| 摘要 |
Open-loop differential amplifiers (120, 140) are disclosed which have accurate and stable gain. The gain of these amplifiers is substantially insensitive to the effects of small-signal emitter resistance re, current gain beta and Early voltage VA. Thus, their gain can be accurately set by resistance ratios which makes them particularly useful in integrated circuits. These advantages are obtained with an output differential pair (67) that has cross-coupled base and collector terminals. In addition, resistors (141, 143, 148, 150) and a current source (146) associated with this differential pair are related to like elements (27, 28, 24, 25 and 26) that are associated with an input differential pair (21) by disclosed numerical ratios, e.g., the nominal gain G of the amplifier. Versions of the amplifiers can be adapted for use as a residue amplifier (162) in a subranging A/D converter (160). |
