AME
High Efficiency 6 White LED Driver
AME5142/5142A/5142B
n General Description
The AME5142/5142A/5142B is a Boost DC/DC converter specifically designed to drive white LEDs with a
constant current. The device can drive 1 to 6 LEDs in
series or multiple strings from a Li-lon cell. Series connection of the LEDs provides identical LED currents resulting in uniform brightness and eliminating the need for
ballast resistors. The AME5142/5142A/5142B switches
at 1.2MHz, allowing the use of tiny external components.
The input and output capacitor can be as small as 1 µF(or
4.7µF), saving space and cost versus alternative solu-
tions. A low feedback voltage minimizes power loss in
the current setting resistor for better efficiency. The
AME5142/5142A/5142B is available in SOT-26/TSOT-26
& SOT-25/TSOT-25 packages.
The only difference between AME5142, AME5142A and
AME5142B is feedback trip point. The AME5142 is 0.15V
and AME5142A/5142B is 0.104V.
n Features
l 1.2MHz Fixed Switching Frequency
l 28V Over Voltage Protection
l Over Temperature Protection
l Under Voltage Lockout Protection
l Internal Soft Start
l 30V Internal Switch
l Drives Up to 6 LEDs from a 2.7V Supply at
20mA
l Only small external Capacitors and Inductor
required
l Cycle-by-Cycle Current Limiting
l Up to 88% Efficiency
l Meet RoHS Standards
n Applications
l LCD Bias
l Hand-held Computers
l Battery Backup
l Digital Cameras
l Personal Navigation Device
l Digital Picture Frame
l Smart Phone
With Open LED Protection
n Typical Application
L1
IN
AME5142
AME5142A
EN
AME5142B
GND
IN
AME5142
AME5142A
EN
AME5142B
GND
IN
AME5142
AME5142A
EN
AME5142B
GND
10µH
SW
OVP
FB
L1
10µH
SW
OVP
FB
L1
10µH
SW
OVP
FB
VIN2.7V to 5.5V
C
IN
4.7µF
Figure 1: Circuit For Driving 2 White LEDs
VIN2.7V to 5.5V
C
IN
4.7µF
Figure 2: Circuit For Driving 4 White LEDs
VIN2.7V to 5.5V
C
IN
4.7µF
Figure 3: Circuit For Driving 6 White LEDs
R1
7.5Ω
R1
7.5Ω
R1
7.5Ω
V
OUT
C
OUT
1µF
V
OUT
C
OUT
1µF
V
OUT
C
OUT
1µF
Rev. C.02
1
AME
High Efficiency 6 White LED Driver
AME5142/5142A/5142B
Function Block Di agra m
IN
FB
Vref
1.25V
0.15V
*
Soft
Start
UVLO
+
GM
-
Rc
OTP
RAMP
GENERATOR
Oscillator
SHUTDOWN
CIRCUITRY
With Open LED Protection
OVPEN
Vref
R
+
-
R
Q
R
S
CURRENT
LIMIT COMP
DRIVER
MS1
SW
MS
C
c
+
-
GND
* AME5142 feedba ck trip point is 0.15V. AME5142A and AME5142B feedba ck trip point is 0.104V.
Figure 4 : AME5142/5142A/5142B Block Di agram
2
Rev. C.02
AME
High Efficiency 6 White LED Driver
AME5142/5142A/5142B
n Pin Configuration
SOT-25/TSOT-25
Top View
5 4
AME5142
AME5142A
1 32
n Pin Description
AME5142AEEV
AME5142AAEEV
1. SW
2. GND
3. FB
4. EN
5. IN
Die Attach:
Conductive Epoxy
With Open LED Protection
SOT-26/TSOT-26
Top View
6 45
AME5142
AME5142A
AME5142B
1 32
(Recommend)
(Recommend)
AME5142AEEY
AME5142AAEEY
AME5142BAEEY
1. SW
2. GND
3. FB
4. EN
5. OVP
6. IN
Die Attach:
Conductive Epoxy
AME5142AEEV/AME5142AAEEV
Pin Number Pin Name Pin Description
Power Switch input.
1 SW
2 GND
3 FB
4 EN
5 IN
This is the drain of the internal NMOS power switch. Minimize the metal
trace area connected to this pin to minimize EMI.
Ground.
Tie directly to ground plane.
Output voltage feedback input.
Connect the ground of the feedback network to an AGND (Analog Ground)
plane which should be tied directly to the GND pin.
Enable control input, active high.
The enable pin is an active high control. Tie this pin above 1.5V to enable
the device. Tie this pin below 0.4V to turn off the device.
Analog and Power input.
Input Supply Pin. Bypass this pin with a capacitor as close to the device
as possible.
Rev. C.02
3
AME
High Efficiency 6 White LED Driver
With Open LED ProtectionAME5142/5142A/5142B
n Pin Description
AME5142AEEY/AME5142AAEEY/AME5142BAEEY (Recommend)
Pin Number Pin Name Pin Description
Power Switch input.
1 SW
This is the drain of the internal NMOS power switch. Minimize the metal
trace area connected to this pin to minimize EMI.
