Macroblock Preliminary Datasheet MBI1802 All-Ways-OnTM High-Power LED Driver Features z 2 constant-current output channels z Constant output current invariant to load voltage change z Maximum output constant current: 360 mA z Thermal protection and report z Output current adjustment z Schmitt trigger input z 5V supply voltage z Package type: SOP8 with thermal pad Current Accuracy Between Channels Between ICs < ±3% < ±6% Conditions IOUT = 40mA ~ 360 mA @ VDS= 0.6V Product Description MBI1802 is an instant On/Off LED driver for high power LED applications and exploits PrecisionDrive™ and All-Ways-On™ technology to enhance its output characteristics. With All-Ways-On™, MBI1802 easily provides users with a consistent current source in their system design. Users may adjust the output current up to 360 mA through an external resistor, Rext, which gives users flexibility in controlling the light intensity of LEDs. Also, users can precisely adjust LED brightness from 0% to 100% via output control with Pulse Width Modulation. Alternatively, MBI1802 provides one-step current adjustment to make a quarter of the output current via enabling the QUAD pin as “High”. Additionally, to ensure the system reliability, MBI1802 is built with TP (Thermal Protection) function and thermal pad. The TP function can protect IC from over temperature (165°C) and the thermal pad can enhance the power dissipation. As a result, a large amount of current can be handled safely in one package. Applications z High-Flux LED Lighting z Automotive Interior Lighting Macroblock, Inc. 2005 Floor 6-4, No.18, Pu-Ting Rd., Hsinchu, Taiwan 30077, ROC. TEL: +886-3-579-0068, FAX: +886-3-579-7534 E-mail: [email protected] -1January 2005, V1.00 All-Ways-OnTM High-Power LED Driver MBI1802 Typical Application Circuit VDD 1 GND Rext VLED VDD 8 2 R-EXT OE 7 3 QUAD ERR 6 4 OUT0 OUT1 5 Figure 1 Block Diagram QUAD OUT0 OUT1 IO Regulator R-EXT VDD Thermal Sensor 2 switches ERR OE -2- January 2005, V1.00 All-Ways-OnTM High-Power LED Driver MBI1802 Pin Configuration GND R-EXT QUAD OUT0 1 2 3 4 8 7 6 5 Thermal Pad VDD OE ERR OUT1 MBI1802 Terminal Description Pin No. Pin Name Function 1 GND Ground terminal for control logic and current sink 2 R-EXT Terminal used to connect an external resistor(Rext) for setting up output current for all output channels 3 QUAD Set all the output current to 25% of the pre-set current when QUAD is high. 4, 5 OUT0 ~ OUT1 6 ERR 7 OE 8 VDD - Thermal Pad Constant current output terminals Thermal error flag, when junction temperature is over 165°C, ERR is going to high.* Output enable terminal When OE (active) low, the output drivers are enabled; when OE high, all output drivers are turned OFF (blanked). 5V supply voltage terminal Power dissipation terminals with ground connection* *To eliminate the noise influence, the thermal pad should be connected to GND. In addition, desired thermal conductivity will be better if the conduction area on PCB connecting to the thermal pad is large enough. -3- January 2005, V1.00 All-Ways-OnTM High-Power LED Driver MBI1802 Maximum Ratings Characteristic Symbol Rating Unit Supply Voltage VDD 0~7.0 V Input Voltage VIN -0.4~VDD + 0.4 V Output Current IOUT 360* Output Voltage VDS -0.5~+17.0 GND Terminal Current IGND 720 mA Power Dissipation* (On PCB, Ta=25°C) PD 0.8 