MP4653 Real LIPS CC/CV Mode LLC TV LED Driver The Future of Analog IC Technology DESCRIPTION The MP4653 is a CC/CV mode LLC TV LED driver for LED backlighting, especially for large size TV LED backlighting. Powered by 9V to 30V input supplies, the MP4653 outputs two 180 degree phase shifted driving signals for the external power stages. Its enhanced 9V gate driver provides adequate driving capability and can directly drive the external MOSFETs through an external gate driving transformer. The MP4653 integrates a constant current control loop for the LED current regulation and also a constant voltage control loop for the DC bus voltage, which is used to generate system power supplies like 12V/5V with other DC/DC converters. The CC/CV control loop programs the operating frequency of the LLC power stage and thus regulates the LED current and also the bus voltage. The MP4653 incorporates both analog dimming and PWM dimming to the LED current. A driving signal is output to directly drive the dimming MOSFET, which helps to achieve fast and high contrast ratio PWM dimming. The PWM dimming signal is also used for the CC/CV mode control. At PWM on interval, the CC mode is effective and the LED current is regulated; at PWM off interval, the CV mode is effective and the DC bus voltage is regulated. The gate driving signal and thus the energy through the power stage are continuous at both the PWM on interval and the PWM off interval. This helps to eliminate the system audible noise at PWM dimming. The MP4653 features sufficient and smart protection to increase system reliability. It protects the fault condition at both the DC bus stage and the LED driver stage. The protection for the DC bus stage includes the over voltage protection and over current protection (short protection). MP4653 Rev 1.01 6/28/2012 The protection for the LED driver stage includes the open LED protection, short LED protection, over LED current protection and any point of LED string short to ground protection. Thermal protection is integrated in MP4653. The MP4653 is available in SOIC20 package. FEATURES Secondary Side “Real LIPS” LLC Controller CC/CV Frequency Control Loop Audible Noise Elimination Continuous driving signal at PWM dimming and LED fault condition 9V to 30V Input Voltage Range Analog and PWM Dimming Input Under Voltage Lockout DC Bus Output Over Voltage Protection DC Bus Short Protection System Auto-recovery and Hiccup Timer LED Open, Short Protection LED Output Over Voltage, Over LED Current Protection Any Point of LED String Short to GND Protection Available in SOIC 20 Package APPLICATIONS LCD TVs and Monitors Desktop LCD Flat Panel Displays Flat Panel Video Displays Street Lighting All MPS parts are lead-free and adhere to the RoHS directive. For MPS green status, please visit MPS website under Products, Quality Assurance “MPS” and “The Future of Analog IC Technology” are Registered Trademarks of Monolithic Power Systems, Inc. www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 1 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER TYPICAL APPLICATION CI 400 V GND VFB T1 MP4653 Rss RFSET VOCP VFB CVCOMP RVCOMP CICOMP RICOMP IFB RVFBH CVbus RSS_FSET Css Vbus T2 400V 1 2 3 SS FSET GND VOCP GL 4 VFB 5 6 7 GR VCC VCOMP PWMOUT ICOMP IFB VIN PWMIN Q1 RVFBL RVOCP 20 VOCP 19 CDRV 18 17 16 15 CVCC Q2 PWMOUT CIN ROVPH Cr Co OVP . . . ROVPL 14 400 V GND OCP 8 SSD 9 OVP 10 A- Dim A- Dim 13 VLED4 VLED1 VLED3 VLED2 12 11 MP MN ROCP PWMOUT IFB Rsense OCP PWM Vbus VIN PWMOUT MP4653 Rev 1.01 6/28/2012 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 2 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER ORDERING INFORMATION Part Number* MP4653GY Package SOIC20 Top Marking MP4653 * For Tape & Reel, add suffix –Z (eg. MP4653GY–Z); PACKAGE REFERENCE MP4653 1 2 3 SS FSET GND VOCP GL 4 VFB 5 6 7 10 VCC VCOMP PWMOUT ICOMP IFB 8 SSD 9 GR VIN PWMIN 20 19 18 17 16 15 14 A- Dim 13 VLED4 VLED1 VLED3 VLED2 12 11 ABSOLUTE MAXIMUM RATINGS (1) Thermal Resistance Supply Voltage Vin.........................-0.3V to +38V GL,GR,VCC, PWMOUT ....................... -0.5V to 10.7V SSD, VOCP ...................................-6.5V to + 4V Other pins .......................................-0.5V to +7V Junction Temperature ...............................150C (2) Continuous Power Dissipation (TA = +25°C) ............................................................ 1.7 W Storage Temperature............... -65C to +150C Operating frequency .............................. 300kHz SOIC20 .................................. 72 ...... 30... C/W Recommended Operating Conditions (3) Supply Voltage Vin.........................-0.3V to +30V operating frequency ................ 20kHz to 250kHz Operating Junction Temp ....... -40C to +125C MP4653 Rev 1.01 6/28/2012 (4) θJA θJC 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. © 2012 MPS. All Rights Reserved. 