Copyright
ANPEC Electronics Corp.
Rev. A.1 - Feb., 2006
APW7071
www.anpec.com.tw
1
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.
2.4V to 6V Input Voltage Range
400mA, Internal Switch Current
Up to 1MHz Switching Frequency
70
A Typical No Load Quiescent Current
0.1
A Typical Shutdown Current
Internal Soft-start
Available in a Tiny 6-Pin SOT-23 Package
Up to 87% efficiency
Operating Output Capacitor down to 0.1
F
Over Voltage Protection included
Lead Free Available (RoHS Compliant)
Features
General Description
The APW7071 is a high frequency step up DC/DC
converter in a small 6 leads SOT-23 package spe-
cially designed to drive white LEDs with a constant
current. The device can drive up to 4 LEDS in a series
from one Li-Ion cell. The APW7071 is ideal for LCD
panels requiring low current and high efficiency as well
as white LED applications for cellular phone back-
lighting.
Applications
Cellar Phones White LED Back Light
PDAs, Handheld Computers
Digital Still Cameras
MP3 Players
GPS Receivers
Package Pin Out
White LED DC/DC Step-Up Converter
A P W 7 0 7 1
Package Code
C : SOT-23-6
Operating Junction Temp. Range
E : -40 to 85C
Handling Code
TU : Tube TR : Tape & Reel
Lead Free Code
L : Lead Free Device Blank : Original Device
Handling Code
Temp. Range
Package Code
A P W 7 0 7 1 C :
W 7 1 X
XXXXX - Date Code
Lead Free Code
Ordering and Marking Information
Notes: ANPEC lead-free products contain molding compounds/die attach materials and 100% matte in plate
termination finish; which are fully compliant with RoHS and compatible with both SnPb and lead-free soldiering
operations. 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.
SOT-23-6 (Top View)
APW7071
S W G N D
V
I N
S H D N
F B
1
2
3
4
5
O V P
6
Copyright
ANPEC Electronics Corp.
Rev. A.1 - Feb., 2006
APW7071
www.anpec.com.tw
2
Pin Description
No
Name
Function
1
SW
Switch Pin. Connect to inductor/diode here. Minimize trace area at this
pin to educe EMI.
2
GND
Ground Pin.
3
FB
Feedback Pin. Reference voltage is 0.25V. Connect cathode of
lowest LED and resistor here. Calculate resistor value according to
RFB = 0.25V/l LED
4
SHDN
Shutdown Pin. Tie to 1.3V or higher to enable device, 0.4V or less to
disable.
5
OVP
Over voltage protection sense pin. Connect this pin to VOUT for over
voltage protection.
6
Vin
Supply voltage Pin.
Block Diagram
Under
Voltage
Lockout
Gate
Driver
Control
Logic
400ns Min.
off-time
Soft
start
6us Max.
on-time
-
+
-
+
OVP
Vref=0.25V
FB(3)
SHDN(4)
GND(2)
VIN(6)
SW(1)
RSENSE
N-MOSFET
Current Limit
Error
Comparator
OVP(5)
-
+
Thermal
Shutdown
Copyright
ANPEC Electronics Corp.
Rev. A.1 - Feb., 2006
APW7071
www.anpec.com.tw
3
Absolute Maximum Ratings
Symbol
Parameter
Rating
Unit
Vin
Supply voltage
7
V
FB
Feedback Voltage
7
V
SHDN
Shutdown Voltage
7
V
SW
Switch Voltage
20
V
T
J
Junction Temperature Range
150
C
T
STG
Storage Temperature Range
-40 to +150
C
Recommend Operating Conditions
Value
Symbol
Parameter
Min.
Typ.
Max.
Unit
Vin
Input supply voltage
2.4
6.0
V
Vsw
Switch voltage
Vin
18
V
L
Inductor
4.7
H
Cin
Input capacitor
4.7
F
Cout
Output capacitor
0.1
F
Ta
Operating ambient temperature
-40
85
C
Tj
Operating junction temperature
-40
125
C
Electrical Characteristics
V
IN
=2.4V, EN=V
IN,
T
A
=-40C to +85C, typical values are at T
A
=+25C (unless otherwise noted)
APW7071
Symbol
Parameter
Test Condition
Min.
Typ. Max.
Unit
Supply Voltage and Current
Vin
Input Voltage Range
2.4
6
V
Iq
Operating quiescent current
Iout=0, not switching,
VFB=0.3V
70
90
A
Isd
Shutdown current
SHDN=GND
0.1
1
A
UVLO
Under-Voltage Lockout threshold
2.1
2.3
V
Under-Voltage Lockout
hysteresis
100
mV
ENABLE
VIH
SHDN high level input voltage
1.3
V
VIL
SHDN low level input voltage
0.4
V
Ii
SHDN input leakage current
SHDN=GND or VIN
0.1
1
A
Power Switch and Current limit
Vsw
Maximum switching voltage
20
V
toff
Minimum off-time
350
400
500
ns
ton
Maximum on-time
4
6
7.5
s
Rds,on
MOSFET on-resistance
Vin=2.4V, Isw=200mA
600
1000
m
MOSFET leakage current
Vsw=20V
1
10
A
ILIM
MOSFET current limit
350
400
450
mA
Copyright
ANPEC Electronics Corp.
Rev. A.1 - Feb., 2006
APW7071
www.anpec.com.tw
4
Electrical Characteristics (Cont.)
APW7071
Symbol
Parameter
Test Condition
Min.
Typ. Max.
Unit
OUTPUT
Vout
Adjustable output voltage range
Vin
18
V
IFB
Feedback input bias current
VFB=0.3V
1
A
VFB
Feedback trip point voltage
2.4
VIN
6.0V
0.237 0.25 0.263
V
OVP threshold
16
17
18
V
OVP hysteresis
5
6
7
V
Typical Application Circuit
Fig.1 Typical 4LED application
Fig.2 4LED application with
lower output voltage ripple
3
2
4.7H
2.7V~6V
4.7F
SW
FB
GND
1
VIN
6
4
R1
13
0.1F
OVP
5
Vin
Vout
off on
MSCD052
L1
D1
C1
C2
SHDN
3
2
10H
2.4V~6V
4.7F
SW
FB
GND
1
VIN
6
4
R1
13
1F
OVP
5
Vin
Vout
off on
MSCD052
L1
D1
C1
C2
SHDN
Copyright
ANPEC Electronics Corp.
Rev. A.1 - Feb., 2006
APW7071
www.anpec.com.tw
5
70
72
74
76
78
80
82
84
86
88
90
2
3
4
5
6
74
76
78
80
82
84
86
88
90
0.1
1
10
100
Typical Characteristics
Efficiency vs LED Current
LED Current(mA)
Efficiency(%)
Supply Voltage(V)
Efficiency(%)
Vin=3.6V
Vin=4.2V
Vin=2.7V
Efficiency vs Supply Voltage
0
0.1
0.2
0.3
0.4
0.5
0.6
-40
-20
0
20
40
60
80
100
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
2
3
4
5
6
Rds,on(
)
Temperature(C)
Supply Voltage(V)
Rds,on(
)
Switch Rds,on vs Supply Voltage
Switch Rds,on vs Temperature
(Circuit of Figure 1, VIN = 3.3V, ILED = 15mA, L1 = 4.7
H, CIN = 4.7
F, COUT = 0.1
F,4 LEDs,
TA = +25
C, unless otherwise noted.)
ILED=15mA
Ta=25
C
Vin=3.3V
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