AP3156-EVM

AP3156 Evaluation Module
HIGH EFFICIENCY CHARGE PUMP WHITE LED DRIVER
Features
Description
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The AP3156 is a low noise, constant frequency
charge pump DC/DC converter that uses a tri-mode
(1X, 1.5X and 2X) conversion to maximize efficiency
for white LED applications. It is capable of driving
LEDs at a total of 120mA maximum from a 2.7V to
5.5V input. The six channels may be operated
individually or in parallel for driving higher-current
LEDs.
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VIN Range: 2.7V to 5.5V
Fully Programmable Current with Single Wire
- 32-Step Logarithmic Scale
- 20/25mA Max Current per Channel
- Four Low Current Settings Down to 50μA
- Low IQ (50μA) for Low Current Mode
Tri-Mode 1X, 1.5X, and 2X Charge Pump for
Maximum Efficiency and VF Coverage
Drives up to Six Channels of LEDs
Individual Main/Sub-Group Control
No Inductors, Low Noise Operation
0.5/1/2MHz Constant Switching Frequency
Built-In Thermal Protection
Built-In Auto-Disable For Open Circuit
Automatic Soft Start
IQ <1μA in Shutdown
Thermally-Enhanced QFN4040-16 Package:
Available in “Green” Molding Compound (No Br,
Sb)
Lead Free Finish / RoHS Compliant
A low external parts count (two 1μF flying capacitors
and two small 1μF capacitors at VIN and VOUT) makes
this device ideally suited for small, battery-powered
applications. A serial digital input is used to enable,
disable and set current for each LED with a 32-level
logarithmic scale plus four low-current settings down
to 50μA for optimal efficiency, with a low quiescent
current of only 50μA. Each output of the AP3156 is
equipped with built-in protection for VOUT short circuit
and auto-disable for LED failure conditions. Built-in
soft-start circuitry prevents excessive inrush current
during start-up. A shutdown feature disconnects the
load from VIN and reduces quiescent current to less
than 1μA.
Ordering Information
Device
Package Code
Packaging
EVM Part Number
AP3156FVG
FV
QFN4040-16
AP3156FVG-EVM
AP3156FVG-EVM Rev.1
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© Diodes Incorporated
AP3156 Evaluation Module
HIGH EFFICIENCY CHARGE PUMP WHITE LED DRIVER
Schematic
AP3156FVG-EVM Rev.1
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© Diodes Incorporated
AP3156 Evaluation Module
HIGH EFFICIENCY CHARGE PUMP WHITE LED DRIVER
PCB Layout
Top Layer Layout of AP3156FVG-EVM
Bottom Layer Layout of AP3156FVG-EVM
AP3156FVG-EVM Rev.1
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© Diodes Incorporated
AP3156 Evaluation Module
HIGH EFFICIENCY CHARGE PUMP WHITE LED DRIVER
Bill of Material
Bill of Material for AP3156FVG-EVM
Ref
P1, P2
J1, J2
J3
JP1-JP6
JP7
C1-C4
C5
C6
C7
R1-R3
R4, R5, R7
R6
LED1-LED6
LED7
LED8
CYCLE,
DOWN, UP
VR1
U1
U2
Count
2
2
1
6
1
4
1
1
1
3
3
1
6
1
1
Size
0.1”
0.1”
0.1”
0603
0805
0805
1210
0805
TH
0805
0805
0805
0805
0805
0805
Mfr
STD
STD
STD
STD
STD
STD
STD
STD
STD
STD
STD
STD
STD
STD
STD
Part Number
STD
STD
STD
STD
STD
STD
STD
STD
STD
STD
STD
STD
STD
STD
STD
3
Omron
B3F-1022
1
1
1
Bourns
Diodes
Microchip
SOP8
SOP8
Description
0.1” x2 headers
0.1” x2 headers and jumpers
0.1” x3 header and jumper
0 Ω resistor/jumper
0 Ω resistor/jumper
1 µF/10V ceramic capacitors
10 µF ceramic capacitor
0.1 µF ceramic capacitor
100 µF electrolytic capacitor
1 kΩ resistors
330 Ω resistors
100 kΩ resistor
White LEDs
Green LED
Red LED
Tactile switches
2 kΩ potentiometer
3362R
AP1212xSG Dual-channel USB power switch
PIC12F683 8-bit microcontroller
I/O Terminals and Test Points
Terminals and Jumpers for AP3156FVG-EVM
I/O and Test Points
Description
Comments
P1 (VIN), P2 (GND)
