ISL97651 ® Data Sheet April 24, 2009 4-Channel Integrated LCD Supply Features The ISL97651 represents a high power, integrated LCD supply IC targeted at large panel LCD displays. The ISL97651 integrates a high power, 4.4A boost converter for AVDD generation, an integrated VON charge pump, a VOFF charge pump driver, VON slicing circuitry and a buck regulator with 2A switch for logic generation. • 4V to 5.5V input supply The ISL97651 have been designed for ease of layout and low BOM cost. Supply sequencing is integrated for both AVDD -> VOFF -> VON and AVDD/VOFF -> VON sequences. The TFT power sequence uses a separate enable to the logic buck regulator for maximum flexibility. Peak efficiencies are 90% for boost and 92% for buck while operating from a 4V to 5.5V input supply. The current mode buck offers superior line and load regulation. Available in the 36 Ld QFN package, the ISL97651 is specified for ambient operation over the -40°C to +105°C temperature range. FN7493.3 • AVDD boost up to 20V, with integrated 4.4A FET • Integrated VON charge pump, up to 34VOUT • VOFF charge pump driver, down to -18V • VLOGIC buck down to 1.2V, with integrated 2A FET • Automatic start-up sequencing - AVDD -> VOFF -> VON or AVDD/VOFF -> VON - Independent logic enable • VON slicing • Thermally enhanced thin QFN package (6mmx6mm) • Pb-free (RoHS compliant) Applications • LCD monitors (15”+) Pinout • LCD-TVs (40”+) • Industrial/medical LCD displays 28 NC 29 CDEL • Notebook displays (up to 16”) 30 ENL 31 DELB 32 CM1 33 VIN2 34 FBB 35 EN 36 NC ISL97651 (36 LD TQFN) TOP VIEW Ordering Information PART NUMBER (Notes 1, 2) PART MARKING PACKAGE (Pb-Free) PKG. DWG. # VIN1 1 27 AGND LX1 2 26 PGND1 LX2 3 25 PGND2 ISL97651ARTZ-TK ISL976 51ARTZ 36 Ld 6x6 TQFN L36.6x6 24 VINL NOTES: CB 4 THERMAL PAD LXL 5 23 NOUT VSUP 6 22 PGND3 1 ISL976 51ARTZ 36 Ld 6x6 TQFN L36.6x6 1. Please refer to TB347 for details on reel specifications. 2. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020. NC 18 C2+ 17 C2- 16 C1+ 15 19 FBP C1- 14 CTL 9 POUT 13 20 VREF COM 12 CM2 8 DRN 11 21 FBN NC 10 FBL 7 ISL97651ARTZ-T CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2006-2008. All Rights Reserved All other trademarks mentioned are the property of their respective owners. ISL97651 Absolute Maximum Ratings (TA = +25°C) Thermal Information Maximum Pin Voltages, All Pins Except Below . . . . . . . . . . . . . 6.5V LX1, LX2, VSUP, NOUT, DELB, C1-, C2- . . . . . . . . . . . . . . . . .24V C1- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14V CB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13V DRN, COM, POUT, C1+, C2+ . . . . . . . . . . . . . . . . . . . . . . . . .36V CB-VINL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.5V Thermal Resistance θJA (°C/W) θJC (°C/W) 6x6 QFN Package (Notes 3, 4) . . . . . . 30 2.5 Maximum Junction Temperature (Plastic Package) . . . . . . . +150°C Maximum Storage Temperature Range . . . . . . . . . .-65°C to +150°C Power Dissipation TA ≤ +25°C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3.3W TA = +70°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.8W TA = +85°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.3W TA = +100°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.8W Pb-Free Reflow Profile. . . . . . . . . . . . . . . . . . . . . . . . .see link below http://www.intersil.com/pbfree/Pb-FreeReflow.asp Recommended Operating Conditions Input Voltage Range, VIN . . . . . . . . . . . . . . . . . . . . . . . . . 4V to 5.5V Boost Output Voltage Range, AVDD . . . . . . . . . . . . . . . . . . . . +20V VON Output Range, VON . . . . . . . . . . . . . . . . . . . . . . +15V to +32V VOFF Output Range, VOFF . . . . . . . . . . . . . . . . . . . . . . -15V to -5V Logic Output Voltage Range, VLOGIC . . . . . . . . . . . +1.5V to +3.3V Input Capacitance, CIN . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 x 10µF Boost Inductor, L1 . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3µH to 10µH Output Capacitance, COUT . . . . . . . . . . . . . . . . . . . . . . . . 2 x 22µF Buck Inductor, L2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3µH to 10µH Operating Ambient Temperature Range . . . . . . . . -40°C to +105°C Operating Junction Temperature . . . . . . . . . . . . . . -40°C to +125°C CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and result in failures not covered by warranty. NOTES: 3. θJA is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. See Tech Brief TB379. 4. For θJC, the “case temp” location is the center of the exposed metal pad on the package underside. Electrical Specifications PARAMETER VIN = 5V, VBOOST = VSUP = 15V, VON = 25V, VOFF = -8V, over-temperature from -40°C to +105°C; Parameters with MIN and/or MAX limits are 100% tested at +25°C, unless otherwise specified. Temperature limits established by characterization and are not production tested. DESCRIPTION CONDITIONS MIN TYP MAX UNIT SUPPLY PINS VIN Supply Voltage (VIN1 and VIN2) 4 5 5.5 V VINL Logic Supply Voltage 4 5 5.5 V VSUP Charge Pumps and VON Slice Positive Supply 4 20 V IVIN Quiescent Current into VIN Enabled, No switching 3 mA Disabled 10 µA 1.0 mA Disabled 10 µA Enabled, No switching and VPOUT = VSUP 0.5 mA Disabled 10 µA IINL ISUP Logic Supply Current VSUP Supply Current Enabled, No switching 0.4 VLOR Undervoltage Lockout Threshold VIN rising 2.0 2.75 2.9 V VLOF Undervoltage Lockout Threshold VIN falling 1.9 2.2 2.5 V VREF Reference Voltage TA = +25°C 1.19 1.205 1.235 V 1.187 1.205 1.238 V 1010 1200 1400 kHz 