2 GND
3 FB
4 EN
5 OVP Over Voltage Protection.
6 IN
Ground.
Tie directly to ground plane.
Output voltage feedback input.
Connect the ground of the feedback network to an AGND(Analog Ground)
plane which should be tied directly to the GND pin.
Enable control input, active high.
The enable pin is an active high control. Tie this pin above 1.5V to enable
the device. Tie this pin below 0.4V to turn off the device.
Analog and Power input.
Input Supply Pin. Bypass this pin with a capacitor as close to the device
as possible.
4
Rev. C.02
AME
A
1. SW
E:
-40OC to +85
O
C
E:
SOT-2X
V:5ADJ:
Adjustable
Y:
3. FB
Z:
Lead free
4. EN
5. IN
A
1. SW
2. GND
3. FB
4. EN
5. OVP
6. IN
profile
High Efficiency 6 White LED Driver
AME5142/5142A/5142B
n Ordering Information
AME5142 x x x x xxx x
Pin
Configuration
Operating Ambient
Temperature
Range
Package
Type
With Open LED Protection
Special Feature
Output Voltage
Number of Pins
Package Type
Operating Ambient Temperature Range
Pin Configuration
Number
of
Pins
Output Voltage Special Feature
(SOT-25) 2. GND Y: 6
(TSOT-25)
(SOT-26)
(TSOT-26)
Lead free & Low
Rev. C.02
5
AME
A
1. SW
E:
-40OC to +85
O
C
E:
SOT-2X
V:5ADJ:
Adjustable
Y:
3. FB
Z:
Lead free
4. EN
5. IN
A
1. SW
2. GND
3. FB
4. EN
5. OVP
6. IN
profile
n Ordering Information
AME5142A x x x x xxx x
High Efficiency 6 White LED Driver
With Open LED ProtectionAME5142/5142A/5142B
Special Feature
Output Voltage
Number of Pins
Package Type
Operating Ambient Temperature Range
Pin Configuration
＊ Note 1.
＊ Note 1. AME5142 feedback trip point is 0.15V. AME5142A feedback trip point is 0.104V.
Pin
Configuration
(SOT-25) 2. GND Y: 6
(TSOT-25)
(SOT-26)
(TSOT-26)
Operating Ambient
Temperature
Range
Package
Type
Number
of
Pins
Output Voltage Special Feature
Lead free & Low
6
Rev. C.02
AME
A
1. SW
E:
-40OC to +85
O
C
E:
SOT-2X
Y:6ADJ:
Adjustable
Z:
Lead free
3. FB
4. EN
5. OVP
High Efficiency 6 White LED Driver
AME5142/5142A/5142B
With Open LED Protection
n Ordering Information
AME5142B x x x x xxx x
Special Feature
Output Voltage
Number of Pins
Package Type
Operating Ambient Temperature Range
Pin Configuration
＊ Note 2.
＊ Note 2. AME5142 feedback trip point is 0.15V. AME5142A and AME5142B feedback trip point is 0.104V.
The only difference between AME5142A and AME5142B is the behavior of OVP.
Please refer to Output Over-Voltage Protection.
Pin
Configuration
(SOT-26) 2. GND
6. IN
Operating Ambient
Temperature
Range
Package
Type
Number
of
Pins
Output Voltage Special Feature
Rev. C.02
7
AME
n Ordering Information
High Efficiency 6 White LED Driver
With Open LED ProtectionAME5142/5142A/5142B
Part Number Marking* Output Voltage Package
Operating Ambient
Temperature Range
AME5142AEEYADJZ BJGww ADJ SOT-26
AME5142AEEYADJY BJGww ADJ TSOT-26
AME5142AEEVADJZ BJHww ADJ SOT-25
AME5142AEEVADJY BJHww ADJ TSOT-25
AME5142AAEEYADJZ BVKww ADJ SOT-26
AME5142AAEEYADJY BVKww ADJ TSOT-26
AME5142BAEEYADJZ BYPww ADJ SOT-26
AME5142BAEEYADJY BYPww ADJ TSOT-26
AME5142AAEEVADJZ BVLww ADJ SOT-25
AME5142AAEEVADJY BVLww ADJ TSOT-25
Note: ww represents the date code and pls refer to Date Code Rule page on Package Dimension.
* A line on top of the first letter represents lead free plating such as BJGww.
Please consult AME sales office or authorized Rep./Distributor for the availability of package type.
-40OC to +85OC
-40OC to +85OC
-40OC to +85OC
-40OC to +85OC
-40OC to +85OC
-40OC to +85OC
-40OC to +85OC
-40OC to +85OC
-40OC to +85OC
-40OC to +85OC
8
Rev. C.02
AME
High Efficiency 6 White LED Driver
AME5142/5142A/5142B
With Open LED Protection
n Absolute Maximum Ratings
Parameter Symbol Maximum Unit
Input Supply Voltage V
EN, FB Voltages VEN,V
SW, OVP Voltage V
ESD Classification
Caution: Stress above the listed in absolute maximum ratings may cause permanent damage to the device.
