Circuitry for maintaining a substantially constant sense current to load current ratio through an electrical load driving device
US6194884A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 23, 1999 |
| Grant date | Feb 27, 2001 |
| Priority date | — |
| Expiry date | Nov 23, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F3/222
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
Circuitry for driving an electrical load (18) and regulating a load current (IL) therethrough includes a multiple output load driving device (20) having an input (26) receiving a gate drive signal (GD) thereat and operable to direct the load current (I.sub.L) therethrough from a collector (28) to main (22) and sense (24) outputs thereof. A control circuit is provided including an error amplifier (52) having a non-inverting input operable to receive a reference voltage and an inverting input operable to receive a sense voltage proportional to the portion of load current (I.sub.L) flowing through the sense output (24) of the load driving device (20), and producing an output based thereon to which a gate drive control circuit (54) is responsive to supply the gate drive signal (GD). A feedback capacitor (CFB) is disposed between the collector (28) of the load driving device (20) and a resistor string (R8, R9, RTRIM) establishing the reference voltage, and provides an AC coupling therebetween. This AC coupling compensates for oscillations in the load current (I.sub.L) during load current regulation operation and therefore provides for a stable load current (I.sub.L) during such operatio…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.