Copyright ANPEC Electronics Corp.
Rev. A.4 - Oct., 2009
APW7001
www.anpec.com.tw1
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.
1X/1.5X/2X Charge Pump White LED Driver for Main and Sub-Displays
Features
•±1.5% LED Current Matching
•Powers Main and Sub-Display LEDs
•High Efficiency Up to 90% Over Li-ion Battery
Discharge
•Output Current Up to 30mA per LED
•2.7V to 5.5V Operating Voltage
•1x/1.5x/2x Charge Pump Modes
•Low Shutdown Current: 2µA Maximum
•Low Input Ripple and EMI
•Internal Soft-Start Limits Inrush Current
•Short Circuit Current Limit
•Thermal Shutdown Protection
•Output Over-Voltage Protection
•16-pin QFN Package
•Lead Free and Green Devices Available
(RoHS Compliant)
Applications
General Description
The APW7001 is a high efficiency charge pump white
LED driver; the device drives up to four white LEDs in the
main display and up to two white LEDs in the sub-display
with regulated constant current for uniform intensity. The
supply voltage ranges from 2.7V to 5.5V and it is opti-
mized for a Li-ion battery application. The APW7001 op-
erates in 1x, 1.5x, and 2x charge pump modes and auto-
matically switches the charge pump modes depend on
the input voltage to maintain the required power for high
power efficiency. The APW7001 provides up to 30mA per
LED and allows several methods such as the PWM sig-
nals on the ENM pin for main-display dimming and on
the ENS pin for sub-display dimming. The two control
logic pins, ENM and ENS, allow disabling or enabling the
main and sub-displays. The supply current is only 2mA in
2x mode, and the ENM and ENS are kept low for 20ms
will allow the device to enter shutdown mode with 2µA
quiescent current. The APW7001 features current limit
and short circuit protection. The APW7001 switches at
1MHz frequency and only requires four 1µF ceramic ca-
pacitors and one resistor, and ensures low input current
ripple and EMI. The APW7001 is available in a 16-pin
QFN package.
•Cellular Phone White LED Back Light
•Portable Device
•PDA, Handheld Computer
•DSC
Pin Configuration
APW7001
QFN4x4-16 Top View
1
3
2
4
65 7 8
ILED 3
ILED 4
ENM
ILED 6
ILED 5
ISET
ENS
VOUT
ILED 2
ILED 1
C1+
C1-
GND
C2+
C2-
VIN
12
10
11
9
1516 14 13
Metal
GND Pad
(Bottem)
Copyright ANPEC Electronics Corp.
Rev. A.4 - Oct., 2009
APW7001
www.anpec.com.tw2
Ordering and Marking Information
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).
APW7001
Handling Code
Temperature Range
Package Code
Package Code
QA : QFN4x4-16
Operating Ambient Temperature Range
I : -40 to 85 oC
Handling Code
TR : Tape & Reel
Assembly Material
G : Halogen and Lead Free Device
Assembly Material
APW7001 QA : APW7001
XXXXX XXXXX - Date Code
Symbol Parameter Rating Unit
VOUT VOUT to GND -0.3 to +6 V
VIN VIN to GND -0.3 to +6 V
VC1+, VC1-,
VC2+, VC2-
C1+, C1-, C2+, C2- to GND -0.3 to +6 V
VILED1-6 ILED1-6 to GND -0.3 to +6 V
VENM, VENS
ENM, ENS to GND -0.3 to +6 V
VISET ISET to GND -0.3 to 2 V
TJ Maximum Junction Temperature +150 °C
TSTG Storage Temperature -65 ~ 150 °C
TSDR Maximum Lead Soldering Temperature, 10 Seconds 260 °C
Absolute Maximum Ratings (Note 1)
Thermal Characteristics (Note 2)
Symbol Parameter Typical Value Unit
θJA Thermal Resistance -Junction to Ambient QFN4x4-16
40 °C/W
Note 2 : θJA is measured with the component mounted on a high effective thermal conductivity test board in free air.
Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
Recommended Operating Conditions
Symbol
Parameter Rating Unit
VIN Input Voltage 2.8 to 4.5 V
VOUT Output Voltage 3 to 4 V
ILED LED Current 5 to 30 mA
Copyright ANPEC Electronics Corp.
Rev. A.4 - Oct., 2009
APW7001
www.anpec.com.tw3
Recommended Operating Conditions (Cont.)
Symbol
Parameter Rating Unit
Output Current, VIN>3.5V, VF=3.1V, 1x mode 180
Output Current, 3.5V<VIN>3.1V, VF=3.1V, 1.5x mode 120
IOUT
Output Current, 3.1V<VIN>2.8V, VF=3.1V, 2X mode 90
mA
TA Ambient Temperature -40 to 85 °C
Electrical Characteristics
APW7001
Symbol
Parameter Test Conditions Min. Typ. Max. Unit
VIN Input Voltage 2.7 - 5.5 V
VUVLO Under-voltage Lockout Threshold VIN falling 2.2 2.4 2.6 V
Under-voltage Lockout Hysteresis - 50 - mV
in 1.5x/2x mode - 2 4 mA
No switching in 1x mode - 0.5 1 mA
IQ Quiescent Current
EN=0 - 0.1 2 µA
ILED-ERR
LED Current Accuracy 5mA<ILED<30mA (Note 3) - ±2 ±8 %
Current Matching 5mA<ILED<30mA (Note 4) - ±1.5 ±5 %
IISET ISET Current 5 - 1000 µA
ISET to LED Current Ratio ILED / (1.2V/RSET)
5mA<ILED<30mA, TA = +25°C 370 400 420
VILED-TH
ILED Threshold Voltage VILED falling - 100 - mV
1.5x mode to 1x mode Transition
Hysteresis VIN rising, VIN-VOUT - 300 - mV
2x mode to 1.5x mode Transition
Hysteresis VIN rising, VOUT-VIN - 300 - mV
FOSC Switching Frequency 0.8 1 1.2 MHz
1x mode (VIN-VOUT) / IOUT - 1.6 3
1.5x mode (1.5xVIN-VOUT) / IOUT - 7 12
ROUT Open Loop VOUT Resistance
2x mode (2xVIN-VOUT) / IOUT - 16 28
Ω
ISHORT Short Circuit Current Limit VOUT < 1V - 40 - mA
VOVP Output Over Voltage Protection 5 5.5 6 V
VIH Logic Pins High Threshold 1.3 0.7 - V
VIL Logic Pins Low Threshold - 0.6 0.3 V
IIH Logic Pins High Current VIH=VIN - - 1 µA
IIL Logic Pins Low Current VIL=GND - - 1 µA
Thermal Shutdown - 150 - °C
Thermal Shutdown Hysteresis - 20 - °C
VIN = 2.85 to 5.5V, CIN = COUT = C1 = C2 = 1µF (ESR = 0.03Ω), ILED = 20mA, TA = -40°C to +85°C, unless otherwise noted. Typical values
are at TA = +25°C.
Note 3: LED current accuracy is defined as: ± (ILED-MEASURED - ILED-SET) / ILED-SET
Note 4: LED current matching is defined as: ± (ILED-MAX - ILED-MIN) / (ILED-MAX + ILED-MIN)
Copyright ANPEC Electronics Corp.
