R1218K041A

R1218x SERIES Step-up DC/DC converter for White LED Backlight NO.EA-166-070905 OUTLINE The R1218x Series are PWM control type step-up DC/DC converter ICs with low supply current. The R1218x is fully dedicated to drive White LED with constant current. Each of these ICs consists of an NMOS FET, an oscillator, a PWM comparator, a voltage reference unit, an error amplifier, an under voltage lockout circuit (UVLO), an over-voltage protection circuit (OVP), and so on. The R1218x can drive white LEDs with high efficiency with low supply current. A diode is built-in the R1218xxx1A, therefore it is possible to drive up to 4LEDs without an external diode. The R1218xxx2A, an external diode is necessary, however, up to 6 serial LEDs can be driven with the R1218xxx2A. Constant current can be set with an external resistance value. Dimming control is possible by PWM signal for CE pin. Feedback voltage is 0.2V, therefore power loss by current setting resistance is small and efficiency is good. Maximum duty cycle is internally fixed, Typ. 91%. LEDs can be driven from low voltage. Protection circuits are the current limit of Lx peak current, the over voltage limit of output, and the under voltage lockout function. Packages are standard SOT-23-6 and very tiny PLP1820-6. FEATURES • • • • • • • • • Operating voltage.......................................... 1.8V to 5.5V Built-in 400mA, 1.5Ω, 20V Nch MOSFET (R1218xxx1A) Built-in 400mA, 1.5Ω, 29V Nch MOSFET (R1218xxx2A) Oscillator Frequency (PWM control)............. 1.2MHz Maximum Duty Cycle .................................... Typ. 91% Feedback Voltage ......................................... Typ. 0.2V UVLO Threshold Voltage .............................. Typ. 1.6V (Hysteresis Typ. 0.1V) Lx Current limit Protection............................. Typ. 700mA Over Voltage Protection (OVP) Threshold .... Typ. 9.5V (R1218x021A) Typ. 14.0V (R1218x031A) Typ. 18.5V (R1218x041A) Typ. 23.0V (R1218x052A) Typ. 27.5V (R1218x062A) • LED dimming control..................................... by external PWM signal (Frequency 200Hz to 5kHz) to CE pin by feedback voltage and filtered PWM signal (high frequency) • Packages ...................................................... SOT-23-6 or PLP1820-6 APPLICATION • White LED Backlight for portable equipment 1 R1218x BLOCK DIAGRAMS R1218xxx1A VFB VIN LX VOUT Error Amp PWM Comp R S Vref OSC Slope Compensation Q UVLO Switch Control OVP Current Protect Current sense Σ Shutdown delay Chip Enable CE R1218xxx2A GND VFB VIN LX VOUT Error Amp PWM Comp R S Vref OSC Slope Compensation Q UVLO Switch Control OVP Current Protect Current sense Σ Shutdown delay Chip Enable CE GND 2 R1218x SELECTION GUIDE The OVP threshold voltage and the package for the ICs can be selected at the user's request. The selection can be available by designating the part number as shown below; R1218xxxxx-xx-x ←Part Number ↑ a Code a ↑ b ↑↑ cd Contents Designation of Package Type: N: SOT-23-6 K: PLP1820-6 Designation of OVP threshold and with/without of built-in diode 021A: 9.5V with built-in diode 031A: 