The LTC®3210 is a low noise charge pump DC/DC converter designed to drive four MAIN LEDs and one high current CAM LED for camera lighting. The LTC3210 requires only four small ceramic capacitors and two current set resistors to form a complete LED power supply and current controller. Built-in soft-start circuitry prevents excessive inrush current during start-up and mode changes. High switching frequency enables the use of small external capacitors. Independent MAIN and CAM full-scale current settings are programmed by two external resistors. Shutdown mode and current output levels are selected via two logic inputs. The full-scale current through the LEDs is programmed via external resistors. ENM and ENC are toggled to adjust the LED currents via internal counters and DACs. The part is shut down when both ENM and ENC are low for 150µs (typ). The charge pump optimizes efficiency based on the voltage across the LED current sources. The part powers up in 1x mode and will automatically switch to boost mode whenever any enabled LED current source begins to enter dropout. The LTC3210 is available in a 3mm × 3mm 16-lead QFN package.
The LTC3210 is a charge‑pump DC/DC converter designed to supply up to 500 mA total LED current for four MAIN LEDs and one high‑current CAM LED used in cell‑phone, DSC and PDA lighting. It features multimode operation (1×, 1.5×, 2×), single‑wire EN/Brightness control, 64:1 brightness range for the MAIN display, and internal soft‑start to limit inrush current.
Electrical characteristics include a 2.9 V‑5 V operating voltage range, 0.8 MHz oscillator frequency, 0.4 ms mode‑switching delay, and a shutdown current of 3 pA when ENM and ENC are low. The device is supplied in a 3 mm × 3 mm 16‑lead plastic QFN package with an exposed pad tied to ground for optimal thermal performance. Pin functions, block diagram, and typical application circuits are detailed for easy integration.
| Total Output Current | Up to 500 mA |
|---|---|
| Package | 3 mm × 3 mm 16‑lead plastic QFN |
| Operating Voltage | 2.9 V – 5 V |
| Shutdown Current (ENM=ENC=LOW) | 3 pA |
| Oscillator Frequency | 0.8 MHz |
| Mode Switching Delay | 0.4 ms |
It can drive four MAIN LEDs and one CAM LED.
The device provides up to 500 mA total output current.
The shutdown current is 3 pA.
The internal oscillator runs at 0.8 MHz.