Rev. A.4 - Oct., 2009
APW7001
www.anpec.com.tw4
20
30
40
50
60
70
80
90
100
2.5 33.5 44.5
6 LEDs at 15mA
VF=3.3V
20
30
40
50
60
70
80
90
100
2.5 33.5 44.5
6 LEDs at 20mA
VF=3.3V
20
30
40
50
60
70
80
90
100
2.5 33.5 44.5
6 LEDs at 15mA
VF=3.1V
20
30
40
50
60
70
80
90
100
2.5 33.5 44.5
6 LEDs at 20mA
VF=3.1V
Typical Operating Characteristics
Efficiency vs. Input Voltage
Efficiency (%)
Input Voltage (V)
Efficiency vs. Input Voltage
Efficiency (%)
Input Voltage (V)
Efficiency vs. Input Voltage
Input Voltage (V)
Efficiency (%)
Efficiency vs. Input Voltage
Input Voltage (V)
Efficiency (%)
50
75
100
125
150
175
200
2.5 33.5 44.5 5
6 LEDs at 15mA
100
150
200
250
300
2.5 33.5 44.5 5
6 LEDs at 20mA
Input Current vs. Input Voltage
Input Current (mA)
Input Voltage (V)
Input Current vs. Input Voltage
Input Current (mA)
Input Voltage (V)
Copyright ANPEC Electronics Corp.
Rev. A.4 - Oct., 2009
APW7001
www.anpec.com.tw5
12
13
14
15
16
17
18
2.5 33.5 44.5 55.5
6 LEDs at 15mA
16
17
18
19
20
21
22
2.5 33.5 44.5 55.5
6 LEDs at 20mA
LED Current vs. Input Voltage
Input Voltage (V)
LED Current (mA)
LED Current vs. Input Voltage
Input Voltage (V)
LED Current (mA)
Typical Operating Characteristics (Cont.)
17
18
19
20
21
22
-40 -20 020 40 60 80 100 120 140
6 LEDs at 20mA
VIN=3.3V, 1.5x mode
17
18
19
20
21
-40 -20 020 40 60 80 100 120 140
6 LEDs at 20mA
VIN=4V, 1x mode
LED Current vs. Temperature
LED Current (mA)
Temperature (°C)
LED Current vs. Temperature
LED Current (mA)
Temperature (°C)
17
18
19
20
21
22
-40 -20 020 40 60 80 100 120 140
6 LEDs at 20mA
V
IN=3V, 2x mode
LED Current vs. Temperature
Temperature (°C)
LED Current (mA)
Quiescent Current (mA)
0
0.5
1
1.5
2
2.5
3
2.5 33.5 44.5
6 LEDs at 15mA
V
F=3.3V
Quiescent Current vs. Input Voltage
Input Voltage(V)
Copyright ANPEC Electronics Corp.
Rev. A.4 - Oct., 2009
APW7001
www.anpec.com.tw6
500
600
700
800
900
1000
1100
1200
-40 -20 020 40 60 80 100 120 140
in 2x mode
V
IN=4V
200
300
400
500
600
700
-40 -20 020 40 60 80 100 120 140
in 1x mode
VIN=4V
800
850
900
950
1000
1050
1100
1150
1200
2.5 33.5 44.5
in 2x mode
0.7
0.8
0.9
1
1.1
1.2
2.5 33.5 44.5 55.5
high threshold
low threshold
Quiescent Current vs. Temperature
Quiescent Current (mA)
Temperature (°C)
Logic Threshold Voltage vs. Input Voltage
Logic Threshold Voltage (V)
Input Voltage (V)
Switching Frequency vs. Input Voltage
Input Voltage (V)
Switching Frequency (kHz)
Switching Frequency vs. Temperature
Temperature (°C)
Switching Frequency (kHz)
Typical Operating Characteristics (Cont.)
Copyright ANPEC Electronics Corp.
Rev. A.4 - Oct., 2009
APW7001
www.anpec.com.tw7
Start Up in 1x Mode
TIME (0.1ms/div)
Start Up in 1.5x Mode
TIME (0.1ms/div)
Start Up in 2x Mode
TIME (0.1ms/div)
Dimming in 1x Mode
TIME (2ms/div)
IIN (100mA/div)
VOUT (2V/div)
ENS=ENM (5V/div)
ILED (20mA/div)
6 LEDs at 20mA
VF=3.1V, VIN=4V
IIN (200mA/div)
VOUT (2V/div)
ILED (20mA/div)
6 LEDs at 20mA
VF=3.1V, VIN=3.3V
ENS=ENM (5V/div)
IIN (200mA/div)
VOUT (2V/div)
ILED (20mA/div)
6 LEDs at 20mA
VF=3.1V, VIN=2.7V
ENS=ENM (5V/div)
VOUT (1V/div)
ENM (2V/div)
ILED (20mA/div)
6 LEDs at 20mA, VF=3.1V,
VIN=4V f=200Hz, ENS=high
Typical Operating Characteristics (Cont.)