* HBM B: 2000V ~ 3999V
IN
FB
SW,VOVP
6 V
V
IN
30 V
B*
n Recommended Operating Conditions
Parameter Symbol Rating Unit
Ambient Temperature Range T
A
-40 to +85
V
Junction Temperature Range T
Storage Temperature Range T
J
STG
n Thermal Information
Parameter Package Die Attach Symbol Maximum Unit
Thermal Resistance*
(Junction to Case)
Thermal Resistance
(Junction to Ambient)
Internal Power Dissipation P
Solder Iron (10Sec)**
* Measure θ
** MIL-STD-202G 210F
on center of molding compound if IC has no tab.
JC
SOT-25
TSOT-25
SOT-26
TSOT-26
Conductive Epoxy
-40 to +125
-65 to +150
θ
C
J
θ
JA
D
o
C
81
o
C / W
260
400 mW
350
o
C
Rev. C.02
9
AME
n Electrical Specifications
V
= 4.2V, EN = VIN, TA = 25oC, Unless otherwise noted.
IN
High Efficiency 6 White LED Driver
With Open LED ProtectionAME5142/5142A/5142B
Parameter Symbol Min Typ Max Units
Input Voltage V
IN
Switching, V
Quiescent Current I
Q
Not Switching, V
Feedback Trip Point (AME5142) V
Feedback Trip Point
(AME5142A/5142B)
FB Pin Bias Current I
Switch Current Limit I
Switch On-Resistance R
SW Leakage Current I
Swich frequency f
Maximum Duty Cycle Dmax 88 92 %
Shutdown Supply Current I
FB
V
FB
FB
CL
DSON
SW
SW
SD
OTP 160
V
FB
I
SW
V
SW
V
FB
V
FB
V
EN
Shutdown, temperature increasing
Over Temperature Protection
Over Voltage Protection
(AME5142)
T
RS
OVP 24 26 28
Restore, temperature decreasing
Rising edge
Test Condition
FB
= 0.2V
= 100mA, V
= 20V
= 0.1V
= 0V
= 0V
= 0V
FB
FB
= 0.2V
= 0.2V
2.7 5.5 V
0.85 1 mA
180 250 µA
0.137 0.15 0.163 V
0.094 0.104 0.114 V
0.1 1 µA
650 850 1000 mA
0.7 1.4 Ω
1 10 µA
0.9 1.2 1.5 MHz
0.01 1 µA
o
140
V
Over Voltage Protection
(AME5142A/5142B)
OVP 26 28 30
Rising edge
C
Input Undervoltage Lockout UVP 2.35 2.5 2.65 V
EN Input Low V
EN Input High V
EN Input Current I
10
EL
EH
EN
VIN rising or falling
EN = GND or V
IN
0.4
1.5
0.1 2 µA
V
Rev. C.02
AME
High Efficiency 6 White LED Driver
AME5142/5142A/5142B
n Detailed Description
The AME5142/5142A/5142B is a constant frequency
step-up converter with an internal switch. The operations
of AME5142/5142A/5142B can be understood from block
diagram clearly figure.2. The oscillator triggers the SET
input of SR latch to turn on the power switch MS at the
start of each cycle. A current sense voltage sum with a
stabilizing ramp is connected to the positive terminal of
the PWM comparator. When this voltage exceeds the
output voltage of the error amplifier, the SR latch is reset
to turn off the power switch till next cycle starts. The
output voltage of the error amplifier is amplified from the
difference between the reference voltage 0.15V and the
feedback voltage. In this manner, if the error amplifiers
voltage increases, more current is delivered to the output; if it decreases, less current is delivered. A 28V Zener diode connects from OVP pin to FB pin internally to
provide an optional protection function which prevents SW
pin from over-voltage damage. Especially when the case
of the feedback loop broken due to component wear-out
or improper connection occurs.
Current Limit Protection
The AME5142/5142A/5142B has current limiting protection to prevent excessive stress on itself and external
components during overload conditions. The internal current limit comparator will disable the NMOS power device
at a typical switch peak current limit of 850mA.
Output Over-Voltage Protection
The AME5142/5142A/5142B contains dedicated circuitry for monitoring the output voltage. In the event that
the primary LED network is disconnected the output will
increase and be limited to 28V (TYP), which will turn the
NMOS off when the output voltage is at 28V (max.) until
the output voltage reach 28V (TYP.) or lower. The 28V
limit allows the use of 28V 1µF ceramic output capacitors
creating an overall small solution for white LED applications. If the output ever exceeds OVP, the AME5142B
will shut down. AME5142B will not switch again until the
power is recycled. If the output exceeds OVP, the OVP
of AME5142/5142A is to clamp the output voltage to 28V
typically.
With Open LED Protection
n Application Information
Inductor Selection
The recommended value of inductor for AME5142/
5142A/5142B applications is 10µH. Small size and better efficiency are the major concerns for portable device,
such as AME5142/5142A/5142B used for dual panel
mobile phone. The inductor should have low DCR for
better efficiency. To avoid inductor saturation, current
rating should be at least 1A. The input range is 2.7V to
5.5V.
