R1208K312A-TR

R1208x Series PWM Low Supply Current Step-up DC/DC Converter NO.EA-314-211027 OUTLINE The R1208x is a low supply current CMOS-based PWM control step-up DC/DC converter. Internally, a single converter consists of an NMOS FET, an oscillator, a PWM comparator, a voltage reference unit, an error amplifier, a current limit circuit, an under voltage lockout circuit (UVLO), an over-voltage protection circuit (OVP), a thermal shutdown protection circuit and current drivers for four white LED channels. By simply using an inductor, a resistor, capacitors and a diode, white LEDs can be driven with constant current and high efficiency. The LED current can be determined by the value of current setting resistor. The brightness of the LEDs can be adjusted quickly by applying a PWM signal (200 Hz to 300 kHz) to the CE pin. Protection circuits included in the R1208x are a current limit circuit which limits the LX peak current, an UVLO circuit which prevents the malfunction of the device at low input voltage, an OVP circuit which monitors the excess output voltage and a thermal shutdown protection circuit which detects the overheating of the device and stops the operation to protect the device from damage. The R1208x is offered in 12-pin DFN(PLP)2730-12 package. FEATURES • Input Voltage Range .................................................. 2.7 V to 22 V • Supply Current ........................................................... Typ. 600 µA • Standby Current ......................................................... Typ. 1.5 µA • Lx Current Limit .......................................................... Typ. 2 A • Overvoltage Protection (OVP) ................................... Typ. 23 V / 33 V / 43.5 V • Oscillator Frequency .................................................. Typ. 750 kHz / 450 kHz • Maximum Duty Cycle ................................................. 95% (750 kHz) / 97% (450 kHz) • Nch MOSFET ON Resistance ................................... Typ. 0.28 Ω • Undervoltage Lockout (UVLO) ................................... Typ. 2.4 V • Thermal Shutdown ..................................................... Typ. 150°C • LED Dimming Control ................................................ By sending a PWM signal (200 Hz to 300 kHz) to the CE pin • Package ..................................................................... DFN(PLP)2730-12 APPLICATIONS • LED backlight driver for LCD displays for portable equipment • LED backlight driver for LCD displays for Tablets and Note PCs. 1 R1208x NO.EA-314-211027 SELECTION GUIDE The OVP threshold voltage and the oscillator frequency are user-selectable options. Selection Guide Product Name R1208Kx12∗-TR Package Quantity per Reel Pb Free Halogen Free DFN(PLP)2730-12 5,000 pcs Yes Yes x: Specify the OVP threshold voltage. (1) 23 V (2) 33 V (3) 43.5 V ∗: Specify the oscillator frequency. (A) 750 kHz (B) 450 kHz 2 R1208x NO.EA-314-211027 BLOCK DIAGRAMS UVLO Ramp Compensation VIN Current Feedback Internal Regulator CE LED OVP Chip Enable LED Feedback Selector PWM Control ISET Current Control VOUT Current Limit LX Switching Control Vref VS VOUT OVP Max Duty Thermal Shutdown PGND LED1 LED Current Source Soft Start LED2 LED Current Source LED3 LED Current Source LED4 GND LED Current Source R1208x Block Diagram 3 R1208x NO.EA-314-211027 PIN DESCRIPTION Top View 12 11 10 9 8 7 Bottom View 7 8 9 10 11 12 *1 1 2 3 4 5 6 6 5 4 3 2 1 DFN(PLP)2730-12 Pin Configurations DFN(PLP)2730-1 Pin Description Pin No. Symbol *1 Description 1 VIN Power Input Pin 2 LED1 LED1 pin 3 ISET LED Current Control Pin 4 VS Power Input Pin (VIN < 5 V), Internal Regulator Pin (VIN > 5 V) 5 CE Chip Enable Pin (Active-high) 6 PGND 7 LX 8 VOUT 9 GND 10 LED4 LED 4 Pin 11 LED3 LED 3 Pin 12 LED2 LED 2 Pin Power GND Pin Switching Pin *1 Output Pin Analog GND Pin The exposed tab is substrate level (GND). It is recommended that the exposed tab be connected to the ground plane on the board or otherwise be left floating. 