I have been off the list for a while, but noticed that there where some posts on the LTZ1000 and LM399 about a month ago. I just have a comment; the requirements on these two references (standard datasheet implementations) are very much opposites: - LTZ1000 requires very stable resistors but is practically immune to supply voltage variations. - LM399 does not require high stability resistors but requirements on stable supply voltage are high. On the $ of one LTZ1000 board, you can get a number of LM399 paralelled & averaged. But one LTZ1000 runs on less power than one LM399 my 2c

Am 10.12.2014 um 16:20 schrieb Jan Fredriksson: > But one LTZ1000 runs on less power than one LM399 > Hello, I cannot agree to the last statement. It mainly depends if you use LTZ1000 or LTZ1000A and temperature setpoint and thermal isolation. Just for comparison: My two LTZ1000A with 50 deg C setpoint are using 20-21 mA each at 23 deg C and 14V stabilized supply (from 12 NiMH cells = 15V battery) My LM399#3 uses 30mA at room temp and 9.35V stabilized supply (from 8 NiMH cells = 10V battery) so total power is around 300mW in both cases. with best regards Andreas