THL6531_Rev.1.01_E THV6531 Boost converter / 2 channel charge pump Description Features THV6531 is a controller IC power supply system with boost converter and 2 channel charge pump circuit. The positive and negative charge pumps provide regulated TFT LCD gate-on and gate-off supplies. The chip includes a VCOM buffer and a gate slop circuit. Soft start / Over current protection / Under voltage lock out protection / Thermal shut down are built in. Mounted area is reducible by 24-pin QFN. ・Input voltage range : 2.5V – 5.5V ・Boost converter Maximum output voltage : 18V Switching limit current : 2.5A Feedback voltage accuracy : +/-1% Switching frequency : 1.2MHz ・Positive charge pump Feedback voltage accuracy : +/-1.5% Switching frequency : 600kHz ・Negative charge pump Feedback voltage accuracy : +/-5% Switching frequency : 600kHz ・Operational amplifier Output short-circuit current : +/-200mA ・Gate slop ・Detector ・Protection circuit Soft start Over current protection Under voltage lock out protection Thermal shut down ・4mm x 4mm QFN 24pin package Application ･Mobile phone display ・Car Navigator display ･Laptop/Netbook/Tablet PC display AMP_NON V_VGH GOUT GR LX PGND Block Diagram GDELAY Pin Configuration 24 23 22 21 20 19 1 VLS VIN FB PC LX VCC 18 PGND Boost PGND OSC AMP_INV 2 17 FB AMP_OUT 3 16 PC VIN VGH DOUT VGH_OUT Exposed Thermal Pad AGND2 4 AVDD UVLO DIN 1/2OSC Detector (Top view) 15 DIN VGH_FB VCC V_VGH 25 GNDEXP AVDD 5 GDELAY 14 AGND1 VGH_OUT GR 13 VCC 6 8 9 10 11 12 VGL_OUT GIN DOUT VGH_FB VGL_FB VREF VREF 7 VGHM GOUT Gate slope GIN OSC VREF OSC 1/2OSC VLS AVDD VGL_FB VGL AMP_NON AVDD VGL_OUT AMP_OUT VCOM 1/2OSC AMP_INV AGND1 Copyright© 2013 THine Electronics, Inc. All rights reserved. 1/11 AGND2 THine Electronics, Inc. THL6531_Rev.1.01_E Absolute Maximum Ratings Parameter Symbol VCC VH1 VH2 VL Pd Tj Tstg VCC voltage AVDD, LX voltage V_VGH voltage DOUT, DIN, VDIN, GIN voltage Power dissipation Junction temperature (*1) Storage temperature range Rating 6.5 22 38 6.5 2.28 125 -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 2.5 6 - VCC voltage AVDD voltage V_VGH voltage Typ - Max 5.5 18 36 Units V V V 2.5 2.0 1.5 1.0 0 0.5 Power Dissipation [W] 3.0 3.5 Power Dissipation -40 -20 0 20 40 60 80 100 120 140 160 Operating Temperature [℃] Copyright© 2013 THine Electronics, Inc. All rights reserved. 2/1１ THine Electronics, Inc. THL6531_Rev.1.01_E Pin Description Number Name Function Operational amplifier non-inverting input pin Operational amplifier inverting input pin Operational amplifier output pin 1 AMP_NON 2 AMP_INV 3 AMP_OUT 4 AGND2 5 AVDD 6 VGH_OUT 7 VGL_OUT 8 9 GIN DOUT 10 VGH_FB 11 VGL_FB 12 VREF 13 14 15 VCC AGND1 DIN 16 PC 17 FB 18, 19 PGND 20 LX 21 GR Gate slop set pin 22 GOUT 23 V_VGH 24 GDELAY Gate slop output pin Supply voltage for gate slop pin Gate slop start delay input pin 25 GND EXP Analog Ground pin Charge pump supply and operational amplifier supply pin Positive charge pump output pin Negative charge pump output pin Gate slop input pin Detector output pin Positive charge pump feedback sense input pin Negative charge pump feedback sense input pin Reference output voltage pin Supply voltage pin Analog ground pin Detector input pin Boost converter error amplifier output pin Boost converter feedback voltage sense input pin Power ground pins Boost converter switching output pin Back side Description This pin is the non-inverting input of operational amplifier. This pin is the inverting input of operational amplifier. This pin is output of operational amplifier. This pin is ground of operational amplifier, positive charge pump, negative charge pump. This pin is input supply for operational amplifier, positive charge pump. This pin is output for positive charge pump. This pin is output for negative charge pump. This pin is input for gate slop timing. This pin is output for detector. GIN is an open-drain output. This pin is feedback input for positive charge pump. This pin is feedback input for negative charge pump. This pin is reference voltage for negative charge pump. Please connect capacitor to GND for stable voltage. Power supply pin. Analog ground of PMIC. This pin is input for detector. 