14.0V with built-in diode 041A: 18.5V with built-in diode 052A: 23.0V without built-in diode 062A: 27.5V without built-in diode Designation of Taping Type: Ex. TR (refer to Taping Specifications; for SOT-23-6 and PLP1820-6) Designation of composition of plating: −F : Lead free plating (SOT-23-6) None : Au plating (PLP1820-6) b c d 3 R1218x PIN CONFIGURATIONS • SOT-23-6 6 5 4 • PLP1820-6 Top View 6 5 4 Bottom View 4 5 6 (mark side) 1 2 3 1 2 3 3 2 1 PIN DESCRIPTIONS • SOT-23-6 Pin No. 1 2 3 4 5 6 Symbol CE VOUT VIN Lx GND VFB Description Chip Enable Pin Output Pin Power Supply Input Pin Switching Pin (Open Drain Output) Ground Pin Feedback Pin • PLP1820-6 Pin No. 1 2 3 4 5 6 Symbol CE VFB Lx GND VIN VOUT Description Chip Enable Pin Feedback Pin Switching Pin (Open Drain Output) Ground Pin Power Supply Input Pin Output Pin ∗ Tab in the parts have GND level. (They are connected to the back side of this IC.) Do not connect to other wires or land patterns. ABSOLUTE MAXIMUM RATINGS Symbol VIN VCE VFB VOUT VIN Pin Voltage CE Pin Voltage VFB Pin Voltage VOUT Pin Voltage R1218xxx1A R1218xxx2A VLX ILX PD Topt Tstg LX Pin Voltage LX Pin Current Power Dissipation (SOT-23-6) * Note1 Note1 (GND=0V) Item Rating 6.5 −0.3 to VIN+0.3 −0.3 to VIN+0.3 −0.3 to 22 −0.3 to 32 −0.3 to 22 −0.3 to 32 800 420 880 −40 to 85 −55 to 125 Unit V V V V R1218xxx1A R1218xxx2A V mA mW °C °C Power Dissipation (PLP1820-6) * Operating Temperature Range Storage Temperature Range *Note1) For Power Dissipation, please refer to PACKAGE INFORMATION to be described. 4 R1218x ELECTRICAL CHARACTERISTICS • R1218xxxxA Symbol VIN IDD Istandby VUVLO1 VUVLO2 VCEH VCEL RCE tshtdn VFB ∆VFB/ ∆Topt IFB RON ILXleak ILXlim Vf IDIODEleak fosc Maxduty Item Operating Input Voltage Supply Current Standby Current UVLO Detector Threshold UVLO Released Voltage CE Input Voltage "H" CE Input Voltage "L" CE Pull Down Resistance CE Shutdown Delay Time VFB Voltage VFB Voltage Temperature Coefficient VFB Input Current Switch On Resistance Switch Leakage Current Switch Current Limit Diode Forward Voltage Diode Leakage Current Oscillator Frequency Maximum Duty Cycle VIN=5.5V, VFB=0V, Lx at no load VIN=5.5V, VCE=0V VIN falling VIN rising VIN=5.5V VIN=1.8V VIN=3.6V VIN=3.6V VIN=3.6V VIN=3.6V, −40°C < = Topt=25°C Conditions Min. 1.8 Typ. Max. 5.5 Unit V mA µA V V V 0.5 0 1.5 1.6 VUVLO1 +0.1 1.5 1.0 3.0 1.7 1.8 0.5 600 1200 10 0.19 Topt < = V kΩ ms V ppm /°C 2200 0.20 ±150 0.21 85 ° C −0.1 VIN=5.5V, VFB=0V or 5.5V VIN=3.6V, ISW=100mA R1218xxx1A R1218xxx2A VIN=3.6V R1218xxx1A IDIODE=100mA R1218xxx1A VOUT=20V, VLX=0V VIN=3.6V, VOUT=VFB=0V VIN=3.6V, VOUT=VFB=0V R1218x021A R1218x031A R1218x041A R1218x052A R1218x062A R1218x021A R1218x031A VLX=20V VLX=29V 0.1 1.5 0 0 3.0 3.0 1000 µA Ω µA µA mA V µA 400 700 0.8 10 1.0 86 8.5 13.0 17.0 21.5 26.0 1.2 91 9.5 14.0 18.5 23.0 27.5 VOVP1 −0.5 VOVP1 −0.75 VOVP1 −1.0 VOVP1 −1.25 VOVP1 −1.5 1.4 MHz % 10.5 15.0 20.0 24.5 29.0 V VOVP1 OVP Detector Threshold VIN=3.6V, VOUT rising VOVP2 OVP Released Voltage VIN=3.6V, VOUT falling R1218x041A R1218x052A R1218x062A V 5 R1218x TYPICAL