From the Analog Devices newsletter:
Seems awful obsessed about "noise" (Phantom should reject noise), and the tutorial beats around a few bushes. You have to dig to find a nominal current; max current will need external datasheet shoveling. They test with 1k load which is 48 (they say 50) mA which is 3 to 12 microphones (4 seems safe). I think there is a disable pin but not explained and turn-on/off thumping not discussed?
Multiple units in one system will want syncing, there's a pin for that.
Clearly they want to sell chips. The LT8362 is $5 at the usual distributors; they won't get rich from the audio market. The final circuit adds a SBCP56 transistor not made by Analog, 35 cents (8 cents by the truckload).
This caveman will continue to double 24VAC to a Zener/BJT regulator, why be fancy?
> the microphone’s output levels are quite low in order to transmit the captured signal in high quality.
Well, no: because Phantom is a poor match to 200 ohm lines, so only a volt or so is possible without trickery too elaborate for the older Phantom mikes.
https://www.analog.com/en/analog-dialogue/raqs/raq-issue-176.htmlUltralow Noise, 48 V, Phantom Microphone Power Supply Using a Tiny DC-to-DC Boost Converter
Professional condenser microphones require a 48 V supply to charge the internal capacitive transducer and power the internal buffer for the high impedance transducer output. This supply is low current, and the power supply must be very low noise because the microphone’s output levels are quite low in order to transmit the captured signal in high quality.
Seems awful obsessed about "noise" (Phantom should reject noise), and the tutorial beats around a few bushes. You have to dig to find a nominal current; max current will need external datasheet shoveling. They test with 1k load which is 48 (they say 50) mA which is 3 to 12 microphones (4 seems safe). I think there is a disable pin but not explained and turn-on/off thumping not discussed?
Multiple units in one system will want syncing, there's a pin for that.
Clearly they want to sell chips. The LT8362 is $5 at the usual distributors; they won't get rich from the audio market. The final circuit adds a SBCP56 transistor not made by Analog, 35 cents (8 cents by the truckload).
This caveman will continue to double 24VAC to a Zener/BJT regulator, why be fancy?
> the microphone’s output levels are quite low in order to transmit the captured signal in high quality.
Well, no: because Phantom is a poor match to 200 ohm lines, so only a volt or so is possible without trickery too elaborate for the older Phantom mikes.