20 V fOSC Oscillator Frequency AVDD BOOST DMax, Maximum Duty Cycle: Minimum 84% VBOOST Boost Output Range ILX LX Leakage Current LX = 0V and 24V -10 .01 10 µA IBOOST Boost Switch Current Current limit 4.4 4.8 6.3 A 2 1.25*VIN FN7493.3 April 24, 2009 ISL97651 Electrical Specifications PARAMETER VIN = 5V, VBOOST = VSUP = 15V, VON = 25V, VOFF = -8V, over-temperature from -40°C to +105°C; Parameters with MIN and/or MAX limits are 100% tested at +25°C, unless otherwise specified. Temperature limits established by characterization and are not production tested. (Continued) DESCRIPTION EFFBOOST Peak Efficiency rDS(ON) Switch ON-Resistance ΔVBOOST/ΔVIN Line Regulation ΔVBOOST/ΔIOUT Load Regulation VFBB Boost Feedback Voltage CONDITIONS MIN See graphs and component recommendations ACCBOOST AVDD Output Accuracy TA = +25°C tSS Soft-start Period for AVDD CDEL = 220nF MAX 90 UNIT % 70 100 mΩ 0.4 1.5 %/V 0.1 0.5 % 1.192 1.205 1.218 V 1.188 1.205 1.222 V +1.5 % PI mode, R1 = 10k and C3 = 4.7nF over a load range of 0mA to 300mA (tested), 0-ILIMIT_ONSET (by design) TA = +25°C TYP -1.5 9.6 ms VLOGIC BUCK DMAX_buck typical maximum duty cycle = 0.85*(VINL-ILOAD*0.3) ILOAD_min, Minimum 1mA for VINL-VBUCK >1.5V, 5mA otherwise VBUCK Buck Output Voltage Output current = 0.5A VREF ILXL LX Leakage Current LX = 0V and 18V -10 .01 IBUCK Buck Switch Current Current limit 2.0 2.7 A EFFBUCK Peak Efficiency See graphs and component recommendations 92 % RDS-ONBK Switch ON-Resistance ΔVBUCK/ΔVIN Line Regulation ΔVBUCK/ΔIOUT Load Regulation VFBL FBL Regulation Voltage PI mode, R1 = 2k and C3 = 4.7nF over a load range of 0mA to 300mA (tested), 0-ILIMIT_ONSET (by design) 4 V 10 µA 200 455 mΩ 0.1 1 %/V 0.04 0.5 % IDRVL = 1mA, TA = +25°C 1.176 1.2 1.224 V IDRVL = 1mA 1.174 1.2 1.226 V +2 % ACCLOGIC VLOGIC Output Accuracy TA = +25°C tSS(L) Soft-Start Period for V(Logic) C(VREF) = 220nF (Note - no soft-start if EN asserted HIGH before ENB) -2 0.5 ms NEGATIVE (VOFF) CHARGE PUMP VOFF VOFF Output Voltage Range 2X Charge Pump ILOAD_NCP_MIN External Load Driving Capability VSUP > 5V rON(NOUT)H High-Side Driver ON-Resistance at NOUT I(NOUT) = +60mA 10 Ω rON(NOUT)L Low-Side Driver ON-Resistance at NOUT I(NOUT) = -60mA 5 Ω IPU(NOUT)LIM Pull-up Current Limit in NOUT V(NOUT) = 0V to V(SUP) - 0.5V IPD(NOUT)LIM Pull-down Current Limit in NOUT V(NOUT) = 0.36V to V(VSUP) I(NOUT)LEAK Leakage Current in NOUT V(FBN) < 0 or EN = LOW VFBN FBN Regulation Voltage IDRVN = 0.2mA, TA = +25°C 0.173 IDRVN = 0.2mA 0.171 ACCN VOFF Output Accuracy D_NCP_max Max Duty Cycle of the Negative Charge Pump rPD(FBN)OFF Pull-Down Resistance, Not Active 3 IOFF = 1mA, TA = +25°C -VSUP+1.4V 0 30 60 mA 270 -200 mA -60 mA 2 µA 0.203 0.233 V 0.203 0.235 V +3 % -2 -3 50 I(FBN) = 500µA 2 V 3 % 4 kΩ FN7493.3 April 24, 2009 ISL97651 Electrical Specifications PARAMETER VIN = 5V, VBOOST = VSUP = 15V, VON = 25V, VOFF = -8V, over-temperature from -40°C to +105°C; Parameters with MIN and/or MAX limits are 100% tested at +25°C, unless otherwise specified. Temperature limits established by characterization and are not production tested. (Continued) DESCRIPTION CONDITIONS MIN TYP MAX UNIT 34 V POSITIVE (VON) CHARGE PUMP VON VON Output Voltage Range 2X or 3X Charge Pump ILOAD_PCP_MIN External Load Driving Capability VON = 25V (2X Charge Pump) 20 mA VON = 34V (3X Charge Pump) 20 mA VSUP + 2V rON(VSUP_SW) ON-Resistance of VSUP Input Switch I(SWITCH) = +40mA 10 17 Ω rON(C1/2-)H High-Side Driver ON-Resistance at C1- and C2- I(C1/2-) = +40mA 10 20 Ω rON(C1/2-)L Low-Side Driver ON-Resistance at C1- and C2- I(C1/2-) = -40mA 4 7 Ω IPU(VSUP_SW) Pull-Up Current Limit in VSUP Input Switch V(C2+) = 0V to V(SUP) - 0.4V - V(DIODE) IPU(C1/2-) Pull-Up Current Limit in C1- and C2- V(C1/2-) = 0V to V(VSUP) - 0.4V IPD(C1/2-) Pull-Down Current Limit in C1- and C2- V(C1/2-) = 0.2V to V(VSUP) I(POUT)LEAK Leakage Current in POUT EN = LOW VFBP FBP Regulation Voltage IDRVP = 0.2mA, TA = +25°C 1.176 IDRVP = 0.2mA 1.172 ACCP VON Output Accuracy D_PCP_max Max Duty Cycle of the Positive Charge Pump V(DIODE) Internal Schottky Diode Forward Voltage ION = 1mA, TA = +25°C 40 100 mA 40 100 mA -100 -40 mA 5 µA 1.2 1.224 V 1.2 1.228 V +2 % -5 -2 50 I(DIODE) = +40mA 600 % 850 mV ENABLE INPUTS VHI-EN Enable “HIGH” 2.2 V VLO_EN Enable “LOW” IEN_pd Enable Pin Pull-Down Current VHI-ENL Logic Enable “HIGH” VLO-ENL Logic Enable “LOW” 0.8 V IENL_pd Logic Enable Pin Pull-Down Current VENL > VLO_ENL 25 µA 100 200 µA CTL = AGND, sequence complete 90 120 µA VEN > VLO_EN 0.8 V 25 µA 2.2 V VON SLICE Positive Supply = V(POUT) I(POUT)_SLICE VON slice Current from POUT Supply CTL = VDD, sequence complete rON(POUT-COM) ON-Resistance between POUT COM CTL = VDD, sequence complete 5 10 Ω rON(DRN-COM) ON-Resistance between DRN COM CTL = ACGND, sequence complete 30 60 Ω rON_COM ON-Resistance between COM and PGND3 During start-up sequence 500 1500 Ω VLO CTL Input LOW Voltage VIN = 4V to 5.5V 0.8 V VHI CTL Input HIGH Voltage VIN = 4V to 5.5V 4 200 2.2 V FN7493.3 April 24, 2009 ISL97651 Electrical Specifications PARAMETER VIN = 5V, VBOOST = VSUP = 15V, VON = 25V, VOFF = -8V, over-temperature from -40°C to +105°C; Parameters with MIN and/or MAX limits are 100% tested at +25°C, unless otherwise specified. Temperature limits established by characterization and are not production tested. (Continued) DESCRIPTION CONDITIONS MIN TYP MAX UNIT FAULT DETECTION THRESHOLDS T_off Thermal Shut-Down (latched and reset by power cycle or EN cycle) Temperature rising 150 °C Vth_AVDD(FBB) AVDD Boost Short