APPLICATIONS R1218x041A L1 22µH C1 1µF R1218x062A L1 22µH C2 0.22µF C1 1µF VIN LX VIN LX C2 0.22µF CE VOUT CE VOUT GND VFB R1 10Ω GND VFB R1 10Ω • LED Current setting LED current can be set with feedback resister(R1) ILED=0.2 / R1 • LED Dimming Control, Softstart (1) LED dimming control by PWM signal to CE pin LED dimming control is possible by forcing PWM signal to CE pin. When the power-on or start up with CE pin, softstart function works, however, after that, if the CE pin is set as "L" and set CE pin "H" again during the shutdown delay time, softstart function is disabled and starts up fast to normal mode, therefore 200Hz to 5kHz PWM signal is standard. By the CE pin input, LED turns on and off. Average LED current varies depending on the duty cycle of CE input. Too high frequency PWM signal is not effective because of its delay. CE VFB R1 Dimming controle by CE pin input 6 R1218x (2) Dimming control by DC voltage LED dimming control is also possible by using the DC voltage to VFB pin. LED current is adjustable by DC voltage and resisters, R1 and R2 in the following figure. ILED=(DC − 0.2) / R2 − 0.2 / R1 R2 VFB R1 DC Dimming control by DC voltage (3) Dimming control by feedback voltage and filtered PWM signal LED dimming control is also possible by using the feedback voltage and filtered PWM signal. LED current is adjustable according to the "H" level (VH) and "L" level(VL) of PWM signal and resisters, R2 VFB R3 C3 R4 R1 VH VL Dimming controle by filtered PWM signal R1, R2, R3, and R4 in the figure5. Duty=0% to 100% PWM signal duty cycle can be used up to the maximum LED current and minimum LED current as in the next formulas. ILEDMIN=(0.2 − R2 × (VH − 0.2) / (R3 + R4)) / R1 ILEDMAX=(0.2 − R2 × (VL − 0.2) / (R3 + R4)) / R1 For example, supposed that the PWM signal level is set as 2.5V/0V, to adjust the LED current range from 0mA to 20mA by the duty cycle, our recommendation external components values are, R1=10Ω, R2=5.1kΩ, R3=51kΩ, R4=5.1kΩ or around. C3 should be set large enough to regard the PWM signal as adjustable DC voltage by the filter. In this method, higher frequency control than the frequency against the CE pin can be used for dimming control. For example, if the frequency is 40kHz, 0.1µF or more capacitor is our recommendation value as C3. 7 R1218x • Selection of Inductors The peak current of the inductor at normal mode can be calculated as next formula: ILXpeak=1.25 × ILED × VOUT / VIN + 0.5 × VIN × (VOUT − VIN) / (L × VOUT × fosc) When the start-up or dimming control by CE pin, transient current flows, the peak current must be equal or less than the current limit of the IC. The peak current should not beyond the rating current of the inductor. For example, for 4 serial LED drive from VIN=3.6V, recommendation value of the inductor is 22µH or more. • Selection of Capacitors Set 1µF or more value bypass capacitor C1 between VIN pin and GND pin as close as posible. Set 0.22µF or more capacitor C2 between VOUT and GND pin. TEST CIRCUITS A VIN R1218x Series CE LX VIN VOUT LX R1218x Series CE VOUT OSCILLOSCOPE GND VFB GND VFB