W Thermal Resistance* (Under good thermal system) SOP8 mA V 33.39** °C/W Rth(j-a) Thermal Resistance* (On PCB, Ta=25°C) 125 Operating Temperature Topr -40~+85 °C Storage Temperature Tstg -55~+150 °C *Users must notice that the power dissipation (almost equaling to IOUT x VDS) should be within the Safe Operation Area shown in Figure 6. ** Good thermal system design can ensure that the heat management of the total system (storage temperature and operating temperature) maintains MBI1802 within the defined temperature limits (Rth(j-a)= 33.39°C/W). -4- January 2005, V1.00 All-Ways-OnTM High-Power LED Driver MBI1802 Electrical Characteristics Characteristic Symbol Condition Min. Typ. Max. Unit Supply Voltage VDD - 4.5 5.0 5.5 V Output Voltage VDS OUT0 ~ OUT1 - - 17.0 V Output Current IOUT DC Test Circuit 40 - 360 mA “H” level VIH Ta= -40~85ºC 0.7*VDD - VDD V “L” level VIL Ta= -40~85ºC GND - 0.3*VDD V Output Leakage Current IOH VOH= 17.0V - - 0.5 µA Output Current 1 IOUT1 VDS= 0.6V Rext= 720 Ω - 204 - mA Current Skew dIOUT1 IOL= 204mA VDS= 0.6V Rext= 720 Ω - ±1 ±3 % Output Current 2 IOUT2 VDS= 0.5V Rext= 1440 Ω - 102 - mA Current Skew dIOUT2 IOL= 102mA VDS= 0.5V Rext= 1440 Ω - ±1 ±3 % Input Voltage Output Current vs. Output Voltage Regulation Output Current vs. Supply Voltage Regulation %/dVDS VDS within 1.0V and 3.0V - ±0.1 - %/V %/dVDD VDD within 4.5V and 5.5V - ±1 - %/V Pull-up Resistor RIN(up) 250 500 800 KΩ Thermal Protection Temperature Tj Junction Temperature - 165 - °C IDD(off) 1 Rext=Open, Off - 1.6 3.6 IDD(off) 2 Rext=720 Ω, Off - 4.5 7.5 IDD(off) 3 Rext=1440 Ω, - 3.2 6.2 IDD(on) 1 Rext=720 Ω, - 4.5 7.5 IDD(on) 2 Rext=1440 Ω, - 3.2 6.2 “OFF” Supply Current “ON” OE OUT0 ~ OUT1 = OUT0 ~ OUT1 = OUT0 ~ OUT1 = OUT0 ~ OUT1 = Off On OUT0 ~ OUT1 = On mA Test Circuit for Electrical Characteristics VDD IDD VDD Function Generator OE QUAD R-EXT Logic input waveform VIH VIL IR-EXT IOUT OUT0 OUT1 GND VDS CL VL Figure 2 -5- January 2005, V1.00 All-Ways-OnTM High-Power LED Driver MBI1802 Switching Characteristics Characteristic Propagation Delay Time (“L” to “H”) Propagation Delay Time (“H” to “L”) Symbol Condition Min. Typ. Max. Unit OE - OUTn tpLH 1 2 3 µs OE - OUTn tpHL VDD= 5.0 V VDS= 1-1.6V VIH= VDD VIL= GND Rext= 600 Ω VL= 4.0 V RL= 10 Ω CL= 10 pF 1 2 3 µs 10 - - µs 1 1.7 3 µs 1 1.7 3 µs Pulse Width tw(OE) OE Output Rise Time of Vout (turn off) tor Output Fall Time of Vout (turn on) tof Test Circuit for Switching Characteristics VDD IDD VDD Function Generator OE QUAD R-EXT Logic input waveform VIH VIL IOUT OUT0 OUT1 GND RL CL IR-EXT V DS VL Figure 3 -6- January 2005, V1.00 All-Ways-OnTM High-Power LED Driver MBI1802 Application Information Constant Current In LED lighting applications, MBI1802 provides nearly no variations in current from channel to channel and from IC to IC. This can be achieved by: 1) The maximum current variation between channels is less than ±3%, and that between ICs is less than ±6%. 