| 摘要 |
The exemplary embodiments concern reference sources for A/D and D/A converters, for example of a PCM telephone exchange system. Two separated stages which are supplied however from the same direct current supply source, contain in each case the series circuiting of at least one IG-FET and at least one load resistor. Between the taps of the stages, a differential voltage appears, which is used itself directly as a reference voltage, or indirectly is used for the setting of the value of a reference voltage, or of a reference current, for example by a voltage divider. The value of the reference voltage, or of the reference current, is also exactly adjustable after production of integrated modules, because in at least one of the two stages, at least one of the IG-FETs contains a memory gate which is at least partially applied between the controllable control gate and the channel area, is on all sides surrounded by an insulator, and thus is floating in the electrical sense.
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