Supply Current Test Circuit UVLO Detector Threshold, UVLO Released Voltage LX R1218x Series VOUT CE VIN VIN OSCILLOSCOPE LX R1218x Series CE VOUT OSCILLOSCOPE GND VFB GND VFB VFB Voltage, Oscillator Frequency, Maximum Duty Test Circuit OVP Detector Threshold, OVP Released Voltage Test Circuit 8 R1218x TYPICAL CHARACTERISTICS 1) Efficiency vs. LED Current (2LED) L:LQH32CN220 (Topt=25°C) R1218x021A 100 90 80 70 60 50 40 30 20 10 0 0 4 VIN=1.8V 100 90 80 70 60 50 40 30 20 10 0 0 4 R1218x021A VIN=3.6V Efficiency η (%) 8 12 16 LED Current lLED (mA) 20 Efficiency η (%) 8 12 16 LED Current lLED (mA) 20 R1218x021A 100 90 80 70 60 50 40 30 20 10 0 0 4 VIN=4.2V Efficiency η (%) 8 12 16 LED Current lLED (mA) 20 2). Efficiency vs. LED Current (3LED) L: LQH32CN220 (Topt=25°C) R1218x031A 100 90 80 70 60 50 40 30 20 10 0 0 4 VIN=2.7V 100 90 80 70 60 50 40 30 20 10 0 0 4 R1218x031A VIN=3.6V Efficiency η (%) 8 12 16 LED Current lLED (mA) 20 Efficiency η (%) 8 12 16 LED Current lLED (mA) 20 9 R1218x R1218x031A 100 90 80 70 60 50 40 30 20 10 0 0 4 VIN=4.2V Efficiency η (%) 8 12 16 LED Current lLED (mA) 20 3) Efficiency vs. LED Current (4 LED ) L: LQH32CN220 (Topt=25°C) R1218x041A 100 90 80 70 60 50 40 30 20 10 0 0 4 VIN=2.7V 100 90 80 70 60 50 40 30 20 10 0 0 4 R1218x041A VIN=3.6V Efficiency η (%) 8 12 16 LED Current lLED (mA) 20 Efficiency η (%) 8 12 16 LED Current lLED (mA) 20 R1218x041A 100 90 80 70 60 50 40 30 20 10 0 0 4 VIN=4.2V Efficiency η (%) 8 12 16 LED Current lLED (mA) 20 10 R1218x 4) Efficiency vs. LED Current (6LED) L: LQH32CN220, Diode: CRS02 (Topt=25°C) R1218x062A 100 90 80 70 60 50 40 30 20 10 0 0 4 VIN=2.7V 100 90 80 70 60 50 40 30 20 10 0 0 4 R1218x062A VIN=3.6V Efficiency η (%) 8 12 16 LED Current lLED (mA) 20 Efficiency η (%) 8 12 16 LED Current lLED (mA) 20 R1218x062A 100 90 80 70 60 50 40 30 20 10 0 0 4 VIN=4.2V Efficiency η (%) 8 12 16 LED Current lLED (mA) 20 5) PWM Dimming Control (2 LED) VIN=3.6V, R1=10Ω 5-1. Duty vs. LED Current (Topt=25°C) R1218x021A 25.0 22.5 20.0 17.5 15.0 12.5 10.0 7.5 5.0 2.5 0 0 20 40 60 Duty (%) LED Current lLED (mA) 5kHz 1kHz 200Hz 80 100 11 R1218x 5-2. Output Voltage Waveform (Topt=25°C) R1218x021A fosc=200Hz 10 Output Voltage VOUT (V) Output Voltage VOUT (V) R1218x021A fosc=5kHz 10 CE Input Voltage VCE (V) CE Input Voltage VCE (V) CE Input Voltage CE Input Voltage VCE(V) 5 0 CE Input Voltage 5 0 10 5 0 0 Output Voltage 10 5 0 Output Voltage 0.8 1.6 2.4 Time (ms) 3.2 0 0.04 0.08 0.12 Time (ms) 0.16 6) PWM Dimming Control (4 LED) VIN=3.6V, R1=10Ω 6-1. Duty vs. LED Current (Topt=25°C) R1218x041A 25.0 22.5 20.0 17.5 15.0 12.5 10.0 7.5 5.0 2.5 0 0 20 40 60 Duty (%) LED Current lLED (mA) 5kHz 1kHz 200Hz 80 100 6-2. Output Voltage Waveform (4 LED) (Topt=25°C) R1218x041A fosc=200Hz 10 Output Voltage VOUT (V) R1218x041A fosc=5kHz 10 CE Input Voltage VCE (V) Output Voltage VOUT (V) CE Input Voltage 5 0 CE Input Voltage 5 0 20 10 0 0 Output Voltage 20 10 0 Output Voltage 0.8 1.6 2.4 Time (ms) 3.2 0 0.04 0.08 0.12 Time (ms) 0.16 12 R1218x 7) PWM Dimming Control (6 LED) VIN=3.6V, R1=10Ω 7-1. Duty vs. LED Current (Topt=25°C) R1218x062A 25.0 22.5 20.0 17.5 15.0 12.5 10.0 7.5 5.0 2.5 0 0 20 40 60 Duty (%) LED Current lLED (mA) 5kHz 1kHz 200Hz 80 100 7-2. Output Voltage Waveform (6 LED) (Topt=25°C) R1218x062A fosc=200Hz 10 Output Voltage VOUT (V) R1218x062A fosc=5kHz 10 CE Input Voltage VCE (V) Output Voltage VOUT (V) CE Input Voltage 5 0 CE Input Voltage 5 0 20 10 0 0 Output Voltage 20 Output Voltage 10 0 0.8 1.6 2.4 Time (ms) 3.2 0 0.04 0.08 0.12 Time (ms) 0.16 8) VFB Voltage vs. Temperature R1218x041A VIN=3.6V 0.215 VFB Voltage VFB (V) 9) UVLO Detector Threshold/Released Voltage vs. Temperature R1218x041A UVLO Detector Threshold UVLO1 (V) VIN=3.6V 1.74 1.70 UVLO Released 1.66 1.62 1.58 1.54 1.50 -40 -25 UVLO Detector 0.210 0.205 0.200 0.195 0.190 0.185 -40 -25 0 25 50 Temperature Topt (°C) 75 85 0 25 50 Temperature Topt (°C) 75 85 CE Input Voltage VCE (V) 13 R1218x 10) Oscillator Frequency vs. Temperature R1218x041A VIN=3.6V Oscillator Frequency fosc (kHz) 11) Maximum duty cycle vs. Temperature R1218x041A VIN=3.6V 99 97 1400 1350 1300 1250 1200 1150 1100 1050 1000 -40 -25 0 25 50 Temperature Topt (°C) 75 85 Maxduty (%) 95 93 91 89 87 85 -40 -25 0 25 50 Temperature Topt (°C) 75 85 12) OVP Detector Threshold/Released Voltage vs. Temperature R1218x041A OVP Detector Threshold VOVP1 (V) 13) Supply Current vs. Temperature R1218x041A VIN=3.6V 360 Supply Current ICC (µA) VIN=3.6V 20.5 20.0 19.5 19.0 18.5 18.0 17.5 17.0 16.5 -40 -25 320 280 240 200 160 120 80 40 0 -40 -25 OVP Detector Threshold OVP Released Voltage 0 25 50 Temperature Topt (°C) 75 85 0 25 50 Temperature Topt (°C) 75 85 14) LX Current Limit vs. Temperature R1218x041A VIN=3.6V 1000 Lx Current Limit Ilim (mA) 900 800 700 600 500 400 300 -40 -25 0 25 50 Temperature Topt (°C) 75 85 14 R1218x 15) OVP Transient Response (Topt=25°C) R1218x021A OVP Detector Threshold VOVP1 (V) R1218x041A OVP Detector Threshold VOVP1 (V) 15.0 12.5 25 OVP Voltage 20 15 10 5 0 0 20 40 60 Time (ms) 80 100 OVP Voltage 10.0 7.5 5.0 2.5 0 0 20 40 60 Time (ms) 80 100 R1218x062A OVP Detector Threshold VOVP1 (V) 35 30 25 20 15 10 5 0 0 20 40 60 Time (ms) 80 100 OVP Voltage 16) Efficiency dependence on inductors (4 LED) R1218x041A (Intemal Diode Type) VIN=3.6V 90 85 Efficiency η (%) 80 75 70 65 60 55 50 0 LQH32CN220K53 LQH32CN100K53 GLF2012T220K GLF2012T100K 5 10 15 LED Current lLED (mA) 20 15 PACKAGE INFORMATION PE-SOT-23-6-0611 • SOT-23-6 (SC-74) Unit: mm PACKAGE DIMENSIONS 2.9±0.2 1.9±0.2 (0.95) (0.95) +0.2 1.1 −0.1 0.8±0.1 4 6 5 +0.2 1.6 −0.1 2.8±0.3 0 to 0.1 1 2 0.2 Min. +0.1 0.4−0.2 +0.1 0.15 −0.05 TAPING SPECIFICATION 0.3±0.1 +0.1 φ1.5 0 4.0±0.1 2.0±0.05 1 2.0Max. 2 3 4.0±0.1 3.3 ∅1.1±0.1 TR User Direction of Feed TAPING REEL DIMENSIONS (1reel=3000pcs) REUSE REEL (EIAJ-RRM-08Bc) 11.4±1.0 9.0±0.3 21±0.8 0 180 −1.5 2±0.5 13±0.2 +1 60 0 3.2 8.0±0.3 6 5 4 3.5±0.05 1.75±0.1 PACKAGE INFORMATION PE-SOT-23-6-0611 POWER DISSIPATION (SOT-23-6) This specification is at mounted on board. Power Dissipation (PD) depends on conditions of mounting on board. This specification is based on the measurement at the condition below: Measurement Conditions Standard Land Pattern Environment Board Material Board Dimensions Copper Ratio Through-hole Measurement Result (Topt=25°C,Tjmax=125°C) Mounting on Board (Wind velocity=0m/s) Glass cloth epoxy plactic (Double sided) 40mm × 40mm × 1.6mm Top side : Approx. 