2) In addition, the current characteristic of output stage is flat and users can refer to the figure as shown below. The output current can be kept constant regardless of the variations of LED forward voltages (VF). This performs as a perfection of load regulation. MBI1802 I OUT vs. VOUT for various Rext IOUT (mA) 400 350 Rext= 2907 ohm 300 Rext= 1455 ohm Rext= 984 ohm 250 Rext= 732 ohm 200 Rext= 586 ohm 150 Rext= 491 ohm 100 Rext= 422 ohm 50 0 0.0 0.2 0.4 0.6 0.8 VOUT (V) 1.0 1.2 1.4 Figure 4 -7- January 2005, V1.00 All-Ways-OnTM High-Power LED Driver MBI1802 Adjusting Output Current The output current of each channel (IOUT) is set by an external resistor, Rext. The relationship between IOUT and Rext is shown in the following figure. MBI1802 IOUT vs. Rext IOUT(mA) 400 350 300 250 200 150 100 50 0 0 500 1000 1500 2000 2500 3000 3500 Rext(ohm) Figure 5 Also, the output current can be calculated from the equation: VR-EXT = 1.28V；Rext= (VR-EXT / IOUT) x 115= (1.28V / IOUT) x 115 where Rext is the resistance of the external resistor connected to R-EXT terminal and VR-EXT is the voltage of R-EXT terminal. The magnitude of current (as a function of Rext) is around 102 mA at 1440Ω and 204 mA at 720Ω. TP Function (Thermal Protection) When the junction temperature exceeds the limit (165°C), TP starts to function and turn off the output current and the thermal error flag, ERR, goes high simultaneously. As soon as the temperature is below 165°C, the output current will be on again. The switching runs at a high frequency, so the blinking is imperceptible. However, the DC output current is limited and thus the driver is protected from overheat. -8- January 2005, V1.00 All-Ways-OnTM High-Power LED Driver MBI1802 Package Power Dissipation (PD) The maximum power dissipation, PD(max) = (Tj – Ta) / Rth(j-a), decreases as the ambient temperature increases. Max. Power Dissipation at Various Ambient Temperature 0.9 Power Dissipation (W) 0.8 SOP-8(CD) Type: Rth(j-a)= 125(°C/W)* 0.7 0.6 0.5 0.4 Safe Operation Area 0.3 0.2 0.1 0 0 25 50 75 100 Ambient Temperature (°C) Figure 6 The maximum allowable package power dissipation is determined as PD(max) = (Tj – Ta) / Rth(j-a). When 2 output channels are turned on simultaneously, the actual package power dissipation is PD(act) = (IDD x VDD) + (IOUT x Duty x VDS x 2). Therefore, to keep PD(act) ≤ PD(max), the allowable maximum output current as a function of duty cycle is: IOUT = { [ (Tj – Ta) / Rth(j-a) ] – (IDD x VDD) } / VDS / Duty / 2, where Tj = 125°C; Duty= tON / T; tON: the time of LEDs turning on; T: OE signal period tON OE T *Note1: The thermal resistor Rth(j-a) =125 °C/W is based on the following structure. Copper foil The PCB area L2xW2 is 4 times to the IC’s area L1xW1. L2 The thickness of the PCB is 1.6mm, L1 copper foil 1 Oz. The thermal pad on the W1 IC’s bottom has to be mounted on the copper foil. W2 -9- January 2005, V1.00 All-Ways-OnTM High-Power LED Driver MBI1802 Load Supply Voltage (VLED) MBI1802 are designed to operate with VDS ranging from 0.4V to 1.0V considering the package power dissipating limits. VDS may be higher enough to make PD(act) > PD(max) when VLED = 5V and VDS = VLED – VF, in which VLED is the load supply voltage. In this case, it is recommended to use the lowest possible supply voltage or to set an external voltage reducer, VDROP. A voltage reducer lets VDS = (VLED –VF) – VDROP. Resistors or Zener diode can be used in the applications as shown in the following figures. Voltage Supply Voltage Supply VDrop VDrop VLED VLED VF VF VDS VDS MBI1802 MBI1802 - 10 - January 2005, V1.00 MBI1802 All-Ways-OnTM High-Power LED Driver Outline Drawing - 11 - January 2005, V1.00