4 R1208x NO.EA-314-211027 ABSOLUTE MAXIMUM RATINGS Absolute Maximum Ratings Symbol *1 (GND / PGND = 0 V) Item Rating Unit VIN VIN Pin Voltage −0.3 to 24 V VS VS Pin Voltage −0.3 to 6.5 V VCE CE Pin Voltage −0.3 to 6.5 V VISET ISET Pin Voltage −0.3 to 6.5 V VOUT VOUT Pin Voltage −0.3 to 48 V VLX LX Pin Voltage −0.3 to 48 V VLED LED1, LED2, LED3, LED4 Pin Voltage −0.3 to 24 V ILX LX Pin Current 2500 mA PD Power Dissipation*1 (JEDEC STD. 51-7 Test Land Pattern) 3100 mW Tj Junction Temperature Range −40 to 125 °C Tstg Storage Temperature Range −55 to 125 °C Refer to POWER DISSIPATION for detailed information. ABSOLUTE MAXIMUM RATINGS Electronic and mechanical stress momentarily exceeded absolute maximum ratings may cause the permanent damages and may degrade the life time and safety for both device and system using the device in the field. The functional operation at or over these absolute maximum ratings is not assured. RECOMMENDED OPERATING CONDITIONS Symbol Item Rating Unit VIN Input Voltage 2.7 to 22 V Ta Operating Temperature Range −40 to 85 °C RECOMMENDED OPERATING CONDITIONS All of electronic equipment should be designed that the mounted semiconductor devices operate within the recommended operating conditions. The semiconductor devices cannot operate normally over the recommended operating conditions, even if when they are used over such ratings by momentary electronic noise or surge. And the semiconductor devices may receive serious damage when they continue to operate over the recommended operating conditions. 5 R1208x NO.EA-314-211027 ELECTRICAL CHARACTERISTICS The specifications surrounded by in production. are over −40°C ≤ Ta ≤ 85°C.and guaranteed by design but not tested Electrical Characteristics Symbol Item VIN (Ta = 25°C) Conditions Operating Input Voltage Min. 2.7 VIN = 5.5 V, no load, no switching IDD Supply Current Istandby Standby Current Typ. VIN = 5.5 V, no load, switching, R1208Kx12A VIN = 5.5 V, no load, switching, R1208Kx12B VIN = 22 V, VCE = 0 V Unit 22 V 0.6 mA 2.2 mA 1.5 mA 1.5 10.0 UVLO Detector Threshold VIN falling VUVLO2 UVLO Released Voltage VIN rising VCEH CE Input Voltage "H" VIN = 22 V VCEL CE Input Voltage "L" VIN = 2.7 V RCE CE Pull-down Resistance VIN = 8 V 1200 kΩ VS VS Active Voltage VIN = 8 V 5 V ILED LED1-4 Current Accuracy RISET = 10 kΩ, 1 string = 20 mA, VIN = 3.6 V, ∆ILED /∆Ta LED1-4 Current Temperature Coefficient −40°C ≤ Ta ≤ 85°C, VIN = 3.6 V ILEDM LED1-4 Current Matching ILEDM2 LED1-4 Current Matching 2 ILEDMAX 2.4 µA VUVLO1 CEduty CE Input Duty Range 2.3 Max. VUVLO1 +0.1 V 2.6 1.5 V 0.4 −3% 20 +3% (IMAX − IAVE) / IAVE, 1 string = 20 mA, VIN = 3.6 V, (IMAX − IAVE) / IAVE, 1 string = 2 mA 2.3 LED1-4 Max. Current Setting (100% dimming) VIN = 3.6 V 80 LED1-4 Active Voltage V mA ppm /°C ±100 VIN = 3.6 V, RISET = 10 kΩ V 2.5 % 10 % 100 % 100 mA VIN = 3.6 V, 1 string = 30 mA 0.75 V LED1-4 Leakage Current VIN = VLED1-4 = 22 V, VCE = 0 V 0 NMOS ON Resistance ILX = 100 mA , VIN = 3.6 V ILXLEAK NMOS Leakage Current VIN = VLED1-4 = 22 V, VCE = 0 V ILXLIM NMOS Current Limit VIN = 3.6 V fosc Oscillator Frequency VLED1 ILEDLEAK RON 3.0 0.28 µA Ω 0 3.0 µA 1.5 2 2.5 A VIN = 3.6 V (R1208Kx12A) 675 750 825 kHz VIN = 3.6 V (R1208Kx12B) 400 450 500 kHz 6 R1208x NO.EA-314-211027 ELECTRICAL CHARACTERISTICS (continued) The specifications surrounded by in production. are over −40°C ≤ Ta ≤ 85°C.and guaranteed by design but not tested Electrical Characteristics Symbol Item Maxduty Maximum Duty Cycle VOVP1 VOVP2 VOVP3 VOUT OVP Detector Threshold VOUT OVP Release Voltage (Ta = 25°C) Conditions VIN = 3.6 V VIN = 3.6 V, VOUT rising VIN = 3.6 V, VOUT falling Typ. Max. 92 Unit % R1208K112∗ 22 23 24 V R1208K212∗ 31.5 33 34.5 V R1208K312∗ 42 43.5 45 V R1208K112∗ 21 VOVP1 −0.5 V R1208K212∗ 30.5 VOVP1 −1 V R1208K312∗ 39.5 VOVP1 −1.5 V LED OVP Detector Threshold VIN = 3.6 V, VLED1-4 rising TSS Soft Start Time VIN = 3.6 V TTSD Thermal Shutdown Temperature VIN = 3.6 V Thermal Shutdown VIN = 3.6 V Release Temperature TTSR Min. 10 10 11.5 V 15 32 ms 150 °C 120 °C All test items listed under ELECTRICAL CHARACTERISTICS are done under the pulse load condition (Tj ≈ Ta = 25°C). 