Capacitor Selection
4.7µF input capacitor can reduce input ripple. For bet-
ter voltage stability, to increase the input capacitor value
or using LC filter is feasible, especially in the Li-ion battery application. 1µF output capacitor is sufficient to re-
duce output voltage ripple. For better voltage filtering,
ceramic capacitors with low ESR are recommended. X5R
and X7R types are suitable because of their wider voltage and temperature ranges.
Diode Selection
Schottky diode is a good choice for AME5142/5142A/
5142B because of its lower forward voltage drop and faster
reverse recovery. Using schottky diode can get better
efficiency. The high speed rectification is also a good
characteristic of schottky diode for high switching frequency. Current rating of the diode must meet the root
mean square of the peak current and output average current multiplication.
Duty Cycle
The maximum duty cycle of the switching regulator
determines the maximum boost ratio of output-toinput voltage that the converter can attain in mode of
operation. The duty cycle for a given boost application is
defined as: This applies for continuous mode operation.
V
D =
+ V
OUT
V
+ V
OUT
DIODE
DIODE
- V
- V
IN
SW
Under Voltage Protection
The AME5142/5142A/5142B has an UVP comparator
to turn the NMOS power device off in case the input voltage or battery voltage is too low preventing an on state of
the power device conducting large amounts of current.
Rev. C.02
11
AME
High Efficiency 6 White LED Driver
With Open LED ProtectionAME5142/5142A/5142B
Calculating Load Current
The load current is related to the average inductor current by the relation:
I
= I
LOAD
Where “ D” is the duty cycle of the application. The switch current can be found by:
(AVG) x (1 - D)
IND
ISW = I
(AVG) + 1 /2 (I
IND
RIPPLE
)
Inductor ripple current is dependent on inductance, duty cycle, input voltage and frequency:
I
= D x (VIN-VSW) / (f x L)
RIPPLE
Combining all terms, we can develop an expression which allows the maximum available load current to be calculated:
I
= ( 1-D ) x ( ICL(max) - )
LOAD
D ( VIN-V
2fL
SW
)
Thermal Considerations
At higher duty cycles, the increased ON time of the FET means the maximum output current will be determined by
power dissipation within the AME5142/5142A/5142B switch. The switch power dissipation from ON-state conduction is
calculated by:
P
(SW)
= D x I
IND(AVE)2
x RDS(ON)
There will be some switching losses as well, so some derating needs to be applied when calculating IC power
dissipation.
Shutdown Pin Operation
The device is turned off by pulling the shutdown pin low. If this function is not going to be used, the pin should be tied
directly to VIN. If the SHDN function will be needed, a pull-up resistor must be used to VIN (approximately 50k-100k
recommended). The EN pin must not be left unterminated.
12
Rev. C.02
AME
High Efficiency 6 White LED Driver
AME5142/5142A/5142B
Evaluation Board Schematic
V
DD
C1
6
Enable
R1
4
2
L1
4.7uH 1A
U1
IN
EN
GND
AME5142AEEYADJZ
SW
OVP
FB
With Open LED Protection
D1
30V_1A
1
5
3
R2
C2
V
LED_Anod
CF
V
LED_cathode
Bill Of Materials
Location
C1 6.3V/4.7uF Ceramic Capacitor C1608Y5V0J475ZT TDK 1608
C7 25V/1uF Ceramic Capacitor C2012X7R1E105KT TDK 2012
R1 51KΩ Chip Resistor FCR05-F-T-5102 PDC 805
R5 7.5Ω Chip Resistor FCR05-F-T-0750 PDC 805
R3 16.9KΩ Chip Resistor FCR05-F-T-1692 PDC 805
L1 4.7uH Inductor CDRH3D14/HP-4R7 Sumida
D1 30V/1A Schottky Rectifier B130 Any SMA
Value
Description Part Num. Manufacture Package
Rev. C.02
13
AME
High Efficiency 6 White LED Driver
With Open LED ProtectionAME5142/5142A/5142B
Operating Instructions
1. Connect VDD to the power source’s positive output.
2. Connect GND to supply ground.
3. Applying a logic signal to EN pin will enable the AME5142. Logic high (V EN>1.5V) turns on AME5142, logic low
puts it into low current shutdown mode.
Application Information
Setting Output Current
The regulated output current is set with an external resistor divider (R5 in Figure 1.) from the output to the VFB pin and
is determined by:
V
I
OUT
=
R
FB
5
To prevent stray capacitance and noises, locate resistors R5 close to AME5142.
The external resistor sets the output current table as below :
I
OUT
20mA 7.5Ω
40mA 3.75Ω
60mA 2.5Ω
80mA 1.875Ω
R5
14
Rev. C.02
AME
High Efficiency 6 White LED Driver
AME5142/5142A/5142B
With Open LED Protection
Board Layout Consideration
High frequency switching regulators require very careful layout of components in order to get stable operation
and low noise. A good PCB layout could make AME5142 work its best performance.
PCB Layout Example
The PCB layout example of AME5142 for six strings of LEDs to be driven in one parallel application. The
placements is suitable and smooth, and follows the layout guide lines.
