AL3158FSG RGBs-EVM

AL3158 Evaluation Module
HIGH EFFICIENCY CHARGE PUMP WHITE LED DRIVER
Device Features
Description
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The AL3158 is a low noise, constant frequency
charge pump DC/DC converter that uses a dualmode load switch (1x), and (2x) conversion for white
LED applications. The AL3158 is capable of driving
three groups of three LED channels at 20mA from a
2.7V to 5.5V input. The current sinks may be
operated using three simple PWM dimming inputs
individually or in parallel for driving higher current
LEDs. Low external part counts (one 1μF flying
capacitor and two 2.2μF capacitors at VIN and VOUT)
make this part ideally suited for small,
battery-powered applications.
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VIN Range: 2.7V to 5.5V
Up to 93% Max Power Efficiency
1% Current Matching Accuracy Between
Channels
Three Simple PWM Dimming for RGB or WLED
Low Transition Threshold Voltage Typical 150 mV
Dual-Mode 1x and 2x Charge Pump
Drives up to 3 + 3 + 3 Channels of LEDs
1.2 MHz Constant Switching Frequency
VOUT Short-Circuit and Thermal Protections
Soft Start for Reducing Inrush Current
Under Voltage Lockout Protection
IQ <1μA in Shutdown
Thermally-Enhanced QFN3030-20 Package:
Available in “Green” Molding Compound (No Br,
Sb)
Lead Free Finish/ RoHS Compliant
This evaluation board uses the AL3158’s three PWM
dimming inputs to enable and disable the device and
to control the current level of R, G and B elements of
the three color LEDs. Each PWM input controls three
LEDs of the same color. The PWM signals are
generated by an on-board microcontroller with three
push buttons for adjusting current levels.
Ordering Information
Device
Package Code
Packaging
EVM Part Number
AL3158FSG
FS
DFN3030-20
AL3158FSG-EVM Rev.2
AL3158FSG-EVM Rev.2
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© Diodes Incorporated
AL3158 Evaluation Module
HIGH EFFICIENCY CHARGE PUMP WHITE LED DRIVER
Schematic
AL3158FSG-EVM Rev.2
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© Diodes Incorporated
AL3158 Evaluation Module
HIGH EFFICIENCY CHARGE PUMP WHITE LED DRIVER
PCB Layout
Top Layer Layout of AL3158FSG-EVM Rev.2
Bottom Layer Layout of AL3158FSG-EVM Rev.2
AL3158FSG-EVM Rev.2
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© Diodes Incorporated
AL3158 Evaluation Module
HIGH EFFICIENCY CHARGE PUMP WHITE LED DRIVER
Bill of Material
Bill of Material for AL3158FSG-EVM Rev.2
Ref
C1, C3
C2, C5
C4
LED1-3
LED10
LED11
JP1-9
JP10
R1-3
R4-5, 7-9
R6
R10-12
U1
U2
Count
Size
Mfr
2
0603
STD
2
0603
STD
1
1210
STD
3
0805
STD
1
0603
STD
1
0603
STD
9
0603
STD
1
0803
STD
1
0603
STD
5
0603
STD
1
0603
STD
3
0603
STD
DFN3030-20
1
Diodes
0
1
QFN6060-28
Microchip
Part Number
STD
STD
STD
LTST-C19FD1WT
STD
STD
STD
STD
STD
STD
STD
STD
AL3158SFG
PIC16F1827
Description
2.2 µF/10V ceramic capacitor
1 µF/16V ceramic capacitor
10 µF/10 ceramic capacitor
RGB color LED
Green LED
Red LED
0 Ω resistor
0 Ω resistor
Not populated
1 kΩ resistor
10 kΩ resistor
100 kΩ resistor
Charge pump WLED driver
8-bit microcontroller
I/O Terminals and Test Points
Terminals and Jumpers for AL3158FSG-EVM Rev.2
I/O and Test Points
Description
Comments
P1 (VIN), P2 (GND)
P3
Power Supply and Ground
Connect to input power supply
Control signal monitoring
Use an oscilloscope to monitor the PWM signals
J11
Input Jumper to AL3158
Jumper for connecting VIN to the AL3158
J12
Input Jumper to PWM control Jumper for connecting VIN PWM controller circuit
VIN, VOUT
Voltage Test Points
AL3158FSG-EVM Rev.2
Input and output voltage test points
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www.diodes.com
SEPTEMBER 2010
© Diodes Incorporated
AL3158 Evaluation Module
HIGH EFFICIENCY CHARGE PUMP WHITE LED DRIVER
Quick Start Guide
1. Insert jumper J11 to connect VIN to the AL3158 and J12 to connect VIN to the onboard PWM
controller.
2. Connect a +2.7V~+5.5V power supply between VIN (P1) and GND (P2) headers. Turn on the
power supply. The red power indicator LED (LED11) will be on.
3. The PWM controller will enter State 1, where three different PWM signals are sent to the AL3158 to
set the current levels of the three groups of LEDs, green, red and blue. Each group will be dimming
from bright to dark and from dark to bright, causing LED1-3 to show changing colors.
4. In State 1, the green LED10 will be blinking. Pressing the UP and DOWN buttons will change the
rate at which LED10 blinks and also change the dimming rate of the color LEDs.
5. Press the CYCLE button to move the PWM controller to the next state. Every time the controller
enters a new state between States 2 and 4, the corresponding LED group will be dimming
automatically while the other LEDs will stay at the current levels set in the previous States.
6. While in any state between State 2 and State 4, press the UP or DOWN button to stop
auto-dimming. Then use the UP button to manually increase the brightness of the LEDs and
DOWN button to decrease it. Press the CYCLE button again to resume auto-dimming of the same
color.
7. Press the CYCLE button while in State 4 will bring the PWM controller back to State 1.
8. Press and hold the CYCLE button at any time will force the PWM controller to enter State 0. In this
state, all color LEDs will be turned off. So will the green LED10. Press the CYCLE button in State 0
will change the PWM controller state to State 1 with all three color LED groups dimming in-synch,
resulting in white color.
9. In order to see only one of the three colors, do the following: (1) Do step 8 and then enter State 1.
(2) Follow step 4 to slow down the dimming rate. (3) Press the Cycle button while all color LEDs
are off so that State 2-4 can be entered with the LEDs of only one color on.
Table: PWM Controller Machine States
Controller
State
Green LED
(LED10)
0
Off
1
Flashing
2
On
Description
All RGB LEDs are turned off
All three groups auto-dimming; UP and DOWN button to
change dimming rate.
Set current level for the green LEDs in LED1-3
3
On
Set current level for the red LEDs in LED1-3
4
On
Set current level for the blue LEDs in LED1-3
AL3158FSG-EVM Rev.2
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SEPTEMBER 2010
© Diodes Incorporated
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