I used the HMC860 with VCC=3.4V and all my outputs are 2.8V.
the load is 10-20 mA each.
I changed the VCC by 0.1V and get ~1mV on the output.
Is it normal?
I expected much higher line regulation.
Is there any other part with similar performance (low noise, at least 2 LDO in 1 package) that will give better results?
From the datasheet: Vdd min is 3.35V and the dropout voltage is 0.3V.
I suspect you are barely meeting the minimum Vdd for that particular IC and the dropout looks more like 0.5V.
You should use more margin on Vdd whenever possible.