AP3156 Evaluation Module
HIGH EFFICIENCY CHARGE PUMP WHITE LED DRIVER
P3156FVG-EVM Rev.1 5 of 5 OCTOBER 2009
www.diodes.com © Diodes Incorporated
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
Controller
State
Green LED
(LED7) First
SDI
Sequence
Second
SDI
Sequence Description
0 Off 33 -
Soft Reset: 1) 1MHz switching frequency
2) 20mA Constant Current Mode
3) All Channels in Current Level 32 (0mA)
1 Flashing 8
1
2
3
Switching frequency selected to 0.5MHz
Switching frequency selected to 1MHz (default)
Switching frequency selected to 2MHz
2 On 9
2
1
3
2mA Low Current Mode, 4 current levels supported
20mA Current Mode, 32 levels supported (default)
25mA Current Mode, 32 current levels supported
3 On 10 1~32* Set current level for all 6 Channels
4 On 11 1~32* Set current level for CH1, CH2, CH3
5 On 12 1~32* Set current level for CH4, CH5, CH6
6 On 13 1~32* Set current level for CH1, CH2, CH3, CH4
7 On 14 1~32* Set current level for CH5, CH6
8 On 15 1~32* Set current level for CH1, CH2, CH3, CH4, CH5
9 On 16 1~32* Set current level for CH6
10 On 17 1~32* Set current level for CH5
11 On 18 1~32* Set current level for CH4
12 On 19 1~32* Set current level for CH3
13 On 20 1~32* Set current level for CH2
14 On 21 1~32* Set current level for CH1
*Only 1~5 in Low Current Mode.
