Drive circuit for controlling current output rise and fall times
US4216393A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 25, 1978 |
| Grant date | Aug 5, 1980 |
| Priority date | — |
| Expiry date | Sep 25, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/00361
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In a drive circuit having output current passing through at least one bipolar transistor, the rise and fall times of the output current are predetermined by controlling the rate of current change in the master path of a current mirror amplifier which has a separate slave path connected to supply base current for each bipolar transistor. The drain-source channel of an MOS transistor is connected to selectively supply current flow through the master path of the current mirror amplifier in one embodiment of the rate control means and the gate of the MOS transistor is connected in parallel with a capacitor to the output of a CMOS inverter to which control signals are applied. Multiple outputs are driven from a single control input in another embodiment having a single master path and multiple slave paths incorporated into the current mirror amplifier with each slave path being connected to supply base current for a separate bipolar output transistor and being coupled to the master path through a separate transmission gate in a decoder which includes a transmission gate for each slave path.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.