Anpec APW7209C Schematic [ru]
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 200kHz PWM Brightness Control
Frequency
• Open-LED Protection
• Under-Voltage Lockout Protection
• Over-Temperature Protection
• <1µA Quiescent Current during Shutdown
• SOT-23-6 and TSOT-23-6A Package
• Lead Free and Green Devices Available
(RoHS Compliant)
Applications
• White LED Display Backlighting
• Cell Phone and Smart Phone
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 identical for uniform brightness. Its low on-resistance of NFET and low feedback voltage reduce power loss and
achieve high effic iency. Fast switching frequency(1MHz
typical) allows us ing small-size inductor and both of input and output capacitors. An over-voltage protec tion
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 eliminates the inrush c urrent during start-up.
The APW7209 also integrates under-voltage lockout, overtemperature protection, and c urrent limit circuits to protect the IC in abnormal conditions.The APW7209 is available in a SOT-23-6 and TSOT-23-6 package.
Simplified Application Circuit
• PDA, PMP, MP3
• Digital Camera
Pin Configuration
LX 1
GND 2
FB 3
SOT-23-6/TSOT-23-6
(Top View )
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.
6 VIN
5 OVP
4 EN
V
IN
C1
4.7µF
OFF ON
22µH
6
VIN
2
GND
APW7209
4
EN
L1
LX
OVP
FB
V
OUT
1
5
3
C2
1µF
Up to 10
WLEDs
R1
15Ω
Copyright ANPEC Electronics Corp.
Rev. A.8 - Sep., 2013
www.anpec.com.tw1
APW7209
Ordering and Marking Information
APW7209
Assembly Material
Handling Code
Temperature Range
Package Code
APW7209 C: X - Date Code
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-020D 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).
W09X
Package Code
C : SOT-23-6 CT : TSOT-23-6A
Operating Ambient Temperature Range
I : -40 to 85 oC
Handling Code
TR : Tape & Reel
Assembly Material
G : Halogen and Lead Free Device
APW7209 CT: X - Date Code
W09X
Absolute Maximum Ratings (Note 1)
Symbol
VIN VIN Supply Voltage (VIN to GND) -0.3 ~ 7 V
FB, EN to GND Voltage -0.3 ~ VIN V
VLX LX to GND Voltage -0.3 ~ 42 V
V
OVP to GND Voltage -0.3 ~ 42 V
OVP
TJ Maximum Junction Temperature 150 °C
T
Storage Temperature -65 ~ 150 °C
STG
T
Maximum Lead Soldering Temperature, 10 Seconds 260 °C
SDR
Note1: 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 rating conditions for extended periods may affect device
reliability.
Parameter Rating Unit
Thermal Characteristics (Note 2)
Symbol
Junction to Ambient Thermal Resistance.
θJA
Note 2: θJA is measured with the component mounted on a high effective thermal conductivity test board in free air.
Recommended Operating Conditions (Note 3)
Parameter Typical Value Unit
SOT-23-6
TSOT-23-6A
250
220
°C/W
Symbol
VIN VIN Input Voltage 2.5~ 6 V
V
Converter Output Voltage Up to 37 V
OUT
CIN Input Capacitor 4.7 or higher
C
Output capacitor 0.68 or higher
OUT
L1 Inductor 6.8 ~ 47
TA Ambient Temperature -40 ~ 85 °C
TJ Junction Temperature -40 ~ 125 °C
Note 3: Refer to the application circuit for further information.
Copyright ANPEC Electronics Corp.
Rev. A.8 - Sep., 2013
Parameter Range Unit
µF
µF
µH
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APW7209
Electrical Characteristics
(Refer to figure 1 in the “Typical Application Circuits”. These specifications apply over VIN = 3.6V, TA = -40°C to 85°C, unless otherwise
noted. Typical values are at TA = 25°C.)
Symbol
Parameter Test Conditions
APW7209
Min. Typ. Max.
SUPPLY VOLTAGE AND CURRENT
VIN Input Voltage Range TA = -40 ~ 85°C, TJ = -40 ~ 125°C 2.5 - 6 V
I
V
DD1
I
Input DC bias current
FB = GND, switching - 1 2 mA
DD2
ISD
= 0.4V, no switching 70 100 130 µA
FB
EN = GND - - 1 µA
UNDER VOLTAGE LOCKOUT
UVLO Threshold Voltage VIN Rising 2.0 2.2 2.4 V
UVLO Hysteresis Voltage 50 100 150 mV
REFERENCE AND OUTPUT VOLTAGES
V
Regulated Feedback Voltage
REF
TA = 25°C 0.285
TA = -40 ~ 85°C (TJ = -40 ~ 125°C) 0.276
0.3 0.315
- 0.324
IFB FB Input Current -50 - 50 nA
INTERNAL POWER SWITCH
FSW Switching Frequency FB=GND 0.8 1.0 1.2 MHz
RON Power Switch On Resistance - 0.6 -
I
Power Switch Current Limit 0.7 1.0 1.4 A
LIM
LX Leakage Current VEN=0V, VLX=0V or 5V, VIN = 5V -1 - 1 µA
D
LX Maximum Duty Cycle 92 95 98 %
MAX
OUTPUT OVER-VOLTAGE PROTECTION
V
Over Voltage Threshold V
OVP
rising 38 40 43 V
OVP
OVP Hysteresis - 3 - V
OVP Leakage Current V
=40V - 50 - µA
OVP
ENABLE AND SHUTDOWN
V
EN Voltage Threshold VEN Rising 0.4 0.7 1 V
TEN
EN Voltage Hysteresis - 0.1 - V
I
EN Leakage Current VEN= 0~5V, VIN = 5V -1 - 1 µ A
LEN
OVER-TEMPERATURE PROTECTION
T
Over-Temperature Protection
OTP
Over-Temperature Protection
Hysteresis
(Note 4)
(Note 4)
TJ Rising - 150 - °C
- 40 - °C
Note 4: Guaranteed by design, not production tested.