3 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER ELECTRICAL CHARACTERISTICS VIN = 12V, TA = +25C, unless otherwise noted. Parameter Symbol Gate driver GL, GR Gate Pull-Down Gate Pull-Up Output Source Current Output Sink Current Dead time Gate Driver Supply Voltage (VCC) Voltage RGD RGU ISOURCE ISINK tdead VVCC Current IVCC Vin UVLO threshold VTH_UVLO_VIN VCC UVLO Hysteresis VTH_VIN_HYST Brightness Dimming Control Range Analog Dimming Full Scale VA-dim PWM Logic Input Threshold VTH-PWM PWM Logic Input Hysteresis VTH-PWM-Hyst Supply Current Supply Current IIN Operating Frequency Minimum Frequency Set Voltage VFSET SS pin voltage Vss Condition Typ 600 2 7.5 1 [5] 2 [5] 750 Igate = 20mA Igate = 20mA With 1nF load With 1nF load IVCC=0mA IVCC=30mA 9 8.8 Max Units 900 Ω Ω A A ns 9.4 9.3 20 4.35 240 9.8 1.18 1.9 0.5 1.23 2.2 V V V 1.6 2.5 mA 0.95 1.45 1 1.49 1.05 1.53 V V 35.6 38.6 41.6 kHz 2.2 2.5 2.8 Fmin 9V 9.4 9.8 V 0.3 V VCC rising 4.2 Analog dimming PWM dimming PWM dimming 1.13 1.6 No driver output At normal operation RFSET=RSS_FSET=40kΩ, IFB=0.1V(ICOMP=2.2V), Minimum operating frequency Fmin_op PWMIN=high RFSET=RSS_FSET=40kΩ,, Maximum Operating Frequency Fmax_op IFB=0.21V(ICOMP=1V), PWMIN=high Output PWM Dimming Signal for LED (PWMOUT) Logic High Voltage VH-PWMOUT Normal Operation At Fault Condition, Logic Low Voltage VL-PWMOUT or PWMIN=0 Output PWM Source Current ISOURCE_PWMOUT 100pF on PWMOUT pin Output PWM Sink Current ISINK_PWMOUT 100pF on PWMOUT pin LED Current Feedback (IFB) Magnitude |VIFB| LED Short Threshold for VIFBS Immediate action LED short detection blanking time Tblank MP4653 Rev 1.01 6/28/2012 Min 50 4.5 5 100 V V mA V mV mA mA 0.192 0.2 0.208 V 540 600 660 mV 100 140 180 ns www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 4 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER ELECTRICAL CHARACTERISTICS (continued) VIN = 12V, TA = +25C, unless otherwise noted. Parameter Symbol Condition LED short threshold for slow VIFBSC action Delay time for slow action Tdelay_IFB 300mV<VIFB<600mV Internal Current Loop Compensation Transconductance Opamp (ICOMP) Gain Bandwidth product GB_I 75pF on ICOMP Open Loop DC Gain AV_I ICOMP open Input Common-mode range VCM_I Transconductance Gm_I Saturated output current Isat_I Low level clamp voltage VICOMP_L Normal operation High level clamp votlage VICOMP_H Normal operation DC Bus Voltage Feedback (VFB) Sampling Delay Time Tdealy_sample PWM falling edge Minimum clamp voltage Vmin_clamp_VFB Min Typ Max Units 270 300 330 mV 100 200 350 μs 1.0[6] 830 50 1 2.2 65 1.05 2.25 MHz dB V μA/V μA V V 1.2 100[6] 1.3 ns V 2 2.1 V 1.05 2.25 35 1 2.2 160 50 65 MHz dB V V μA/V μA 2.25 2.40 2.55 V 1.7 14.7 19 2.3 16.3 23 2.9 17.9 27 μs kΩ 0.35 2.7 0.45 3 0.55 3.3 V V 1.6 2 2.4 µA 1.6 2 2.4 µA 0.35 0.45 0.55 V [6] 60 -0.3[6] 35 0.95 2.15 1.1 1.9 Internal Voltage Loop Compensation Transconductance Opamp (VCOMP) Maximum clamp voltage Vmax_clamp_VFB Gain Bandwidth product GB_V Open Loop DC Gain AV_V Low level clamp voltage VVCOMP_L High level clamp votlage VVCOMP_H Transconductance Gm_V Saturated output current Isat_V Over LED Voltage Protection (VLED1~VLED4) Over LED Voltage Protection VTH(OVP_LED) Threshold Over LED voltage delay time Tdelay_VLED Gain of differential voltage Internal resistance RVLED Hiccup mode fault delay timer(ICOMP, VCOMP) ICOMP Valley Threshold Vth_low(ICOMP) ICOMP Peak Threshold Vth_peak(ICOMP) ICOMP charging current at hiccup Icharge_fault(ICOMP) mode ICOMP discharging current at Idischarge_fault(ICOM hiccup mode P) VCOMP Valley Threshold Vth_low(VCOMP) MP4653 Rev 1.01 6/28/2012 75pF on VCOMP VCOMP open Normal operation Normal operation 4[6] 1.0[6] 60[6] 0.95 2.15 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 5 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER ELECTRICAL CHARACTERISTICS (continued) VIN = 12V, TA = +25C, unless otherwise noted. Parameter Symbol Condition VCOMP Peak Threshold Vth_peak(VCOMP) VCOMP charging current at Icharge_fault(VCOMP) hiccup mode VCOMP discharging current at Idischarge_fault(VCO hiccup mode MP) Burst mode (Pulse Skipping) threshold (VCOMP, ICOMP,VFB, IFB) VCOMP threshold for burst mode VTH_burst_VCOMP VFB>1.1VSH VCOMP hysteresis for burst mode VFB threshold for burst mode VTH_burst_VFB VFB reset threshold for burst VTH_reset_burst_VFB mode ICOMP threshold for burst mode VTH_burst_ICOMP VIFB>1.1VIFB_REF ICOMP hysteresis for burst mode IFB threshold for burst mode VTH_burst_IFB IFB reset threshold for burst VTH_reset_burst_IFB mode Over Bus Voltage Protection (VFB) Over bus Voltage Protection VTH(OVP_VFB) Threshold Delay Time VFB>2.4V Short LED stage Detection (SSD) SSD Threshold VTH_SSD SSD Detection Delay Time TD_SSD SSD<-200mV Short Bus Stage Detection (OCP) OCP detection threshold VTH_OCP OCP delay time TD_OCP OCP<-100mV Min Typ Max Units 2.7 3 3.3 V 1.6 2 2.4 µA 1.6 2 2.4 µA 1.05 1.1 1.15 V 70 90 110 mV 1 1.1 1.2 VSH 1 1.05 70 1 1.1 90 1.1 VSH 1.15 110 1.2 1 V mV VIFB_REF VIFB_REF 2.25 2.40 2.55 V 1.7 2.3 2.9 µs -225 1.8 -200 2.4 -175 3 mV µs -120 -100 -80 mV 1.8 2.4 3 µs *: For design reference, not test