I'm considering using one of the Linear Technology push-pull driver chips, e.g. LT1533, LT1683 or LT3439. At over $4 they are pretty pricey, so I'm looking for alternatives. Do ADI have anything equivalent?
LT1533
Production
The LT1533 is a new class of switching regulator designed to reduce conducted and radiated electromagnetic interference (EMI). Ultralow noise and EMI are...
Datasheet
LT1533 on Analog.com
LT1683
Production
The LT1683 is a switching regulator controller designed to lower conducted and radiated electromagnetic interference (EMI). Ultralow noise and EMI are...
Datasheet
LT1683 on Analog.com
LT3439
Production
The LT3439 is a push-pull DC/DC transformer driver that reduces conducted and radiated electromagnetic interference (EMI). Ultralow noise and EMI are achieved...
Datasheet
LT3439 on Analog.com
I'm considering using one of the Linear Technology push-pull driver chips, e.g. LT1533, LT1683 or LT3439. At over $4 they are pretty pricey, so I'm looking for alternatives. Do ADI have anything equivalent?
Oliver,
we do have a few of those type of parts. Mostly they are associated with our isoPower product group.
As an example the ADuM3070 drives an external transformer and has the loop closed through the iCoupler
Also the ADuM5010 is fully integrated for lower power applications.
What voltages and current are you talking about?
Do you need isolation and regulation or just a open loop push pull driver?
LucaV
Thanks LucaV. I don't need closed loop control so isolation isn't particularly relevant. The transformer center tap is at 24V, so the driver FETs need to be rated at 50V. I believe the power required is less than 2W (clarification still being sought!!!), but low switching noise is what I'm looking for.
Oliver,
for low noise you may want to consider a resonant topology rather than a forced push pull. Unfortunately we do not have any product in this power class for you.
If you are still interested in a forced push pull then you can reduce noise by using the ADuM3070 as a gate driver and adding external HV FET. You would control the switch speed (and noise) with gate drive impedance (a resistor) in series with the FET gate.
Best of luck,
LucaV
Oliver,
here is an example using the ADuM3xxx as a driver for external HV FETs.
LucaV
My hands are tied on a lot of issues, but I can certainly go for external FETs in a cascode configuration. Thanks.
Could you use a normal buck/boost... whatever and make the output voltage a bit higher...
Then use a LDO after, followed by a large polymer low ESR capacitor.
Most noise is due to bad PCB layout not the converter itself.
You need split ground planes and never mix signal return with power ground