7 R1208x NO.EA-314-211027 THEORY OF OPERATION Operation of Step-Up DC/DC Converter and Output Current i2 VIN IOUT Diode L VOUT i1 Lx Tr CL GND Discontinuous mode Continuous mode IL ILmax IL ILmax ILmin ILmin topen t toff ton T=1/fosc t ton toff T=1/fosc There are two operation modes of the step-up PWM control-DC/DC converter. That is the continuous mode and discontinuous mode by the continuousness inductor. When the transistor turns ON, the voltage of inductor L becomes equal to VIN voltage. The increase value of inductor current (i1) will be ∆i1 = VIN × ton / L ........................................................................................................... Formula 1 As the step-up circuit, during the OFF time (when the transistor turns OFF) the voltage is continually supply from the power supply. The decrease value of inductor current (i2) will be ∆i2 = (VOUT − VIN) × topen / L .......................................................................................... Formula 2 8 R1208x NO.EA-314-211027 At the PWM control-method, the inductor current become continuously when topen=toff, the DC/DC converter operate as the continuous mode. In the continuous mode, the variation of current of i1 and i2 is same at regular condition. VIN × ton / L = (VOUT - VIN) × toff / L .................................................................................. Formula 3 The duty at continuous mode will be duty (%)= ton / (ton + toff) = (VOUT - VIN) / VOUT ................................................................ Formula 4 The average of inductor current at tf = toff will be IL(Ave.) = VIN × ton / (2 × L) ........................................................................................... Formula 5 If the input voltage = output voltage, the IOUT will be IOUT = VIN2 × ton / (2 × L × VOUT) ...................................................................................... Formula 6 If the IOUT value is large than above the calculated value (Formula 6), it will become the continuous mode, at this status, the peak current (ILmax) of inductor will be ILmax = IOUT × VOUT / VIN + VIN × ton / (2 × L) ................................................................... Formula 7 ILmax = IOUT × VOUT / VIN + VIN × T × (VOUT - VIN) / (2 × L × VOUT) ..................................... Formula 8 The peak current value is larger than the IOUT value. In case of this, selecting the condition of the input and the output and the external components by considering of ILmax value. The explanation above is based on the ideal calculation, and the loss caused by LX switch and the external components are not included. The actual maximum output current will be between 50% and 80% by the above calculations. Especially, when the IL is large or VIN is low, the loss of VIN is generated with on resistance of the switch. Moreover, it is necessary to consider Vf of the diode (approximately 0.8V) about VOUT. 9 R1208x NO.EA-314-211027 • Soft-Start Function At startup, by forcibly switching Lx for a certain period of time, VOUT is raised with the LED current flowing about 4mA. During this period, the rush current is suppressed by gradually increasing the current limit. After the time required to raise the VOUT has elapsed, gradually change the LED current from about 4mA to the set current value. The soft start time (Tss = typ.15ms) is the time from CE= ”L”→”H” to 90% of the set current for ILED. CE 0V VOUT 0V Tss 90% ILED about 4mA 0mA • Current Limit Function If the peak current of inductor (ILmax) exceeds the current limit, current limit function turns the driver off and turns it on in every switching cycle to continually monitor the driver current. • Under Voltage Lockout (UVLO) Function UVLO function stops DC/DC operation to prevent malfunction