parameter. [5]: for bench evaluation only [6]: for design only, not to be test MP4653 Rev 1.01 6/28/2012 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 6 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER TYPICAL CHARACTERISTICS IFB Voltage Line Regulation 9.4 101.0 VCC Load Regulation VCC Line Regulation VIN=12V IVCC=20mA 10 9 VCC VOLTAGE (V) 100.5 100.0 99.5 VCC VOLTAGE (V) 9.2 9.0 8.8 8.6 8.4 5 10 15 20 25 INPUT VOLTAGE (V) 8.0 30 0 10 20 30 40 50 LOAD CURRENT (mA) I_IN(mA) 20 4.4 1.4 1.0 0.8 0.6 9.40 4.12 4.1 4.08 4.06 4.04 4.02 4 -50 -30 -10 10 30 50 70 90110130 MP4653 Rev 1.01 6/28/2012 4.37 4.36 4.35 4.34 4.33 Dead Time vs. Temperature IVCC=30mA 840 820 9.35 4.14 VCC_30mA( V) CHAR_UVLO_F( V) 4.16 4.38 4.3 -50 -30 -10 10 30 50 70 90110130 VCC vs. Temperature 4.18 30 4.31 0 -50 -30 -10 10 30 50 70 90 110130 VUVLO_falling vs. Temperature 10 15 20 25 INPUT VOLTAGE (V) 4.32 0.2 0 -50 -30 -10 10 30 50 70 90 110130 5 4.39 0.4 10 3 VUVLO_rising vs. Temperature 9.30 9.25 9.20 T_DEAD(nS) VIN_BV( V) 30 4 1.6 1.2 40 5 0 60 CHAR_UVLO_R( V) 50 6 1 Supply Current vs. Temperature 60 7 2 8.2 99.0 8 800 780 760 740 9.15 720 9.10 -50 -30 -10 10 30 50 70 90 110130 700 -50 -30 -10 10 30 50 70 90 110130 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 7 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER TYPICAL CHARACTERISTICS (continued) 1.192 0.202 1.191 1.498 0.202 1.496 0.201 1.494 0.201 1.492 1.490 1.190 VA-DIMH( V) V_IFB( V) 0.202 1.500 0.201 0.201 1.189 1.188 1.187 1.488 0.201 1.486 0.200 1.484 0.200 1.185 1.482 -50 -30 -10 10 30 50 70 90 110130 0.200 -50 -30 -10 10 30 50 70 90 110130 1.184 -50 -30 -10 10 30 50 70 90 110130 VICOMP_clampL vs. Temperature 2.220 1.186 VICOMP_clampH vs. Temperature 38.3 2.215 0.996 0.994 0.992 VVFB_clamp_L vs. Temperature 2.205 2.200 2.195 2.190 VCLAMP_VFB_H( V) 1.192 VVFB_clamp_H vs. Temperature 2.010 2.005 2.000 1.995 1.190 1.990 1.188 -50 -30 -10 10 30 50 70 90 110130 1.985 -50 -30 -10 10 30 50 70 90 110130 MP4653 Rev 1.01 6/28/2012 37.8 37.6 -50 -30 -10 10 30 50 70 90 110130 2.015 1.194 37.9 2.180 -50 -30 -10 10 30 50 70 90 110130 1.202 1.196 38.0 37.7 2.020 1.198 38.1 2.185 1.204 1.200 FMIN_OP_CV(KHZ) 0.998 38.2 2.210 RVLED vs. Temperature 35 30 R_LED_IN(KOHM) 1.000 0.990 -50 -30 -10 10 30 50 70 90 110130 VCLAMP_VFB_L( V) VA-dim vs. Temperature 1.502 1.002 V_ICOMP_CLAMPL( V) VIFB vs. Temperature V_ICOMP_CLAMPH( V) V_SS( V) VSS vs. Temperature 25 20 15 10 5 0 -50 -30 -10 10 30 50 70 90 110130 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 8 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER TYPICAL CHARACTERISTICS (continued) VVFB_OVP vs. Temperature -0.15 2.43 -0.16 2.42 -0.17 -0.18 -0.19 V_VFB_OVP( V) 2.425 2.420 2.415 2.410 2.405 2.400 2.395 2.390 2.385 2.380 2.375 2.370 -50 -30 -10 10 30 50 70 90 110130 VSSD vs. Temperature V_SSD( V) CHAR_LED1_OVP( V) VVLED_OVP vs. Temperature 2.41 2.40 2.39 2.38 -0.20 2.37 -0.21 -50 -30 -10 10 30 50 70 90 110130 2.36 -50 -30 -10 10 30 50 70 90 110130 VVOCP_OCP vs. Temperature -0.080 V_VOCP_OCP( V) -0.085 -0.090 -0.095 -0.100 -0.105 -0.110 -50 -30 -10 10 30 50 70 90 110130 MP4653 Rev 1.01 6/28/2012 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 9 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER TYPICAL PERFORMANCE CHARACTERISTICS (continued) Performance waveforms are tested on the evaluation board of the Design Example section. VIN = 12V, 400V_bus=380V, VLED = 120V, ILED=130mA*4 strings, DC/DC output=12V/1.5A, TA = 25°C, unless otherwise noted. Efficiency vs. V400V_bus PWM Dimming Curve 91.1 LED CURRENT (mA) 91.1 91.0 91.0 90.9 90.9 90.8 90.8 90.7 360 365 370 375 380 385 390 395 400 VIN (V) MP4653 Rev 1.01 6/28/2012 600 600 500 500 LED CURRENT (mA) 91.2 Analog dimming curve 400 300 200 100 0 0 20 40 60 80 100 120 400 300 200 100 0 0 0.2 0.4 0.6 0.8 1 1.2 1.4 ADIM VOLTAGE (V) www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 10 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER TYPICAL PERFORMANCE CHARACTERISTICS (continued) Performance waveforms are tested on the evaluation board of the Design Example section. VIN = 12V, 400V_bus=380V, VLED = 120V, ILED=130mA*4 strings, DC/DC output=12V/1.5A, TA = 25°C, unless otherwise noted. Start Up with CV Mode 12V OUTPUT 10V/div. Start Up with CC Mode VGL 5V/div. VGL 5V/div. VGR 5V/div. VFSET 500mV/div. VBUS 10V/div. VIN_IC 10V/div. VFSET 1V/div. VBUS 10V/div. VBUS 5V/div. IPRI 1A/div. ILED 200mA/div. Shut Down at CC Mode VGL 5V/div. VFSET 1V/div. VBUS 5V/div. ILED 200mA/div. Steady State VGL 5V/div. VFSET 500mV/div. VBUS 5V/div. ILED 200mA/div. VFSET 500mV/div. VBUS 5V/div. ILED 200mA/div. PWM Dimming+ Analog Dimming ADIM=0.655V VFSET 500mV/div. VBUS 5V/div. ILED 200mA/div. MP4653 Rev 1.01 6/28/2012 PWM Dimming, 50%, 480Hz VGL 5V/div. Analog Dimming VGL 5V/div. Shut Down at CV Mode VGL 5V/div. VFSET 500mV/div. VBUS 5V/div. ILED 200mA/div. Open LED Protection VGL 5V/div. VOPEN 50V/div. VICOMP 1V/div. VBUS 5V/div. www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 