IL7150 IKSEMICON | Alldatasheet
Document overview
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Technical content
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 Temperature range from - 40 to +85 C Only 5 external components required TO-263-5L IL7150D2T IL7150AD2T
Applications
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 current s 0.8 & 1.5A. Main application areas are automotive, DC/DC LED driver, lighting equipments and light indicators. IL7150, IL7150A
ORDERING INFORMATION
Temperature Range Package Packing IL7150D2T TA = -40 to 125 C TO-263 Tape & Reel IL7150AD2T TO-263 Tape & Reel
Table 1. Contact Pad Description
Table 3. Recommended Operation Conditions Table 4. Maximum Ratings
- Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device.
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
2012, June, Rev. 00 VD1 VD2 VD3 VCC CS OUT OCS GND L1+ 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 out put 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.
2012, June, Rev. 00 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: mV330IO Average LED current is determined by amplitude of oscillating (puls ating) cu rrent, that depends on inductivity of coil L1. For example , average current of LED is 550 mA (pulsating) current is 100 mA. Then: mV3301R In order to driving current not exceed recommended max r ating 1.5 A for I L7150, (0.8A for IL7150A), R1 value has to be more than 200 m. Inductor The Inductor L 1 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 cur rent ripple on LEDs, the L value should high enough to keep the system working at continuous- conduction 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 T Ts Ton LLL ON dtVdtVdtV 0 0 Where, TS = TON + TOFF Therefore LEDSATRCC FLED VVVV VV Toff Ton 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 timing capacitor C1, the switch turn-on time can also be known by f DTsDTon , Where duty cycle ToffTon TonD With knowledge of the peak switch current and switch on time, the value of inductance can be calculated: ON PK LEDSATRCC TI
2012, June, Rev. 00 0,5 15 20 25 30 35 40 mA 1,0 1,5 2,0 2,5 3,0 Та = 85 ОС Та = 25 ОС Та = -40 ОС 100 4,0 ICC Ucc V Fig. 3. Supply Current as a Function of Supply Voltage
2012, June, Rev. 00 TO-263-5L