IL7150, IL7150A

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