11 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER TYPICAL PERFORMANCE CHARACTERISTICS (continued) Performance waveforms are tested on the evaluation board of the Design Example section. VIN = 12V, 400V_bus=380V, VLED = 120V, ILED=130mA*4 strings, DC/DC output=12V/1.5A, TA = 25°C, unless otherwise noted. Open LED Protection Recovery VGL 5V/div. VOPEN 50V/div. VICOMP 1V/div. VBUS 5V/div. Short LED+ to LEDProtection Short LED+ to LEDRecover VGL 5V/div. VGL 5V/div. VICOMP 1V/div. VBUS 5V/div. ILED 500mA/div. VICOMP 1V/div. VBUS 5V/div. ILED 500mA/div. Short LED- to GND Protection Short LED- to GND Recover VSSD 100mV/div. VSSD 100mV/div. VICOMP 1V/div. VBUS 5V/div. VICOMP 1V/div. VBUS 5V/div. ISHORT 500mA/div. ISHORT 500mA/div. Short LED+ to GND Protection and Recovery VSSD 500mV/div. VBUS 5V/div. VICOMP 1V/div. ILED 500mA/div. Short DC bus to GND Protection and Recover VCOP 100mV/div. VBUS 10V/div. VGL 5V/div. VCOMP 2V/div. MP4653 Rev 1.01 6/28/2012 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 12 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER PIN FUNCTIONS Pin # 1 2 3 4 5 6 7 8 Name Description Soft Start. This pin functions soft start and also sets the operating frequency together with FSET pin. Connect a resistor (RSS_FSET) in parallel with a resistor (Rss) and a capacitor (Css) in series to this pin. The sourcing current of this pin together with the sourcing current of FSET pin determines the operating frequency. The resistor RSS_FSET together with the resistor on FSET pin sets the operating frequency; the resistor Rss and the capacitor Css functions SS the soft start. The normal voltage on this pin is 1.49V and is pulled low to 0V at bus voltage stage fault condition. The Rss and Css network sets the start up operating frequency and the soft start time. Frequency Set. Connect a resistor from this pin to GND. The operating frequency is determined by the sourcing current through this pin and SS pin. The voltage of FSET pin is FSET programmed by the current control loop and the voltage control loop, and so does the operating frequency. Over current protection of bus stage. This pin senses the secondary current of the bus stage, VOCP when the VOCP voltage is lower than -100mV, IC triggers bus stage protection. Bus voltage feedback. This pin feeds back the bus voltage for regulation. MP4653 automatically samples the VFB voltage at PWM ON interval and uses it as the reference voltage of the bus voltage control loop at PWM OFF interval. VFB The voltage on VFB pin is also used for over voltage protection of bus voltage stage. When the voltage on VFB pin exceeds 2.4V, the over voltage protection of bus voltage stage is triggered. Feedback Compensation Node of voltage control loop. Connect a compensation capacitor or a R-C network from this pin to GND. VCOMP pin is also used as the hiccup timer for the fault protection of the Bus voltage stage. VCOMP When fault condition occurs in the bus voltage stage, the VCOMP is disconnected from the internal voltage loop and the hiccup timer for the voltage bus voltage stage starts. An internal current source charges VCOMP until 3V and then discharges it to 0.45V. Feedback Compensation Node of current control loop. Connect a compensation capacitor or a R-C network from this pin to GND. ICOMP pin is also used as the hiccup timer for the LED stage protection. When fault ICOMP condition of the LED stage occurs, the ICOMP pin is disconnected from the internal amplifier and LED stage hiccup timer starts. An internal current source charges ICOMP until 3V and then discharges it to 0.45V. LED Current Feedback Input. This pin feeds back the LED current through a sensing resistor. The internal error amplifier sinks a current from the ICOMP pin proportional to the absolute value of the voltage at this pin. The average voltage at this pin is regulated to the reference voltage (controlled by the A-dim voltage, 0.2V when A-dim is high). IFB The voltage on this pin is also used for over LED current detection. When the voltage on this pin gets higher than 0.3V for 200μs or when the voltage gets higher than 0.6V, the IC triggers the LED stage protection. Short string protection. This pin feeds back the secondary side current of the LED driver SSD stage. When the voltage on this pin is less than -200mV, IC triggers the LED driver stage protection. 9 VLED4 Voltage feedback of LED string4. 10 VLED3 Voltage feedback of LED string3. 11 VLED2 Voltage feedback of LED string2. MP4653 Rev 1.01 6/28/2012 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 13 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER PIN FUNCTIONS (continued) Pin # Name 12 VLED1 13 A-Dim 14 PWMIN 15 VIN 16 Description Voltage feedback of LED string1. VLED1, VLED2, VLED3 and VLED4 corporate for the protection of the LED driver stage. The maximum voltage of these pins and the voltage difference among these pins are detected for LED stage protection. If the number of LED strings is less than 4, connect the left pins together with others. Analog dimming input. 