Detection V(FBB) falling less than 0.9 V Vth_VLOGIC(FBL) VLOGIC Buck Short Detection V(FBL) falling less than 0.9 V Vth_POUT(FBP) POUT Charge Pump Short Detection V(FBP) falling less than 0.9 V Vth_NOUT(FBN) NOUT Charge Pump Short Detection V(FBN) rising more than 0.4 V tFD Fault Delay Time to Chip Turns Off CDEL = 220nF 52 ms 80 ms START-UP SEQUENCING tSTART-UP Enable to AVDD Start Time CDEL = 220nF IDELB_ON DELB Pull-Down Current or Resistance when Enabled by the Start-Up Sequence VDELB > 0.9V 36 50 70 µA VDELB < 0.9V 1000 1326 1750 Ω IDELB_OFF DELB Pull-Down Current or Resistance when Disabled VDELB < 20V 500 nA tVOFF AVDD to VOFF CDEL = 220nF 9 ms tVON VOFF to VON Delay CDEL = 220nF 20 ms tVON-SLICE VON to VON-SLICE Delay CDEL = 220nF 17 ms Typical Performance Curves 0.10 100 VIN = 5V, AVDD = 15V AVDD LOAD REGULATION (%) 0.05 EFFICIENCY (%) 80 VIN = 5V, AVDD = 15V 60 40 20 0 0 -0.05 -0.10 -0.15 -0.20 -0.25 -0.30 -0.35 0 200 400 600 800 IOUT (mA) FIGURE 1. AVDD EFFICIENCY vs IOUT 5 1000 0 200 400 600 800 IOUT (mA) 1000 1200 FIGURE 2. AVDD LOAD REGULATION vs IOUT FN7493.3 April 24, 2009 ISL97651 Typical Performance Curves (Continued) L1 = 10µH, COUT = 40µF, CM1 = 4.7nF, RM1 CH1 = AVDD(200mV/DIV), CH2 = IAVDD(200mA/DIV) 100 VLOGIC EFFICIENCY (%) 90 80 VIN = 5V, VLOGIC = 3.3V 70 60 50 40 30 20 10 0 0 500 1000 1500 2000 OUTPUT CURRENT (mA) 1ms/DIV FIGURE 3. AVDD TRANSIENT RESPONSE FIGURE 4. VLOGIC EFFICIENCY vs OUTPUT CURRENT L2 = 6.8µH, COUT = 30µF, CM2 = 4.7nF, RM2 0.1 CH1 = VLOGIC(50mV/DIV), CH2 = ILOGIC(200mA/DIV) VLOGIC LOAD REGULATION (%) VIN = 5V, VLOGIC = 3.3V 0 -0.1 -0.2 -0.3 -0.4 -0.5 0 500 1000 1500 2000 2500 OUTPUT CURRENT (mA) 1ms/DIV FIGURE 5. VLOGIC LOAD REGULATION vs OUTPUT CURRENT FIGURE 6. VLOGIC TRANSIENT RESPONSE 0 VLOGIC LOAD REGULATION (%) VON LOAD REGULATION (%) 0 -0.05 -0.10 -0.15 VON = 25V -0.20 -0.25 -0.30 -0.35 0 10 20 30 ION (mA) 40 50 FIGURE 7. VON LOAD REGULATION vs ION 6 60 VIN = 5V, VLOGIC = 3.3V -0.01 -0.02 -0.03 -0.04 -0.05 -0.06 -0.07 -0.08 -0.09 -0.10 0 200 400 600 800 1000 1200 1400 1600 1800 2000 OUTPUT CURRENT(mA) FIGURE 8. VLOGIC LOAD REGULATION vs OUTPUT CURRENT FN7493.3 April 24, 2009 ISL97651 Typical Performance Curves (Continued) CH1 = COM(10V/DIV), CH2 = CTL(2V/DIV) CH1 = CDLY, CH2 = VREF, CH3 = VLOGIC, CH4 = VON, R1 = AVDD, R2 = AVDD_DELAY, R3 = VOFF 4ms/DIV FIGURE 9. VON-SLICE CIRCUIT OPERATION 7 FIGURE 10. START-UP SEQUENCE FN7493.3 April 24, 2009 ISL97651 Pin Descriptions PIN NUMBER PIN NAME 1 VIN1 Input voltage, connect to pin 33 (VIN2) 2 LX1 Internal boost switch connection 3 LX2 Internal boost switch connection 4 CB Logic buck, boost strap pin 5 LXL Buck converter output 6 VSUP 7 FBL Logic buck feedback pin 8 CM2 Buck compensation network pin 9 CTL Input control for VON slice output 10, 18, 28, 36 NC No connect. Connect to die pad and GND for improved thermal efficiency. 11 DRN Lower reference voltage for VON slice output 12 COM VON slice output: when CTL = 1, COM is connected to SRC through a 5Ω resistor; when CTL = 0, COM is connected to DRN through a 30Ω resistor. 13 POUT Positive charge pump out 14 C1- Charge pump capacitor 1, negative connection 15 C1+ Charge pump capacitor 1, positive connection 16 C2- Charge pump capacitor 2, negative connection 17 C2+ Charge pump capacitor 2, positive connection 19 FBP Positive charge pump feedback pin 20 VREF 21 FBN 22 PGND3 23 NOUT 24 VINL 25, 26 PGND2, 1 27 AGND Signal ground pin 29 CDEL Delay capacitor for start up sequencing, soft-start and fault detection timers. 30 ENL 31 DELB Open drain NFET output to drive optional AVDD delay PFET 32 CM1 Boost compensation network pin 33 VIN2 Input voltage, connect to pin 1 (VIN1) 34 FBB Boost feedback pin 35 EN Enable for Boost, charge pumps and VON slice (independent of ENL). (Exposed Die Plate) N/A Connect exposed die plate on rear of package to ACGND and the PGND1, 2 pins. See “Layout Recommendation” on page 18 for PCB layout thermal considerations. 8 DESCRIPTION Positive supply for charge pumps Reference voltage Negative charge pump feedback pin Power ground for VOFF, VON and VON slice Negative charge pump output Logic buck supply voltage Boost power grounds Buck enable for VLOGIC output FN7493.3 April 24, 2009 ISL97651 Block Diagram VREF SAWTOOTH GENERATOR CM1 FBB VREF + VOLTAGE FEEDBACK SLOPE COMPENSATION REFERENCE AND BIAS UVLO COMPARATOR CONTROL LOGIC ℘ + LX1 LX2 BUFFER THRESHOLDS AND BIAS RSENSE PGND1 PGND2 CURRENT FEEDBACK 0.75VREF 1.2MHz OSCILLATOR PGND3 CURRENT LIMIT COMPARATOR VIN1, VIN2 ACGND CURRENT LIMIT THRESHOLD SEQUENCE AND FAULT CONTROL EN CDEL DELB ENL VINL CB NOUT CONTROL VSUP LXL NOUT CONTROL LOGIC CURRENT LIMIT COMPARATOR + FBN CURRENT FEEDBACK + 0.2V + ℘ FBL VREF SLOPE COMPENSATION CURRENT LIMIT THRESHOLD UVLO COMPARATOR CM2 VOLTAGE FEEDBACK BUFFER SAWTOOTH GENERATOR + 0.4V UVLO COMPARATOR 0.75 VREF + FBP + POUT CONTROL 0.75 VREF VSUP + VREF POUT VSUP C1- C1+ POUT C2+ C2- DRN CTL COM FIGURE 11. BLOCK DIAGRAM 9 FN7493.3 April 24, 2009 ISL97651 Typical Application Diagram 6.8µF R18 4.7Ω 4.7nF 15V R3 55k C2 40µF VIN1 C1 2.2µ C3 AVDD_DELAY AVDD D1 L1 VIN R4 300kΩ C4 OPEN C5 1µF VIN2 R1 LX1 CM1 10k PGND1 LX2 R17* FBB R5 BOOST PGND2 C18* ENB DELB EN CDEL C6 0.22µF 500kΩ VREF FBN PGND3 5k R20 BIAS AND SEQUENCE CONTROL C20 820p C11 220nF R6 40k R7 VOFF CP NOUT 328k D2 C12 D3 C13 470nF VSUP C1+ POUT C1VON CP C2+ C8 220nF -8V VOFF 220nF C7 220nF C19 100p C2- C21 100p R8 983k FBP R9 50k C22 2.2nF DRN +25V VON C14 470nF R12 R10 68k R11 C15 0.1µF VON SLICE CTL COM 1k VON SLICE R13 100kΩ VINL TO GATE DRIVER IC CB C10 10µF C9 4.7nF R2 C16 1µF CM2 LXL BUCK 2k D4 ENL FBL AGND L2 6.8µH 3.3V VLOGIC R14 2k R15 C17 20µF 1.2k *Open component positions. 