LM129/LM329 Precision Reference

General description
The LM129 and LM329 families are mostly precision current temperature compensated reference dynamic 6.9V zener impedances 10 to 100 times less discrete diodes. Built on a single silicon chip, the LM129 uses active circuitry to buffer the internal Zener allowing the device to operate in the 0.5 mA to 15 mA range with little change in performance. The LM129 and LM329 are available with selected temperature coefficients of 0.001, 0.002, 0.005 and 0.01%/°C. These formulations also have excellent long-term stability and low noise. A new ground-level Zener breakdown using the LM129 provides lower noise and better long-term stability than conventional IC Zener diodes. Further Zener and temperature compensation transistors are made by a planar process so that they are immune to the problems that plague ordinary Zener diodes. For example, there is almost no voltage change in the Zener voltage due to temperature cycling and the device is not sensitive to stress on the leads. The LM129 can be used in place of conventional Zener diodes to improve performance. Low dynamic impedance simplifies biasing and wide operating current allows replacement of many Zener types. The LM129 is packaged in a 2-pin TO-46 package and is specified over the -55°C to +125°C temperature operating range. The LM329 operating at 0°C to 70°C is available in both a hermetic TO-46 package and a TO-92 epoxy package.

Features
0.6 mA to 15 mA operating current
0.6W dynamic impedance at any current available with a temperature coefficient of 0.001%/°C
7μV wideband noise
5% initial tolerance
0.002% Long Term Stability Low Cost Underground Zener