0~1.18V sets the LED current from 0 to 100%. If not used pull it high to VCC through a 100kΩ resistor. PWM Dimming control Input. Apply a 100Hz to 2kHz PWM signal to this pin for PWM dimming Supply Input. Bypass this pin with a ceramic capacitor larger than 0.1μF. PWMOUT Output of the driving signal for the dimming MOSFET. 17 VCC 18 GL 19 GND 20 GR MP4653 Rev 1.01 6/28/2012 Power Supply for the gate driver and internal circuit. Bypass this pin with a ceramic capacitor larger than 1μF. Driving signal output, 180 degree phase shifted of GR Ground Reference. Driving signal output, 180 degree phase shifted of GL www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 14 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER FUNCTION BLOCK DIAGRAM Figure 1—MP4653 Function Block Diagram MP4653 Rev 1.01 6/28/2012 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 15 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER OPERATION The MP4653 is a CC/CV mode LLC TV LED driver, especially designed for the real LIPS structure for the large size TV LED backlighting. Powered by 9V to 30V input supplies, the MP4653 outputs two 180 degree phase shifted driving signals for the external power stages. Its enhanced 9V gate driver provides adequate driving capability and can directly drive the external MOSFETs through an external gate driving transformer. The MP4653 employs frequency control for the LLC power stage. Both the LED current and the bus voltage are controlled. Figure 1 shows the block diagram of MP4653. Internal Regulator The MP4653 includes an internal linear regulator VCC. It is the supply voltage for the gate driver and also for the internal circuit. The MP4653 features Under Voltage Lockout. The chip is disabled until VCC exceeds the UVLO threshold. System Startup When the MP4653 is powered up, the VCC is charged up, and when it passes the UVLO threshold, IC starts up. It resets the voltage control loop, the current control loop and discharges the soft start capacitor. The MP4653 enjoys a soft start up. The MP4653 gets a 4.35V input UVLO threshold, and it can start up directly from the system 5V standby power supply. Please refer to figure 2. The PWM dimming signal controls the start up of the LED driver stage. The system operates in constant voltage mode and the DC bus voltage is controlled before PWM signal applied. CC/CV Mode Operation The MP4653 integrates a constant voltage control loop (CV) and a constant current control loop (CC). Both the LED current of the LED stage and the bus voltage of the bus voltage stage are controlled. The PWM dimming signal is used to distinguish these two modes. At PWM on interval, the current control loop is effective (CC mode) and the LED current is MP4653 Rev 1.01 6/28/2012 regulated. At PWM off interval, the voltage control loop is effective and the DC bus voltage is controlled (CV mode). For the current control loop for the LED current regulation, the LED current is fed back to IFB pin. The internal error amplifier regulates the average value of IFB signal to the internal 200mV reference voltage. Its output is connected to the external current-loop compensation network on ICOMP pin through an inner switch S1. At PWM on interval, S1 is on, and the output of the error amplifier is connected to the external compensation network on ICOMP pin. The LED current is regulated by this control loop. At PWM off interval, S1 is turned off, and the compensation network on ICOMP is disconnected from the error amplifier and holds its value until next PWM on interval. The output of the error amplifier is pulled low at PWM off interval. MP4653 integrates burst mode for the LED current regulation. When IFB voltage is higher than 1.1 times of its reference voltage and the ICOMP voltage is sufficiently low (which means a highest operating frequency), the IC skips some switching cycles until IFB voltage decreases sufficiently. For the voltage control loop for the bus voltage regulation, the bus voltage is fed back on VFB pin. MP4653 automatically samples the VFB voltage at PWM on interval and uses it as the reference for the voltage control loop. The internal voltage-loop error amplifier regulates the average value of the VFB voltage to this reference voltage at PWM off interval. Its output is connected to the external voltage-loop compensation network on VCOMP pin through an inner switch S2. At PWM off interval, S2 is on, and the output of the voltage-loop error amplifier is connected to the external compensation network on VCOMP pin. The bus voltage is regulated by this control loop. At PWM on interval, S2 is turned off, and the compensation network on VCOMP is disconnected from the error amplifier and holds its value until next PWM off interval. The output www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 16 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER of the voltage-loop error amplifier is pulled low at PWM on