Diodes AP3036B User Manual
AP3036B
Document number: DS37004 Rev. 1 - 2
1 of 11
www.diodes.com
March 2014
© Diodes Incorporated
AP3036B
A Product Line of
Diodes Incorporated
NE W P R OD U C T
Description
The AP3036B is an inductor-based DC/DC converter designed to
drive up to eight white LEDs in series for backlight. Only one
feedback resistor is needed to control the LED current and obtain
required brightness.
A constant frequency 1.0MHz PWM control scheme is employed in
this IC, which means tiny external components can be used.
Specifically, 1mm tall inductor and 0.22µF output capacitor for a
typical application is sufficient. Additionally, the Schottky diode in
boost circuit is integrated on this chip. The AP3036B also provides a
disable pin to ease its use for different systems.
The output over-voltage protection is implemented in AP3036B. When
any LED is broken or in other abnormal conditions, the output voltage
will be clamped.
The AP3036B is available in standard SOT26 package.
Applications
Cellular Phones
Digital Cameras
LCD Modules
GPS Receivers
PDAs, Handheld Computers
Pin Assignments
(Top View)
SW
GND
FBCTRL
VOUT
VIN
1
2
3 4
5
Pin 1 Mark
6
SOT26
Features
Inherently Uniform LED Current
High Efficiency up to 84%
No Need for External Schottky Diode
Output Over-voltage Protection (OVP)
Fixed 1.0MHz Switching Frequency
Uses Tiny 1mm Tall Inductor
Requires Only 0.22µF Output Capacitor
High Frequency Dimming Control
Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
Halogen and Antimony Free. “Green” Device (Note 3)
22
1F
0.22F
10
VIN
SW VOUT
FB
GND
CTRL
AP3036B
Control
Signal
L
C
IN
C
OUT
V
IN
3V
WHITE LED STEP-UP CONVERTER
Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.
2. See http://www.diodes.com/quality/lead_free.html for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green"
and Lead-free.
3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and
<1000ppm antimony compounds.
Typical Applications Circuit (Note 4)
Note 4: C: X5R or X7R type dielectric, L: SUMIDA CDRH5D28R-220NC or equivalent. And, this circuit can work in full temperature.
AP3036B
Document number: DS37004 Rev. 1 - 2
2 of 11
www.diodes.com
March 2014
© Diodes Incorporated
AP3036B
A Product Line of
Diodes Incorporated
NE W P R OD U C T
Pin Number
Pin Name
Function
1
CTRL
Shutdown and dimming pin. Connect to 1.5V or higher to enable device; Connect to 0.4V or less to
disable device; Connect to a PWM signal to achieve LEDs brightness dimming
2
VOUT
Output pin. Connect to the cathode of internal Schottky diode
3
VIN
Input supply pin. Must be connected to a local bypass capacitor
4
SW
Switch pin. Connect external inductor
5
GND
Ground 6 FB
Voltage feedback pin. The reference voltage is 200mV
Q1
A2
A1
R
S
Q
1.0MHz
OSCILLATOR
RAMP
GENERATOR
V
REF
6
3
1
5
2
DRIVER
1.25V
COMPARATOR
OVP
200 mV
4
SOFT
START
FB SW
VOUT
GND
CTRL
VIN
Pin Descriptions
Functional Block Diagram
AP3036B
Document number: DS37004 Rev. 1 - 2
3 of 11
www.diodes.com
March 2014
© Diodes Incorporated
AP3036B
A Product Line of
Diodes Incorporated
NE W P R OD U C T
Symbol
Parameter
Rating
Unit
VIN
Input Voltage
20
V
VSW
SW Pin Voltage
38
V
VFB
Feedback Voltage
20
V
V
CTRL
CTRL Pin Voltage
20
V
θ
JA
Thermal Resistance (Junction to Ambient, No Heat Sink)
265
C/W
TJ
Operating Junction Temperature
+150
C
T
STG
Storage Temperature Range
-65 to +150
C
T
LEAD
Lead Temperature (Soldering, 10sec)
+260
C
–
ESD (Machine Model)
250
V
–
ESD (Human Body Model)
2000
V
Symbol
Parameter
Min
Max
Unit
TOP
Operating Temperature Range
-40
+85
C
VIN
Input Voltage
2.5
16
V
V
CTRL
CTRL Pin Voltage
–
16
V
Absolute Maximum Ratings (Note 5)
Note 5: Stresses greater than 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 Ratings" for extended periods may affect device reliability.
Recommended Operating Conditions
AP3036B
Document number: DS37004 Rev. 1 - 2
4 of 11
www.diodes.com
March 2014
© Diodes Incorporated
AP3036B
A Product Line of
Diodes Incorporated
NE W P R OD U C T
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
VIN (Min)
Minimum Operating Voltage
–
2.5 – –
V
VIN (Max)
Maximum Operating Voltage
–
– – 16
VFB
Feedback Voltage
I
OUT
= 20mA, 4 LEDs
188
200
212
mV
IFB
FB Pin Bias Current
– – 35
100
nA
IQ
Quiescent Current
V
FB
= VIN, No Switching
1.6
3.1
3.9
mA
I
SHDN
Shutdown Quiescent Current
V
CTRL
= 0V
–
45
75
µA
f
Switching Frequency
– – 1.0 – MHz
D
MAX
Maximum Duty Cycle
–
90
93 – %
I
LIMIT
Switch Current Limit (Note 6)
D = 40% or 80%
–
550 – mA
V
CESAT
Switch VCE Saturation Voltage
I
SW
= 250mA
–
360 – mV
–
Switch Leakage Current
V
SW
= 5V
–
0.01 5 µA
V
CTRL
CTRL Pin Voltage
High
1.5
–
–
V
Low
– – 0.4
I
CTRL
CTRL Pin Bias Current
– – 100 – µA
VOV
OVP Voltage
– – 30 – V
V
DROP
Schottky Forward Drop
ID = 150mA
–
0.7 – V
–
Schottky Leakage Current
VR (Reverse Voltage) = 23V
–
0.1
4
µA
VR (Reverse Voltage) = 27V
– – 150
t
Soft Start Time
–
–
100 – µs
θ
JC
Thermal Resistance
(Junction to Case)
SOT26 – 60
–
C/W
Electrical Characteristics (@V
= 3V, V
IN
CTRL
= 3V, T
= +25°C, unless otherwise specified.)
A
Note 6: The switch current limit is related to duty cycle. Please refer to Figure LED Current vs. Duty (PWM Frequency = 0.5kHz).
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