when the supply voltage falls below the UVLO detector threshold. • Overvoltage Protection (OVP) Circuit OVP circuit monitors the VOUT pin voltage and halts oscillation once it reaches the OVP detect voltage. Oscillation resumes when the VOUT pin voltage decreases below 0.3 V. In case the cause of the excess VOUT pin voltage is not removed the OVP circuit will stop and resume repeatedly in order to limit the VOUT pin voltage. • Thermal Shutdown Function Thermal shutdown circuit detects overheating of the converter if the output pin is shorted to the ground pin (GND) etc. and stops the converter operation to protect it from damage. If the junction temperature of the device exceeds the specified temperature, the thermal shutdown stops the converter operation and resumes the converter operation if the junction temperature decreases below the thermal shutdown release temperature. 10 R1208x NO.EA-314-211027 APPLICATION INFORMATION Typical Applications VIN = 5 V～22 V C4 VIN LED2 LED1 LED3 ISET LED4 RSET C3 R1208x VS GND CE VOUT 10 LEDs x 4 Parallels LX PGND D1 C2 L1 C1 Typical Application 1. 10 LEDs in series x 4 parallels, up to 80 mA per LED, 5 V or higher power supply voltage, using 4 LED channels VIN = 2.7V ～ 5 V C4 VIN LED2 LED1 LED3 ISET LED4 RSET R1208x VS GND CE VOUT LX PGND C1 10 LEDs x 4 Parallels D1 L1 C2 Typical Application 2. 10 LEDs in series x 4 parallels, up to 80 mA per LED, less than 5 V power supply voltage, using 4 LED channels 11 R1208x NO.EA-314-211027 VIN = 5 V ～ 22 V VIN LED2 10 LEDs x 4 Parallels C4 LED1 LED3 ISET LED4 RSET C3 R1208x VS GND CE VOUT 10 LEDs x 4 Parallels 10 LEDs x 4 Parallels 10 LEDs x 16 Parallels LX PGND D1 C2 L1 C1 Typical Application 3. 10 LEDs in series x 16 parallels, up to 20 mA per LED, 5 V or higher power supply voltage, using 4 LED channels VIN = 5 V ～ 22 V C4 VIN LED2 LED1 LED3 ISET LED4 RSET C3 R1208x VS GND CE VOUT LX PGND C1 10 LEDs x 6 Parallels D1 L1 C2 Typical Application 4. 10 LEDs in series x 6 parallels, up to 40 mA per LED, 5 V or higher power supply voltage, using 3 LED channels 12 R1208x NO.EA-314-211027 VIN = 5 V ～ 22 V C4 VIN LED2 LED1 LED3 ISET LED4 RSET C3 10 LEDs x 2 Parallels R1208x VS GND CE VOUT LX PGND D1 C2 L1 C1 Typical Application 5. 10 LEDs in series x 2 parallels, up to 160 mA per LED, 5 V or higher power supply voltage, using 4 LED channels VIN = 2.7 V ～ 5 V C4 VIN LED2 LED1 LED3 ISET LED4 RSET R1208x VS GND CE VOUT LX PGND C1 10 LEDs x 2 Parallels D1 L1 C2 Typical Application 6. 10 LEDs in series x 2 parallels, up to 80 mA per LED, less than 5 V power supply voltage, using 2 LED channels 13 R1208x NO.EA-314-211027 Recommended Inductors Frequency (kHz) L1 (μH) 750 10 450 22 Parts No. Rated Current (mA) Size (mm) VLS252010ET-100M 550 2.5 × 2.0 × 1.0 VLF302512MT-100M 620 3.0 × 2.5 × 1.2 VLF403212MT-100M 900 4.0 × 3.2 × 1.2 VLF504012MT-100M 1320 5.0 × 4.0 × 1.2 VLF302512MT-220M 430 3.0 × 2.5 × 1.2 VLF403212MT-220M 540 4.0 × 3.2 × 1.2 VLF504012MT-220M 890 5.0 × 4.0 × 1.2 VLS5045EX-220M 1800 5.0 × 5.0 × 4.5 Recommended Components Symbol • Parts No. 60 CRS12 60 RB060M-60 C1 25 C3225JB1E475M C2 50 C3 25 C1608X5R1E224M C4 6.3 CM105B105K06 D1 *1 Rated Voltage (V) C2012X5R1H225K C2012X5R1H105K*1 When ILED = 80 mA or lower at 750 kHz Selection of Inductor Peak current of inductor (ILmax) in normal mode when the efficiency is 80% can be calculated by the following formula. ILmax = 1.25 x IOUT x VOUT / VIN + 0.5 x VIN x (VOUT − VIN) / (L1 x VOUT x fosc) When starting up the IC or when adjusting the brightness of LEDs, a large transient current may flow into an inductor (L1). ILmax should be equal or smaller than the current limit of the IC. When deciding the rated current of inductor, ILmax should be considered. It is recommended that L1 with 10 µH to 22 µH be used. • Selection of Capacitor Set a 1 µF or more input capacitor (C1) between the VIN and GND pins as close as possible to the pins. Set a 1 µF output capacitor (C2) between the VOUT and