Ampliifer with a stable gain upto 500khz needed

Status
Not open for further replies.
V

vinayakdabholkar

Advanced Member level 4
Joined
Nov 29, 2009
Messages
114
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,296
Location
goa
Visit site
Activity points
2,195
Need a opamp with a stable gain upto 500khz to sense the voltage across the sense resistor in a synchronous buck converter
The specs are Vin=12
Vout=1.2V
Iout=12A
Fsw=500Khz
Rsense=10m ohms
Please help
 

Attachments

  • upload.png
    51.3 KB · Views: 70

chuckey said:
out of idle curiosity, why are you sensing the ripple current and not the smoothed DC current?
Frank
Click to expand...
I had thought the ripple current is directly given as a ramp to the pwm comparator, so that a separate ramp wont be generated.
Another thing that i had tried was sensing the inductor DCR current by using a RC in parallel with it and matched the time constants L/DCR to RC so that voltage across DCR is equal to voltage across Capacitor. But could not figure out how to go foward with it to get the average current.
 

Can any operational amplifier be connected across the sense resistor in a differential amplifier configuration with unity gain to sense the voltage and convert it into a single ended one and then use a resistor to sense the current ?
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…