Copyright ANPEC Electronics Corp.
Rev. A.4 - Oct., 2009
APW7001
www.anpec.com.tw8
Dimming in 1.5x Mode
TIME (2ms/div)
Dimming in 2x Mode
TIME (2ms/div)
OVP Even with LED Open Circuit
TIME (0.2ms/div)
Line Transient Response in 1x to 1.5x Mode
TIME (0.1ms/div)
VOUT (1V/div)
ENM (1V/div)
ILED (20mA/div)
6 LEDs at 20mA, VF=3.1V,
VIN=3.3V, f=200Hz, ENS=high
VOUT (1V/div)
VIN (1V/div)
ILED (10mA/div)
6 LEDs at 20mA
VF=3.1V, VIN=4V
LED1 is open
VOUT (1V/div)
VIN (1V/div)
ILED (20mA/div)
6 LEDs at 20mA, VF=3.1V
VIN=3.2V to 3.8V
VOUT (1V/div)
ENM (1V/div)
ILED (20mA/div)
6 LEDs at 20mA, VF=3.1V,
VIN=2.7V, f=200Hz, ENS=high
Typical Operating Characteristics (Cont.)
Copyright ANPEC Electronics Corp.
Rev. A.4 - Oct., 2009
APW7001
www.anpec.com.tw9
Line Transient Response in 1.5x to 2x Mode
TIME (0.1ms/div)
VOUT (1V/div)
VIN (1V/div)
ILED (20mA/div)
6 LEDs at 20mA, VF=3.1V
VIN=2.8V to 3.4V
Typical Operating Characteristics (Cont.)
Pin Description
PIN
NO. NAME FUNCTION
1 ILED5
2 ILED6 Sub-
Display LEDs Cathode Connection. The LED current flows from VOUT through LED into ILED_ pin. The
charge pump regulates the lowest VILED to 180mV. Connect ILED_ pin to VOUT if the LED is not used.
3 ENM On/Off and Dimming Control for LED1-4 (Main-Display).
4 ENS On/Off and Dimming Control for LED5-6 (Sub-Display).
5 ISET
LED Current Set Input. Connect a resistor from ISET to GND to set the LED current. VISET is typically 1.2V.
6 VOUT Output Voltage Pin. Connect VOUT to the LED anodes. Connect a 1µF capacitor from VOUT to GND.
7 VIN Supply Voltage Input Pin. Connect a 1µF capacitor from VIN to GND.
8 C2+ Bucket Capacitor1 Positive Terminal. Connect a 1µF capacitor from C2+ to C2-.
9 C2- Bucket Capacitor1 Negative Terminal. Connect a 1µF capacitor from C2+ to C2-.
10 C1+ Bucket Capacitor1 Positive Terminal. Connect a 1µF capacitor from C1+ to C1-.
11 C1- Bucket Capacitor1 Negative Terminal. Connect a 1µF capacitor from C1+ to C1-.
12 GND Device Ground Pin.
13 ILED1
14 ILED2
15 ILED3
16 ILED4
Main-
Display LEDs Cathode Connection. The LED current flows from VOUT through LED into ILED_ pin.
The charge pump regulates the lowest VILED to 180mV. Connect ILED_ pin to VOUT if the LED is not used.
Copyright ANPEC Electronics Corp.