10 FN7493.3 April 24, 2009 ISL97651 Applications Information The ISL97651 provides a complete power solution for TFT LCD applications. The system consists of one boost converter to generate the AVDD voltage for column drivers, one buck converter to provide voltage to logic circuit in the LCD panel, one integrated VON charge pump and one VOFF linear-regulator controller to provide the voltage to row drivers. This part also integrates VON-slice circuit which can help to optimize the picture quality. With the high output current capability, this part is ideal for big screen LCD TV and monitor panel application. The integrated boost converter and buck converter operate at 1.2MHz which can allow the use of multilayer ceramic capacitors and low profile inductor which result in low cost, compact and reliable system. The logic output voltage is independently enabled to give flexibility to the system designers. This restricts the maximum output current (average) based on Equation 3: ΔI L V IN I OMAX = ⎛ I LMT – --------⎞ × --------⎝ 2 ⎠ VO (EQ. 3) Where ΔIL is peak to peak inductor ripple current, and is set by Equation 4: V IN D ΔI L = --------- × ----L fS (EQ. 4) where fS is the switching frequency (1.2MHz). Table 1 gives typical values (margins are considered 10%, 3%, 20%, 10% and 15% on VIN, VO, L, fS and IOMAX: TABLE 1. MAXIMUM OUTPUT CURRENT CALCULATION VIN (V) VO (V) L (µH) FS (MHz) IOMAX (mA) Boost Converter 4 9 6.8 1.2 1661 The boost converter is a current mode PWM converter operating at a fixed frequency of 1.2MHz. It can operate in both discontinuous conduction mode (DCM) at light load and continuous mode (CCM). In continuous current mode, current flows continuously in the inductor during the entire switching cycle in steady state operation. The voltage conversion ratio in continuous current mode is given by Equation 1: 4 12 6.8 1.2 1173 4 15 6.8 1.2 879 5 9 6.8 1.2 2077 5 12 6.8 1.2 1466 5 15 6.8 1.2 1099 V BOOST 1 ------------------------ = ------------1–D V IN (EQ. 1) Where D is the duty cycle of the switching MOSFET Figure 11 shows the functional block diagram of the boost regulator. It uses a summing amplifier architecture consisting of gm stages for voltage feedback, current feedback and slope compensation. A comparator looks at the peak inductor current cycle by cycle and terminates the PWM cycle if the current limit is reached. An external resistor divider is required to divide the output voltage down to the nominal reference voltage. Current drawn by the resistor network should be limited to maintain the overall converter efficiency. The maximum value of the resistor network is limited by the feedback input bias current and the potential for noise being coupled into the feedback pin. A resistor network in the order of 60kΩ is recommended. The boost converter output voltage is determined by Equation 2: ( R3 + R5 ) V BOOST = -------------------------- × V REF R5 (EQ. 2) The current through the MOSFET is limited to a minimum of 4.4APEAK (maximum values can be up to 6.3APEAK. 11 Boost Converter Input Capacitor An input capacitor is used to suppress the voltage ripple injected into the boost converter. A ceramic capacitor with capacitance larger than 10µF is recommended. The voltage rating of input capacitor should be larger than the maximum input voltage. Examples of recommended capacitors are given in Table 2 below. TABLE 2. BOOST CONVERTER INPUT CAPACITOR RECOMMENDATION CAPACITOR SIZE VENDOR PART NUMBER 10µF/16V 1206 TDK C3216X7R1C106M 10µF/10V 0805 Murata GRM21BR61A106K 22µF/10V 1210 Murata GRB32ER61A226K Boost Inductor The boost inductor is a critical component which influences the output voltage ripple, transient response, and efficiency. Values of 3.3µH to 10µH are to match the internal slope compensation. The inductor must be able to handle without saturating the following average and peak current: IO I LAVG = ------------1–D ΔI L I LPK = I LAVG + -------2 (EQ. 5) FN7493.3 April 24, 2009 ISL97651 Table 5 shows some selections of output capacitors. Some inductors are recommended in Table 3. TABLE 3. BOOST INDUCTOR RECOMMENDATION INDUCTOR DIMENSIONS (mm) VENDOR CAPACITOR PART NUMBER 6.8µH/ 12.95x9.4x5.21 Coilcraft 4.6APEAK DO3316P-682ML 10µH/ 5.5APEAK 10x10x5 CDR10D48MNNP-100NC 5.2µH/ 4.55APEAK 10x10.1x3.8 Sumida TABLE 5. BOOST OUTPUT CAPACITOR RECOMMENDATION SIZE VENDOR PART NUMBER 10µF/25V 1210 TDK C3225X7R1E106M 10µF/25V 1210 Murata GRM32DR61E106K PI Loop Compensation (Boost Converter) Cooper CD1-5R2 Bussmann Rectifier Diode (Boost Converter) A high-speed diode is necessary due to the high switching frequency. Schottky diodes are recommended because of their fast recovery time and low forward voltage. The reverse voltage rating of this diode should be higher than the maximum output voltage. The rectifier diode must meet the output current and peak inductor current requirements. Table 4 shows some recommendations for boost converter diode. TABLE 4. BOOST CONVERTER RECTIFIER DIODE RECOMMENDATION VR/IAVG RATING PACKAGE SS23 30V/2A SMB Fairchild Semiconductor MBRS340 40V/3A SMC International Rectifier SL23 30V/2A SMB Vishay Semiconductor VENDOR Output Capacitor The output capacitor supplies the load directly and reduces the ripple voltage at the output. Output ripple voltage consists of two components: the voltage drop due to the inductor ripple current