1. Use a ground plane under the switching regulator to minimize inter-plane coupling.
2. Using 20mil wide track for GND (as wide as possible), and all GND nodes are as close as possible.
3. The SW node, schottky diode and output capacitor C2 signal path should be kept extremely short.
4. The feedback components R1,R2 and CF must be kept close to the FB pin of U1 to prevent noise injection
on the FB pin trace and keeping faraway from SW node.
V
LED
_Anode
SW IN L1
V
LED_
D1
C2
CF
Cathode
Vout SW
Vout
GND
1 SW
2 GND
3 FB
FBVo
GND IN C1
U1
GND
FB
R2
6 IN
5 OVP
4 EN
EN EN
R1
Enable
Rev. C.02
15
AME
High Efficiency 6 White LED Driver
With Open LED ProtectionAME5142/5142A/5142B
Dimming Control
A. Using a PWM Signal to EN Pin
For controlling the LED brightness, the AME5142/5142A/5142B can perform the dimming control by applying a PWM
signal to EN pin.
The average LED current is proportional to the PWM signal duty cycle. The magnitude of the PWM signal should be
higher than the maximum enable voltage of EN pin, in order to let the dimming control perform correctly.
L1
22µH
AME5142
AME5142A
AME5142B
SW
OVP
FB
R1
7.5Ω
V
OUT
2.2µF
C
OUT
C
IN
4.7µF
Dimming
Control
150KHz
V
3.3V
IN
IN
EN
GND
Figure 5. PWM Dimming Control Using the EN Pin
VFB VS Duty Cycle I
150
125
100
(mV)
75
FB
V
50
25
0
0.2 0.4 0.6 0.8
Duty Cycle
VS Duty Cycle
20
18
16
14
12
10
(mA)
8
OUT
I
6
4
2
0
0.2 0.4 0.6 0.8
OUT
Duty Cycle
16
Rev. C.02
AME
High Efficiency 6 White LED Driver
AME5142/5142A/5142B
With Open LED Protection
B. Using a DC Voltage
Using a variable DC voltage to adjust the brightness is a popular method in some applications. The dimming control
using a DC voltage circuit is shown in Figure 6. According to the Superposition Theorem, as the DC voltage increases,
the voltage contributed to VFB increases and the voltage drop on R2 decreases, i.e. the LED current decreases. For
example, if the VDC range is from 0V to 2.8V, the selection of resistors in Figure 6 sets dimming control of LED current
from 20mA to 0mA.
L1
IN
10µH
SW
V
OUT
C
OUT
1µF
VIN2.7V to 5.5V
C
IN
4.7µF
AME5142
AME5142A
EN
AME5142B
GND
OVP
FB
5.1K
R4
91K
R3
R2
7.5Ω
Figure 6. Dimming Control Using a DC Voltage
VFB VS VDC I
150
125
100
75
(mV)
FB
V
50
25
0
0 0.56 1.12 1.68 2.24 2.80
VDC(V)
VDC Dimming
0V to 2.8V
VS VDC
OUT
20
15
(mA)
10
OUT
I
5
0
0 0.56 1.12 1.68 2.24 2.80
VDC(V)
Rev. C.02
17
AME
High Efficiency 6 White LED Driver
With Open LED ProtectionAME5142/5142A/5142B
C. Using a Filtered PWM Signal
The filtered PWM signal can be considered as an adjustable DC voltage. It can be used to replace the variable DC
voltage source in dimming control. The circuit is shown in Figure 7.
L1
IN
AME5142
AME5142A
EN
AME5142B
GND
10µH
SW
OVP
FB
5.1K
R4
91K
R3
R2
7.5Ω
V
OUT
C
OUT
1µF
VIN2.7V to 5.5V
C
IN
4.7µF
Figure 7. Dimming Control Using a Filtered PWM Signal
VFB VS Duty Cycle
150
125
100
75
(mV)
FB
V
50
25
0
0 0.2 0.4 0.6 0.8 1
Duty Cycle
R
10K
C
DC
DC
1µF
2.8V
0V
PWM Signal
20KHZ
I
VS Duty Cycle
OUT
20
15
(mA)
10
OUT
I
5
0
0 0.2 0.4 0.6 0.8 1
Duty Cycle
18
Rev. C.02
AME
High Efficiency 6 White LED Driver
AME5142/5142A/5142B
n Typical Operating Characteristics
L1
IN
AME5142A
EN
AME5142B
GND
IN
AME5142
AME5142A
EN
AME5142B
10µH
