Tek-Tips is the largest IT community on the Internet today!
Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!
-
Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!
Linear Technology LT1166
- Thread starter sreid
- Start date
Why? Its harmonic distortion performance suggests that it's not necessarily suited for audiophile applications.
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
Contact Linear Technologies and ask who they distribute through or just beg for a sample.
The problem may be that you don't have a part number, you have a series number. One part number is available from Digikey:
You can see the available part numbers in the linear orderinfo page.
The problem may be that you don't have a part number, you have a series number. One part number is available from Digikey:
You can see the available part numbers in the linear orderinfo page.
- Thread starter
- #4
1) So no one can answer the question I asked.
2) The harmonic distortion is based on the reference circuits. They are not very sophisticated.
3) The LT1166 is a bias current IC. This is not easy to do by other means.
4) Especially if you are putting out tens of kilowatts to drive a US Navy Active Sonar based on
Terfenol-D with Analog FETs. And the spec does not allow crossover distortion when the water
to the water cooled heat sink fails due to battle damage.
2) The harmonic distortion is based on the reference circuits. They are not very sophisticated.
3) The LT1166 is a bias current IC. This is not easy to do by other means.
4) Especially if you are putting out tens of kilowatts to drive a US Navy Active Sonar based on
Terfenol-D with Analog FETs. And the spec does not allow crossover distortion when the water
to the water cooled heat sink fails due to battle damage.
Oh - you want a finished product that happens to have the chip in it? Not the chip by itself? Linear Technologies may still be able to help by telling who bought them for that purpose.
Otherwise that's not an easy answer. Maybe find an audio enthusiast blog?
Otherwise that's not an easy answer. Maybe find an audio enthusiast blog?
- Thread starter
- #6
The LT1166 is intended for class AB amplifier biasing, but you seem to imply that you want to drive a sonar with a class AB amplifier?
Why wouldn't you be using a class D amplifier?
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
Why wouldn't you be using a class D amplifier?
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
- Thread starter
- #8
I can't see your system spec from here, but it would seem to be relatively simple from the system design perspective to use a digital class amplifier and add shielding and filtering, and still end up with a better solution than an analog amplifier in the 'tens of kilowatts' class. Maybe. Maybe not. It should not be rejected outright.
Keep in mind that you're going to need filtering and shielding in spades anyway to keep the kHz (?) sonar signal itself (meaning the conducted and radiated EMI emissions from the system and its wiring) in check anyway. MHz switching noise is probably easier to filter and shield than your kHz primary signal with 'tens of kilowatts'.
Plus, the system is likely to require a massive power supply, which would presumably be switching (as opposed to linear) these days. So there's going to be some switching I'd think.
If the amplifier can be installed next to the transducer, in the depths of a Navy ship, then it should be easy to keep the EMI in check.
Just some thoughts in case they help. Cheers.
PS: I did use my best Google-Fu on your original post, but found nothing.
Keep in mind that you're going to need filtering and shielding in spades anyway to keep the kHz (?) sonar signal itself (meaning the conducted and radiated EMI emissions from the system and its wiring) in check anyway. MHz switching noise is probably easier to filter and shield than your kHz primary signal with 'tens of kilowatts'.
Plus, the system is likely to require a massive power supply, which would presumably be switching (as opposed to linear) these days. So there's going to be some switching I'd think.
If the amplifier can be installed next to the transducer, in the depths of a Navy ship, then it should be easy to keep the EMI in check.
Just some thoughts in case they help. Cheers.
PS: I did use my best Google-Fu on your original post, but found nothing.
Couldn't find an amplifier that uses the IC, but I did find the IC by itself on Ebay.
"Class D. Military, EMI. Switching amplifiers a No-No!"
This is not true, in general. The motors in the modern submarines are commutating megawatts of power, and couldn't even begin to be efficient if the drivers were class AB.
Moreover, even if you used a class AB, you'd still be running as digital, as there is no plausible operational requirement to halfway between the rails during operation, and under normal operation, being in the middle costs a truckload of inefficiency, which a military system can ill afford.
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
This is not true, in general. The motors in the modern submarines are commutating megawatts of power, and couldn't even begin to be efficient if the drivers were class AB.
Moreover, even if you used a class AB, you'd still be running as digital, as there is no plausible operational requirement to halfway between the rails during operation, and under normal operation, being in the middle costs a truckload of inefficiency, which a military system can ill afford.
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
- Thread starter
- #12
- Thread starter
- #13
Way to bury the lead! ;-)
Requirements trump the laws of physics, of course...
Figure 14 of the datasheet shows you how to scale up their topology to handle higher powers. Hypothetically, 30 "slices" would get you about 9 kW. However, at that point, you might need a slice to buffer the front end as well.
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
Requirements trump the laws of physics, of course...
Figure 14 of the datasheet shows you how to scale up their topology to handle higher powers. Hypothetically, 30 "slices" would get you about 9 kW. However, at that point, you might need a slice to buffer the front end as well.
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
- Thread starter
- #15
- Status
Similar threads
- Locked
- Question
- Locked
- Question
- Locked
- Question