flowing through the ESR of output capacitor, and the charging and discharging of the output capacitor. s An RC network across feedback resistor R5 may be required to optimize boost stability when AVDD voltage is set to less than 12V. This network reduces the internal voltage feedback used by the IC. This RC network sets a pole in the control loop. This pole is set to approximately fp = 10kHz for COUT = 10µF and fp = 4kHz for COUT = 30µF. Alternatively, adding a small capacitor (20pF to 100pF) in parallel with R5 (i.e. R17 = short) may help to reduce AVDD noise and improve regulation, particularly if high value feedback resistors are used. 1 1 –1 R17 = ⎛ ⎛ -------------------------⎞ – ----------⎞ ⎝ ⎝ 0.1 × R5 ⎠ R3 ⎠ 1 C18 = ------------------------------------------------------( 2 × 3.142 × fp × R5 ) (EQ. 7) (EQ. 8) Cascaded MOSFET Application IO V O – V IN 1 V RIPPLE = I LPK × ESR + ------------------------ × ---------------- × ---f C V OUT The stability can be examined by repeatedly changing the load between 100mA and a max level that is likely to be used in the system being used. The AVDD voltage should be examined with an oscilloscope set to AC 100mV/div and the amount of ringing observed when the load current changes. Reduce excessive ringing by reducing the value of the resistor in series with the CM1 pin capacitor. Boost Converter Feedback Resistors and Capacitor DIODE O The boost converter of ISL97651 can be compensated by a RC network connected from CM1 pin to ground. C3 = 4.7nF and R1 = 10k RC network is used in the demo board. A higher resistor value can be used to lower the transient overshoot - however, this may be at the expense of stability to the loop. (EQ. 6) For low ESR ceramic capacitors, the output ripple is dominated by the charging and discharging of the output capacitor. The voltage rating of the output capacitor should be greater than the maximum output voltage. An 20V N-channel MOSFET is integrated in the boost regulator. For the applications where the output voltage is greater than 20V, an external cascaded MOSFET is needed, as shown in Figure 12. The voltage rating of the external MOSFET should be greater than AVDD. Note: Capacitors have a voltage coefficient that makes their effective capacitance drop as the voltage across then increases. COUT in Equation 6 assumes the effective value of the capacitor at a particular voltage and not the manufacturer’s stated value, measured at 0V. 12 FN7493.3 April 24, 2009 ISL97651 VIN AVDD potential for noise being coupled into the feedback pin. A resistor network in the order of 1kΩ is recommended. Buck Converter Input Capacitor The capacitor should support the maximum AC RMS current which happens when D = 0.5 and maximum output current. LX1, LX2 FBB INTERSIL ISL97651 I ACRMS ( C IN ) = D ⋅ ( 1 – D ) ⋅ IO (EQ. 13) Where IO is the output current of the buck converter. Table 6 shows some recommendations for input capacitor. TABLE 6. INPUT CAPACITOR (BUCK) RECOMMENDATION FIGURE 12. CASCADED MOSFET TOPOLOGY FOR HIGH OUTPUT VOLTAGE APPLICATIONS Buck Converter The buck converter is the step down converter, which supplies the current to the logic circuit of the LCD system. The ISL97651 integrates an 20V N-Channel MOSFET to save cost and reduce external component count. In the continuous current mode, the relationship between input voltage and output voltage is shown in Equation 9: V LOGIC ---------------------- = D V IN (EQ. 9) Where D is the duty cycle of the switching MOSFET. Because D is always less than 1, the output voltage of buck converter is lower than input voltage. The peak current limit of buck converter is set to 2A, which restricts the maximum output current (average) based on the Equation 10: I OMAX = 2A – ΔI pp (EQ. 10) Where ΔIPP is the ripple current in the buck inductor as the Equation 11: V LOGIC ΔI pp = ---------------------- ⋅ ( 1 – D ) L ⋅ fs (EQ. 11) Where L is the buck inductor, fs is the switching frequency (1.2MHz). CAPACITOR SIZE VENDOR PART NUMBER 10µF/16V 1206 TDK C3216X7R1C106M 10µF/10V 0805 Murata GRM21BR61A106K 22µF/16V 1210 Murata C3225X7R1C226M Buck Inductor An inductor value in the range 3.3µH to 10µH is recommended for the buck converter. Besides the inductance, the DC resistance and the saturation current should also be considered when choosing buck inductor. Low DC resistance can help maintain high efficiency, and the saturation current rating should be at least 2A. Table 7 shows some recommendations for buck inductor. TABLE 7. BUCK INDUCTOR RECOMMENDATION INDUCTOR DIMENSIONS (mm) VENDOR PART NUMBER 4.7µH/2.7APEAK 5.7x5.0x4.7 Murata LQH55DN4R7M01K 6.8µH/3APEAK 7.3x6.8x3.2 TDK RLF7030T-6R8M2R8 10µH/2.4APEAK 12.95x9.4x3.0 Coilcraft DO3308P-103 Rectifier Diode (Buck Converter) A Schottky diode is recommended due to fast recovery and low forward voltage. The reverse voltage rating should be higher than the maximum input voltage. The peak current rating is 2A, and the average current should be as the Equation 14: I AVG = ( 1 – D )*I o Feedback Resistors (EQ. 14) The buck converter output voltage is determined by the Equation 12: Where IO is the output current of buck converter. Table 8 shows some diode recommended. TABLE 8. BUCK RECTIFIER DIODE RECOMMENDATION R 14 + R 15 V LOGIC = --------------------------- × V REF R 15 (EQ. 12) Where R14 and R15 are the feedback resistors of buck converter to set the output voltage current drawn by the resistor network should be limited to maintain the overall converter efficiency. The maximum value of