interval. MP4653 also integrates burst mode for the voltage regulation. When VFB voltage is higher than 1.1 times of the reference voltage and the VCOMP voltage is sufficiently low (which means a highest operating frequency), the IC skips some switching cycles until VFB voltage decreases sufficiently. The operating frequency is controlled by the larger one of the outputs of the current-loop error amplifier and the voltage-loop error amplifier. A high compensation output voltage gets a low operating frequency. Dimming Control The MP4653 provides two dimming methods: PWM Dimming Mode and Analog Dimming Mode. Applying a digital PWM signal on the PWMIN pin allows the PWM dimming. The brightness of the LED string is proportional to the duty cycle of the external PWM signal. A driving signal on PWMOUT pin is output to directly drive the dimming MOSFET, which helps to achieve fast and high contrast ratio PWM dimming. MP4653 achieves 500:1 PWM dimming ratio (0.2% minimum PWM dimming duty) at 200Hz PWM dimming frequency. The PWM dimming ratio may decrease with a higher PWM dimming frequency. A DC analog signal from 0V to 1.18V on A-Dim pin dims the LED current amplitude from 0 to 100%. For PWM and analog dimming control, apply the PWM dimming signal on PWMIN pin and apply the analog dimming signal on A-dim pin. Bus Voltage Stage Protection The MP4653 features rich and smart protection to increase system reliability. It protects the fault condition at both the DC bus voltage stage and the LED driver stage. The protection for the DC bus voltage stage includes the over voltage protection and over current protection (short protection). The VFB pin senses the bus stage voltage for voltage regulation and also for over voltage MP4653 Rev 1.01 6/28/2012 protection. When the VFB pin voltage gets higher than 2.4V for 2us, IC triggers the Bus Voltage Stage Protection. The secondary side current of bus voltage stage is sensed on VOCP pin. When VOCP voltage gets lower than -100mV, IC triggers the Bus Voltage Stage Protection. At Bus Voltage Stage Protection, the whole gate driving signals are disabled and no power is delivered to the output, including both the DC bus voltage stage and the LED driver stage. The current loop compensation node ICOMP pin and the soft start SS pin are pulled low. The hiccup timer for the bus voltage stage starts. The voltage-loop compensation node VCOMP pin is disconnected from the internal amplifier and holds its value until the fault condition disappears. A 2μA current source charges the VCOMP pin capacitor till VCOMP voltage hits 3V, and then a 2μA current source discharges VCOMP pin until 0.45V and then the system recovers. LED Driver Stage Protection The fault protection for the LED driver stage includes the open LED protection, short LED protection, over LED current protection and any point of LED string short to ground protection. The voltage of the LED strings are sensed on VLED1~VLED4 pins. The maximum value of VLED1~VLED4 and their voltage difference are used for protection. When the maximum value of VLED1~VLED4 gets higher than 2.4V or their voltage difference get larger than 150mV (this value can be adjusted by the external input resistance on VLED# pins), IC triggers the LED Driver Stage Protection. The LED current feedback IFB is also used for over LED current protection. When IFB voltage gets higher than 300mV for 200us or when IFB voltage gets higher than 600mV, IC triggers the LED Driver Stage Protection. The secondary side current of the LED driver stage is sensed on SSD pin. When SSD pin voltage gets lower than -200mV for 2us, IC triggers the LED Driver Stage Protection. At the LED Driver Stage Protection, the driving signal for the dimming MOSFET is disabled to www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 17 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER turn off the dimming MOSFET and also to disconnect the LED driver stage from the power stage. The current loop compensation node ICOMP is disconnected from the internal amplifier and holds its value until the fault condition on the LED driver stage disappears. A 2μA current source charges the ICOMP pin capacitor till ICOMP voltage hits 3V, and then a 2μA current source discharges ICOMP pin until 0.45V and then the LED driver stage recovers. The gate driving signals for the MOSFETs in the power stage are continuous and the DC bus voltage is regulated at the fault condition of LED driver stage. Therefore, the system power supplies are not influenced by the fault protection of the LED driver stage. Thermal protection is integrated in MP4653. 