Rev. A.4 - Oct., 2009
APW7001
www.anpec.com.tw10
Block Diagram
Error
Amp
+
-
+
-
+
-
+
-
+
-
+
-
+
-
SUB CONTROL
MAIN CONTROL
1.2V
CONTROLLED
CURRENT
MIRROR
ISET
ENS
ENM
VIN
GND
VOUT
ILED1
ILED2
ILED3
ILED4
ILED5
ILED6
POR &
SOFT-START
1x/1.5x/2x MODE CHARGE PUMP AND
GATE CONTROL LOGIC
MODE SELECT
AND
MIN ILED SELECT
C1+ C1- C2+ C2-
CURRENT
LIMIT
+
-
+
-
0.1V
1MHz
OSCILLATOR
+
-
0.18V
+
-
1.2V
Typical Application Circuit
APW7001
CIN
1µF
C2
1µF
C2+VIN
VOUTISET
ILED1ILED2ILED3ILED4
C2-
C1+
C1-
GND
ENS
ENM
ILED6
ILED5
C1
1µF
Battery
Digital
Inputs
RSET
4
3
2
1
5 6 7 8
9
10
11
12
16 15 14 13
COUT
1µF
Copyright ANPEC Electronics Corp.
Rev. A.4 - Oct., 2009
APW7001
www.anpec.com.tw11
Function Description
ENM ENS LED Status
0 (for more
than 20ms)
0 (for more
than 20ms)
IC enters shutdown
1 0 LED1, 2, 3, 4 are turned on /
LED5, 6 are turned off
0 1 LED1, 2, 3, 4 are turned off /
LED5, 6 are turned on
1 1 LED1, 2, 3, 4 are turned on /
LED5, 6 are turned on
Soft-Start
The APW7001 provides the soft-start function to limit the
inrush current during startup. When the input voltage is
supplied to the device and exceeds the UVLO voltage, the
output capacitor is charged directly from input with a lim-
ited current source. Approximate 100µs after the output
voltage approaches the input voltage, the device starts to
provide the programmed LED current and determines
which of 1x, and 1.5x, or 2x mode is required. When the
programmed LED current can be reached with 1x mode,
the soft-start is completed and the device operates in 1x
mode. When the programmed LED current cannot be
reached, the charge pump goes into 1.5x mode. If the
1.5x mode charge pump cannot suffice for the LED cur-
rent need, the charge pump will switch to 2x mode.
Mode Transition
The APW7001 operates in 1x, 1.5x, and 2x charge pump
modes and automatically switches the charge pump
modes depend on the input voltage to maintain the re-
quired power for high power efficiency. If the APW7001
operates in 1x mode, the VOUT is pulled up to VIN. When
VIN decreases, the VILED will decease to maintain the regu-
lated LED current. Until VILED is below 100mV, the device
will switch to 1.5x mode. In 1.5x mode, the VILED is regu-
lated to 0.18V, and the output voltage is VF+0.18V. If VIN
continues to decrease until VILED is below 100mV again,
the device will switch to 2x mode. When the VIN rises and
reaches by approximately VOUT-300mV, the APW7001
switches back to 1.5x mode. If the VIN continues to rise
and reaches by approximately VOUT+300mV, the
APW7001 switches back to 1x mode. The 2x charge pump
is enough to suffice the White LED for a Li-ion battery
application. The APW7001 ensures that in the 1x mode
for as long as possible to increase the efficiency and
extend the operating range by using the 2x mode. The
transition voltages from 1x to 1.5x, and 1.5x to 2x are given
by:
VTRANS1X = VF + 0.1V + (IOUT x ROUT1X)
VTRANS1.5X = [VF + 0.1V + (IOUT x ROUT1.5X)] / 1.5
where
VF is the forward voltage of LED
IOUT is the output current
ROUT1X is the output impedance in 1x mode = 1.6Ω
ROUT1.5X is the output impedance in 1.5x mode = 7Ω
ENM/ENS Control Logic Pins
The APW7001 provides two logic input pins to enable or
disable the main-display and sub-display. When the ENM
or ENS is high, the VOUT is supplied and the respective
LEDs are enabled. When ENM or ENS is low, the respec-
tive LEDs are disabled. If both logic pins are kept low for
more than 20ms, the APW7001 enters shutdown mode.
