Longitudinal PnP tube and transverse PnP tube

The PNP tube on the IC has two longitudinal and transverse types:

The longitudinal PnP tube is also called the substrate tube, due to the structural relationship of the internal carrier along the longitudinal movement. The characteristic of this tube is that the base-area width of the tube can be accurately controlled and made very thin. Therefore, the β of the longitudinal pnp tube is very large. The β value of the super-β tube is at 200.015 million (α=0.995-0.9998). The disadvantage is that the isolation tank can only be connected to the lowest potential of the circuit, and the use of the limit is large.


In another transverse PnP tube, the hole carriers in the launching area can only reach the collector zone in the horizontal direction, and its base width is impossible to make a very good book. In this way, the current amplification factor β is very low, and some are only 3-5. It has the advantage that both JE and JC have higher reverse breakdown voltages.


In the design of integrated circuits, transverse PnP and longitudinal pnp pipes are often cleverly connected to composite configurations, which constitute an amplifier with excellent performance. such as mirror power supply, micro-current source, active load, co-base-co-injection, common-base-common-collector amplifier.