AME5142
L1
10µH
SW
OVP
SW
OVP
FB
R2
7.5Ω
V
OUT
C
1µF
V
OUT
VIN2.7V to 5.5V
C
IN
4.7µF
Figure 8: Circuit For Driving 6 White LEDs
VIN3.3V to 5.5V
C
IN
4.7µF
OUT
C
1µF
OUT
With Open LED Protection
Efficiency Vs I
90
85
VIN = 3.6V
80
75
70
65
Efficiency (%)
60
55
50
0 5 10 15 20
I
OUT
Efficiency Vs V
100
95
90
VIN = 2.7V
(mA)
OUT
VIN = 4.2V
VIN = 3.3 V
IN
I
LED
V
OUT
= 20mA
=18.6V
GND
FB
R2
7.5Ω
Figure 9: Circuit For Driving 2 Strings of 3 White LEDs
L1
IN
10µH
SW
VIN3.3V to 5.5V
C
IN
4.7µF
AME5142
AME5142A
EN
AME5142B
GND
OVP
FB
R2
7.5Ω
Figure 10: Circuit For Driving 2 Strings of 3 White LEDs
Rev. C.02
R2
7.5Ω
V
R2
7.5Ω
OUT
C
1µF
OUT
Efficiency (%)
85
I
= 40mA
OUT
V
= 9.3V
OUT
80
3 3.5 4 4.5 5 5.5
VIN(v)
Efficiency Vs I
90
85
80
75
70
65
Efficiency (%)
60
55
50
0 10 20 30 40
VIN = 3.3V
VIN = 4.2V
VIN = 3.6V
I
(mA)
OUT
OUT
I
LED
V
OUT
= 20mA
= 9.3V
19
AME
High Efficiency 6 White LED Driver
With Open LED ProtectionAME5142/5142A/5142B
L1
IN
10µH
SW
VIN3.3V to 5.5V
C
IN
4.7µF
AME5142
AME5142A
EN
AME5142B
GND
OVP
FB
R2
7.5Ω
Figure 11: Circuit For Driving 2 Strings of 4 White LEDs
L1
IN
10µH
SW
VIN3.3V to 5.5V
C
IN
4.7µF
AME5142
AME5142A
EN
AME5142B
GND
OVP
FB
R2
7.5Ω
Figure 12: Circuit For Driving 2 Strings of 4 White LEDs
V
R2
7.5Ω
R2
7.5Ω
OUT
C
1µF
OUT
Efficiency Vs V
100
95
90
Efficiency (%)
85
80
3 3.5 4 4.5 5 5.5
IN
V
I
OUT
OUT
= 40mA
= 12.5V
VIN(v)
V
OUT
C
1µF
OUT
90
85
80
75
70
65
Efficiency (%)
60
55
50
0 10 20 30 40
Efficiency Vs I
VIN = 3.3V
VIN = 3.6V
VIN = 4.2V
I
(mA)
OUT
OUT
I
V
LED
OUT
= 20mA
=12.5V
L1
IN
10µH
SW
VIN3.3V to 5.5V
C
IN
4.7µF
AME5142
AME5142A
EN
AME5142B
GND
OVP
FB
Figure 13: Circuit For Driving 2 Strings of 5 White LEDs
20
R2
7.5Ω
V
R2
7.5Ω
OUT
C
1µF
OUT
Efficiency Vs V
100
95
90
Efficiency (%)
85
80
3 3.5 4 4.5 5 5.5
IN
I
OUT
V
OUT
VIN(v)
= 40mA
= 15.6V
Rev. C.02
AME
High Efficiency 6 White LED Driver
AME5142/5142A/5142B
L1
IN
AME5142
AME5142A
EN
AME5142B
GND
IN
AME5142
AME5142A
EN
AME5142B
10µH
SW
OVP
FB
R2
7.5Ω
L1
10µH
SW
OVP
VIN3.3V to 5.5V
C
IN
4.7µF
Figure 14: Circuit For Driving 2 Strings of 5 White LEDs
VIN3.3V to 5.5V
C
IN
4.7µF
V
R2
7.5Ω
V
OUT
OUT
C
1µF
C
1µF
OUT
OUT
With Open LED Protection
Efficiency Vs I
90
VIN = 3.3V
85
80
75
70
65
Efficiency (%)
60
55
50
0 10 20 30 40
I
OUT
VIN = 3.6V
VIN = 4.2V
(mA)
Efficiency Vs V
100
95
OUT
IN
I
LED
V
OUT
= 20mA
=15.6V
GND
FB
R2
7.5Ω
Figure 15: Circuit For Driving 2 Strings of 6 White LEDs
L1
IN
10µH
SW
VIN3.3V to 5.5V
C
IN
4.7µF
AME5142
AME5142A
EN
AME5142B
GND
OVP
FB
R2
7.5Ω
Figure 16: Circuit For Driving 2 Strings of 6 White LEDs
R2
7.5Ω
V
R2
7.5Ω
OUT
C
1µF
OUT
90
Efficiency (%)
85
80
3 3.5 4 4.5 5 5.5
I
OUT
V
OUT
VIN(v)
Efficiency Vs I
90
85
VIN = 3.3V
80
75
70
65
Efficiency (%)
60
55
50
0 10 20 30 40
VIN = 4.2V
VIN = 3.6V
I
OUT
(mA)
OUT
I
LED
V
OUT
= 20mA
=18.6V
= 40mA
= 18.6V
Rev. C.02
21
AME
n Characterization Curves
High Efficiency 6 White LED Driver
With Open LED ProtectionAME5142/5142A/5142B
Max Duty Cycle vs. Temperature
92.0
91.8
91.6
91.4
91.2
91.0
90.8
90.6
90.4
90.2
90.0
89.8
89.6
89.4
89.2
89.0
Max Duty Cycle (%)
88.8
88.6
88.4
88.2
88.0
-25 0 25 50 75 100 125
Temperature (oC)
Switch RDSON
1.80
1.60
1.40
TA = 85oC
TA = 25oC
2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5
