APW7209
1MHz, High-Efficiency, Step-Up Converter for 2 to 10 White LEDs
Features
•
•
•
•
•
•
•
•
•
•
•
Wide Input Voltage from 2.5V to 6V
0.3V Reference Voltage
Fixed 1MHz Switching Frequency
High Efficiency up to 88%
100Hz to 100kHz PWM Brightness Control Fre-
quency
Open-LED Protection
Under-Voltage Lockout Protection
Over-Temperature Protection
<1µA Quiescent Current during Shutdown
SOT-23-6 Package
Lead Free and Green Devices Available
(RoHS Compliant)
General Description
The APW7209 is a current-mode and fixed frequency
boost converter with an integrated N-FET to drive up to 10
white LEDs in series.
The series connection allows the LED current to be iden-
tical for uniform brightness. Its low on-resistance of N-
FET and low feedback voltage reduce power loss and
achieve high efficiency. Fast switching frequency(1MHz
typical) allows using small-size inductor and both of in-
put and output capacitors. An over voltage protection
function, which monitors the output voltage via OVP pin,
stops switching of the IC if the OVP voltage exceeds the
over voltage threshold. An internal soft-start circuit elimi-
nates the inrush current during start-up.
The APW7209 also integrates under-voltage lockout, over-
temperature protection, and current limit circuits to pro-
tect the IC in abnormal conditions.The APW7209 is avail-
able in a SOT-23-6 package.
Applications
•
•
•
•
White LED Display Backlighting
Cell Phone and Smart Phone
PDA, PMP, MP3
Digital Camera
Simplified Application Circuit
V
IN
L1
22µH
V
OUT
Pin Configuration
SOT-23-6 Top View
LX 1
GND 2
FB 3
6 VIN
5 OVP
4 EN
C1
4.7µF
6
2
4
VIN
GND
EN
LX
OVP
FB
1
5
3
C2
1µF
Up to
10
WLEDs
APW7209
OFF ON
R1
15Ω
ANPEC reserves the right to make changes to improve reliability or manufacturability without notice, and
advise customers to obtain the latest version of relevant information to verify before placing orders.
Copyright
©
ANPEC Electronics Corp.
Rev. A.3 - Jul., 2008
1
www.anpec.com.tw
APW7209
Ordering and Marking Information
APW7209
Assembly Material
Handling Code
Temperature Range
Package Code
Package Code
C : SOT-23-6
Operating Ambient Temperature Range
I : -40 to 85
o
C
Handling Code
TR : Tape & Reel
Assembly Material
L : Lead Free Device
G : Halogen and Lead Free Device
X - Date Code
APW7209 CI:
W09X
Note: ANPEC lead-free products contain molding compounds/die attach materials and 100% matte tin plate termination finish; which
are fully compliant with RoHS. ANPEC lead-free products meet or exceed the lead-free requirements of IPC/JEDEC J-STD-020C for
MSL classification at lead-free peak reflow temperature. ANPEC defines “Green” to mean lead-free (RoHS compliant) and halogen
free (Br or Cl does not exceed 900ppm by weight in homogeneous material and total of Br and Cl does not exceed 1500ppm by
weight).
Absolute Maximum Ratings
Symbol
V
IN
VIN Supply Voltage (VIN to GND)
FB, EN to GND Voltage
V
LX
V
OVP
T
J
T
STG
T
SDR
LX to GND Voltage
OVP to GND Voltage
Maximum Junction Temperature
Storage Temperature
(Note 1)
Parameter
Rating
-0.3 ~ 7
-0.3 ~ V
IN
-0.3 ~ 42
-0.3 ~ 42
150
-65 ~ 150
260
Unit
V
V
V
V
°C
°C
°C
Maximum Lead Soldering Temperature, 10 Seconds
Note 1: 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 in the operational sections of the specifications is
not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Thermal Characteristics
(Note 2)
Symbol
θ
JA
Parameter
Junction to Ambient Thermal Resistance.
SOT-23-6
250
Typical Value
Unit
°C/W
Note 2:
θ
JA
is measured with the component mounted on a high effective thermal conductivity test board in free air.
Recommended Operating Conditions
(Note 3)
Symbol
V
IN
C
IN
C
OUT
L1
T
A
T
J
VIN Input Voltage
Input Capacitor
Output capacitor
Inductor
Ambient Temperature
Junction Temperature
Parameter
Range
2.5~ 6
4.7 or higher
0.68 or higher
6.8 ~ 47
-40 ~ 85
-40 ~ 125
Unit
V
µF
µF
µH
°C
°C
Note 3: Refer to the application circuit for further information.
Copyright
©
ANPEC Electronics Corp.
Rev. A.3 - Jul., 2008
2
www.anpec.com.tw
APW7209
Electrical Characteristics
(Refer to figure 1 in the “Typical Application Circuits”. These specifications apply over V
IN
= 3.6V, T
A
= -40°C to 85°C, unless otherwise
noted. Typical values are at T
A
= 25°C.)
Symbol
Parameter
Test Conditions
APW7209
Min.
Typ.
Max.