J1
Power Supply and Ground
Connect to input power supply
Input Jumper to AP3156
Jumper for connecting VIN to the AP3156
J2
Input Jumper to SDI
Jumper for connecting VIN SDI controller circuit
J3
SDI Connecter/Jumper
Select onboard or external SDI signal
VIN, VOUT
Voltage Test Points
Input and output voltage test points
AP3156FVG-EVM Rev.1
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© Diodes Incorporated
AP3156 Evaluation Module
HIGH EFFICIENCY CHARGE PUMP WHITE LED DRIVER
Quick Start Guide
1. Insert jumper J1 to connect VIN to the AP3156 and J2 to connect VIN to the onboard SDI controller.
Also insert a jumper between pin 1 and pin 2 of J3 to use the onboard controller to send SDI
commands to the AP3156.
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 (LED8) will be on.
3. The SDI controller will enter State 3, where SDI commands are sent to the AP3156 to set the
current levels of all six channels. All six white LEDs will be dimming from bright to dark and from
dark to bright. The following table shows the SDI controller States and associated SDI commands.
4. Press the CYCLE button to change the SDI controller state to the next state. Every time the SDI
controller enters a new state between States 3 and 14, the corresponding LED(s) will be dimming
automatically while the other LEDs will stay at the current levels set in the previous States. Adjust
VR1 to change the repetition rate at which the LEDs are auto-dimmed.
5. While in any state between State 3 and State 14, press the UP or DOWN button to stop the
auto-dimming. Then use the UP button to manually increase the current level of the LED(s) and
DOWN button to decrease it. Press the CYCLE button again to resume auto-dimming.
6. Press the CYCLE button while in State 14 will bring the SDI controller to State 1, where the
AP3156’s switching frequency can be set by using the UP and DOWN buttons. The green LED
(LED7) will flash slowly for lower switching frequency and faster for higher switching frequency.
7. Press the CYCLE button while in State 1 will advance to State 2, where the maximum LED current
can be set by using the UP and DOWN buttons.
8. Press and hold the CYCLE button at any time will force the SDI controller to enter State 0 and
soft-reset the AP3156. In this state, all white LEDs (LED1-6) will be turned off. So will the green
LED (LED7). Press the CYCLE button in State 0 will change the SDI controller state to State 1.
9. If an external SDI controller is to be used, remove the jumper on J3 and connect the external SDI
signal to between pin 2 and pin 3 (GND) of J3. The jumper on J2 can also be removed.
Table: SDI Controller Machine States
SDI
Green LED
Controller
(LED7)
State
First
SDI
Sequence
Second
SDI
Sequence
-
0
Off
33
1
Flashing
8
2
On
9
3
On
10
4
On
11
5
On
12
6
On
13
7
On
14
8
On
15
9
On
16
10
On
17
11
On
18
12
On
19
13
On
20
14
On
21
* Only 1~5 in Low Current Mode.
AP3156FVG-EVM Rev.1
1
2
3
2
1
3
1~32*
1~32*
1~32*
1~32*
1~32*
1~32*
1~32*
1~32*
1~32*
1~32*
1~32*
1~32*
Description
Soft Reset: 1) 1MHz switching frequency
2) 20mA Constant Current Mode
3) All Channels in Current Level 32 (0mA)
Switching frequency selected to 0.5MHz
Switching frequency selected to 1MHz (default)
Switching frequency selected to 2MHz
2mA Low Current Mode, 4 current levels supported
20mA Current Mode, 32 levels supported (default)
25mA Current Mode, 32 current levels supported
Set current level for all 6 Channels
Set current level for CH1, CH2, CH3
Set current level for CH4, CH5, CH6
Set current level for CH1, CH2, CH3, CH4
Set current level for CH5, CH6
Set current level for CH1, CH2, CH3, CH4, CH5
Set current level for CH6
Set current level for CH5
Set current level for CH4
Set current level for CH3
Set current level for CH2
Set current level for CH1
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