400V 5V STBY VIN Vbus 12V/5V PWM,EN LED current Figure 2—Real LIPS Power System and Start Up Sequence MP4653 Rev 1.01 6/28/2012 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 18 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER Start Vcc pass UVLO N Y Logic reset Monitor fault signals Y LED stage fault triggered Hiccup timer for LED stage N Bus stage fault triggered Y Y DC bus stage fault protection Hiccup delay timer for bus stage N PWMIN= high LED stage fault protection N Voltage loop regulation Current loop regulation Figure 3—System Operation Flow Chart MP4653 Rev 1.01 6/28/2012 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 19 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER APPLICATION INFORMATION Setting the LED Current (Pin7, IFB) The external LED current sensing resistor sets the maximum LED current (refer to TYPICAL APPLICATION CIRCUIT) and value can be determined using the equation: Rsense 0.2V ILED Setting the Voltage Loop Feedback (Pin4 VFB) The voltage on VFB pin should between 1.2V and 2V at normal operation. Set the voltage feedback divider (RVFBH and RVFBL) and make sure the feedback voltage is in this range at normal operation. 1.2V VVFB The ILED is the total current of the LED strings. It is recommended a 1k resistor between the IFB pin and the current sensing resistor for short proteciton. Setting the minimum/maximum operating frequency (Pin1 SS, Pin2 FSET) The operating frequency of MP4653 is determined by the sourcing current through SS pin and FSET pin. fop ( 2 1.49V VFSET ) 1.98 109 RSS _ FSET RFSET The VFSET voltage is the larger value of the outputs of internal amplifiers for voltage loop and current loop. It is in range of 1~2.2V. The minimum operating frequency is set by: fmin ( 2 1.49V 2.2V ) 1.98 109 RSS _ FSET RFSET The maximum operating frequency is set by: fmax ( 2 1.49V 1V ) 1.98 109 RSS _ FSET RFSET Setting the Soft Start up Frequency and Soft Start Time (Pin1 SS) The soft start up frequency is: fs _ start ( 2 1.49V (RSS _ FSET RSS ) RSS _ FSET * RSS 1V ) 1.98 109 RFSET Usually, the soft start up frequency could be 1.5 to 3 times of the maximum operating frequency. The soft start time is determined by the RC Constant of Rss and CSS. The soft start time could be estimated with 3 times of the RC Constant: R VFBL Vbus 2V R VFBH R VFBL The VFB pin also functions as the over voltage protection for the bus stage. When the voltage on VFB gets higher than 2.4V, IC triggers bus stage protection. Setting Over-Voltage Protection of the LED Stage (Pin9,10,11,12) The voltage divider sets the over-voltage protection point (refer to TYPICAL APPLICATION CIRCUIT) through the equation: VOVP ROVPH ROVPL 2.4V ROVPL Normally, the OVP point is setting about 10%30% higher than the maximum LED voltage. Setting the Voltage Difference Protection of the LED Strings (Pin9,10,11,12) MP4653 implements the protection when LED string voltage is different from each other, in order to protect the condition that several LEDs in a string are shorted. It is used only for multiplestrings application. The protection point of the voltage difference between LED strings is set by: Vpro 23k Rinput ROVPH ROVPL 2.4V ROVPL 16 23k Where Rinput is the input resistance of the LED# pin. Adjust the input resistance to program the protection point. Application can add a resistor RX between the voltage divider and LED# pins to adjust the input resistance. Rinput ROVPH ROVPL RX ROVPL ROVPH TSS 3 RSS CSS MP4653 Rev 1.01 6/28/2012 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 20 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER Setting the Over Current Protection for the bus stage (Pin3 VOCP) This pin implements the over current protection for the bus stage. The current of the bus stage is sensed to this pin with a negative polarity. When the voltage on this pin is lower than -100mV, the IC triggers the bus stage protection. IOCP _ Bus 100mV R VOCP Usually, the protection point is around 1.5 to 3 times of the normal current of the bus stage. Setting the Over Current Protection for the LED stage (Pin8 SSD) This pin detects the current through the LED stage with a negative polarity. When the voltage on this pin gets lower than -200mV, IC triggers LED stage protection. IOCP _ LED 200mV ROCP The over current protection point for the LED stage could usually set at around 1.5 to 2 times of the total current through the LED strings. Setting the Voltage loop compensation (Pin5 VCOMP) This pin is connected to the output of the inner error amplifier for the voltage control loop through an internal switch. Place a RC (RVCOMP, CVCOMP) network on this pin for compensating the voltage control loop. Usually, a ceramic capacitor in range of 47nF to 470nF and a resistor in range of 2kΩ to 200kΩis recommended for the compensation. This pin is also used as the hiccup mode fault timer. When fault condition in the bus stage occurs, the inner switch which connects this pin to the output of error amplifier for voltage control loop turns off and a 2μA current source will charge this pin to 3V and then discharge it to 0.45V. IC auto recovers after the hiccup timer. The hiccup delay time is: (3V VVCOMP ) C VCOMP 2.5V C Thiccup _ V VCOMP 2A 2A MP4653 Rev 1.01 6/28/2012 Setting the current loop compensation (Pin6 ICOMP) This pin is connected to the output of the inner error amplifier for the current control loop