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sinara-hw / Phaser

Quad channel 1GS/s RF generator card with dual IQ upconverter and dual 5MS/s ADC and FPGA in EEM form factor
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replace TRN 3-1222 #121

Closed hartytp closed 3 years ago

hartytp commented 3 years ago

phaser burns off a lot of power. We should be careful not to be wasteful and let the usage creep up unneccecarily.

The TRN 3-1222 uses 480mW (40mA) quiescent, which is a lot bearing in mind that we only need ~20mA from each rail.

Replacing this with the 1W converter in the same family would halve the quiescent current, which would help a lot.

gkasprow commented 3 years ago

True. We don't need that much.

gkasprow commented 3 years ago

I will replace them with dedicated buck and inverting synchronous converters

hartytp commented 3 years ago

:+1:

gkasprow commented 3 years ago

Not that easy. the negative sync converters work up to -5.5V. And we need to create 12V out of input voltage which can be less than 12V. We have to use SEPIC converter, for example LT8582 which delivers +/- 12V. We can also go for LTM8049.

gkasprow commented 3 years ago

But it is overkill. Let's go for NMJ1212SC. it consumes 250mW of quiescent power.

gkasprow commented 3 years ago

we can also go for MTU1D1212MC, it has higher efficiency and lower ripples, but has a non-standard footprint. NMV1212SC has standard pinout and higher efficiency. The same with TRN 1-1222 which has better output stability.

gkasprow commented 3 years ago

Let's use TRN 1-1222 then