(19)
(11) EP 2 249 622 A8

(12) CORRECTED EUROPEAN PATENT APPLICATION
Note: Bibliography reflects the latest situation

(15) Correction information:
Corrected version no 1 (W1 A1)

(48) Corrigendum issued on:
09.02.2011 Bulletin 2011/06

(43) Date of publication:
10.11.2010 Bulletin 2010/45

(21) Application number: 10161521.9

(22) Date of filing: 29.04.2010
(51) International Patent Classification (IPC): 
H05B 33/08(2006.01)
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK SM TR
Designated Extension States:
AL BA ME RS

(30) Priority: 04.05.2009 IT TO20090358

(71) Applicants:
  • Osram Gesellschaft mit Beschränkter Haftung
    81543 München (DE)
  • OSRAM S.P.A. - SOCIETA' RIUNITE OSRAM EDISON CLERICI
    20144 Milano (IT)

    IT 

(72) Inventors:
  • Brieda, Alessandro
    33077, Sacile (Pordenone) (IT)
  • Toscan, Matteo
    31010, Maser (Treviso) (IT)

(74) Representative: Bosotti, Luciano 
Buzzi, Notaro & Antonielli d'Oulx Via Maria Vittoria, 18
10123 Torino
10123 Torino (IT)

   


(54) Temperature-stabilized current regulation driver


(57) A driver device generates, from an input voltage (VDC1), a regulated current (ILED) supplied, for example, to a LED light source (LED1, LED2). The device comprises a driver transistor (T2) to supply the regulated current (ILED) and a stabilization circuit (T1a, T1b, R1, R2, R3, R4, RS) to generate a stable reference voltage (VBE1ON) to be applied to the driver transistor (T2). The circuit comprises a first (T1a) and a second (T1b) stabilization bipolar transistor. The base-emitter voltage (VBE1bON) of the second stabilization transistor (T1b) identifies the stable reference voltage (VBE10N) for the driver transistor (T2). A voltage divider (R3, R4) is interposed between the bases of the stabilization transistors (T1a, T1b), with the first resistance (R3), arranged between the base of the second stabilization transistor (T1b) and the partition point (Q) of the divider, having a lower value (for example of 1/10) than the second resistance of the divider (R4). The base-emitter voltage (VBE1aON) of the first stabilization transistor (T1a) is set to be higher than the base-emitter voltage (VBE1bON) of the second stabilization transistor (T1b).