The driver is a continuous mode driver, but it supports PWM input for dimming which I'm not using. With continuous mode, the LED is always on, but the output does "ripple" at a high frequency, which is filtered by the output capacitor. When you watch videos of some hacked flashlights, you notice either lines in the video or the light itself seemingly strobing, that is a pwm chopper-circuit which is old-school IMHO. Continuous mode is more refined, and I feel causes less eye strain.
Here's the specifics on the chip I am using:
Diodes Inc ZXLD1356 LED driverAt the very end, they do talk about how to sync the output with a low frequency pwm signal, to behave more like a chopper.
With a 12v rv system, I think four leds might cause trouble if your house battery becomes run down. The driver needs the supply voltage to be at least 1.25v higher than the led voltage for proper operation. However, you could run six or nine leds, in parallel strips of three. The chip I'm using has a bigger brother, the 1362 which outputs up to 1 amp, just enough to drive three parallel strings of three 1-watt leds on a 12v system
