DC1224A

DC1224A demonstration circuit is a LED driver with one wire control and output disconnect featuring the LT3593. The LT3593 is a step-up current mode DC/DC converter designed to drive up to 10 white LEDs in series from a Li-Ion cell. The demo board has two sections. The top section showcases the small size LED drive. The maximum current is 20mA. The bottom section is the control section that generates pulses for the CTRL pin of LED driver. The number of pulses and its timing determine the current and brightness of the LEDs. The LCD display in the bottom section shows the status of the commanding LED current level in the format as “LEVEL=value” and LED current level as “ILED=value”. The LEVEL value responses to the UP button SW1 and DOWN button SW2 immediately. The ILED value only changes to the commanding LEVEL value after the SEND/STORE button SW3 is pushed. Pushing SEND/STORE button also saves the LEVEL value in the memory of the micro-controller U2 as the default LED current level.

• Input supply range from 3V to 5V
• 20mA maximum output LED current, 40V maximum output voltage
• 81% efficiency (VIN=5V, 8 white LEDs )
• 1MHz switching frequency

Avisos

Do not look at operating LED. This circuit produces light that can damage eyes.