the resistor network is limited by the feedback input bias current and the 13 DIODE VR/IAVG RATING PACKAGE PMEG2020EJ 20V/2A SOD323F Philips Semiconductors SS22 20V/2A SMB Fairchild Semiconductor VENDOR FN7493.3 April 24, 2009 ISL97651 Output Capacitor (Buck Converter) Four 10µF or two 22µF ceramic capacitors are recommended for this part. The overshoot and undershoot will be reduced with more capacitance, but the recovery time will be longer. TABLE 9. BUCK OUTPUT CAPACITOR RECOMMENDATION CAPACITOR SIZE VENDOR PART NUMBER 10µF/6.3V 0805 TDK C2012X5R0J106M 10µF/6.3V 0805 Murata GRM21BR60J106K 22µF/6.3V 1210 TDK C3216X5R0J226M 100µF/6.3V 1206 Murata GRM31CR60J107M PI Loop Compensation (Buck Converter) The buck converter of ISL97651 can be compensated by a RC network connected from CM2 pin to ground. C9 = 4.7nF and R2 = 2k RC network is used in the demo board. The larger value resistor can lower the transient overshoot, however, at the expense of stability of the loop. The stability can be optimized in a similar manner to that described in “PI Loop Compensation (Boost Converter)” on page 12. Bootstrap Capacitor (C16) This capacitor is used to provide the supply to the high driver circuitry for the buck MOSFET. The bootstrap supply is formed by an internal diode and capacitor combination. A 1µF is recommended for ISL97651. A low value capacitor can lead to overcharging and in turn damage the part. If the load is too light, the on-time of the low side diode may be insufficient to replenish the bootstrap capacitor voltage. In this case, if VIN - VBUCK < 1.5V, the internal MOSFET pullup device may be unable to turn-on until VLOGIC falls. Hence, there is a minimum load requirement in this case. The minimum load can be adjusted by the feedback resistors to FBL. The pumps use pulse width modulation to adjust the pump period, depending on the load present. The pumps can provide 30mA for VOFF and 20mA for VON. The positive charge pump can generate double or triple VSUP voltage depending on the configuration of C2+ and C2- pins. If the C2+ pin connects to C1+, it is the voltage doubler, and if C2+ connects C2- via a capacitor, it configured a voltage tripler. Positive Charge Pump Design Consideration The positive charge pump integrates all the diodes (D1, D2 and D3 shown in the block diagram in Figure 13) required for x2 (VSUP doubler) and x3 (VSUP tripler) modes of operation. During the chip start-up sequence the mode of operation is automatically detected when the charge pump is enabled. With both C7 and C8 present, the x3 mode of operation is detected. With C7 present, C8 open and with C1+ shorted to C2+, the x2 mode of operation will be detected. Due to the internal switches to VSUP (M1, M2 and M3), POUT is independent of the voltage on VSUP until the charge pump is enabled. This is important for TFT applications where the negative charge pump output voltage (VOFF) and AVDD supplies need to be established before POUT. The maximum POUT charge pump current can be estimated from Equation 15 assuming a 50% switching duty: I MAX ( 2x ) ∼ min of 50mA or 2 • V SUP – 2 • V DIODE ( 2 • I MAX ) – V ( V ON ) ---------------------------------------------------------------------------------------------------------------------- • 0.95A ( 2 • ( 2 • R ONH + R ONL ) ) (EQ. 15) I MAX ( 3x ) ∼ min of 50mA or 3 • V SUP – 3 • V DIODE ( 2 • I MAX ) – V ( V ON ) ---------------------------------------------------------------------------------------------------------------------- • 0.95V ( 2 • ( 3 • R ONH + 2 • R ONL ) ) Note: VDIODE (2 • IMAX) is the on-chip diode voltage as a function of IMAX and VDIODE (40mA) < 0.7V. The bootstrap capacitor can only be charged when the higher side MOSFET is off. If the load is too light which can not make the on time of the low side diode be sufficient to replenish the boot strap capacitor, the MOSFET can’t turn on. Hence there is minimum load requirement to charge the bootstrap capacitor properly. In voltage doubler configuration, the maximum VON is as given by Equation 16: Linear-Regulator Controllers (VON and VOFF) V ON_MAX(3x) = 3 • ( V SUP – V DIODE ) – 2 • I OUT • ( 3 • r ONH + 2 • r ONL ) The ISL97651 include 2 independent charge pumps (see Figure 13). The negative charge pump inverters the VSUP voltage and provides a regulated negative output voltage. The positive charge pump doubles or triples the VSUP voltage and provides a regulated positive output voltage. The regulation of both the negative and positive charge pumps is generated by internal comparator that senses the output voltage and compares it with the internal reference. 14 V ON_MAX(2x) = 2 • ( V SUP – V DIODE ) – 2 • I OUT • ( 2 • r ONH + r ONL ) (EQ. 16) For Voltage Tripler: (EQ. 17) VON output voltage is determined by Equation 18: R 8⎞ ⎛ V ON = V FBP • ⎜ 1 + -------⎟ R ⎝ 9⎠ (EQ. 18) FN7493.3 April 24, 2009 ISL97651 External Connections and Components x2 Mode x3 Mode Both VSUP M2 C1C7 M4 C1+ VSUP M1 Control D3 D2 D1 1.2MHz POUT C14 0.9V VSUP C2+ Error M3 VREF C8 C2- FB C21 R8 M5 FBP C22 R9 FIGURE 13. VON FUNCTION DIAGRAM Negative Charge Pump Design Consideration The negative charge pump consists of an internal switcher M1, M2 which drives external steering diodes D2 and D3 via a pump capacitor (C12) to generate the negative VOFF supply. An internal comparator (A1) senses the feedback voltage on FBN and turns on M1 for a period up to half a CLK period to maintain V(FBN) in regulated operation at 0.2V. External feedback resistor R6 is referenced to