I have a simple LED driver circuit like this:
simulate this circuit– Schematic created using CircuitLab
The op-amp is OPA354250-MHz,Rail-to-RailI/O, CMOSOperationalAmplifier supplied from a single +5V rail. The LED is a 100mA, 1.4V forward voltage type. The input is a 0.5V pulse from a signal generator.
What I see is that everything works more or less as expected, the LED current during a pulse is around 50mA, except that at the beginning of each pulse there is a distinct oscillation with a period of ~10ns (around 5-10 cycles are visible). Somewhat more disturbingly, there is a bit of random noise on top of each pulse, maybe 50mV peak to peak, that comes and goes.
The LED has a decently large capacitance of some tens of pF. I've read a lot about stabilizing op amps driving capacitive loads, but these would have the capacitive load where R1 is, not inside the feedback loop.
How do I stabilize the op-amp and prevent this kind of noise/oscillations?