CCxW Driver Technical information

TASKLED - Smart LED drivers

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CC1A Technical Information

Magnetic Field Warning:

The CC1A is a switching regulator based driver and contains an Inductor (L1 in the picture below). Strong external magnetic fields such as from a magnet used to operate a Hall sensor or Reed switch can interfere with the Inductor's operation. It is recommended to maintain a minimum of 1" from the Inductor and any external magnet. If the magnet is very powerful, then the distance needs to be increased (more than 1") as needed to minimise interference to the Inductor.

Potting Warning:

Areas of the circuitry on the CC1A drivers utilize high impedance paths and if potting (not required) is to be utilized, the user must ensure than the compound is non-conductive and non-capacitive otherwise correct operation may be compromised.

Hookup information:

The circuitry (all surface mount) fits neatly on a 1" x 0.8" PCB.

Connections:

IN+ to Battery positive
IN- to Battery negative
LED+ to LED positive
LED- to LED negative
PWM. Leave disconnected if unused.

Voltage Headroom:

The CC1A is a buck driver and requires input voltage to be a minimum of 2V higher than the total LED Vf to be in full current regulation. If the input voltage drops lower, the driver will stop regulating and the output current will drop below the regulated value (350mA/750mA or 1000mA depending on version).

Design Hint:

The PWM input is optoisolated to protect the driver and to provide noise immunity for the control signal if run large distances in a vehicle. The input has a series resistor (220 ohms) with the LED inside the optoisolator. Recommended maximum current on the PWM input is 20mA.

It may be necessary to provide an external resistor in series with the PWM input if the voltage level is too high.

Example: PWM signal is 12V. What series resistor is required?.

Resistor value = (12V- 2V) / 0.02 - 220 = 500 - 220 = 280 ohms.

Typical Efficiency:

The following graph shows the typical efficiency that is expected from the CC1A driver (at 1000mA). The efficiency improves with more series LEDs (greater total output voltage) and when the input voltage is relatively close to the output voltage.