AP3156 Evaluation Module HIGH EFFICIENCY CHARGE PUMP WHITE LED DRIVER Features Description • • 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. • • • • • • • • • • • 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 1 of 5 www.diodes.com OCTOBER 2009 © Diodes Incorporated AP3156 Evaluation Module HIGH EFFICIENCY CHARGE PUMP WHITE LED DRIVER Schematic AP3156FVG-EVM Rev.1 2 of 5 www.diodes.com OCTOBER 2009 © 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 3 of 5 www.diodes.com OCTOBER 2009 © 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 4 of 5 www.diodes.com OCTOBER 2009 © 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 5 of 5 www.diodes.com OCTOBER 2009 © Diodes Incorporated