sulemanzp
Newbie level 5
I am working on HMCAD1520, for this I have to create a two stage input circuit, which translates 0v to 5v signal to -1v to +1v.
For this I created a circuit (PDF attached in the end) with AD8056 for -1 offset (adjustable with +/- 200mV), AD8009 for amplitude mapping (0v <-> 5v signal to 0v <-> 2v) and LMH6553 for single to differential driver.
The circuit is working fine, the only issue is ripples and noise in the circuit (input and output both sides) and these are not acceptable for me in the ADC.
I confirm that the Pulse Generator is fine, and outputting signal without ripples or noise.
Below i am attaching the screen shots of sin wave and pulses as well.
In all pictures Blue is Input and Yellow is Differential Output.
Sin Wave but noise is there.
Sin Wave 50ns/Div, clearly i can see the noise.
Pulse Width 100ns, Look at the ripples.
couple of pulses
10 ns pulse width
I need help to remove the ripples, What i should do (add, remove or replace ) in the circuit to remove the ripple and what could be the cause for this.
Note: Schematic Updates:
R11 = R9 = 1000R,
R13 = R12 = 400R,
R1 = R2 = R3 = 0R soldered.
Thank you experts.
For this I created a circuit (PDF attached in the end) with AD8056 for -1 offset (adjustable with +/- 200mV), AD8009 for amplitude mapping (0v <-> 5v signal to 0v <-> 2v) and LMH6553 for single to differential driver.
The circuit is working fine, the only issue is ripples and noise in the circuit (input and output both sides) and these are not acceptable for me in the ADC.
I confirm that the Pulse Generator is fine, and outputting signal without ripples or noise.
Below i am attaching the screen shots of sin wave and pulses as well.
In all pictures Blue is Input and Yellow is Differential Output.
Sin Wave but noise is there.
Sin Wave 50ns/Div, clearly i can see the noise.
Pulse Width 100ns, Look at the ripples.
couple of pulses
10 ns pulse width
I need help to remove the ripples, What i should do (add, remove or replace ) in the circuit to remove the ripple and what could be the cause for this.
Note: Schematic Updates:
R11 = R9 = 1000R,
R13 = R12 = 400R,
R1 = R2 = R3 = 0R soldered.
Thank you experts.