UNISONIC TECHNOLOGIES CO., LTD
L3012
Preliminary
LINEAR INTEGRATED CIRCUIT
1A HIGH POWER LED DRIVER
WITH 4.5~40V INPUT
DESCRIPTION
The UTC
L3012
is a step-down PWM control LED driver with
a built-in power Switch. It achieves 1A continuous output current
in 4.5~40V input voltage range. It has high efficiency up to more
than 96%, with the excellent current accuracy within ±1%.
FEATURES
SOP-8
* 4.5~40V input voltage range
* Maximum 1A output current
* 0.15Ω built-in power MOSFET
* 280kHz fixed frequency
* Excellent constant current accuracy ±1%
* Thermal shutdown
* Cycle-by-cycle over current protection
* PWM dimming function
ORDERING INFORMATION
Ordering Number
Lead Free
L3012L-S08-T
L3012L-S08-R
Halogen Free
L3012G-S08-T
L3012G-S08-R
Package
SOP-8
SOP-8
Packing
Tube
Tape Reel
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Copyright © 2013 Unisonic Technologies Co., Ltd
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L3012
PIN CONFIGURATION
Preliminary
LINEAR INTEGRATED CIRCUIT
SW 1
GND 2
SENSE 3
V
IN
4
8 ADJ
7 V
DD
6 PWM
5 COMP
PIN DESCRIPTION
PIN NAME
SW
GND
SENSE
V
IN
COMP
PWM
V
DD
ADJ
DESCRIPTION
Power Switch output.
Ground.
Current sense pin.
Input supply voltage.
Compensation pin, connects to external capacitor.
PWM dimming pin.
5V LDO output
Thermal compensation pin or linear dimming pin.
PIN NO.
1
2
3
4
5
6
7
8
BLOCK DIAGRAM
V
IN
4
SENSE
3
COMP
5
V
DD
7
+
-
Internal
reference
1 SW
ADJ 8
Current
setting
Osc
OSC
Vsense
-
+
S
Q
Driver
Vgate
M1
R
PWM 6
PWM
Control
Current
comparator
+
Slope
compensation
-
3
GND
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L3012
PARAMETER
Preliminary
LINEAR INTEGRATED CIRCUIT
ABSOLUTE MAXIMUM RATING
(unless otherwise specified)
SYMBOL
RATINGS
UNIT
Supply Voltage
V
IN
40
V
Switch Voltage
V
SW
-1~V
IN
+1
V
Comp Voltage
V
COMP
-0.3~6
V
SENSE Voltage
V
SENSE
-0.3~V
IN
V
Input Voltage
V
IN
4.5~40
V
Junction Temperature
T
J
150
°C
Operating Temperature
T
OPR
-40 ~ +125
°C
Storage Temperature
T
STG
-65 ~ +150
°C
Note: Absolute maximum ratings are those values beyond which the device could be permanently damaged.
Absolute maximum ratings are stress ratings only and functional device operation is not implied.
ELECTRICAL CHARACTERISTICS
(T
A
=25°C, unless otherwise specified, V
IN
=12V, I
OUT
=700mA)
SYMBOL
V
IN
I
IN
I
L
I
LIM
D
MAX
f
OSC
V
COMP
R
ON
V
IN
-V
SENSE
TSD
TSD-hys
TEST CONDITIONS
V
CC
=4/40V (Switch Off)
V
SW
=40V
V
IN
=SENSE=12V
3LED, V
IN
=9V
Open without load
1LED, I
OUT
=1A
Drop voltage between V
IN
and SENSE
MIN
6
TYP
2.2
0
2
94
280
2
0.15
100
160
30
MAX UNIT
36
V
4
mA
5
μA
3
A
96
%
320
kHz
2.2
V
0.5
Ω
mV
°C
°C
PARAMETER
Supply Voltage
Operating Current
Upper Switch Leakage
Current Limit
Maximum Duty Cycle
Oscillator Frequency
COMP Clamp Voltage
Switch Transistor on Resistance
Sampling Voltage Threshold
Thermal Shutdown Threshold
Thermal Shutdown Hysteresis
1.7
250
1.6
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L3012
FUNCTION DESCRIPTION
Preliminary
LINEAR INTEGRATED CIRCUIT
The UTC
L3012
is a current mode and fixed frequency (280kHz) LED driver.
1. Output current setting
The output current is determined by the sampling resistor (R
S
) and setting voltage (V
IN
-V
SENSE
a built-in fixed
100mV).
V
V
SENSE
I
OUT
½
IN
=100mV/Rs
R
S
2. Current limiting
UTC
L3012
has internal current limiting function, and the voltage on COMP is clamped at about 2V, the output
current of the power MOSFET is limited at about 2A by current comparator.
3. Diode Selection
UTC
L3012
driver LED need a Schottky diode. If output current is 700mA or smaller then SS14 (D1N5819) is ok.
The average current through the diode is I
D
:
I
D
= (1-D)
·
I
LED
I
LED
is the current of LED
TYPICAL APPLICATION CIRCUIT
1
L
SBD
Cout
Rs
V
IN
10µF
4
2
3
SW
GND
SENSE
V
IN
ADJ
V
DD
PWM
COMP
8
7
6
5
100nF
1µF
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L3012
Preliminary
LINEAR INTEGRATED CIRCUIT
UTC assumes no responsibility for equipment failures that result from using products at values that
exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or
other parameters) listed in products specifications of any and all UTC products described or contained
herein. UTC products are not designed for use in life support appliances, devices or systems where
malfunction of these products can be reasonably expected to result in personal injury. Reproduction in
whole or in part is prohibited without the prior written consent of the copyright owner. The information
presented in this document does not form part of any quotation or contract, is believed to be accurate
and reliable and may be changed without notice.
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