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. Power ground of boost converter. This pin is switching output of boost converter. This pin is controlled gate slop voltage by external resistance. This pin is output for gate slop. This pin is input supply for gate slop circuit. This pin is set by delay for gate slop start time. GND EXP should be soldered to GND to improve the thermal characteristics. Copyright© 2013 THine Electronics, Inc. All rights reserved. 3/1１ THine Electronics, Inc. THL6531_Rev.1.01_E Electrical Characteristics （at VCC＝5V ,AVDD=13V , Ta=25℃, unless otherwise noted） Parameter Symbol Test Conditions Min Typ Max Units System supply Input quiescent Current 1 Icc1 Vfb=1.35V(No switching) - 0.6 0.9 mA Input quiescent Current 2 Icc2 Vfb=1.15V(Switching) - 3 4.5 mA Reference voltage Vref Iref=-50uA 1.238 1.250 1.262 V - - 5 mV - - 5 mV 2.15 2.25 2.35 V Reference Load Regulation Line Regulation voltage Reference voltage dVref1 dVref2 Iref=0uA to -100uA Iref=-100uA VCC=2.5V to 5.5V UVLO threshold voltage Vuvlo UVLO hysteresis voltage dVuvloh - 0.1 - V Tscp 47 55 65 msec Vfb 1.238 1.250 1.262 V Ifb -40 0 40 nA Fosc1 1.0 1.2 1.4 MHz Dmax 86 90 94 % LX ON-resistance Ron1 - 160 - mΩ LX leakage current Ileak - - 20 uA LX current limit Ilim 2.5 3 3.5 A FB Soft start Tss - 14 - msec Vuvp1 0.95 1 1.05 V Vfbp 1.230 1.250 1.270 V Short circuit delay time VCC rising Boost converter FB voltage FB input bias current Boost converter switching frequency Boost converter maximum duty cycle FB short circuit voltage Vlx=19V Positive charge pump Regulator FBP voltage FBP input bias current Ifbp_bias -40 0 40 nA FBP Switching frequency Fosc2 - 1/2Fosc1 - MHz FBP high-side ON-resistance Ron2h Vavdd=10V - 3 6 Ω FBP low-side ON-resistance Ron2l Vavdd=10V - 3 6 Ω FBP Soft start Tss2 - 3.4 - msec Vuvp2 0.95 1 1.05 V Vfbn 0.235 0.250 0.265 V FBP short circuit voltage Negative charge pump Regulator FBN voltage FBN input bias current Ifbn_bias -40 0 40 nA FBN Switching frequency Fosc3 - 1/2Fosc1 - MHz FBN high-side ON-resistance Ron3h Vavdd =10V - 3 6 Ω FBN low-side ON-resistance Ron3l Vavdd =10V - 3 6 Ω FBN Soft start Tss3 - 3.4 - msec Vuvp3 0.4 0.45 0.5 V FBN short circuit voltage Copyright© 2013 THine Electronics, Inc. All rights reserved. 4/1１ THine Electronics, Inc. THL6531_Rev.1.01_E Parameter Symbol Test Conditions Min Typ Max Units Operational amplifier AVDD quiescent Current Iavdd Input offset voltage Voff Input bias current Iamp_non Input common-mode voltage Vamp_non Vamp_non=1/2VLS Output high voltage Vout_h Iamp_out=20mA Output low voltage Vout_l Iamp_out=-20mA Slew rate Short circuit high current Short circuit low current SR Vamp_out=20% to 80% CL=10pF, RL=10kΩ - 2 - mA - 2 15 mV -40 - 40 nA 0 - AVDD V - - V - - 0.35 V - 40 - AVDD0.35 V/ usec Iamp_h Vamp_out=0V - 200 - mA Iamp_l Vamp_out=AVDD - 200 - mA Vuvloavdd - 4 - V Vovp 19 20 21 V Detector threshold voltage Vdet 1.225 1.250 1.275 V Detector hysteresis voltage dVdeth - 50 - mV Detector input bias current Idet_in -40 0 40 nA Detector output voltage Vdet_o - - 0.2 V - 163 - msec AVDD UVLO threshold voltage AVDD over voltage protection threshold Detector Detector output delay Idet=1mA Tdet Gate slope VGH input current 1 Ivgh1 Vgin>2V - - 600 uA VGH input current 2 Ivgh2 Vgin<0.6V - - 300 uA VGIN input bias current -40 0 40 nA Propagation delay Tdelay Igin V_vgh=25V - 100 - nsec VGH to GOUT ON-resistance Ron2h Vavdd=10V - 15 30 Ω GOUT to GR ON-resistance Ron2l Vavdd=10V - 30 60 Ω GOUT pull down resistance Rvgm - 2.5 - kΩ Copyright© 2013 THine Electronics, Inc. All rights reserved. 5/1１ THine Electronics, Inc. THL6531_Rev.1.01_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 1.2MHz. During the on-period, TON, the synchronous the compensator operational transconductance amplifier. FET connects one end of the inductor to ground, This amplifier is compensated by an external R-C therefore increasing the inductor current. After the FET network to allow the user to optimize the transient turns off, the inductor switching node, LX, is charged to response and loop stability for the specific application 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 Fig. 1 VIN 1 D 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 VIN I IN VLS IVSL 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. 