GND pins if ILED ≤ 80 mA and an inductor is 10 µH. In other cases, set a 2.2 µF or more output capacitor (C2) between the VOUT and GND pins. 14 R1208x NO.EA-314-211027 • Selection of Diode For a rectifier diode, use a schottky barrier diode that has low VF. It is recommended to select a schottky barrier diode that has low reverse current and low parasitic capacitance. • VS Pin Connection at VIN < 5 V When using the VS pin at VIN < 5 V, it is recommended that the VIN pin and the VS pin be short-circuited each other. Refer to Typical Application 2 and 6. There’s no capacitor required between the VS pin and the GND pin. If the VIN pin and the VS pin are not shorted each other, a capacitor (C3) is required between the VS pin and the GND pin. Refer to Typical Application 1, 3, 4, and 5. • LED Current Setting The LED current (ILEDSET) when a ”H” PWM signal is applied to the CE pin (Duty = 100%) can be determined by the value of feedback resistor (RSET). If a 10 kΩ resistor (RSET) is placed between the ISET pin and the GND pin, the LED pin current will be set to 20 mA. ILEDSET = 0.103 × RSET / (41.5 k + RSET) Choose 4.4 kΩ (10 mA) to 143 kΩ (80 mA) for RSET. By using the application example of Typical Application 5, the LED current can be set between 80 mA to 160 mA. The LED current can be set up to 320 mA by using the four LED pins. • LED Dimming Control The brightness of the LEDs can be adjusted by applying a PWM signal to the CE pin. If the High-Duty of PWM input of the CE is Hduty, the current of LED can be calculated by the following formula. ILED = Hduty × ILEDSET The minimum High-duty of a PWM signal can be controlled up to 2.3% (Ta = 25°C). However,the ILED current is controlled to approximately 4mA during the soft start time. By inputting “L” voltage for a certain period of time (Typ. 12 ms for R1208KxxxA/ 18 ms for R1208KxxxB), the IC goes into standby mode and turns off LEDs. 15 R1208x NO.EA-314-211027 • PWM Dimming Adjustment Frequency The frequency range of a PWM signal should be set within the range of 200 Hz to 300 kHz. In the case of using a 20 kHz or less PWM signal for dimming the LEDs, the increasing or decreasing of the inductor current (IL) may generate noise in the audible band. In this case, connect a capacitor (C4) between the ISET pin and GND pin. In the case of using a 20 kHz or more PWM signal, connecting a capacitor is not required. Refer to Typical Application 2, Typical Application 5 and Typical Application 6 for details. ISET • RSET C4 (opt.) Unused LED Current Source Unused LED pin should be connected to GND. When using two or three LED pins, it is recommended that the rest of the LED pins should be connected as below. Using two LED pins: LED 2 and LED 4 should be connected to GND. Refer to Typical Application 6. Using three LED pins: LED 4 should be connected to GND. Refer to Typical Application 4. 16 R1208x NO.EA-314-211027 TECHNICAL NOTES  Current Path on PCB Figure 1 and Figure 2 show flows of current paths of the application circuits when MOSFET is ON and when MOSFET is OFF, respectively. Parasitic elements (impedance, inductance or capacitance) in the paths pointed with red arrows in Figure 1 and Figure 2 influence stability of the system and cause noise outbreak. It is recommended that these parasitic elements be minimized. In addition, except for the paths of LED load, it is recommended that the all wirings of the current paths be made as short and wide as possible. Load Load Figure 1. MOSFET-ON Figure 2. MOSFET-OFF  Layout Guide for PCB ⋅ Place C1 as close as possible to the VIN and GND pins. Also, connect the GND pin to the wider GND plane. ⋅ Make the LX land pattern as small as possible. ⋅ Make the wirings between the LX pin, the inductor and the diode as short as possible. Also, connect C2 as close as possible to the cathode of the diode. ⋅ Place C2 as close as possible to the GND pin. 17 R1208x NO.EA-314-211027  PCB Layout Topside Backside DFN(PLP)2730-12 Typical Board Layout