L7986ta Ripple issue at various Vin voltages

[Harshwardhana]

Hi..

We are using L7986TA IC in our buck converter circuit.

Vin : 20.4VDC to 38VDC

Vout: 3.7V

Iout: 0.250A

L : 15uH

Cin: 220uF x 3

Cout: 470uF

We are observing high ripple around 400mV above 30VDC supply..

can u please help us resolve the issue.