Unit
V
Ω
Copyright ANPEC Electronics Corp.
www.anpec.com.tw3
Rev. A.8 - Sep., 2013
APW7209
≅
Typical Operating Characteristics
(Refer to figure 1 in the section “Typical Application Circuits”, VIN=3.6V, TA=25oC, 10WLEDs unless otherwise specified)
Efficiency vs. WLED Current
95
90
85
80
75
70
Efficiency (η)
65
60
VIN=3.3V
55
50
0 5 10 15 20 25 30
VIN=3.6V
WLED Current, I
VIN=4.2V
10 WLEDs 33V@20mA
(mA)
LED
WLED Current vs. Supply Voltage
21.0
20.8
20.6
20.4
(mA)
LED
20.2
20.0
19.8
19.6
WLED Current, I
19.4
19.2
19.0
2.5 3 3.5 4 4.5 5 5.5 6
Supply Voltage, V
IN
Switching Frequency vs. Supply
1.2
1.1
(MHz)
1
SW
0.9
0.8
0.7
0.6
0.5
Switching Frequency, F
0.4
2.5 3 3.5 4 4.5 5 5.5 6
Copyright ANPEC Electronics Corp.
Rev. A.8 - Sep., 2013
Voltage
Supply Voltage, V
IN
(V)
(V)
η=P
VIN=5V
OUT/PIN
WLED Current vs. PWM Duty Cycle
20
18
16
14
(mA)
LED
12
10
8
6
WLED Current, I
4
2
0
0 20 40 60 80 100
100Hz
1kHz
PWM Duty Cycle (%)
Maximum Duty Cycle vs. Supply
Voltage
100
90
(%)
MAX
80
70
60
50
Maximum Duty Cycle, D
40
2.5 3 3.5 4 4.5 5 5.5 6
Supply Voltage, V
IN
Switch ON Resistance vs. Supply
0.8
0.7
(Ω)
ON
0.6
0.5
0.4
0.3
0.2
0.1
Switch ON Resistance, R
0
2.5 3 3.5 4 4.5 5 5.5 6
Voltage
Supply Voltage, V
IN
100kHz
(V)
(V)
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APW7209
Operating Waveforms
(Refer to the application circuit in the section “Typical Application Circuits”, VIN=3.6V, TA=25oC, 10WLEDs unless otherwise
specified )
1
2
3
CH1: VEN, 1V/Div, DC
CH2: V
OUT
CH3: IIN, 0.2A/Div, DC
Time: 0.5ms/Div
Start-up
V
EN
V
, 10V/Div
OUT
IIN, 0.2A/Div
10WLEDs, L=22µH, VIN=3.6V, I
, 10V/Div, DC
LED
=20mA
Normal Operating Waveform
1
2
3
CH1: VLX, 20V/Div, DC
CH2: V
OUT
CH3: IL, 0.2A/Div, DC
Time: 500ns/Div
VLX, 20V/Div, DC
V
, 100mV/Div, AC
OUT
IL, 0.2A/Div
10WLEDs, L=22µH, VIN=3.6V, I
, 100mV/Div, AC
LED
=20mA
Open-LED Protection
V
, 10V/Div
OUT
1
CH1: V
Time: 20ms/Div
Copyright ANPEC Electronics Corp.
Rev. A.8 - Sep., 2013
, 10V/Div, DC
OUT
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APW7209
Σ
Pin Description
PIN
NO. NAME
1 LX Switch pin. Connect this pin to inductor/diode here.
2 GND Power and signal ground pin.
3 FB
4 EN
5 OVP Over Voltage Protection Input Pin. OVP is connected to the output capacitor of the converter.
6 VIN Main Supply Pin. Must be closely decoupled to GND with a 4.7µ F or greater ceramic capacitor.
Feedback Pin. Reference voltage is 0.3V(typical). Connect this pin to cathode of the lowest LED
and current-sense resistor (R1). Calculate resistor value according to R1=0.3V/I
Enable Control Input. Forcing this pin above 1.0V enables the device, or forcing this pin below 0.4V
to shut it down. In shutdown, all functions are disabled to decrease the supply current below 1µA.
Do not leave this pin floating.
FUNCTION
Block Diagram
VIN
EN
UVLO
OVP
LED
.
GND
Over-
Temperature
Protection
Slope
Compensation
Oscillator
Soft-
start
Control Logic
Current
limit
ICMP
COMP
Gate Driver
Current Sense
Amplifier
Error
Amplifier
EAMP
V
REF
0.3V
LX
FB
Copyright ANPEC Electronics Corp.
Rev. A.8 - Sep., 2013
www.anpec.com.tw6
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