less than 5 V power supply voltage Topside Backside DFN(PLP)2730-12 Typical Board Layout more than 5 V power supply voltage 18 R1208x NO.EA-314-211027 TYPICAL CHARACTERISTICS 1) Efficiency vs. Output Current of R1208xx12A/B 1-1) Efficiency vs. Output Current with Different Input Voltages R1208x312B VLF504012MT-100M / 6LED × 4 Parallel (VOUT=17.3V at 80mA) R1208x312B VLF504012MT-220M / 6LED × 4 Parallel (VOUT=17.3V at 80mA) EFFICIENCY [%] 95 90 85 80 75 70 VIN=3.6V 65 VIN=5V 60 55 VIN=8V EFFICIENCY [%] 100 VIN=12V 50 0 80 160 240 Output Currrent 4Parallel [mA] 100 95 90 85 80 75 70 65 60 55 50 VIN=3.6V VIN=5V VIN=8V VIN=12V 0 320 95 90 95 90 85 80 VIN=3.6V 65 VIN=5V 60 55 VIN=12V VIN=8V 50 EFFICIENCY [%] EFFICIENCY [%] 100 320 85 80 75 70 65 VIN=3.6V 60 55 VIN=8V VIN=5V VIN=12V 50 80 160 240 Outpu Currrent 4Parallel [mA] 240 R1208x312B VLF504012MT-220M / 8LED × 4 Parallel (VOUT=22.8V at 80mA) 100 0 160 Output Current 4Parallel [mA] R1208x312B VLF504012MT-100M / 8LED × 4 Parallel (VOUT=22.8V at 80mA) 75 70 80 320 0 80 160 240 Output Current 4Parallel [mA] 320 19 R1208x NO.EA-314-211027 TYPICAL CHARACTERISTICS (continued) R1208x312A VLF504012MT-100M / 10LED × 4 Parallel(VOUT=28V at 80mA) 100 100 95 90 95 90 85 80 75 70 VIN=3.6V 65 VIN=5V 60 55 VIN=8V EFFICIENCY [%] EFFICIENCY [%] R1208x312B VLF504012MT-220M / 10LED × 4 Parallel (VOUT=28V at 80mA) VIN=12V 50 0 80 160 240 Output Current 4Parallel [mA] 85 80 75 70 VIN=3.6V 65 VIN=5V 60 VIN=8V 55 VIN=12V 50 0 320 100 100 95 90 95 90 85 80 50 0 320 85 80 VIN=3.6V VIN=5V VIN=8V 65 60 VIN=8V VIN=12V 55 VIN=12V VIN=5V 55 240 75 70 VIN=3.6V 65 60 160 R1208x312A VLF504012MT-100M / 12LED × 4 Parallel(VOUT=33.7V at 80mA) EFFICIENCY [%] EFFICIENCY [%] R1208x312B VLF504012MT-220M / 12LED × 4 Parallel (VOUT=33.7V at 80mA) 75 70 80 Output Current 4Parallel [mA] 80 160 240 Output Current 4Parallel [mA] 50 320 0 80 160 240 320 Outpur Current 4Parallel [mA] 20 R1208x NO.EA-314-211027 TYPICAL CHARACTERISTICS (continued) 1-2) Efficiency vs. Output Current with Different Inductors (VOUT = 28 V at 80 mA) R1208x312B VIN = 3.6V / 10LED × 4 Parallel 100 100 95 95 90 90 85 85 80 75 70 VLF302512MT-100M 65 VLF403212MT-100M 60 EFFICIENCY [%] EFFICIENCY [%] R1208x312A VIN = 3.6V / 10LED × 4 Parallel VLF504012MT-100M 55 0 20 40 60 75 70 VLF302512MT-220M 65 VLF403212MT-220M 60 VLF504012MT-220M 55 VLF504012MT-220M 50 80 VLF504012MT-100M 50 80 0 20 100 100 95 95 90 90 85 85 80 75 VLF302512MT-100M VLF403212MT-100M 60 VLF504012MT-100M 55 VLF504012MT-220M 50 0 40 80 120 Output Current 4Parallel [mA] 80 R1208x312B VIN = 5V / 10LED × 4 Parallel 160 EFFICIENCY [%] EFFICIENCY [%] R1208x312A VIN = 5V / 10LED × 4 Parallel 65 60 IOUT [mA] Output Current 4Parallel [mA] 70 40 80 75 70 VLF302512MT-220M 65 VLF403212MT-220M 60 VLF504012MT-220M 55 VLF504012MT-100M 50 0 40 80 120 160 Output Current 4Parallel [mA] 21 R1208x NO.EA-314-211027 TYPICAL CHARACTERISTICS (continued) R1208x312A VIN = 8V / 10LED × 4 Parallel 100 100 95 95 80 75 70 VLF302512MT-100M 65 VLF403212MT-100M 60 VLF504012MT-100M 55 0 80 160 80 75 70 VLF403212MT-220M VLF504012MT-220M VLF504012MT-100M 50 240 0 80 160 Output Current 4Parallel [mA] Output Current 4Parallel [mA] R1208x312A VIN = 12V / 10LED × 4 Parallel R1208x312B VIN = 12V / 10LED × 4 Parallel 100 100 95 95 90 90 85 85 80 75 70 VLF302512MT-100M 65 VLF403212MT-100M 60 VLF504012MT-100M 55 VLF504012MT-220M 50 0 VLF302512MT-220M 65 55 VLF504012MT-220M 50 85 60 80 160 240 Output Current 4Parallel [mA] 320 EFFICIENCY [%] EFFICIENCY [%] 85 EFFICIENCY [%] 90 90 EFFICIENCY [%] R1208x312B VIN = 8V / 10LED × 4 Parallel 240 80 75 70 VLF302512MT-220M 65 VLF403212MT-220M 60 VLF504012MT-220M 55 VLF504012MT-100M 50 0 80 160 240 Output Current 4Parallel [mA] 320 22 R1208x NO.EA-314-211027 TYPICAL CHARACTERISTICS (continued) 2) Onduty vs. ILED (ISET = 10 kΩ) R1208x312A VIN = 5.0V / 10LED × 4Paralle 25 f = 200Hz ILED1 [mA] 20 f = 2kHz f = 20kHz f = 300kHz 15 10 5 0 0 10 20 30 40 50 60 Duty [%] 70 80 90 