VREF. Faults on VOFF which cause VFBN to rise to more than 0.4V, are detected by comparator (A2) and cause the fault detection system to start a fault ramp on CDLY pin which will cause the chip to power down if present for more than the time TFD (see "Electrical Specification" on page 2 and also Figure 15). R6 and R7 in the “Typical Application Diagram” on page 10 determine VOFF output voltage. R7 R7 V OFF = V FBN • ⎛ 1 + --------⎞ – V REF • ⎛ --------⎞ ⎝ R6⎠ ⎝ R6⎠ (EQ. 20) Improving Charge Pump Noise Immunity Depending on PCB layout and environment, noise pick-up at the FBP and FBN inputs, which may degrade load regulation performance, can be reduced by the inclusion of capacitors across the feedback resistors (e.g. in the “Typical Application Diagram” on page 10, C21 and C22 for the positive charge pump). Set R6 • C20 = R7 • C19 with C19 ~ 100pF. The maximum VOFF output voltage of a single stage charge pump is: V OFF_MAX ( 2x ) = – V SUP+ V DIODE+ 2• I OUT• ( r ON( NOUT )H +r ON ( NOUT )L (EQ. 19) 15 FN7493.3 April 24, 2009 ISL97651 VREF A2 C19 100pF VSUP VDD FAULT 0.4V FBN C20 820pF R6 40k A1 R7 328k 0.2V 1.2MHz STOP M2 CLK NOUT C12 220nF D2 VOFF (-8V) D3 PWM CONTROL EN C13 470nF M1 PGND FIGURE 14. NEGATIVE CHARGE PUMP BLOCK DIAGRAM VON Slice Circuit Start-Up Sequence The VON Slice Circuit functions as a three way multiplexer, switching the voltage on COM between ground, DRN and SRC, under control of the start-up sequence and the CTL pin. Figure 15 shows a detailed start up sequence waveform. For a successful power up, there should be 6 peaks at VCDLY. When a fault is detected, the device will latch off until either EN is toggled or the input supply is recycled. During the start-up sequence, COM is held at ground via an NDMOS FET, with ~1k impedance. Once the start-up sequence has completed, CTL is enabled and acts as a multiplexer control such that if CTL is low, COM connects to DRN through a 30Ω internal MOSFET, and if CTL is high, COM connects to POUT internally via a 5Ω MOSFET. The slew rate of start-up of the switch control circuit is mainly restricted by the load capacitance at COM pin as Equation 21: Vg ΔV -------- = -----------------------------------( R i || R L ) × C L Δt (EQ. 21) RWhere Vg is the supply voltage applied to DRN or voltage at POUT, which range is from 0V to 36V. Ri is the resistance between COM and DRN or POUT including the internal MOSFET rDS(On), the trace resistance and the resistor inserted, RL is the load resistance of switch control circuit, and CL is the load capacitance of switch control circuit. In the “Typical Application Diagram” on page 10, R10, R11 and C15 give the bias to DRN based on Equation 22: V ON ⋅ R 11 +AVDD ⋅ R 10 V DRN = --------------------------------------------------------------R 10 + R 11 And R12 can be adjusted to adjust the slew rate. 16 (EQ. 22) When the input is higher than 2.75V; if either EN or ENL is H, VREF turns on. If ENL is H, VLOGIC turns on. If EN is H, an internal current source starts to charge CCDLY to an upper threshold using a fast ramp followed by a slow ramp. Several more ramps follow, during which time the device checks for fault conditions. If a fault is found, the sequence is halted. Initially the boost is not enabled so AVDD rises to VIN - VDIODE through the output diode. Hence, there is a step at AVDD during this part of the start up sequence. If this step is not desirable, an external PMOS FET can be used to delay the output until the boost is enabled internally. The delayed output appears at AVDD. AVDD soft-starts at the beginning of the third ramp. The softstart ramp depends on the value of the CDLY capacitor. The range of CDLY capacitor value is from 10nF to 220nF. For CDLY of 220nF, the soft-start time is ~8ms. VOFF turns on at the start of the fourth peak, at the same time DELB gate goes low to turn on the external PMOS to generate a delayed AVDD output. VON is enabled at the beginning of the sixth ramp. Once the start-up sequence is complete, the voltage on the CDLY capacitor remains at 1.15V until either a fault is detected or the EN pin is disabled. If a fault is detected, the voltage on CDLY rises to 2.4V at which point the chip is disabled until the power is cycled or enable is toggled. FN7493.3 April 24, 2009 ISL97651 AVDD_delay Generation Using DELB across the source and gate, hence M0 will be off. Please note that the maximum leakage of DELB in this period is 500nA. To avoid any mis-trigger, the maximum value of R4 should be less than: DELB pin is an open drain internal N-FET output used to drive an external optional P-FET to provide a delayed AVDD supply which also has no initial pedistal voltage (see Figure 15 and compare the AVDD and AVDD_delayed curves). When the part is enabled, the N-FET is held off until CDLY reaches the 4th peak in the start-up sequence. During this period, the voltage potential of the source and gate of the external P-FET (M0 in application diagram) should be almost the same due to the presence of the resistor (R4) V GS ( th )_min(M0) R 4_max < -------------------------------------------500nA CHIP DISABLED VOFF, DELB ON VON SOFT-START FAULT DETECTED Where VGS(th)_min(M0) is the minimum value of gate threshold voltage of M0. AVDD SOFT-START VREF, VLOGIC ON (EQ. 23) VCDLY VIN EN VREF VBOOST (AVDD) tSTART-UP tSS VLOGIC VOFF tVOFF DELAYED VBOOST (AVDD_delay) tVON VON VON SLICE tVON-SLICE START-UP SEQUENCE TIMED BY CDLY NOTE: Not to scale NORMAL OPERATION FAULT PRESENT FIGURE 15. START-UP SEQUENCE 17 FN7493.3 April 24, 