My devices (Technix) differs from the datasheet. The divice is composed by two 5,36V@5mA zeners connected in
Common Kathode.
So with the connection suggested in DS, color dot (pin1: Yel in my 232's Red in my 233's) on the negaive side and pin 2 on the positive side, one diode is used as a true zener and the other as a temperature compensating diode.
My device (random pick from a batch of 20) is mounted alone in a small cardbox and is connected to a quite stable power supply (Tek PS501-1) via a 770 ohm 50 ppM resistor.
The voltage of the compensated zener (two diodes in series) @5mA is 6.06236V (Datron 1062) and the Tc (with the normal room temperature variation) il less than 5 ppm/°C.
(DUT or measuring instrument drift?)
Heating it with a finger, shows a little positive Tc, but it fully agrees with the DS data: the zero Tc point is obtained at about 60°C @5mA, with a positive Tc under this temp and a negative Tc over.
I am running the device at 25..28°C so it is operating on the positive Tc side of the curve. A brief test a 3.3mA shows a better behaviour in this range of temperature.
I need to do a more extensive and accurate test on the device, but at first sight it seems to me very good.
No test on noise and long term drift (WIP).