100 3) Electrical Characteristics 3-1) Supply Current (No switching) vs. Ambient Temperature No switching VIN Current R1208Kx12x 1100 VIN=2.7V VIN=3.6V 1000 VIN=5.5V VIN=22V ICC1 (uA) 900 800 700 600 500 400 300 -40 -15 10 35 60 85 Temperature Ta (ﾟC) 23 R1208x NO.EA-314-211027 TYPICAL CHARACTERISTICS (continued) 3-2) Supply Current (Switching) vs. Ambient Temperature Switching VIN Current with No Load R1208Kx12A Switching VIN Current with No Load R1208Kx12B 2400 1900 2200 1700 2000 ICC2 (uA) 1600 1400 1200 VIN=2.7V VIN=3.6V VIN=5.5V VIN=22V 1000 800 600 -40 -15 10 35 60 Temperature Ta (ﾟC) 1100 900 VIN=2.7V VIN=3.6V VIN=5.5V VIN=22V 700 500 300 -40 -15 10 35 60 Temperature Ta (ﾟC) 85 3-4) VS Voltage vs. Ambient Temperature VS Voltage UVLO Voltage 2.6 1300 85 3-3) UVLO Voltage vs. Ambient Temperature 5.9 Detect 2.55 5.7 Release 5.5 2.5 VS (V) UVLO (V) ICC2 (uA) 1500 1800 2.45 2.4 5.3 5.1 4.9 2.35 VIN=8V 4.7 2.3 VIN=22V 4.5 -40 -15 10 35 Temperature Ta (ﾟC) 60 85 -40 -15 10 35 60 85 Temperature Ta (ﾟC) 24 R1208x NO.EA-314-211027 TYPICAL CHARACTERISTICS (continued) 3-5) LED Current Accuracy vs. Ambient Temperature LED Current ILED/1string=20mA 20.6 VIN=2.7V ILED (mA) 20.4 VIN=3.6V VIN=22V 20.2 20 19.8 19.6 19.4 -40 -15 10 35 60 85 Temperature Ta (ﾟC) 3-6) Channnel Matching vs. Ambient Temperature 1 String: 20 mA 3-7) Channel Matching vs. Ambient Temperature 1 String: 2 mA LED Current 1-4 matching ILED/1string=20mA LED Current 1-4 matching ILED/1string=2mA 2.5 5 VIN=2.7V VIN=3.6V VIN=22V 1.5 1 2 1 0 0 -15 10 35 Temperature Ta (ﾟC) 60 85 VIN=3.6V VIN=22V 3 0.5 -40 VIN=2.7V 4 ILEDM2 (%) ILEDM (%) 2 -40 -15 10 35 60 85 Temperature Ta (ﾟC) 25 R1208x NO.EA-314-211027 TYPICAL CHARACTERISTICS (continued) 3-8) NMOS ON Resistance vs. Ambient Temperature 3-9) NMOS Limit Current vs. Ambient Temperature 2500 0.45 2400 0.4 2300 0.35 2200 ILXLIM (mA) RON (Ω) NMOS ON Resistance 0.5 0.3 0.25 0.2 0.15 0.05 0 -40 -15 10 35 60 Temperature Ta (ﾟC) VIN=2.7V VIN=3.6V VIN=5.5V VIN=22V 2100 2000 1900 1800 VIN=2.7V VIN=3.6V VIN=5.5V VIN=22V 0.1 NMOS Limit Current 1700 1600 1500 -50 85 -25 0 25 50 75 100 Temperature Ta (ﾟC) 3-10) Operating Frequency vs. Ambient Temperature Oscillator Frequency R1208Kx12A 825 VIN=2.7V VIN=3.6V VIN=22V 775 750 725 VIN=2.7V VIN=3.6V VIN=22V 490 480 FOSC (kHz) FOSC (kHz) 800 Oscillator Frequency R1208Kx12B 500 470 460 450 440 430 420 700 410 400 675 -40 -15 10 35 Temperature Ta (ﾟC) 60 85 -40 -15 10 35 60 85 Temperature Ta (ﾟC) 26 R1208x NO.EA-314-211027 TYPICAL CHARACTERISTICS (continued) 3-11) Maxduty vs. Ambient Temperature Maximum Duty R1208Kx12B Maximum Duty R1208Kx12A 98 98 VIN=2.7V 97 VIN=3.6V VIN=22V 96 95 94 MAXDUTY (%) MXDUTY (%) 97 96 95 94 93 93 92 92 -40 -15 10 35 60 VIN=2.7V VIN=3.6V VIN=22V -40 85 -15 35 60 85 Temperature Ta (ﾟC) Temperature Ta (ﾟC) 3-12) VOUT OVP Detector Threshold vs. Ambient Temperature 3-13) LED OVP Detector Threshold vs. Ambient Temperature VOUTOVP Voltage(VIN=3.6V) R1208K312x LEDOVP Detect Voltage 45 44.5 44 VOUTOVP (V) 10 Detect 11.5 Release 11.0 VOVP3 (V) 43.5 43 42.5 42 VIN=2.7V VIN=3.6V VIN=22V 10.5 10.0 9.5 9.0 41.5 41 -40 -15 10 35 Temperature Ta (ﾟC) 60 85 8.5 -40 -15 10 35 60 85 Temperature Ta (ﾟC) 27 R1208x NO.EA-314-211027 TYPICAL CHARACTERISTICS (continued) 3-14) Soft-start Time vs. Ambient Temperature Soft Start Time 45 VIN=2.7V VIN=3.6V 40 VIN=22V TSS (ms) 35 30 25 20 15 10 -40 -15 10 35 60 85 Temperature Ta (ﾟC) 28 POWER DISSIPATION DFN(PLP)2730-12 Ver. A The power dissipation of the package is dependent on PCB material, layout, and environmental conditions. The following measurement conditions are based on JEDEC STD. 51-7. Measurement Conditions Item Measurement Conditions Environment Mounting on Board (Wind Velocity = 0 m/s) Board Material Glass Cloth Epoxy Plastic (Four-Layer Board) Board Dimensions 76.2 mm × 114.3 mm × 0.8 mm Copper Ratio Outer Layer (First Layer): Less than 95% of 50 mm Square Inner Layers (Second and Third Layers): Approx. 