. 3/9 THine Electronics, Inc. THV6511_Rev.1.00_E Electrical Characteristics Parameter （at VCC＝3.3V , Ta=25℃, unless otherwise noted） Symbol Min Typ Max Units Vfb=1.34V(No switching) - 350 500 uA Vfb=1.14V(Switching) - 2 5 mA Ven<(0.3xVCC) - 0.1 1 uA Venh 0.7xVCC - - V Venl - - 0.3xVCC V Ren - 250 - kΩ 1.9 2.0 2.1 V - 0.1 - V Input quiescent Current 1 Icc1 Input quiescent Current 2 Icc2 Standby current Oscillator and Ist EN threshold voltage Oscillator and EN pull down resistance UVLO threshold voltage Vuvlo UVLO hysteresis voltage Vuvloh Boost converter switching Test Conditions VCC rising Fosc1 Vosc<(0.3xVCC) 540 640 740 kHz Fosc2 Vosc>(0.7xVCC) 1.0 1.2 1.4 MHz Dmax 85 90 95 % FB voltage Vfb 1.222 1.240 1.258 V LX ON-resistance Ron - 200 500 mΩ LX current limit Ilim 1.2 1.6 2.0 A LX leakage current Ioff - - 10 uA frequency 1 Boost converter switching frequency 2 Boost converter maximum duty cycle Vlx=18V Soft start charge current Iss - 4 - uA FB short circuit voltage Vuvp - 1 - V FB short circuit delay time Tuvp - 54 - msec Copyright© 2013 THine Electronics, Inc. All rights reserved. 4/9 THine Electronics, Inc. THV6511_Rev.1.00_E current through the inductor equals to the current Function computed by the compensator. This loop acts within one Boost converter switching cycle. A slope compensation ramp is added to The LCD panel VLS supply is generated from a suppress sub-harmonic oscillations. An outer voltage high-efficiency PWM boost converter operating with feedback loop subtracts the voltage on the FB pin from current mode control, and the switching frequency is the internal reference voltage and feeds the difference to selectable 640kHz or 1.2MHz. During the on-period, TON, the compensator operational transconductance amplifier. the synchronous FET connects one end of the inductor to This amplifier is compensated by an external R-C ground, therefore increasing the inductor current. After network to allow the user to optimize the transient the FET turns off, the inductor switching node, LX, is response and loop stability for the specific application charged to a positive voltage by the inductor current. The conditions. freewheeling diode turns on and the inductor current The output voltage VLS can be set by external resistor flows to the output capacitor. divider R1 and R2 connected to FB. The converter operates in continuous conduction mode R VLS VFB 1 1 R2 when the load current IVLS is at least one-half of the inductor ripple current ΔIrip. I IN I rip I rip VLS 2 (VLS VIN ) VIN L FOSC VLS LX R1 FB The output voltage (VLS) is determined by the duty R2 cycle(D) of the power FET on-time and the input voltage, VIN. VLS VIN 1 D Fig. 1 FB setup The average load current, IVLS, can be calculated from [Compensator selection] the power conservation law. This current mode boost converter has a current sense V IN I IN VLS I VLS loop and a voltage feedback loop. The where η is the power conversion efficiency. For a lower loop does not need any load current, the inductor current would decay to zero feedback loop is during the free-wheeling period and the R-C network would be disconnected from the output node current sense compensation. The voltage compensated by an external series RPC and CPC from PC pin to ground. inductor for the RCOMP is set to define the high frequency integrator gain remaining portion of the switching period. The converter for loop bandwidth which relates to the transient would operate in the response. CPC is set to ensure the loop stability. discontinuous conduction mode . Current mode control is well known for its robustness and fast transient response. An inner current feedback [Output capacitor selection] loop sets the on-time and the duty cycle such that the The output voltage ripple due to converter switching is Copyright© 2013 THine Electronics, Inc. All rights reserved. 5/9 THine Electronics, Inc. THV6511_Rev.1.00_E determined by the output capacitor total capacitance, the maximum input and output current that the converter COUT, and the output VLS rip can operate with before reaching the current limit of the D I OUT I peak ESR FOSC COUT I peak I IN chip or the rated current of the inductor. I peak I IN I rip 2 I rip 2 I MAX For example, ΔIrip could be set to 20% of IMAX The first ripple component can be reduced by increasing COUT. Changing COUT may require adjustment of compensation R and C in order to provide adequate Protection circuits phase margin and loop bandwidth. Under voltage lock out protection (UVLO) The second ripple component can be reduced by The UVLO function is carried in order to prevent selecting low-ESR ceramic capacitors and using several malfunction in the state where input voltage is low. A smaller capacitors in parallel instead of just one large boost converter is suspended to the power supply voltage capacitor. which can carry out operational stability. UVLO is released by more than 1.9V input voltage. And a boost [Inductor selection] converter carries out, after starting soft start operation. To prevent magnetic saturation of the inductor core the If the feedback voltage pin FB is below 1V, the inductor has to be rated for a maximum current larger THV6511 activates an internal fault timer. If any than IPK in a given application. Since the chip provides condition indicates a continuous fault for the fault timer current limit protection of 1.6A, it is generally duration 54ms, the IC sets the fault latch to shut down its recommended that the inductor be rated at least for 1.6A. output except the reference. Once the fault condition is Selection of the inductor requires trade-off between the removed, cycle the input voltage (below the UVLO physical size (footprint x height) and its electrical falling threshold) to clear the fault latch and reactivate properties (current rating, inductance, resistance). Within the device. a given footprint and height, an inductor with larger inductance typically comes with lower current rating and often larger series resistance. Larger inductance typically Soft start (SS) requires more turns on the winding, a smaller core gap or The boost converter carries the soft start function in a core material with a larger relative permeability. An order to prevent the rush current at a start-up. This inductor with a larger physical size has better electrical function is to raise output voltage slowly. It is because properties than a smaller inductor. overshooting and rush current occur when input voltage It is desirable to reduce the ripple current ΔIrip in order to is inputted. This function is available in THV6511only. reduce voltage noise on the input and output capacitors. This IC uses a soft start circuit to minimize the inrush In practice, the inductor is often much larger than the current. Connecting a capacitor CSS between SS pin and capacitors and it is easier and cheaper to increase the size ground determines the soft start time TSS. of the capacitors. The ripple current TSS ΔIrip is then chosen the largest possible while at the same time not degrading Copyright© 2013 THine Electronics, Inc. All rights reserved. 6/9 1.24V C SS 4A THine Electronics, Inc. THV6511_Rev.1.00_E If CSS is too small or not present at all, the internal soft start circuit ensures that the soft start period is at least 3.4ms. Over current protection (OCP) In order to restrict the over-current by the abnormalities of load, etc., the over-current protection circuit is built in. Over-current detection of pulse-by-pulse system is adopted. An output transistor is turned off if the current which flows into an output transistor reaches boost converter limit current (Ilim). An over-current protection circuit detects the peak current of an inductor. Input-and-output voltage and ripple current is taken into consideration. Thermal shut down (TSD) In order to prevent destruction by heat, the thermal 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 20oC. If Tj falls, output voltage will return. Copyright© 2013 THine Electronics, Inc. All rights reserved. 7/9 THine Electronics, Inc. THV6511_Rev.1.00_E Package Dimensions MSOP-8pin Copyright© 2013 THine Electronics, Inc. All rights reserved. 8/9 THine Electronics, Inc. THV6511_Rev.1.00_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.