EP 0366680 A4 19910320 - A NONVOLATILE NONLINEAR REPROGRAMMABLE ELECTRONIC POTENTIOMETER
Title (en)
A NONVOLATILE NONLINEAR REPROGRAMMABLE ELECTRONIC POTENTIOMETER
Publication
Application
Priority
US 5458487 A 19870526
Abstract (en)
[origin: WO8809581A1] A variable impedance circuit (10) for use in an external circuit is disclosed. The impedance value is selected by an external circuit. The variable impedance is generated between terminals (14, 16) which are accessible for connection to external circuitry. The impedance provided between these terminals is determined by a control circuit (18) responsive to electrical signals coupled to the control circuit. An internal register in the control circuit stores a value which specifies the impedance between the two terminals. The stored value is copied into a programmable nonvolatile read-only memory (22) in response to a first predetermined electrical signal. Similarly, the value stored in the read-only memory is selectively copied into the internal control circuit register in response to a second predetermined electrical signal. A number of embodiments for variable impedance elements are disclosed which minimize the number of separate resistors required to achieve the equivalent resolution achievable using a series arrangement of resistors.
IPC 1-7
IPC 8 full level
G01R 17/20 (2006.01); G05B 19/07 (2006.01); H01C 10/00 (2006.01); H03G 3/02 (2006.01)
CPC (source: EP)
G05B 19/075 (2013.01); G05B 2219/23029 (2013.01); G05B 2219/23041 (2013.01)
Citation (search report)
- [X] WO 8700710 A1 19870129 - XICOR INC [US]
- [A] GB 2091918 A 19820804 - PHILIPS NV
- [A] WO 8001632 A1 19800807 - MICHEL A
- See references of WO 8809581A1
Designated contracting state (EPC)
AT BE CH DE FR GB IT LI LU NL SE
DOCDB simple family (publication)
WO 8809581 A1 19881201; EP 0366680 A1 19900509; EP 0366680 A4 19910320; JP H02504577 A 19901220; JP H0666612 B2 19940824
DOCDB simple family (application)
US 8801749 W 19880525; EP 88905304 A 19880525; JP 50494788 A 19880525