low negative voltage PSU for precision ADC

We are looking for a design which would give us -1V or -2V with low noise. This is the negative rail for our op-amps.

The ADCs are 16 and 18 bit so a very clean power supply would be required.

Looking at the ADP1621 CUK design tool we are getting a circuit with 28 components.

Could anyone suggest another possible solution with a lower component count?