2009 ISL97651 After CDLY reaches the 4th peak, the internal N-FET is turned-on and produces an initial current output of IDELB_ON1 (~50µA). This current allows the user to control the turn-on inrush current into the AVDD_delay supply capacitors by a suitable choice of C4. This capacitor can provide extra delay and also filter out any noise coupled into the gate of M0, avoiding spurious turn-on, however, C4 must not be so large that it prevents DELB reaching 0.6V by the end of the start-up sequence on CDLY, else a fault time-out ramp on CDLY will start. A value of 22nF is typically required for C4. The 0.6V threshold is used by the chip's fault detection system and if V(DELB) is still above 0.6V at the end of the power sequencing then a fault time-out ramp will be initiated on CDLY. When the voltage at DELB falls below ~0.6V it's current is increased to IDELB_ON2 (~1.4mA) to firmly pull the DELB voltage to ground. If the maximum VGS voltage of M0 is less than the AVDD voltage being used, then a resistor may be inserted between the DELB pin and the gate of M0 such that it's potential divider action with R4 ensures the gate/source stays below VGS(M0)max. This additional resistor allows much larger values of C4 to be used, and hence longer AVDD delay, without affecting the fault protection on DELB. Component Selection for Start-up Sequencing and Fault Protection The CREF capacitor is typically set at 220nF and is required to stabilize the VREF output. The range of CREF is from 22nF to 1µF and should not be more than five times the capacitor on CDEL to ensure correct start-up operation. The CDEL capacitor is typically 220nF and has a usable range from 47nF minimum to several microfarads – only limited by the leakage in the capacitor reaching µA levels. CDEL should be at least 1/5 of the value of CREF (see above). Note with 220nF on CDEL the fault time-out will be typically 50ms and the use of a larger/smaller value will vary this time proportionally (e.g., 1µF will give a fault time-out period of typically 230ms). Over-Temperature Protection An internal temperature sensor continuously monitors the die temperature. In the event that the die temperature exceeds the thermal trip point of +150°C, the device will shut down. Operation with die temperatures between +125°C and +150°C can be tolerated for short periods of time, however, in order to maximize the operating life of the IC, it is recommended that the effective continuous operating junction temperature of the die should not exceed +125°C. Layout Recommendation The device’s performance including efficiency, output noise, transient response and control loop stability is dramatically affected by the PCB layout. PCB layout is critical, especially at high switching frequency. There are some general guidelines for layout: 1. Place the external power components (the input capacitors, output capacitors, boost inductor and output diodes, etc.) in close proximity to the device. Traces to these components should be kept as short and wide as possible to minimize parasitic inductance and resistance. 2. Place VREF and VDC bypass capacitors close to the pins. 3. Reduce the loop with large AC amplitudes and fast slew rate. 4. The feedback network should sense the output voltage directly from the point of load, and be as far away from LX node as possible. 5. The power ground (PGND) and signal ground (SGND) pins should be connected at only one point. 6. The exposed die plate, on the underneath of the package, should be soldered to an equivalent area of metal on the PCB. This contact area should have multiple via connections to the back of the PCB as well as connections to intermediate PCB layers, if available, to maximize thermal dissipation away from the IC.” 7. To minimize the thermal resistance of the package when soldered to a multi-layer PCB, the amount of copper track and ground plane area connected to the exposed die plate should be maximized and spread out as far as possible from the IC. The bottom and top PCB areas especially should be maximized to allow thermal dissipation to the surrounding air. 8. Minimize feedback input track lengths to avoid switching noise pick-up. A demo board is available to illustrate the proper layout implementation. All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems. Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries. For information regarding Intersil Corporation and its products, see www.intersil.com 18 FN7493.3 April 24, 2009 ISL97651 Package Outline Drawing L36.6x6 36 LEAD THIN QUAD FLAT NO-LEAD PLASTIC PACKAGE Rev 5, 08/08 6.00 6 PIN #1 INDEX AREA 32x 0.50 A B 36 28 6 27 6.00 PIN 1 INDEX AREA 1 4.15 +0.10/-0.15 4X 4.00 9 19 (4X) 0.15 10 18 36X 0.55 ± 0.10 36X 0.25 +0.05/-.07 4 0.10 M C A B BOTTOM VIEW TOP VIEW ( 5.65 ) ( 4.15) Exp. Dap. SEE DETAIL "X" ( 5.65 ) 0.10 C Max 0.80 C ( 32x 0.50) 0.08 C ( 4.15) Exp. Dap. SIDE VIEW (36X .25) C 0 . 2 REF 5 0 . 00 MIN. 0 . 05 MAX. ( 4X 4.00) (36X 0.75) TYPICAL RECOMMENDED LAND PATTERN DETAIL "X" 1. Dimensions are in millimeters. 2. Dimensioning and tolerancing conform to AMSEY14.5m-1994. 3. Unless otherwise specified, tolerance : Decimal ± 0.05 4. Dimension applies to the metallized terminal and is measured between 0.15mm and 0.30mm from the terminal tip. 5. Tiebar shown (if present) is a non-functional feature. 6. The configuration of the pin #1 identifier is optional, but must be located within the zone indicated. The pin #1 identifier may be either a mold or mark feature. 19 FN7493.3 April 24, 2009