50% , Back side : Approx. 50% φ0.5mm × 44pcs Standard Land Pattern Power Dissipation Thermal Resistance 600 Free Air 250mW 400°C/W 420mW θja=(125−25°C)/0.42W=263°C/W Power Dissipation PD(mW) 500 420 400 300 On Board 40 100 0 0 25 50 75 85 100 Ambient Temperature (°C) 125 150 Power Dissipation 40 200 Measurement Board Pattern IC Mount Area Unit : mm RECOMMENDED LAND PATTERN 0.7 MAX. 1.0 0.95 0.95 1.9 2.4 (Unit: mm) PACKAGE INFORMATION PE-PLP1820-6-0611 • PLP1820-6 1.6±0.1 Unit: mm PACKAGE DIMENSIONS 1.80 A B 4 0.20±0.1 0.05 M AB 6 0.05 1.0±0.1 2.00 INDEX 3 0.6Max. 0.5 0.1NOM. 1 0.3±0.1 Bottom View Attention: Tabs or Tab suspension leads in the parts have VDD or GND level.(They are connected to the reverse side of this IC.) Refer to PIN DISCRIPTION. Do not connect to other wires or land patterns. 0.05 TAPING SPECIFICATION 0.25±0.1 1.5 +0.1 0 4.0±0.1 2.0±0.05 3.5±0.05 1.75±0.1 2.4 1.1±0.1 2.2 1.1Max. 4.0±0.1 TR User Direction of Feed TAPING REEL DIMENSIONS (1reel=5000pcs) (R5323K,R5325K : 1reel=3000pcs) REUSE REEL (EIAJ-RRM-08Bc) 11.4±1.0 9.0±0.3 21±0.8 ∅60 +1 0 0 ∅180 −1.5 2±0.5 ∅13±0.2 8.0±0.3 0.25±0.1 0.25±0.1 ×4 PACKAGE INFORMATION PE-PLP1820-6-0611 POWER DISSIPATION (PLP1820-6) This specification is at mounted on board. Power Dissipation (PD) depends on conditions of mounting on board. This specification is based on the measurement at the condition below: Measurement Conditions Standard Land Pattern Environment Board Material Board Dimensions Copper Ratio Through-hole Measurement Result (Topt=25°C,Tjmax=125°C) Mounting on Board (Wind velocity=0m/s) Glass cloth epoxy plactic (Double sided) 40mm × 40mm × 1.6mm Top side : Approx. 50% , Back side : Approx. 50% φ0.54mm × 30pcs Standard Land Pattern Power Dissipation Thermal Resistance 1200 880mW θja=(125−25°C)/0.88W=114°C/W Power Dissipation PD(mW) 1000 800 600 400 200 0 0 On Board 880 40 25 50 75 85 100 Ambient Temperature (°C) 125 150 Power Dissipation 40 Measurement Board Pattern IC Mount Area Unit : mm RECOMMENDED LAND PATTERN 0.5 0.5 0.75 0.45 1.00 1.60 0.35 0.25 (Unit: mm) MARK INFORMATION ME-R1218N-0610 R1218N SERIES MARK SPECIFICATION • SOT-23-6 (SC-74) 1 3 1 2 3 4 , , 2 4 : Product Code (refer to Part Number vs. Product Code) : Lot Number • Part Number vs. Product Code Product Code 1 2 Part Number R1218N021A R1218N031A R1218N041A R1218N022A R1218N032A R1218N042A R1218N052A R1218N062A 2 2 2 2 2 2 2 2 A B C D E F G H MARK INFORMATION ME-R1218K-0610 R1218K SERIES MARK SPECIFICATION • PLP1820-6 1 5 1 2 3 to , 6 4 : Product Code (refer to Part Number vs. Product Code) : Lot Number 4 5 6 • Part Number vs. Product Code Product Code 1 2 3 4 Part Number R1218K021A R1218K031A R1218K041A R1218K022A R1218K032A R1218K042A R1218K052A R1218K062A Y Y Y Y Y Y Y Y 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 3 4 5 6 7 8