V
(V)
IN
RDSON (Ω)
1.20
1.00
0.80
0.60
0.40
0.20
Oscillator Frequency vs. Temperature
1.50
1.45
1.40
1.35
1.30
1.25
1.20
1.15
1.10
1.05
1.00
Oscillator Frequency (MHz)
0.95
0.90
-25 0 25 50 75 100 125
Temperature (oC)
Efficiency vs. Load Current
Dirving 3 LEDs
100
90
80
70
Efficiency (%)
60
50
2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5
VIN (V)
22
Efficiency vs. Load Current
Dirving 4 LEDs
100
90
80
70
Efficiency (%)
60
50
2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5
VIN (V)
Efficiency vs. Load Current
Dirving 6 LEDs
100
90
80
70
Efficiency (%)
60
50
2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5
VIN (V)
Rev. C.02
AME
High Efficiency 6 White LED Driver
AME5142/5142A/5142B
Current Limit vs. V
1000
950
900
850
800
750
Current Limit (mA)
700
650
2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5
Dimming Control for Driving 6LEDs
VIN (V)
With Open LED Protection
IN
0.177
0.173
0.169
0.165
0.161
(V)
0.157
FB
V
0.153
0.149
0.145
0.141
0.137
-25 0 25 50 75 100 125
Dimming Control for Driving 6LEDs
VFB vs. Temperature
Temperature (oC)
2
3
1
1mS / div
V
= 2.7V; 6 LEDs
IN
I
= 20mA
OUT
2) EN = 1V / div, DC f = 200Hz
3) V
, 10V / div, DC
OUT
1) VSW= 10V / div, DC
2
3
1
1mS / div
V
= 5.5V; 6 LEDs
IN
I
= 20mA
OUT
2) EN = 1V / div, DC f = 200Hz
3) V
1) V
, 10V / div, DC
OUT
= 10V / div, DC
SW
Rev. C.02
23
AME
High Efficiency 6 White LED Driver
With Open LED ProtectionAME5142/5142A/5142B
Dimming Control for Driving 6LEDs
2
3
1
4µS / div
V
= 2.7V; 6 LEDs
IN
I
= 20mA
OUT
2) EN = 1V / div, DC f = 200KHz
3) V
1) V
, 10V / div, DC
OUT
= 10V / div, DC
SW
Start-Up / Shutdown
Dimming Control for Driving 6LEDs
2
3
1
4µS / div
V
= 5.5V; 6 LEDs
IN
I
= 20mA
OUT
2) EN = 1V / div, DC f = 200KHz
3) V
1) V
, 10V / div, DC
OUT
= 10V / div, DC
SW
Start-Up / Shutdown
24
1
2
3
200µS / Div
V
= 2.7V; 1 LEDs
IN
I
= 20mA
OUT
1) EN = 2V/div, DC
2) Inductor Current, 100mA / div, DC
3) V
, 2V / div, DC
OUT
1
2
3
200µS / div
V
= 2.7V; 6 LEDs
IN
I
= 20mA
OUT
1) EN = 2V / div, DC
2) Inductor Current, 500mA / div, DC
3) V
, 10V / div, DC
OUT
Rev. C.02
AME
High Efficiency 6 White LED Driver
AME5142/5142A/5142B
Start-Up / Shutdown
1
2
3
200µS / div
V
= 5.5V; 6 LEDs
IN
I
= 20mA
OUT
1) EN = 2V / div, DC
2) Inductor Current, 500mA / div, DC
3) V
, 10V / div, DC
OUT
Typical Switching Waveform Start up into Openload
With Open LED Protection
Typical Switching Waveform
1
2
3
1µS / div
V
= 2.7V; 6 LEDs
IN
I
= 20mA
OUT
1) V
= 10V / div, DC
SW
2) V
3) Input Current, 100mA / div, DC
Inductor = 10µH, C
, 20mV / div, AC
OUT
AME5142B
OUT
= 1µF
Rev. C.02
1
2
3
1µS / div
V
= 5.5V; 6 LEDs
IN
I
= 20mA
OUT
1) V
= 10V / div, DC
SW
2) V
, 20mV / div, AC
OUT
3) Input Current, 100mA / div, DC
Inductor = 10µH, C
OUT
= 1µF
1
3
2
1) VEN = 2V / div
2) VSW, 10V / div
3) V
, 10V / div
OUT
100µS / div
25
AME
n Date Code Rule
High Efficiency 6 White LED Driver
With Open LED ProtectionAME5142/5142A/5142B
Marking Date Code
A A A W W xxx0
A A A W W xxx1
A A A W W xxx2
A A A W W xxx3
A A A W W xxx4
A A A W W xxx5
A A A W W xxx6
A A A W W xxx7
A A A W W xxx8
A A A W W xxx9
n Tape and Reel Dimension
Year
SOT-25
Package Carrier Width (W) Pitch (P) Part Per Full Reel Reel Size
P
W
AME AME
PIN 1