6/1１ THine Electronics, Inc. THL6531_Rev.1.01_E determined by the output capacitor total capacitance, of the capacitors. The ripple current COUT, and the output VLS rip the largest possible while at the same time not degrading D I OUT I peak ESR FOSC COUT I peak I IN ΔIrip is then chosen the maximum input and output current that the converter can operate with before reaching the current limit of the I rip chip or the rated current of the inductor. 2 I peak I IN The first ripple component can be reduced by increasing COUT since FOSC is fixed 1.2MHz(typ). Changing COUT I rip 2 I MAX For example, ΔIrip could be set to 20% of IMAX may require adjustment of compensation R and C in order to provide adequate phase margin and loop Voltage detector circuit bandwidth. The second ripple component can be reduced by During power-up, once VIN exceeds VUVLO, the controller initiates a 163ms blanking period during which selecting low-ESR ceramic capacitors and using several the input voltage at DIN is ignored and the DOUT pin is smaller capacitors in parallel instead of just one large floated to high impedance. An external pull up resistor capacitor. should pull DOUT high. After this blanking period, the DIN function is enabled, with DOUT driven low if DIN falls below VDIN, or floated high if DIN rises above VDIN. [Inductor selection] To the external voltage Vext, the rising and falling To prevent magnetic saturation of the inductor core the detection thresholds VDET,High and VDET,Low, respectively inductor has to be rated for a maximum current larger than IPK in a given application. Since the chip provides current limit protection of 3A, it is generally are set by the external voltage divider R3, R4. VDet , High R4 R3 (VDin VDin ) R3 VDet , Low R4 R3 VDin R3 recommended that the inductor be rated at least for 3A. Selection of the inductor requires trade-off between the physical size (footprint x height) and its electrical properties (current rating, inductance, resistance). Within VIN a given footprint and height, an inductor with larger inductance typically comes with lower current rating and often larger series resistance. Larger inductance typically R3 requires more turns on the winding, a smaller core gap or DIN a core material with a larger relative permeability. An inductor with a larger physical size has better electrical R4 properties than a smaller inductor. It is desirable to reduce the ripple current ΔIrip in order to reduce voltage noise on the input and output capacitors. Fig. 2 Detector setup In practice, the inductor is often much larger than the capacitors and it is easier and cheaper to increase the size Copyright© 2013 THine Electronics, Inc. All rights reserved. 7/1１ THine Electronics, Inc. THL6531_Rev.1.01_E VGL Positive charge pump (VGH) The positive charge pump is used to generate the TFT LCD gate on voltage. The output voltage, VGH, can be VGL_OUT set by an external resistive divider. R8 VGL_FB Voltage VVGH_FB is typically 1.25V. A single stage charge pump can produce an output voltage less than R7 approximately twice the charge pump input voltage VLS. VREF The maximum voltage VGH should not exceed 36V if it is used to supply the Gate slope circuit. The output voltage VGH is regulated as the following equation. VGH VVGH _ FB R5 R6 R5 Fig. 4 VGL setup VLS Gate slope The Gate slope is a flicker compensation circuit to VGH_OUT reduce the coupling effect of gate lines, and is controlled VGH by timing controller to modulate GOUT, the Gate-On voltage. This block is not activated until the below 3 R6 conditions are satisfied: 1) The input voltage exceeds its VGH_FB UVLO, 2) No fault condition is detected, and 3) R5 GDELAY exceeds its turn-on threshold. Once Gate slope Fig. 3 VGH setup activates and GIN is high, the internal switch between V_VGH and GOUT turns on and the switch between Negative charge pump (VGL) GOUT and GR turns off. If GIN is low, the internal The negative charge pump is used to generate the TFT switch