DC824A Analog Devices

QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 824 MULTIDISPLAY LED CONTROLLER LTC3208 WARNING: The LEDs on this demo board produce very bright light. Do not look directly at LEDs when power is applied. Serious eye damage may occur. DESCRIPTION Demonstration circuit 824 is a multi-display LED 256 dimming states exist for the MAIN and SUB controller featuring the LTC3208. panels. 16 states are available for the RGB, CAM, and AUX displays. The RGB LED may display up The LTC3208 is a highly integrated multi-display to 4096 color combinations. LED controller. This device contains a high effi- ciency, low noise charge pump to provide power The LTC3208 charge pump optimizes efficiency for a MAIN, SUB, and auxiliary (AUX) white LED based on the voltage across the LED current displays, an RGB color display, and a camera sources. The part powers up in 1X mode and will (CAM) display with flash capabilities. The four aux- automatically switch to boost mode whenever any iliary LEDs may be individually configured to the enabled LED current source begins to drop out. MAIN, SUB, CAM, or AUX display. The LTC3208 The first dropout switches the part to 1.5X mode requires only four small ceramic capacitors plus and a subsequent dropout switches the part into one resistor to form a complete 5-panel LED 2X mode. The charge pump can also be pro- 2 power supply and current controller. grammed to 1.5X mode or 2X mode via the I C interface. The maximum display currents are set with a sin- gle 24.3K ohm resistor. Current for each LED is Design files for this circuit board are available. Call controlled with a precision internal current source. the LTC factory. Dimming and ON/OFF control for all displays are , LTC and LT are registered trademarks of Linear Technology Corporation. 2 achieved via a 2-wire I C interface. The RGB or SUB panel may be disabled via the ENRGB/S pin. QUICK START PROCEDURE Demonstration circuit 824 is easy to setup to evalu- 4. Attach a 2.9 4.5V power source to the Vin and ate the performance of the LTC3208. Refer to Figure GND turrets of the DC824 demo circuit as shown 1 and Figure 2 for proper measurement equipment in Figure 2. This is the Vin power supply for the setup and follow the procedure below. LTC3208 (see application schematic). DC824 has an extra 4.7uF de-coupling capacitor on Vin to 1. Refer to the DC590 Quick Start guide for DC590 help accommodate long lead lengths. DC590 TM and QuickEval setup and software installation gets its power from the USB cable. details. TM 5. Run the QuickEval program. The program 2. Make sure the USB cable is connected between detects the DC824 and displays the LTC3208 the computer and the DC590 controller board. control window (shown in Figure 3). 3. Connect DC824 to the DC590 USB Serial Con- troller using the supplied 14-conductor ribbon cable as shown in Figure 1. 1 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 824 MULTIDISPLAY LED CONTROLLER Figure 1. Proper Serial Interface Connection Figure 2. Proper Measurement and Equipment Setup 2