I just got my prototyping PCB for LTZ1000 voltage reference characterization:
The PCB is based on the standard schematics in the LTZ1000 datasheet. Only the dual channel op amp LT1013 is replaced with 2xLTC2057. All critical resistors are from Vishay's PTF series with 5ppm/°C TC. The LTZ1000 will be not soldered directly to the PCB, but through 8 pin socket. For every resistor, there is a jumper where additional resistor can be added. By this way characterization of the output voltage can be made with simulation of resistor change.
This time I used www.elecrow.com PCB service instead of my usual OSHPark because I didn't need ENIG and looked for a cheap and fast delivery. I ordered the PCB on 30th September, but the company was closed for the next 7 days due to China's golden week. I was surprised when I got an e-mail from the company at 8th October that the PCB was shipped with DHL. After 12 days, I had the PCB. I pay 4.9 USD for 2 layer, 5x5 cm PCB plus 3.72 USD for delivery to Europe. I highly recommend this service for fast prototyping.
So in the next days I will solder the parts and will start monitoring and characterizing the LTZ1000 voltage reference.