In shutdown mode, all internal control circuits are turned
off and the quiescent current is below 2µA. When the
device exits shutdown mode, the output has the soft-start
function as the input voltage startup.
Table 1. The Truth Table of ENM and ENS
LED Current Setting
Connect a resistor from ISET pin to GND to set the LED
current. The ISET voltage is 1.2V, and the LED current is
typically 400 times the current through the ISET resistor.
The LED current is given by:
LED
SET IV2.1400
R×
=
The APW7001 provides up to 30mA of LED current per
LED and the device has a max current matching of ±5%
between any two LED currents and a max current accu-
racy of ±8%. If high accuracy is required, using a 1% pre-
cision surface mount resistor for the need.
ILED (mA) RSET (kΩ)
5 92
10 47
15 32
20 24
30 16.5
Table 2. RSET Value Selection
Copyright ANPEC Electronics Corp.
Rev. A.4 - Oct., 2009
APW7001
www.anpec.com.tw12
Figure 1. RSET Value vs. LED Current
0
50
100
150
200
250
300
350
400
0 5 10 15 20 25 30
ILED (mA)
RSET (Ohm)
LED Current Setting (Cont.)
Function Description (Cont.)
Over-Voltage Protection
If any of LEDs is failed or unused, LED channel is not
connected to VOUT, the charge pump mode will go into
2x mode and the output voltage will be pumped to 2
times the input voltage. If the output voltage is over 5.5V,
the over-voltage protection circuit will limit the output volt-
age to approximately 5.5V.
Copyright ANPEC Electronics Corp.
Rev. A.4 - Oct., 2009
APW7001
www.anpec.com.tw13
Application Information
Figure 2. PWM Dimming Application Circuit
ENS
ENM
4
3
APW7001
ON
OFF
PWM ON
OFF
PWM
Figure 3. PWM Dimming Frequency vs. LED Current
Figure 4. ENM/ENS Timing
0
2
4
6
8
10
12
14
16
18
20
010 20 30 40 50 60 70 80 90 100
LED Current (mA)
f=100Hz
LED=20mA
in 2x mode
f=10kHz
Dimming Duty (%)
f=40kHz
f=50kHz
Capacitor Selection
For lower input and output voltage ripples, both input and
output capacitors should be larger values and lower ESR
capacitors. However, the larger output capacitor values
will increase the soft-start time. The lower charge pump
flying capacitors values and ESR improve the efficiency,
but lower capacitor values may limit the LED’s currents at
low input voltage.
It is recommended that the low ESR and low variation
over temperature, such as the ceramic capacitors with
X7R or X5R and the value is 1µF for the input capacitor,
output capacitor, and the charge pump flying capacitors.
Brightness Control
1. PWM dimming using ENM, or/and EMS
The first method for dimming the LEDs is to apply a PWM
signal into the ENM or/and ENS pins. Figure 2 shows the
application circuit. The average LED current is propor-
tional to the PWM signal duty cycle. Note that the frequency
of PWM signal will affect the minimum dimming duty.
Figure 3 shows the LED current vs. dimming frequency
and dimming duty, the recommend dimming frequency
is below 10kHz. The PWM signal can either be applied to
ENM or ENS, or both inputs can be tied together and the
PWM signal can be applied to both pins. Table 3 shows
the truth table of ENM and ENS dimming control. The
average LED current is calculated by the following
equation:
Where:
ILED(max) is programmed LED current by ISET pin
toff is the off time of the PWM signal
ton is the on time of the PWM signal
VOUT
ENM
ILED
Bright ness
ENS
ILED
Bright ness
100%
100%
25%
50% Shutdown
75%
20ms
(main)
(main)
(sub)
(sub)
ENM ENS LED Status
0 PWM LED1, 2, 3, 4 are turned off
LED5, 6 are PWM dimming
PWM 0 LED1, 2, 3, 4 are PWM dimming
LED5, 6 are turned off
1 PWM LED1, 2, 3, 4 are turned on
LED5, 6 are PWM dimming
PWM 1 LED1, 2, 3, 4 are PWM dimming
LED5, 6 are turned on
PWM PWM LED1, 2, 3, 4 are PWM dimming
LED5, 6 are PWM dimming
Table 3. The Truth Table of ENM and
ENS Dimming Control
tofftonIton
I(max)LED
)avg(LED +
×
=
Copyright ANPEC Electronics Corp.