Carrier Tape, Number of Components Per Reel and Reel Size
SOT-25 8.0±0.1 mm 4.0±0.1 mm 3000pcs 180±1 mm
26
Rev. C.02
AME
High Efficiency 6 White LED Driver
AME5142/5142A/5142B
n Tape and Reel Dimension
TSOT-25
P
AME AME
PIN 1
Carrier Tape, Number of Components Per Reel and Reel Size
Package Carrier Width (W) Pitch (P) Part Per Full Reel Reel Size
With Open LED Protection
W
SOT-26
TSOT-25 8.0±0.1 mm 4.0±0.1 mm 3000pcs 180±1 mm
P
W
AME AME
PIN 1
Carrier Tape, Number of Components Per Reel and Reel Size
Package Carrier Width (W) Pitch (P) Part Per Full Reel Reel Size
SOT-26 8.0±0.1 mm 4.0±0.1 mm 3000pcs 180±1 mm
Rev. C.02
27
AME
n Tape and Reel Dimension
TSOT-26
P
AME AME
PIN 1
Carrier Tape, Number of Components Per Reel and Reel Size
High Efficiency 6 White LED Driver
With Open LED ProtectionAME5142/5142A/5142B
W
Package Carrier Width (W) Pitch (P) Part Per Full Reel Reel Size
TSOT-26 8.0±0.1 mm 4.0±0.1 mm 3000pcs 180±1 mm
28
Rev. C.02
AME
High Efficiency 6 White LED Driver
AME5142/5142A/5142B
n Package Dimension
SOT-25
Top View Side View
D
E
H
PIN1
S1
e
Front View
A
θ1
With Open LED Protection
SYMBOLS
A 0.90 1.30 0.0354 0.0512
A
1
b 0.30 0.55 0.0118 0.0217
D 2.70 3.10 0.1063 0.1220
E 1.40 1.80 0.0551 0.0709
L
e
H 2.60 3.00 0.10236 0.11811
L
θ 1
S
1
MILLIMETERS INCHES
MIN MAX MIN MAX
0.00 0.15 0.0000 0.0059
1.90 BSC 0.07480 BSC
0.37BSC 0.0146BSC
o
0
0.95BSC 0.0374BSC
10
o
o
0
10
o
TSOT-25
E
H
PIN1
b
Top View Side View
D
S1
e
Front View
A1
A
θ1
SYMBOLS
MILLIMETERS INCHES
MIN MAX MIN MAX
A+A
1
0.90 1.25 0.0354 0.0492
b 0.30 0.50 0.0118 0.0197
D 2.70 3.10 0.1063 0.1220
E 1.40 1.80 0.0551 0.0709
L
H 2.40 3.00 0.0945 0.1181
L
θ 1
S
1
e
1.90 BSC 0.07480 BSC
0.35BSC 0.0138BSC
o
0
0.95BSC 0.0374BSC
10
o
o
0
10
o
Rev. C.02
b
A1
29
AME
n Package Dimension
SOT-26
High Efficiency 6 White LED Driver
With Open LED ProtectionAME5142/5142A/5142B
E
H
TSOT-26
PIN1
b
Top View
D
e
S1
Front View
Side View
MILLIMETERS INCHES
SYMBOLS
θ 1
MIN MAX MIN MAX
A 0.90 1.30 0.0354 0.0512
A
1
0.00 0.15 0.0000 0.0059
b 0.30 0.55 0.0118 0.0217
D 2.70 3.10 0.1063 0.1220
L
E 1.40 1.80 0.0551 0.0709
e
1.90 BSC 0.07480 BSC
H 2.60 3.00 0.10236 0.11811
L
θ 1 0
A
A1
S
1
0.37BSC 0.0146BSC
o
10
o
o
0
0.95BSC 0.0374BSC
10
o
30
Top View
D
e
Side View
θ 1
SYMBOLS
A+A
1
MILLIMETERS INCHES
MIN MAX MIN MAX
0.90 1.25 0.0354 0.0492
b 0.30 0.50 0.0118 0.0197
E
H
D 2.70 3.10 0.1063 0.1220
E 1.40 1.80 0.0551 0.0709
PIN1
b
S1
Front View
L
e
H 2.40 3.00 0.0945 0.1181
L
θ 1
S
A
A1
1
1.90 BSC 0.07480 BSC
0.35BSC 0.0138BSC
o
0
0.95BSC 0.0374BSC
10
o
o
0
Rev. C.02
10
o
E-Mail: sales@ame.com.tw
These products of AME, Inc. are not authorized for use as critical components in life-support
devices or systems, without the express written approval of the president
AME, Inc. reserves the right to make changes in the circuitry and specifications of its devices and
advises its customers to obtain the latest version of relevant information.
Document: 1229-DS5142/5142A/5142B-C.02
Corporate Headquarter
AME, Inc.
2F, 302 Rui-Guang Road, Nei-Hu District
Taipei 114, Taiwan.
Tel: 886 2 2627-8687
Fax: 886 2 2659-2989
www.ame.com.tw
Life Support Policy:
of AME, Inc.
AME, Inc. , April 2009
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