Here is the press release:
"Coilcraft’s new AGM2222 Series power inductors offer current ratings up to 110 Amps and very low DCR in a package measuring just 22 X 22 X 23 mm, a 73% volume reduction from previous-generation products. This significant improvement in power density makes the AGM2222 ideal for high-current applications including automotive bi-directional 12 V – 48 V DC-DC converters.
The AGM2222 Series is available in 13 inductance values from 1.9 to 10 µH. It is qualified to AEC-Q200 Grade 1 (-40°C to 125°C ambient), making it ideal for automotive and other high-temperature applications. Soft saturation is stable over temperature and enables high peak current handling. Magnetic shielding reduces EMI at high switching frequencies."
Here are the specifications: AGM2222 High Current Power Inductors | Coilcraft
Here are Inductance vs Current graphics: Typical Current vs Frequency - AGM2222 Shielded Power Inductors
Here are Inductance vs Frequency graphics: Typical Inductance vs Frequency - AGM2222 Shielded Power Inductors
I asked Coilcraft for the voltage ratings of these inductors and they responded, that all are tested at 100Vrms for 1 second, when they are manufactured.
So, I think these inductors will be very good for TPA3255 and similar power amplifiers, with single power supply under 80V, or for dual power supply up to +/-40V.
What do you think about them?
Will they be good for Class D amplifiers?
"Coilcraft’s new AGM2222 Series power inductors offer current ratings up to 110 Amps and very low DCR in a package measuring just 22 X 22 X 23 mm, a 73% volume reduction from previous-generation products. This significant improvement in power density makes the AGM2222 ideal for high-current applications including automotive bi-directional 12 V – 48 V DC-DC converters.
The AGM2222 Series is available in 13 inductance values from 1.9 to 10 µH. It is qualified to AEC-Q200 Grade 1 (-40°C to 125°C ambient), making it ideal for automotive and other high-temperature applications. Soft saturation is stable over temperature and enables high peak current handling. Magnetic shielding reduces EMI at high switching frequencies."
Here are the specifications: AGM2222 High Current Power Inductors | Coilcraft
Here are Inductance vs Current graphics: Typical Current vs Frequency - AGM2222 Shielded Power Inductors
Here are Inductance vs Frequency graphics: Typical Inductance vs Frequency - AGM2222 Shielded Power Inductors
I asked Coilcraft for the voltage ratings of these inductors and they responded, that all are tested at 100Vrms for 1 second, when they are manufactured.
So, I think these inductors will be very good for TPA3255 and similar power amplifiers, with single power supply under 80V, or for dual power supply up to +/-40V.
What do you think about them?
Will they be good for Class D amplifiers?
With the maximum inductance of 10uH they might well be OK for 4ohm speakers. Higher impedances though would need to look to another range. Since the core material is powdered iron, what are the losses like at ~500kHz? Normally powdered iron is fairly lossy at higher frequencies and the wire doesn't look to be litz.
They have online calculator, but AGM2222 is not added yet: Coilcraft Power Inductor Analysis & Comparison Tool
https://www.coilcraft.com/pdfs/agm2222.pdf
As far as I can see they are still fine with a few MHz, maybe 10 with the 10uH coil.
As far as I can see they are still fine with a few MHz, maybe 10 with the 10uH coil.
I'm seeing a low-Q self-resonance for the 10uH just under 20MHz. The question is - is the inductor equally low Q at 0.5MHz?
OK, I thought this diagram would show the interesting region, so it is critical sub 1.0 MHz?
How can we know? The wire is flat copper.
How can we know? The wire is flat copper.
The low distortion inductors have flat L vs A like these
Typical Current vs Frequency - SER2900 Series Power Inductors
Typical Current vs Frequency - SER2900 Series Power Inductors
I've received 3 free samples of AGM2222 with 10uH inductance:
When I have time, I will try to compare AGM2222 to the SER2918H, but it is 22uH...
Both look very massive!
And both are heavy 🙂
When I have time, I will try to compare AGM2222 to the SER2918H, but it is 22uH...
Both look very massive!
And both are heavy 🙂
Exactly this.
These AGM2222 are not really suitable for Class-D power amplifiers since the inductance really change vs current (load).
This results in more distortion.
All measurements I've seen proved gapped ferrite being the most linear core material. Any kind of iron powder including carbonyl is inferior.
Btw coilcraft recommends these inductors for dc-dc converter claiming compact size and low loss - but no recommandation for class-D here.
Linearity is not related to low loss - I found lowest losses with carbonyl cores.
Btw coilcraft recommends these inductors for dc-dc converter claiming compact size and low loss - but no recommandation for class-D here.
Linearity is not related to low loss - I found lowest losses with carbonyl cores.
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