100% of 50 mm Square Outer Layer (Fourth Layer): Approx. 100% of 50 mm Square Through-holes  0.3 mm × 23 pcs Measurement Result Item (Ta = 25°C, Tjmax = 125°C) Measurement Result Power Dissipation 3100 mW Thermal Resistance (ja) ja = 32°C/W Thermal Characterization Parameter (ψjt) ψjt = 8°C/W ja: Junction-to-Ambient Thermal Resistance ψjt: Junction-to-Top Thermal Characterization Parameter Power Dissipation vs. Ambient Temperature Measurement Board Pattern i PACKAGE DIMENSIONS DFN(PLP)2730-12 DM-DFN(PNP)2730-12-JE-B DFN(PLP)2730-12 Package Dimensions (Unit: mm) i 1. The products and the product specifications described in this document are subject to change or discontinuation of production without notice for reasons such as improvement. Therefore, before deciding to use the products, please refer to Ricoh sales representatives for the latest information thereon. 2. The materials in this document may not be copied or otherwise reproduced in whole or in part without prior written consent of Ricoh. 3. Please be sure to take any necessary formalities under relevant laws or regulations before exporting or otherwise taking out of your country the products or the technical information described herein. 4. The technical information described in this document shows typical characteristics of and example application circuits for the products. The release of such information is not to be construed as a warranty of or a grant of license under Ricoh's or any third party's intellectual property rights or any other rights. 5. The products listed in this document are intended and designed for use as general electronic components in standard applications (office equipment, telecommunication equipment, measuring instruments, consumer electronic products, amusement equipment etc.). Those customers intending to use a product in an application requiring extreme quality and reliability, for example, in a highly specific application where the failure or misoperation of the product could result in human injury or death (aircraft, spacevehicle, nuclear reactor control system, traffic control system, automotive and transportation equipment, combustion equipment, safety devices, life support system etc.) should first contact us. 6. We are making our continuous effort to improve the quality and reliability of our products, but semiconductor products are likely to fail with certain probability. In order to prevent any injury to persons or damages to property resulting from such failure, customers should be careful enough to incorporate safety measures in their design, such as redundancy feature, fire containment feature and fail-safe feature. We do not assume any liability or responsibility for any loss or damage arising from misuse or inappropriate use of the products. 7. Anti-radiation design is not implemented in the products described in this document. 8. The X-ray exposure can influence functions and characteristics of the products. Confirm the product functions and characteristics in the evaluation stage. 9. WLCSP products should be used in light shielded environments. The light exposure can influence functions and characteristics of the products under operation or storage. 10. There can be variation in the marking when different AOI (Automated Optical Inspection) equipment is used. In the case of recognizing the marking characteristic with AOI, please contact Ricoh sales or our distributor before attempting to use AOI. 11. Please contact Ricoh sales representatives should you have any questions or comments concerning the products or the technical information. Halogen Free Ricoh is committed to reducing the environmental loading materials in electrical devices with a view to contributing to the protection of human health and the environment. Ricoh has been providing RoHS compliant products since April 1, 2006 and Halogen-free products since April 1, 2012. Official website https://www.n-redc.co.jp/en/ Contact us https://www.n-redc.co.jp/en/buy/