Rev. A.4 - Oct., 2009
APW7001
www.anpec.com.tw14
Figure 6. Digital Dimming Application Circuit
Application Information (Cont.)
2. Analog Dimming With Analog Voltage
The second method for dimming the LEDs is to apply a
voltage through a resistor into the ISET pin. The variation
of LED current is proportional to the variation of the ana-
log voltage. If the resistor values are chosen correctly, the
analog control voltage varies the output current from 0mA
to full LED current. Figure 5 shows the application circuit,
and the LED current is calculated by the following
equation:
Brightness Control (Cont.)
Figure 5. Analog Voltage Dimming Application Circuit
ISET
R1
5
APW7001
VADJ
R2
3. Digital dimming with external NMOS transistors
The third method for dimming the LEDs is to change the
equivalent resistance for RSET with the external NMOS
transistors. The equivalent resistance is the parallel com-
binations of the R1, R2, R3, and R4. R4 is always con-
nected and selected for the minimum LED current. Fig-
ure 6 shows the application circuit.
Layout Consideration
The APW7001 is a high frequency charge pump for white
LED driver and requires some care when laying out the
printed circuit board. The metal GND pad of the bottom of
the package must be soldered to the PCB and connected
to the GND plane on the backside through several ther-
mal vias. Place the CIN, COUT, C1, and C2 as close to IC
as possible for reducing the switching noise.
4. PWM dimming with EN pin
Another method for dimming the LEDs is to apply a PWM
signal into the EN pin. The average LED current is pro-
portional to the PWM signal duty cycle. Note that the fre-
quency of PWM signal will affect the minimum dimming
duty. The recommend dimming frequency is between
100Hz and 1kHz. The average LED current is calculated
by the following equation:
Where:
ILED(max) is programmed LED current by ISET pin
toff is the off time of the PWM signal
ton is the on time of the PWM signal
tofftonIton
I(max)LED
)avg(LED +
×
=
+
−
×= 1RV2.1
2RVV2.1
400IADJ
LED
ISET
5
APW7001
R1
R2
R4
R3
Copyright ANPEC Electronics Corp.
Rev. A.4 - Oct., 2009
APW7001
www.anpec.com.tw15
Package Information
QFN4x4-16
S
Y
M
B
O
LMIN. MAX.
1.00
0.00
0.25 0.35
2.50 2.80
0.05
2.50
A
A1
b
D
D2
E
E2
e
L
MILLIMETERS
A3 0.20 REF
QFN4x4-16
0.30 0.50
2.80
0.008 REF
MIN. MAX.
INCHES
0.039
0.000
0.010 0.014
0.098 0.110
0.098
0.012 0.020
0.80
0.110
0.031
0.002
0.65 BSC 0.026 BSC
3.90 4.10 0.154 0.161
3.90 4.10 0.154 0.161
0.20 0.008
K
e
LK
Pin 1 Corner
E2
D2 A1
A3
b
A
Pin 1
D
E
Copyright ANPEC Electronics Corp.