through an internal switch. Place a RC (RICOMP, CICOMP) network on this pin for the current control loop compensation. Usually, a ceramic capacitor in range of 47nF to 470nF and a resistor in range of 200Ω to 5kΩis recommended for the compensation. This pin is also used as the hiccup mode fault timer for the LED stage. When fault condition occurs in the LED stage, the inner switch which connects this pin to the output of the error amplifier for current control loop turns off and a current source will charge this pin to 3V and then discharge it to 0.45V. The control for the LED stage auto recovers after this hiccup timer. The hiccup delay time is: Thiccup _ I CICOMP (3V VICOMP0 ) CICOMP 2.5V 2A 2A Analog Dimming (Pin 13, A-Dim) This pin is for analog dimming. Applying a voltage in range of 0V to 1.18V dims the LED current from 0 to 100%. It has positive polarity for the analog dimming. A ceramic capacitor is recommended on this pin to bypass it. PWM Dimming input (Pin 14, PWMIN) This pin is for PWM dimming input. Applying a PWM dimming signal with frequency in range of 100Hz to 2kHz on this pin. It has positive polarity for the PWM dimming. At PWM on interval, the LED current is regulated and at PWM off interval, the voltage control loop for the DC bus functions. The DC bus voltage is regulated at the value of that in PWM on interval. Supply Input (Pin 15, VIN) This pin is the supply input voltage for the IC. Bypass this pin with a 0.1uF or larger ceramic capacitor. IC starts to work when the VIN voltage is applied. If PWMIN pin is high, the LED current control loop is effective and if the PWMIN pin is low, the voltage control loop for the DC bus control is effective. If an “Enable” signal is required to www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 21 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER control the starting operation of the IC, use this “Enable” signal to control this supply input voltage with following circuit in figure 4. Figure 4—MP4653 Enable control circuit PWM dimming signal output (Pin 16, PWMOUT) This pin outputs a PWM dimming signal to drive the external dimming MOSFET (MN) in series with the LED string, and achieves fast PWM dimming. Connect a resistor in series with this pin to adjust the driving speed. The PWMOUT signal is also used to control the external P-MOS (MP) for protection, as shown in figure 5A. Figure 5B shows the operating scheme of this driving circuit. A negative voltage source (Vbus) is generated from the secondary winding of DC bus stage. A pulse waveform at “VX“ is generated through the PWMOUT signal. By summing the negative voltage source and VX, a pulse waveform with a negative magnitude is generated on “P_Drive” (the P-MOS gate) and is used to drive the P-MOS. Figure 5B—Scheme of the PWMOUT Driving the P_MOS Gate Driver Supply (Pin 17, VCC) This pin supplies the gate drive signals GL,GR and PWMOUT. Bypass this pin with a 1uF or larger ceramic capacitor. This pin could also be used to supply an external circuit. Gate Drive Signals (Pin 18,20 GL,GR) GL and GR provide the driving signal for the power stage. GL and GR are 180 degree phase shifted gate drive signals. With the enhanced drive capability, GL and GR can directly drive the external MOSFET in the power stage through a gate driving transformer. The gate driving transformer also isolates the primary power stage and the secondary control circuit. Place a 2.2nF Y cap between the power stage ground and the reference ground for the control circuit to improve the EMI performance. Vbus RVFBH CVbus VFB RVFBL RVOCP VOCP Primary LLC power stage ROVPH Co OVP . . . ROVPL MP4653 PWMOUT MP PWMOUT IFB 15 PWMOUT MN ROCP Rsense OCP VX -Vbus Vbus P_Drive PWMOUT Figure 5A—PWMOUT for the P_MOS Driver MP4653 Rev 1.01 6/28/2012 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 22 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER Vbus T2 400V CI 400 V GND RVFBH CVbus VFB RSS_FSET T1 MP4653 Css Rss 1 2 RFSET 3 VOCP SS FSET GND VOCP GL 4 VFB VFB CVCOMP RVCOMP 5 CICOMP RICOMP 6 7 IFB GR VCC VCOMP PWMOUT ICOMP IFB VIN PWMIN RVFBL RVOCP Q1 20 VOCP 19 CDRV 18 17 16 15 CVCC Q2 PWMOUT CIN Cr Cb Co2 ROVPH1 Co1 14 400 V GND 8 SSD OCP OVP1 ROVPIN1 9 10 OVP1 A- Dim 13 VLED4 VLED1 VLED3 VLED2 ROVPH2 ROVPL1 OVP2 . . . . . . ROVPL2 12 ROVPIN2 11 OVP2 ROCP MP MN PWMOUT A- Dim IFB OCP PWM Rsense Vbus VIN PWMOUT Figure 6—MP4653 Based LED Driver for 2 Strings MP4653 Rev 1.01 6/28/2012 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 23 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER Figure 7—MP4653 Based LED Driver for 4 Strings Please refer to MP4653 application note for the design procedure and example. MP4653 Rev 1.01 6/28/2012 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 24 MP4653—REAL LIPS CC/CV MODE LLC TV LED DRIVER PACKAGE INFORMATION SOIC20 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. MP4653 Rev 1.01 6/28/2012 www.MonolithicPower.com MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 25