Unit
SUPPLY VOLTAGE AND CURRENT
V
IN
I
DD1
I
DD2
I
SD
UNDER VOLTAGE LOCKOUT
UVLO Threshold Voltage
UVLO Hysteresis Voltage
V
IN
Rising
2.0
50
2.2
100
2.4
150
V
mV
Input DC bias current
Input Voltage Range
T
A
= -40 ~ 85°C, T
J
= -40 ~ 125°C
V
FB
= 0.4V, no switching
FB = GND, switching
EN = GND
2.5
70
-
-
-
100
1
-
6
130
2
1
V
µA
mA
µA
REFERENCE AND OUTPUT VOLTAGES
V
REF
I
FB
F
SW
R
ON
I
LIM
D
MAX
V
OVP
Regulated Feedback Voltage
FB Input Current
T
A
= 25°C
T
A
= -40 ~ 85°C (T
J
= -40 ~ 125°C)
0.285
0.276
-50
0.3
-
-
0.315
0.324
50
V
nA
INTERNAL POWER SWITCH
Switching Frequency
Power Switch On Resistance
Power Switch Current Limit
LX Leakage Current
LX Maximum Duty Cycle
V
EN
=0V, V
LX
=0V or 5V, V
IN
= 5V
FB=GND
0.8
-
0.7
-1
92
1.0
0.6
0.9
-
95
1.2
-
1.2
1
98
MHz
Ω
A
µA
%
OUTPUT OVER VOLTAGE PROTECTION
Over Voltage Threshold
OVP Hysteresis
OVP Leakage Current
ENABLE AND SHUTDOWN
V
TEN
I
LEN
T
OTP
EN Voltage Threshold
EN Voltage Hysteresis
EN Leakage Current
Over-Temperature Protection
(Note 4)
V
EN
= 0~5V, V
IN
= 5V
T
J
Rising
V
EN
Rising
0.4
-
-1
0.7
0.1
-
1
-
1
V
V
µA
V
OVP
=40V
V
OVP
rising
-
-
-
40
3
50
-
-
-
V
V
µA
OVER-TEMPERATURE PROTECTION
-
-
150
40
-
-
°C
°C
Over-Temperature Protection
Hysteresis
(Note 4)
Note 4: Guaranteed by design, not production tested.
Copyright
©
ANPEC Electronics Corp.
Rev. A.3 - Jul., 2008
3
www.anpec.com.tw
APW7209
Typical Operating Characteristics
(Refer to figure 1 in the section “Typical Application Circuits”, V
IN
=3.6V, T
A
=25
o
C, 10WLEDs unless otherwise specified)
Efficiency vs. WLED Current
95
90
85
20
18
WLED Current vs. PWM Duty Cycle
WLED Current, I
LED
(mA)
16
14
12
10
8
6
4
2
0
100Hz
0
20
40
60
80
100
1KHz
100KHz
Efficiency (η)
80
75
70
65
60
55
50
0
5
10
15
20
25
30
V
IN
=3.3V
V
IN
=3.6V
10 WLEDs
V
IN
=4.2V
V
IN
=5V
≅
33V@20mA
η=
P
OUT
/P
IN
WLED Current, I
LED
(mA)
PWM Duty Cycle (%)
WLED Current vs. Supply Voltage
21.0
Maximum Duty Cycle vs. Supply
Voltage
100
Maximum Duty Cycle, D
MAX
(%)
2.5
3
3.5
4
4.5
5
5.5
6
20.8
WLED Current, I
LED
(mA)
20.6
20.4
20.2
20.0
19.8
19.6
19.4
19.2
19.0
90
80
70
60
50
40
2.5
3
3.5
4
4.5
5
5.5
6
Supply Voltage, V
IN
(V)
Supply Voltage, V
IN
(V)
1.2
Switching Frequency vs. Supply
Voltage
Switch ON Resistance, R
ON
(Ω
)
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Switch ON Resistance vs. Supply
Voltage
Switching Frequency, F
SW
(MHz)
1.1
1
0.9
0.8
0.7
0.6
0.5
0.4
2.5
3
3.5
4
4.5
5
5.5
6
2.5
3
3.5
4
4.5
5
5.5
6
Supply Voltage, V
IN
(V)
Supply Voltage, V
IN
(V)
Copyright
©
ANPEC Electronics Corp.
Rev. A.3 - Jul., 2008
4
www.anpec.com.tw
APW7209
Operating Waveforms
(Refer to the application circuit in the section “Typical Application Circuits”, V
IN
=3.6V, T
A
=25
o
C, 10WLEDs unless otherwise
specified )
Start-up
V
EN
V
OUT
, 10V/Div
Normal Operating Waveform
1
1
V
LX
, 20V/Div, DC
2
2
I
IN
, 0.2A/Div
3
10WLEDs, L=22µH, V
IN
=3.6V, I
LED
=20mA
CH1: V
EN
, 1V/Div, DC
CH2: V
OUT
, 10V/Div, DC
CH3: I
IN
, 0.2A/Div, DC
Time: 0.5ms/Div
V
OUT
, 100mV/Div, AC
3
CH1: V
LX
, 20V/Div, DC
CH2: V
OUT
, 100mV/Div, AC
CH3: I
L
, 0.2A/Div, DC
Time: 500ns/Div
I
L
, 0.2A/Div
10WLEDs, L=22µH, V
IN
=3.6V, I
LED
=20mA
Open-LED Protection
V
OUT
, 10V/Div
1
CH1: V
OUT
, 10V/Div, DC
Time: 20ms/Div
Copyright
©
ANPEC Electronics Corp.
Rev. A.3 - Jul., 2008
5
www.anpec.com.tw
