TECHNICAL DATA Light Emitting Diode (LED) Driver IL7150, IL7150A Features Supply voltage from 4.0 to 40 V Output driving current up to 0.8 A (IL7150A), 1.5 A (IL7150) Current consumption 4 mA ESD protection up to 2kV TO-263-5L Temperature range from - 40 to +85 C IL7150D2T IL7150AD2T Only 5 external components required ORDERING INFORMATION Device Applications IL7150D2T Package Packing TO-263 Tape & Reel TO-263 Tape & Reel TA = -40 to 125 C IL7150AD2T Operating Temperature Range Automotive DC/DC LED Driver Lighting Equipments Light Indicators Description IL7150, IL7150A (functional equivalent AMC7150 of ADDtek) - LED (Light Emitting Diode) driver with peak output current 0.8A (IL7150A) & 1.5A (IL7150). Microcircuit designed for driving of power LEDs in the wide range of supply voltages and load currents with peak output currents 0.8 & 1.5A. Main application areas are automotive, DC/DC LED driver, lighting equipments and light indicators. 1 2012, June, Rev. 00 IL7150 Table 1. Contact Pad Description Contact pad Number Pin Number Symbol 01 01 VCC Supply voltage input 02, 03, 04, 05 02 CS Current sensor input 09, 15 03 GND Ground 06, 07 04 OUT Driver output 08 05 OSC Oscillator output Function Note: Contact pads 10 – 14 are purposed only for testing during IC manufacturing and are not used by customer Vcc CS OUT - + Driver Control unit OCS Oscilator GND Fig. 1 – Block Diagram 2 2012, June, Rev. 00 IL7150 Table 3. Recommended Operation Conditions Parameter Target Symbol Supply voltage Junction temperature VCC Min Max 4.0 40 TJ 125 Unit V o C Table 4. Maximum Ratings Target Parameter Symbol Unit Supply voltage VCC Min -0.3 Output voltage Junction temperature VO -0.3 -60 TJ Storage temperature TSTG Max 40 40 V V 150 o 150 o C C * Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. Table 5. Electrical Characteristics Value Symbol ICC Parameter Testing mode Supply current 4.0 V VCC 40 V Output saturation voltage VCC = 5.0 V Min Max - 4.0 4.4 VCC = 5.0 V 300 270 50 1.3 1.4 3.0 3.0 1.3 1.4 3.0 3.0 300 330 360 396 99 VCC = 5.0 V 20 50 IO = 1.0 A IZ7150 IO = 1.5 A VDP - IO= 0.5 A IZ7150A IO= 0.8 A IOL Output leakage current VCC = 40 V VCS Current sensor voltage VCC = 5.0 V Max duty cycle Capacitor charging current DCMAX ICH - Ambient tempera ture, °C 25 10 -40; 85 Unit mA V A mV 25 10; -40; 85 % A 3 2012, June, Rev. 00 IL7150 R1 D1 + G1 VCC - CS OUT C1 L1 VD1 VD2 C2 OCS GND VD3 C1 – capacitor 47 F ± 10%; C2 – capacitor 680 pF ± 10%; D1 – microcircuit ; G1 – supply voltage source from 4.0 to 40 V; L1 – inductance coil 220 H ± 10%; R1 – resistor 330 m ± 1%; VD1 – Zener diode with stabilization voltage 40 V (1N5819 or equivalent); VD2, VD3 - LEDs Fig. 2. Application Diagram Functionality Starting current is regulated in the range from few milliamps up to 1.5 A. The regulation is performed by means of PWM (pulse-width modulation).Load is repetitively connected to the supply voltage via output switch. Changing of pulses porosity, adjusts average output voltage that allows regulating of output current. Inductive energy storage is applied in the circuit because of output voltage is pulse Input decoupling capacitor Input decoupling capacitor C1 regulates the input voltage and rejects switching interference. Limiting diode Zener diode with fast recovering VD1 is recommended as limiting diode. High reverse recovery current will cause on R1 voltage drop more than 330 mV, therefore switch that has to be on will turned off. 4 2012, June, Rev. 00 IL7150 LED driving current Resistor R1 determine max output peak current to the LED. Output peak current IO, flowing thought the LED, can be calculated by formula: 330mV IO . R1 Average LED current is determined by amplitude of oscillating (pulsating) current, that depends on inductivity of coil L1. For example , average current of LED is 550 mA (pulsating) current is 100 mA. Then: 330mV R1 0,55 . 550mA 0,5 100mA In order to driving current not exceed recommended max rating 1.5 A for IL7150, (0.8A for IL7150A), R1 value has to be more than 200 m. Inductor The Inductor L1 stores energy during switch turn-on period and discharge driving current to LEDs via flywheel diode while switch turn-off. In order to reduce the current ripple on LEDs, the L value should high enough to keep the system working at continuousconduction mode that inductor current won’t fall to zero. Since in steady-state operation the waveform must repeat from one time period to the next, the integral of the inductor voltage VL over one time period must be zero: Ts TON 0 0 VL dt Ts VL dt VL dt 0 , Ton Where, TS = TON + TOFF Therefore VLED VF Ton , Toff VCC VR VSAT VLED Where, VLED is the total forward voltage (at expecting current) of the LED string, VF is the forward voltage of the flywheel diode VD1, VR is the peak value of the voltage drop across R1 which is 300mV, VSAT is the saturation voltage of the switch which has a typical value of 1V. Since the operation frequency f is determined by choosing appropriate value for D timing capacitor C1, the switch turn-on time can also be known by Ton D Ts , f Ton Where duty cycle D Ton Toff With knowledge of the peak switch current and switch on time, the value of inductance can be calculated: V VR VSAT VLED L CC TON I PK 5 2012, June, Rev. 00 IL7150 Та = 85 ОС Та = 25 ОС Та = -40 ОС ICC mA 3,0 2,5 2,0 1,5 1,0 0,5 0 4,0 10 15 20 25 30 35 40 Ucc V Fig. 3. Supply Current as a Function of Supply Voltage 6 2012, June, Rev. 00 IL7150 TO-263-5L 7 2012, June, Rev. 00