EP 0443238 A2 19910828 - Precision switched current source.
Title (en)
Precision switched current source.
Title (de)
Präzisionsgeschaltete Stromquelle.
Title (fr)
Source de courant de précision à commutation.
Publication
Application
Priority
US 48231990 A 19900220
Abstract (en)
A precision switched current source uses two transistors, preferably bipolar devices, with one transistor (Q1) establishing a reference current and the second transistor (Q2) connected to provide an output current which proportionately mirrors the reference current. A voltage controlled switch, preferably a field effect transistor (FET) (T1), is connected between the bases of the two bipolar transistors (Q1, Q2), and is switched to open and close that connection. The mirrored output current is thus switched on and off, under the control of the FET switch (T1). A second switch (T2) may be provided and operated inverse to the first FET switch (T1) to discharge the base of the output bipolar transistor (Q2) when that transistor is off. <IMAGE>
IPC 1-7
IPC 8 full level
G05F 3/22 (2006.01); G05F 3/20 (2006.01); H02M 3/155 (2006.01); H03K 17/567 (2006.01); H03K 17/60 (2006.01)
CPC (source: EP)
G05F 3/20 (2013.01)
Designated contracting state (EPC)
DE FR GB IT NL
DOCDB simple family (publication)
EP 0443238 A2 19910828; EP 0443238 A3 19920108; JP H03252217 A 19911111
DOCDB simple family (application)
EP 90309885 A 19900910; JP 28411890 A 19901022