[Weird PCB added again] Voltage reference based on LM399

The 7V gear is basically stable with 6 and a half digits per digit. The 10V gear depends on what kind of resistor you guys are willing to use:)

Don't buy components according to the BOM list. The adjustment resistors here need to have very low temperature drift, preferably below 5PPM.

The operational amplifier LT1001 can be sealed in plastic or gold. In actual testing, the impact is not significant. The most important thing is a few adjustment resistors R5 R6 R5A R5B R6A R6B. Just use R3 within 50PPM;

For LM399, you can go to Taobao or Xianyu to buy a second-hand disassembled unit. I used a printed windshield. In actual testing, if you use a metal shell, you can skip the windshield and it won’t be a big problem;

It is recommended that the casing be enclosed with all metal and leave a grounding screw for grounding:)

The actual product is as shown below. Because the 10V resistor is too expensive, I am too lazy to bring out the 10V resistor. I just use the 7V resistor as a benchmark and it is enough!

The last thing I want to say is that you need to be careful when playing the benchmark, it is more terrifying than the gold-eating beast! ! !