between V_VGH and GOUT turns off and the LCD gate off voltage. The output voltage, VGL, is set switch between GOUT and GR turns on. At that time, with an external resistive divider from its output to the falling time and delay time of the Gate-On voltage VREF with the midpoint connected to VGL_FB. The are programmable by an external resistor connected error amplifier compares the feedback signal from between GR and GND. VGL_FB with an internal reference 250mV. The output voltage VGL is regulated as the following equation. VGL VVGL _ FB R8 (VVREF VVGL _ FB ) R7 Operational amplifier The operational amplifier is typically used for LCD VCOM buffer. The VCOM buffer generates the bias supply for the back plane of an LCD screen which is capacitively coupled to the pixel drive voltage. The Copyright© 2013 THine Electronics, Inc. All rights reserved. 8/1１ THine Electronics, Inc. THL6531_Rev.1.01_E purpose of the VCOM buffer is to hold the bias voltage steady while pixel voltage changes dynamically. The Soft start (SS) buffer is designed to sustain up to ±200mA of output The boost converter carries the soft start function in short-circuit current. In transients, it can deliver up to order to prevent the rush current at a start-up. This 200mA at which point the over current protection circuit function is to raise output voltage slowly. It is because limits the output current. Excessive current draw over a overshooting and rush current occur when input voltage period of time may cause the chip temperature to rise and is inputted. set off the over temperature protection circuit. The soft-start time of the boost controller is 14ms, and the soft-start time of positive and negative charge pump is 3.4ms. Protection circuits Under voltage lock out protection (UVLO) The UVLO function is carried in order to prevent Over current protection (OCP) malfunction in the state where input voltage is low. A In order to restrict the over-current by the abnormalities boost converter is suspended to the power supply voltage of load, etc., the over-current protection circuit is built in. which can carry out operational stability. UVLO is Over-current detection of pulse-by-pulse system is released by more than 2.25V input voltage. And a boost adopted. An output transistor is turned off if the current converter carries out, after starting soft start operation. which flows into an output transistor reaches boost During steady-state operation, if the feedback voltage pin converter limit current (Ilim). An over-current protection FB is below 1V of the nominal value, the THV6531 circuit detects the peak current of an inductor. activates an internal fault timer. If any condition Input-and-output voltage and ripple current is taken into indicates a continuous fault for the fault timer duration consideration. 55ms, the IC sets the fault latch to shut down all its outputs except the reference. Once the fault condition is removed, cycle the VIN (below the UVLO falling Thermal shut down (TSD) threshold) to clear the fault latch and reactivate the In order to prevent destruction by heat, the thermal device. The fault-detection circuit is disabled during the shutdown circuit is built in. If the junction temperature soft-start ramp. Tj is 125oC or more, the thermal shutdown circuit will The positive and negative charge pump controller also operate and it will stop switching operation. Moreover, provide the under voltage protection function during the hysteresis of a thermal shutdown circuit is 15 oC. If steady-state operation. If VGH_FB voltage is lower than Tj falls, output voltage will return. 1V or VGL_FB voltage is higher than 0.45V, and the fault duration is over 55ms, the IC sets the fault latch to shut down all its outputs as well. Copyright© 2013 THine Electronics, Inc. All rights reserved. 9/1１ THine Electronics, Inc. THL6531_Rev.1.01_E Package Dimensions QFN 24-pin Recommend connecting Back Exposed Pad with GND for a thermal characteristic improvement. Copyright© 2013 THine Electronics, Inc. All rights reserved. 10/1１ THine Electronics, Inc. THL6531_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. 11/1１ THine Electronics, Inc.