Rev. A.4 - Oct., 2009
APW7001
www.anpec.com.tw16
Carrier Tape & Reel Dimensions
H
T1
A
d
A
E1
A
B
W
F
T
P0
OD0
BA0
P2
K0
B0
SECTION B-B
SECTION A-A
OD1
P1
Application
A H T1 C d D W E1 F
330.0±2.00
50 MIN.
12.4+2.00
-
0.00
13.0+0.50
-0.20
1.5 MIN.
20.2 MIN.
12.0±0.30
1.75±0.10
5.5±0.05
P0 P1 P2 D0 D1 T A0 B0 K0
QFN4x4-16
4.0±0.10
8.0±0.10
2.0±0.05
1.5+0.10
-0.00
1.5 MIN.
0.6+0.00
-0.40
4.30±0.20
4.30±0.20
1.30±0.20
(mm)
Package Type Unit Quantity
QFN4x4-16 Tape & Reel 3000
Devices Per Unit
Copyright ANPEC Electronics Corp.
Rev. A.4 - Oct., 2009
APW7001
www.anpec.com.tw17
Taping Direction Information
QFN4x4-16
Classification Profile
USER DIRECTION OF FEED
Copyright ANPEC Electronics Corp.
Rev. A.4 - Oct., 2009
APW7001
www.anpec.com.tw18
Classification Reflow Profiles
Profile Feature Sn-Pb Eutectic Assembly Pb-Free Assembly
Preheat & Soak
Temperature min (Tsmin)
Temperature max (Tsmax)
Time (Tsmin to Tsmax) (ts)
100 °C
150 °C
60-120 seconds
150 °C
200 °C
60-120 seconds
Average ramp-up rate
(Tsmax to TP) 3 °C/second max. 3°C/second max.
Liquidous temperature (TL)
Time at liquidous (tL) 183 °C
60-150 seconds 217 °C
60-150 seconds
Peak package body Temperature
(Tp)* See Classification Temp in table 1 See Classification Temp in table 2
Time (tP)** within 5°C of the specified
classification temperature (Tc) 20** seconds 30** seconds
Average ramp-down rate (Tp to Tsmax)
6 °C/second max. 6 °C/second max.
Time 25°C to peak temperature 6 minutes max. 8 minutes max.
* Tolerance for peak profile Temperature (Tp) is defined as a supplier minimum and a user maximum.
** Tolerance for time at peak profile temperature (tp) is defined as a supplier minimum and a user maximum.
Table 2. Pb-free Process – Classification Temperatures (Tc)
Package
Thickness Volume mm3
<350 Volume mm3
350-2000 Volume mm3
>2000
<1.6 mm 260 °C 260 °C 260 °C
1.6 mm – 2.5 mm 260 °C 250 °C 245 °C
≥2.5 mm 250 °C 245 °C 245 °C
Table 1. SnPb Eutectic Process – Classification Temperatures (Tc)
Package
Thickness Volume mm3
<350 Volume mm3
≥350
<2.5 mm 235 °C 220 °C
≥2.5 mm 220 °C 220 °C
Test item Method Description
SOLDERABILITY JESD-22, B102 5 Sec, 245°C
HOLT JESD-22, A108 1000 Hrs, Bias @ 125°C
PCT JESD-22, A102 168 Hrs, 100%RH, 2atm, 121°C
TCT JESD-22, A104 500 Cycles, -65°C~150°C
HBM MIL-STD-883-3015.7 VHBM≧2KV
MM JESD-22, A115 VMM≧200V
Latch-Up JESD 78 10ms, 1tr≧100mA
Reliability Test Program
Copyright ANPEC Electronics Corp.
Rev. A.4 - Oct., 2009
APW7001
www.anpec.com.tw19
Customer Service
Anpec Electronics Corp.
Head Office :
No.6, Dusing 1st Road, SBIP,
Hsin-Chu, Taiwan, R.O.C.
Tel : 886-3-5642000
Fax : 886-3-5642050
Taipei Branch :
2F, No. 11, Lane 218, Sec 2 Jhongsing Rd.,
Sindian City, Taipei County 23146, Taiwan
Tel : 886-2-2910-3838
Fax : 886-2-2917-3838
