LM329

LM329 Precision Reference January 17, 2008 LM329 Precision Reference General Description The LM329 is a precision multi-current temperature-compensated 6.9V zener reference with dynamic impedance a factor of 10 to 100 less than discrete diodes. Constructed in a single silicon chip, the LM329 uses active circuitry to buffer the internal zener allowing the device to operate over a 0.5 mA to 15 mA range with virtually no change in performance. The LM329 is available with a temperature coefficients of 0.01%/ °C. This reference also has excellent long term stability and low noise. A new subsurface breakdown zener used in the LM329 gives lower noise and better long-term stability than conventional IC zeners. Further the zener and temperature compensating transistor are made by a planar process so they are immune to problems that plague ordinary zeners. For example, there is virtually no voltage shift in zener voltage due to temperature cycling and the device is insensitive to stress on the leads. The LM329 can be used in place of conventional zeners with improved performance. The low dynamic impedance simpli- fies biasing and the wide operating current allows the replacement of many zener types. The LM329 for operation over 0°C to 70°C is available in a TO-92 epoxy package. Features ■ 0.6 mA to 15 mA operating current ■ 0.8Ω dynamic impedance at any current ■ Available with temperature coefficient of 0.01%/°C ■ 7μV wideband noise ■ 5% initial tolerance ■ 0.002% long term stabili...